| /* | 
 |  * Copyright(c) 2015, 2016 Intel Corporation. | 
 |  * | 
 |  * This file is provided under a dual BSD/GPLv2 license.  When using or | 
 |  * redistributing this file, you may do so under either license. | 
 |  * | 
 |  * GPL LICENSE SUMMARY | 
 |  * | 
 |  * This program is free software; you can redistribute it and/or modify | 
 |  * it under the terms of version 2 of the GNU General Public License as | 
 |  * published by the Free Software Foundation. | 
 |  * | 
 |  * This program is distributed in the hope that it will be useful, but | 
 |  * WITHOUT ANY WARRANTY; without even the implied warranty of | 
 |  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU | 
 |  * General Public License for more details. | 
 |  * | 
 |  * BSD LICENSE | 
 |  * | 
 |  * Redistribution and use in source and binary forms, with or without | 
 |  * modification, are permitted provided that the following conditions | 
 |  * are met: | 
 |  * | 
 |  *  - Redistributions of source code must retain the above copyright | 
 |  *    notice, this list of conditions and the following disclaimer. | 
 |  *  - Redistributions in binary form must reproduce the above copyright | 
 |  *    notice, this list of conditions and the following disclaimer in | 
 |  *    the documentation and/or other materials provided with the | 
 |  *    distribution. | 
 |  *  - Neither the name of Intel Corporation nor the names of its | 
 |  *    contributors may be used to endorse or promote products derived | 
 |  *    from this software without specific prior written permission. | 
 |  * | 
 |  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | 
 |  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | 
 |  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | 
 |  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | 
 |  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | 
 |  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | 
 |  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | 
 |  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | 
 |  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | 
 |  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | 
 |  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 
 |  * | 
 |  */ | 
 |  | 
 | #include <linux/delay.h> | 
 | #include "hfi.h" | 
 | #include "qp.h" | 
 | #include "trace.h" | 
 |  | 
 | #define SC_CTXT_PACKET_EGRESS_TIMEOUT 350 /* in chip cycles */ | 
 |  | 
 | #define SC(name) SEND_CTXT_##name | 
 | /* | 
 |  * Send Context functions | 
 |  */ | 
 | static void sc_wait_for_packet_egress(struct send_context *sc, int pause); | 
 |  | 
 | /* | 
 |  * Set the CM reset bit and wait for it to clear.  Use the provided | 
 |  * sendctrl register.  This routine has no locking. | 
 |  */ | 
 | void __cm_reset(struct hfi1_devdata *dd, u64 sendctrl) | 
 | { | 
 | 	write_csr(dd, SEND_CTRL, sendctrl | SEND_CTRL_CM_RESET_SMASK); | 
 | 	while (1) { | 
 | 		udelay(1); | 
 | 		sendctrl = read_csr(dd, SEND_CTRL); | 
 | 		if ((sendctrl & SEND_CTRL_CM_RESET_SMASK) == 0) | 
 | 			break; | 
 | 	} | 
 | } | 
 |  | 
 | /* defined in header release 48 and higher */ | 
 | #ifndef SEND_CTRL_UNSUPPORTED_VL_SHIFT | 
 | #define SEND_CTRL_UNSUPPORTED_VL_SHIFT 3 | 
 | #define SEND_CTRL_UNSUPPORTED_VL_MASK 0xffull | 
 | #define SEND_CTRL_UNSUPPORTED_VL_SMASK (SEND_CTRL_UNSUPPORTED_VL_MASK \ | 
 | 		<< SEND_CTRL_UNSUPPORTED_VL_SHIFT) | 
 | #endif | 
 |  | 
 | /* global control of PIO send */ | 
 | void pio_send_control(struct hfi1_devdata *dd, int op) | 
 | { | 
 | 	u64 reg, mask; | 
 | 	unsigned long flags; | 
 | 	int write = 1;	/* write sendctrl back */ | 
 | 	int flush = 0;	/* re-read sendctrl to make sure it is flushed */ | 
 |  | 
 | 	spin_lock_irqsave(&dd->sendctrl_lock, flags); | 
 |  | 
 | 	reg = read_csr(dd, SEND_CTRL); | 
 | 	switch (op) { | 
 | 	case PSC_GLOBAL_ENABLE: | 
 | 		reg |= SEND_CTRL_SEND_ENABLE_SMASK; | 
 | 	/* Fall through */ | 
 | 	case PSC_DATA_VL_ENABLE: | 
 | 		/* Disallow sending on VLs not enabled */ | 
 | 		mask = (((~0ull) << num_vls) & SEND_CTRL_UNSUPPORTED_VL_MASK) << | 
 | 				SEND_CTRL_UNSUPPORTED_VL_SHIFT; | 
 | 		reg = (reg & ~SEND_CTRL_UNSUPPORTED_VL_SMASK) | mask; | 
 | 		break; | 
 | 	case PSC_GLOBAL_DISABLE: | 
 | 		reg &= ~SEND_CTRL_SEND_ENABLE_SMASK; | 
 | 		break; | 
 | 	case PSC_GLOBAL_VLARB_ENABLE: | 
 | 		reg |= SEND_CTRL_VL_ARBITER_ENABLE_SMASK; | 
 | 		break; | 
 | 	case PSC_GLOBAL_VLARB_DISABLE: | 
 | 		reg &= ~SEND_CTRL_VL_ARBITER_ENABLE_SMASK; | 
 | 		break; | 
 | 	case PSC_CM_RESET: | 
 | 		__cm_reset(dd, reg); | 
 | 		write = 0; /* CSR already written (and flushed) */ | 
 | 		break; | 
 | 	case PSC_DATA_VL_DISABLE: | 
 | 		reg |= SEND_CTRL_UNSUPPORTED_VL_SMASK; | 
 | 		flush = 1; | 
 | 		break; | 
 | 	default: | 
 | 		dd_dev_err(dd, "%s: invalid control %d\n", __func__, op); | 
 | 		break; | 
 | 	} | 
 |  | 
 | 	if (write) { | 
 | 		write_csr(dd, SEND_CTRL, reg); | 
 | 		if (flush) | 
 | 			(void)read_csr(dd, SEND_CTRL); /* flush write */ | 
 | 	} | 
 |  | 
 | 	spin_unlock_irqrestore(&dd->sendctrl_lock, flags); | 
 | } | 
 |  | 
 | /* number of send context memory pools */ | 
 | #define NUM_SC_POOLS 2 | 
 |  | 
 | /* Send Context Size (SCS) wildcards */ | 
 | #define SCS_POOL_0 -1 | 
 | #define SCS_POOL_1 -2 | 
 |  | 
 | /* Send Context Count (SCC) wildcards */ | 
 | #define SCC_PER_VL -1 | 
 | #define SCC_PER_CPU  -2 | 
 | #define SCC_PER_KRCVQ  -3 | 
 |  | 
 | /* Send Context Size (SCS) constants */ | 
 | #define SCS_ACK_CREDITS  32 | 
 | #define SCS_VL15_CREDITS 102	/* 3 pkts of 2048B data + 128B header */ | 
 |  | 
 | #define PIO_THRESHOLD_CEILING 4096 | 
 |  | 
 | #define PIO_WAIT_BATCH_SIZE 5 | 
 |  | 
 | /* default send context sizes */ | 
 | static struct sc_config_sizes sc_config_sizes[SC_MAX] = { | 
 | 	[SC_KERNEL] = { .size  = SCS_POOL_0,	/* even divide, pool 0 */ | 
 | 			.count = SCC_PER_VL },	/* one per NUMA */ | 
 | 	[SC_ACK]    = { .size  = SCS_ACK_CREDITS, | 
 | 			.count = SCC_PER_KRCVQ }, | 
 | 	[SC_USER]   = { .size  = SCS_POOL_0,	/* even divide, pool 0 */ | 
 | 			.count = SCC_PER_CPU },	/* one per CPU */ | 
 | 	[SC_VL15]   = { .size  = SCS_VL15_CREDITS, | 
 | 			.count = 1 }, | 
 |  | 
 | }; | 
 |  | 
 | /* send context memory pool configuration */ | 
 | struct mem_pool_config { | 
 | 	int centipercent;	/* % of memory, in 100ths of 1% */ | 
 | 	int absolute_blocks;	/* absolute block count */ | 
 | }; | 
 |  | 
 | /* default memory pool configuration: 100% in pool 0 */ | 
 | static struct mem_pool_config sc_mem_pool_config[NUM_SC_POOLS] = { | 
 | 	/* centi%, abs blocks */ | 
 | 	{  10000,     -1 },		/* pool 0 */ | 
 | 	{      0,     -1 },		/* pool 1 */ | 
 | }; | 
 |  | 
 | /* memory pool information, used when calculating final sizes */ | 
 | struct mem_pool_info { | 
 | 	int centipercent;	/* | 
 | 				 * 100th of 1% of memory to use, -1 if blocks | 
 | 				 * already set | 
 | 				 */ | 
 | 	int count;		/* count of contexts in the pool */ | 
 | 	int blocks;		/* block size of the pool */ | 
 | 	int size;		/* context size, in blocks */ | 
 | }; | 
 |  | 
 | /* | 
 |  * Convert a pool wildcard to a valid pool index.  The wildcards | 
 |  * start at -1 and increase negatively.  Map them as: | 
 |  *	-1 => 0 | 
 |  *	-2 => 1 | 
 |  *	etc. | 
 |  * | 
 |  * Return -1 on non-wildcard input, otherwise convert to a pool number. | 
 |  */ | 
 | static int wildcard_to_pool(int wc) | 
 | { | 
 | 	if (wc >= 0) | 
 | 		return -1;	/* non-wildcard */ | 
 | 	return -wc - 1; | 
 | } | 
 |  | 
 | static const char *sc_type_names[SC_MAX] = { | 
 | 	"kernel", | 
 | 	"ack", | 
 | 	"user", | 
 | 	"vl15" | 
 | }; | 
 |  | 
 | static const char *sc_type_name(int index) | 
 | { | 
 | 	if (index < 0 || index >= SC_MAX) | 
 | 		return "unknown"; | 
 | 	return sc_type_names[index]; | 
 | } | 
 |  | 
 | /* | 
 |  * Read the send context memory pool configuration and send context | 
 |  * size configuration.  Replace any wildcards and come up with final | 
 |  * counts and sizes for the send context types. | 
 |  */ | 
 | int init_sc_pools_and_sizes(struct hfi1_devdata *dd) | 
 | { | 
 | 	struct mem_pool_info mem_pool_info[NUM_SC_POOLS] = { { 0 } }; | 
 | 	int total_blocks = (dd->chip_pio_mem_size / PIO_BLOCK_SIZE) - 1; | 
 | 	int total_contexts = 0; | 
 | 	int fixed_blocks; | 
 | 	int pool_blocks; | 
 | 	int used_blocks; | 
 | 	int cp_total;		/* centipercent total */ | 
 | 	int ab_total;		/* absolute block total */ | 
 | 	int extra; | 
 | 	int i; | 
 |  | 
 | 	/* | 
 | 	 * When SDMA is enabled, kernel context pio packet size is capped by | 
 | 	 * "piothreshold". Reduce pio buffer allocation for kernel context by | 
 | 	 * setting it to a fixed size. The allocation allows 3-deep buffering | 
 | 	 * of the largest pio packets plus up to 128 bytes header, sufficient | 
 | 	 * to maintain verbs performance. | 
 | 	 * | 
 | 	 * When SDMA is disabled, keep the default pooling allocation. | 
 | 	 */ | 
 | 	if (HFI1_CAP_IS_KSET(SDMA)) { | 
 | 		u16 max_pkt_size = (piothreshold < PIO_THRESHOLD_CEILING) ? | 
 | 					 piothreshold : PIO_THRESHOLD_CEILING; | 
 | 		sc_config_sizes[SC_KERNEL].size = | 
 | 			3 * (max_pkt_size + 128) / PIO_BLOCK_SIZE; | 
 | 	} | 
 |  | 
 | 	/* | 
 | 	 * Step 0: | 
 | 	 *	- copy the centipercents/absolute sizes from the pool config | 
 | 	 *	- sanity check these values | 
 | 	 *	- add up centipercents, then later check for full value | 
 | 	 *	- add up absolute blocks, then later check for over-commit | 
 | 	 */ | 
 | 	cp_total = 0; | 
 | 	ab_total = 0; | 
 | 	for (i = 0; i < NUM_SC_POOLS; i++) { | 
 | 		int cp = sc_mem_pool_config[i].centipercent; | 
 | 		int ab = sc_mem_pool_config[i].absolute_blocks; | 
 |  | 
 | 		/* | 
 | 		 * A negative value is "unused" or "invalid".  Both *can* | 
 | 		 * be valid, but centipercent wins, so check that first | 
 | 		 */ | 
 | 		if (cp >= 0) {			/* centipercent valid */ | 
 | 			cp_total += cp; | 
 | 		} else if (ab >= 0) {		/* absolute blocks valid */ | 
 | 			ab_total += ab; | 
 | 		} else {			/* neither valid */ | 
 | 			dd_dev_err( | 
 | 				dd, | 
 | 				"Send context memory pool %d: both the block count and centipercent are invalid\n", | 
 | 				i); | 
 | 			return -EINVAL; | 
 | 		} | 
 |  | 
 | 		mem_pool_info[i].centipercent = cp; | 
 | 		mem_pool_info[i].blocks = ab; | 
 | 	} | 
 |  | 
 | 	/* do not use both % and absolute blocks for different pools */ | 
 | 	if (cp_total != 0 && ab_total != 0) { | 
 | 		dd_dev_err( | 
 | 			dd, | 
 | 			"All send context memory pools must be described as either centipercent or blocks, no mixing between pools\n"); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	/* if any percentages are present, they must add up to 100% x 100 */ | 
 | 	if (cp_total != 0 && cp_total != 10000) { | 
 | 		dd_dev_err( | 
 | 			dd, | 
 | 			"Send context memory pool centipercent is %d, expecting 10000\n", | 
 | 			cp_total); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	/* the absolute pool total cannot be more than the mem total */ | 
 | 	if (ab_total > total_blocks) { | 
 | 		dd_dev_err( | 
 | 			dd, | 
 | 			"Send context memory pool absolute block count %d is larger than the memory size %d\n", | 
 | 			ab_total, total_blocks); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	/* | 
 | 	 * Step 2: | 
 | 	 *	- copy from the context size config | 
 | 	 *	- replace context type wildcard counts with real values | 
 | 	 *	- add up non-memory pool block sizes | 
 | 	 *	- add up memory pool user counts | 
 | 	 */ | 
 | 	fixed_blocks = 0; | 
 | 	for (i = 0; i < SC_MAX; i++) { | 
 | 		int count = sc_config_sizes[i].count; | 
 | 		int size = sc_config_sizes[i].size; | 
 | 		int pool; | 
 |  | 
 | 		/* | 
 | 		 * Sanity check count: Either a positive value or | 
 | 		 * one of the expected wildcards is valid.  The positive | 
 | 		 * value is checked later when we compare against total | 
 | 		 * memory available. | 
 | 		 */ | 
 | 		if (i == SC_ACK) { | 
 | 			count = dd->n_krcv_queues; | 
 | 		} else if (i == SC_KERNEL) { | 
 | 			count = INIT_SC_PER_VL * num_vls; | 
 | 		} else if (count == SCC_PER_CPU) { | 
 | 			count = dd->num_rcv_contexts - dd->n_krcv_queues; | 
 | 		} else if (count < 0) { | 
 | 			dd_dev_err( | 
 | 				dd, | 
 | 				"%s send context invalid count wildcard %d\n", | 
 | 				sc_type_name(i), count); | 
 | 			return -EINVAL; | 
 | 		} | 
 | 		if (total_contexts + count > dd->chip_send_contexts) | 
 | 			count = dd->chip_send_contexts - total_contexts; | 
 |  | 
 | 		total_contexts += count; | 
 |  | 
 | 		/* | 
 | 		 * Sanity check pool: The conversion will return a pool | 
 | 		 * number or -1 if a fixed (non-negative) value.  The fixed | 
 | 		 * value is checked later when we compare against | 
 | 		 * total memory available. | 
 | 		 */ | 
 | 		pool = wildcard_to_pool(size); | 
 | 		if (pool == -1) {			/* non-wildcard */ | 
 | 			fixed_blocks += size * count; | 
 | 		} else if (pool < NUM_SC_POOLS) {	/* valid wildcard */ | 
 | 			mem_pool_info[pool].count += count; | 
 | 		} else {				/* invalid wildcard */ | 
 | 			dd_dev_err( | 
 | 				dd, | 
 | 				"%s send context invalid pool wildcard %d\n", | 
 | 				sc_type_name(i), size); | 
 | 			return -EINVAL; | 
 | 		} | 
 |  | 
 | 		dd->sc_sizes[i].count = count; | 
 | 		dd->sc_sizes[i].size = size; | 
 | 	} | 
 | 	if (fixed_blocks > total_blocks) { | 
 | 		dd_dev_err( | 
 | 			dd, | 
 | 			"Send context fixed block count, %u, larger than total block count %u\n", | 
 | 			fixed_blocks, total_blocks); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	/* step 3: calculate the blocks in the pools, and pool context sizes */ | 
 | 	pool_blocks = total_blocks - fixed_blocks; | 
 | 	if (ab_total > pool_blocks) { | 
 | 		dd_dev_err( | 
 | 			dd, | 
 | 			"Send context fixed pool sizes, %u, larger than pool block count %u\n", | 
 | 			ab_total, pool_blocks); | 
 | 		return -EINVAL; | 
 | 	} | 
 | 	/* subtract off the fixed pool blocks */ | 
 | 	pool_blocks -= ab_total; | 
 |  | 
 | 	for (i = 0; i < NUM_SC_POOLS; i++) { | 
 | 		struct mem_pool_info *pi = &mem_pool_info[i]; | 
 |  | 
 | 		/* % beats absolute blocks */ | 
 | 		if (pi->centipercent >= 0) | 
 | 			pi->blocks = (pool_blocks * pi->centipercent) / 10000; | 
 |  | 
 | 		if (pi->blocks == 0 && pi->count != 0) { | 
 | 			dd_dev_err( | 
 | 				dd, | 
 | 				"Send context memory pool %d has %u contexts, but no blocks\n", | 
 | 				i, pi->count); | 
 | 			return -EINVAL; | 
 | 		} | 
 | 		if (pi->count == 0) { | 
 | 			/* warn about wasted blocks */ | 
 | 			if (pi->blocks != 0) | 
 | 				dd_dev_err( | 
 | 					dd, | 
 | 					"Send context memory pool %d has %u blocks, but zero contexts\n", | 
 | 					i, pi->blocks); | 
 | 			pi->size = 0; | 
 | 		} else { | 
 | 			pi->size = pi->blocks / pi->count; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	/* step 4: fill in the context type sizes from the pool sizes */ | 
 | 	used_blocks = 0; | 
 | 	for (i = 0; i < SC_MAX; i++) { | 
 | 		if (dd->sc_sizes[i].size < 0) { | 
 | 			unsigned pool = wildcard_to_pool(dd->sc_sizes[i].size); | 
 |  | 
 | 			WARN_ON_ONCE(pool >= NUM_SC_POOLS); | 
 | 			dd->sc_sizes[i].size = mem_pool_info[pool].size; | 
 | 		} | 
 | 		/* make sure we are not larger than what is allowed by the HW */ | 
 | #define PIO_MAX_BLOCKS 1024 | 
 | 		if (dd->sc_sizes[i].size > PIO_MAX_BLOCKS) | 
 | 			dd->sc_sizes[i].size = PIO_MAX_BLOCKS; | 
 |  | 
 | 		/* calculate our total usage */ | 
 | 		used_blocks += dd->sc_sizes[i].size * dd->sc_sizes[i].count; | 
 | 	} | 
 | 	extra = total_blocks - used_blocks; | 
 | 	if (extra != 0) | 
 | 		dd_dev_info(dd, "unused send context blocks: %d\n", extra); | 
 |  | 
 | 	return total_contexts; | 
 | } | 
 |  | 
 | int init_send_contexts(struct hfi1_devdata *dd) | 
 | { | 
 | 	u16 base; | 
 | 	int ret, i, j, context; | 
 |  | 
 | 	ret = init_credit_return(dd); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	dd->hw_to_sw = kmalloc_array(TXE_NUM_CONTEXTS, sizeof(u8), | 
 | 					GFP_KERNEL); | 
 | 	dd->send_contexts = kcalloc(dd->num_send_contexts, | 
 | 					sizeof(struct send_context_info), | 
 | 					GFP_KERNEL); | 
 | 	if (!dd->send_contexts || !dd->hw_to_sw) { | 
 | 		kfree(dd->hw_to_sw); | 
 | 		kfree(dd->send_contexts); | 
 | 		free_credit_return(dd); | 
 | 		return -ENOMEM; | 
 | 	} | 
 |  | 
 | 	/* hardware context map starts with invalid send context indices */ | 
 | 	for (i = 0; i < TXE_NUM_CONTEXTS; i++) | 
 | 		dd->hw_to_sw[i] = INVALID_SCI; | 
 |  | 
 | 	/* | 
 | 	 * All send contexts have their credit sizes.  Allocate credits | 
 | 	 * for each context one after another from the global space. | 
 | 	 */ | 
 | 	context = 0; | 
 | 	base = 1; | 
 | 	for (i = 0; i < SC_MAX; i++) { | 
 | 		struct sc_config_sizes *scs = &dd->sc_sizes[i]; | 
 |  | 
 | 		for (j = 0; j < scs->count; j++) { | 
 | 			struct send_context_info *sci = | 
 | 						&dd->send_contexts[context]; | 
 | 			sci->type = i; | 
 | 			sci->base = base; | 
 | 			sci->credits = scs->size; | 
 |  | 
 | 			context++; | 
 | 			base += scs->size; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | /* | 
 |  * Allocate a software index and hardware context of the given type. | 
 |  * | 
 |  * Must be called with dd->sc_lock held. | 
 |  */ | 
 | static int sc_hw_alloc(struct hfi1_devdata *dd, int type, u32 *sw_index, | 
 | 		       u32 *hw_context) | 
 | { | 
 | 	struct send_context_info *sci; | 
 | 	u32 index; | 
 | 	u32 context; | 
 |  | 
 | 	for (index = 0, sci = &dd->send_contexts[0]; | 
 | 			index < dd->num_send_contexts; index++, sci++) { | 
 | 		if (sci->type == type && sci->allocated == 0) { | 
 | 			sci->allocated = 1; | 
 | 			/* use a 1:1 mapping, but make them non-equal */ | 
 | 			context = dd->chip_send_contexts - index - 1; | 
 | 			dd->hw_to_sw[context] = index; | 
 | 			*sw_index = index; | 
 | 			*hw_context = context; | 
 | 			return 0; /* success */ | 
 | 		} | 
 | 	} | 
 | 	dd_dev_err(dd, "Unable to locate a free type %d send context\n", type); | 
 | 	return -ENOSPC; | 
 | } | 
 |  | 
 | /* | 
 |  * Free the send context given by its software index. | 
 |  * | 
 |  * Must be called with dd->sc_lock held. | 
 |  */ | 
 | static void sc_hw_free(struct hfi1_devdata *dd, u32 sw_index, u32 hw_context) | 
 | { | 
 | 	struct send_context_info *sci; | 
 |  | 
 | 	sci = &dd->send_contexts[sw_index]; | 
 | 	if (!sci->allocated) { | 
 | 		dd_dev_err(dd, "%s: sw_index %u not allocated? hw_context %u\n", | 
 | 			   __func__, sw_index, hw_context); | 
 | 	} | 
 | 	sci->allocated = 0; | 
 | 	dd->hw_to_sw[hw_context] = INVALID_SCI; | 
 | } | 
 |  | 
 | /* return the base context of a context in a group */ | 
 | static inline u32 group_context(u32 context, u32 group) | 
 | { | 
 | 	return (context >> group) << group; | 
 | } | 
 |  | 
 | /* return the size of a group */ | 
 | static inline u32 group_size(u32 group) | 
 | { | 
 | 	return 1 << group; | 
 | } | 
 |  | 
 | /* | 
 |  * Obtain the credit return addresses, kernel virtual and bus, for the | 
 |  * given sc. | 
 |  * | 
 |  * To understand this routine: | 
 |  * o va and dma are arrays of struct credit_return.  One for each physical | 
 |  *   send context, per NUMA. | 
 |  * o Each send context always looks in its relative location in a struct | 
 |  *   credit_return for its credit return. | 
 |  * o Each send context in a group must have its return address CSR programmed | 
 |  *   with the same value.  Use the address of the first send context in the | 
 |  *   group. | 
 |  */ | 
 | static void cr_group_addresses(struct send_context *sc, dma_addr_t *dma) | 
 | { | 
 | 	u32 gc = group_context(sc->hw_context, sc->group); | 
 | 	u32 index = sc->hw_context & 0x7; | 
 |  | 
 | 	sc->hw_free = &sc->dd->cr_base[sc->node].va[gc].cr[index]; | 
 | 	*dma = (unsigned long) | 
 | 	       &((struct credit_return *)sc->dd->cr_base[sc->node].dma)[gc]; | 
 | } | 
 |  | 
 | /* | 
 |  * Work queue function triggered in error interrupt routine for | 
 |  * kernel contexts. | 
 |  */ | 
 | static void sc_halted(struct work_struct *work) | 
 | { | 
 | 	struct send_context *sc; | 
 |  | 
 | 	sc = container_of(work, struct send_context, halt_work); | 
 | 	sc_restart(sc); | 
 | } | 
 |  | 
 | /* | 
 |  * Calculate PIO block threshold for this send context using the given MTU. | 
 |  * Trigger a return when one MTU plus optional header of credits remain. | 
 |  * | 
 |  * Parameter mtu is in bytes. | 
 |  * Parameter hdrqentsize is in DWORDs. | 
 |  * | 
 |  * Return value is what to write into the CSR: trigger return when | 
 |  * unreturned credits pass this count. | 
 |  */ | 
 | u32 sc_mtu_to_threshold(struct send_context *sc, u32 mtu, u32 hdrqentsize) | 
 | { | 
 | 	u32 release_credits; | 
 | 	u32 threshold; | 
 |  | 
 | 	/* add in the header size, then divide by the PIO block size */ | 
 | 	mtu += hdrqentsize << 2; | 
 | 	release_credits = DIV_ROUND_UP(mtu, PIO_BLOCK_SIZE); | 
 |  | 
 | 	/* check against this context's credits */ | 
 | 	if (sc->credits <= release_credits) | 
 | 		threshold = 1; | 
 | 	else | 
 | 		threshold = sc->credits - release_credits; | 
 |  | 
 | 	return threshold; | 
 | } | 
 |  | 
 | /* | 
 |  * Calculate credit threshold in terms of percent of the allocated credits. | 
 |  * Trigger when unreturned credits equal or exceed the percentage of the whole. | 
 |  * | 
 |  * Return value is what to write into the CSR: trigger return when | 
 |  * unreturned credits pass this count. | 
 |  */ | 
 | u32 sc_percent_to_threshold(struct send_context *sc, u32 percent) | 
 | { | 
 | 	return (sc->credits * percent) / 100; | 
 | } | 
 |  | 
 | /* | 
 |  * Set the credit return threshold. | 
 |  */ | 
 | void sc_set_cr_threshold(struct send_context *sc, u32 new_threshold) | 
 | { | 
 | 	unsigned long flags; | 
 | 	u32 old_threshold; | 
 | 	int force_return = 0; | 
 |  | 
 | 	spin_lock_irqsave(&sc->credit_ctrl_lock, flags); | 
 |  | 
 | 	old_threshold = (sc->credit_ctrl >> | 
 | 				SC(CREDIT_CTRL_THRESHOLD_SHIFT)) | 
 | 			 & SC(CREDIT_CTRL_THRESHOLD_MASK); | 
 |  | 
 | 	if (new_threshold != old_threshold) { | 
 | 		sc->credit_ctrl = | 
 | 			(sc->credit_ctrl | 
 | 				& ~SC(CREDIT_CTRL_THRESHOLD_SMASK)) | 
 | 			| ((new_threshold | 
 | 				& SC(CREDIT_CTRL_THRESHOLD_MASK)) | 
 | 			   << SC(CREDIT_CTRL_THRESHOLD_SHIFT)); | 
 | 		write_kctxt_csr(sc->dd, sc->hw_context, | 
 | 				SC(CREDIT_CTRL), sc->credit_ctrl); | 
 |  | 
 | 		/* force a credit return on change to avoid a possible stall */ | 
 | 		force_return = 1; | 
 | 	} | 
 |  | 
 | 	spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags); | 
 |  | 
 | 	if (force_return) | 
 | 		sc_return_credits(sc); | 
 | } | 
 |  | 
 | /* | 
 |  * set_pio_integrity | 
 |  * | 
 |  * Set the CHECK_ENABLE register for the send context 'sc'. | 
 |  */ | 
 | void set_pio_integrity(struct send_context *sc) | 
 | { | 
 | 	struct hfi1_devdata *dd = sc->dd; | 
 | 	u32 hw_context = sc->hw_context; | 
 | 	int type = sc->type; | 
 |  | 
 | 	write_kctxt_csr(dd, hw_context, | 
 | 			SC(CHECK_ENABLE), | 
 | 			hfi1_pkt_default_send_ctxt_mask(dd, type)); | 
 | } | 
 |  | 
 | static u32 get_buffers_allocated(struct send_context *sc) | 
 | { | 
 | 	int cpu; | 
 | 	u32 ret = 0; | 
 |  | 
 | 	for_each_possible_cpu(cpu) | 
 | 		ret += *per_cpu_ptr(sc->buffers_allocated, cpu); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static void reset_buffers_allocated(struct send_context *sc) | 
 | { | 
 | 	int cpu; | 
 |  | 
 | 	for_each_possible_cpu(cpu) | 
 | 		(*per_cpu_ptr(sc->buffers_allocated, cpu)) = 0; | 
 | } | 
 |  | 
 | /* | 
 |  * Allocate a NUMA relative send context structure of the given type along | 
 |  * with a HW context. | 
 |  */ | 
 | struct send_context *sc_alloc(struct hfi1_devdata *dd, int type, | 
 | 			      uint hdrqentsize, int numa) | 
 | { | 
 | 	struct send_context_info *sci; | 
 | 	struct send_context *sc = NULL; | 
 | 	dma_addr_t dma; | 
 | 	unsigned long flags; | 
 | 	u64 reg; | 
 | 	u32 thresh; | 
 | 	u32 sw_index; | 
 | 	u32 hw_context; | 
 | 	int ret; | 
 | 	u8 opval, opmask; | 
 |  | 
 | 	/* do not allocate while frozen */ | 
 | 	if (dd->flags & HFI1_FROZEN) | 
 | 		return NULL; | 
 |  | 
 | 	sc = kzalloc_node(sizeof(*sc), GFP_KERNEL, numa); | 
 | 	if (!sc) | 
 | 		return NULL; | 
 |  | 
 | 	sc->buffers_allocated = alloc_percpu(u32); | 
 | 	if (!sc->buffers_allocated) { | 
 | 		kfree(sc); | 
 | 		dd_dev_err(dd, | 
 | 			   "Cannot allocate buffers_allocated per cpu counters\n" | 
 | 			  ); | 
 | 		return NULL; | 
 | 	} | 
 |  | 
 | 	spin_lock_irqsave(&dd->sc_lock, flags); | 
 | 	ret = sc_hw_alloc(dd, type, &sw_index, &hw_context); | 
 | 	if (ret) { | 
 | 		spin_unlock_irqrestore(&dd->sc_lock, flags); | 
 | 		free_percpu(sc->buffers_allocated); | 
 | 		kfree(sc); | 
 | 		return NULL; | 
 | 	} | 
 |  | 
 | 	sci = &dd->send_contexts[sw_index]; | 
 | 	sci->sc = sc; | 
 |  | 
 | 	sc->dd = dd; | 
 | 	sc->node = numa; | 
 | 	sc->type = type; | 
 | 	spin_lock_init(&sc->alloc_lock); | 
 | 	spin_lock_init(&sc->release_lock); | 
 | 	spin_lock_init(&sc->credit_ctrl_lock); | 
 | 	INIT_LIST_HEAD(&sc->piowait); | 
 | 	INIT_WORK(&sc->halt_work, sc_halted); | 
 | 	init_waitqueue_head(&sc->halt_wait); | 
 |  | 
 | 	/* grouping is always single context for now */ | 
 | 	sc->group = 0; | 
 |  | 
 | 	sc->sw_index = sw_index; | 
 | 	sc->hw_context = hw_context; | 
 | 	cr_group_addresses(sc, &dma); | 
 | 	sc->credits = sci->credits; | 
 |  | 
 | /* PIO Send Memory Address details */ | 
 | #define PIO_ADDR_CONTEXT_MASK 0xfful | 
 | #define PIO_ADDR_CONTEXT_SHIFT 16 | 
 | 	sc->base_addr = dd->piobase + ((hw_context & PIO_ADDR_CONTEXT_MASK) | 
 | 					<< PIO_ADDR_CONTEXT_SHIFT); | 
 |  | 
 | 	/* set base and credits */ | 
 | 	reg = ((sci->credits & SC(CTRL_CTXT_DEPTH_MASK)) | 
 | 					<< SC(CTRL_CTXT_DEPTH_SHIFT)) | 
 | 		| ((sci->base & SC(CTRL_CTXT_BASE_MASK)) | 
 | 					<< SC(CTRL_CTXT_BASE_SHIFT)); | 
 | 	write_kctxt_csr(dd, hw_context, SC(CTRL), reg); | 
 |  | 
 | 	set_pio_integrity(sc); | 
 |  | 
 | 	/* unmask all errors */ | 
 | 	write_kctxt_csr(dd, hw_context, SC(ERR_MASK), (u64)-1); | 
 |  | 
 | 	/* set the default partition key */ | 
 | 	write_kctxt_csr(dd, hw_context, SC(CHECK_PARTITION_KEY), | 
 | 			(SC(CHECK_PARTITION_KEY_VALUE_MASK) & | 
 | 			 DEFAULT_PKEY) << | 
 | 			SC(CHECK_PARTITION_KEY_VALUE_SHIFT)); | 
 |  | 
 | 	/* per context type checks */ | 
 | 	if (type == SC_USER) { | 
 | 		opval = USER_OPCODE_CHECK_VAL; | 
 | 		opmask = USER_OPCODE_CHECK_MASK; | 
 | 	} else { | 
 | 		opval = OPCODE_CHECK_VAL_DISABLED; | 
 | 		opmask = OPCODE_CHECK_MASK_DISABLED; | 
 | 	} | 
 |  | 
 | 	/* set the send context check opcode mask and value */ | 
 | 	write_kctxt_csr(dd, hw_context, SC(CHECK_OPCODE), | 
 | 			((u64)opmask << SC(CHECK_OPCODE_MASK_SHIFT)) | | 
 | 			((u64)opval << SC(CHECK_OPCODE_VALUE_SHIFT))); | 
 |  | 
 | 	/* set up credit return */ | 
 | 	reg = dma & SC(CREDIT_RETURN_ADDR_ADDRESS_SMASK); | 
 | 	write_kctxt_csr(dd, hw_context, SC(CREDIT_RETURN_ADDR), reg); | 
 |  | 
 | 	/* | 
 | 	 * Calculate the initial credit return threshold. | 
 | 	 * | 
 | 	 * For Ack contexts, set a threshold for half the credits. | 
 | 	 * For User contexts use the given percentage.  This has been | 
 | 	 * sanitized on driver start-up. | 
 | 	 * For Kernel contexts, use the default MTU plus a header | 
 | 	 * or half the credits, whichever is smaller. This should | 
 | 	 * work for both the 3-deep buffering allocation and the | 
 | 	 * pooling allocation. | 
 | 	 */ | 
 | 	if (type == SC_ACK) { | 
 | 		thresh = sc_percent_to_threshold(sc, 50); | 
 | 	} else if (type == SC_USER) { | 
 | 		thresh = sc_percent_to_threshold(sc, | 
 | 						 user_credit_return_threshold); | 
 | 	} else { /* kernel */ | 
 | 		thresh = min(sc_percent_to_threshold(sc, 50), | 
 | 			     sc_mtu_to_threshold(sc, hfi1_max_mtu, | 
 | 						 hdrqentsize)); | 
 | 	} | 
 | 	reg = thresh << SC(CREDIT_CTRL_THRESHOLD_SHIFT); | 
 | 	/* add in early return */ | 
 | 	if (type == SC_USER && HFI1_CAP_IS_USET(EARLY_CREDIT_RETURN)) | 
 | 		reg |= SC(CREDIT_CTRL_EARLY_RETURN_SMASK); | 
 | 	else if (HFI1_CAP_IS_KSET(EARLY_CREDIT_RETURN)) /* kernel, ack */ | 
 | 		reg |= SC(CREDIT_CTRL_EARLY_RETURN_SMASK); | 
 |  | 
 | 	/* set up write-through credit_ctrl */ | 
 | 	sc->credit_ctrl = reg; | 
 | 	write_kctxt_csr(dd, hw_context, SC(CREDIT_CTRL), reg); | 
 |  | 
 | 	/* User send contexts should not allow sending on VL15 */ | 
 | 	if (type == SC_USER) { | 
 | 		reg = 1ULL << 15; | 
 | 		write_kctxt_csr(dd, hw_context, SC(CHECK_VL), reg); | 
 | 	} | 
 |  | 
 | 	spin_unlock_irqrestore(&dd->sc_lock, flags); | 
 |  | 
 | 	/* | 
 | 	 * Allocate shadow ring to track outstanding PIO buffers _after_ | 
 | 	 * unlocking.  We don't know the size until the lock is held and | 
 | 	 * we can't allocate while the lock is held.  No one is using | 
 | 	 * the context yet, so allocate it now. | 
 | 	 * | 
 | 	 * User contexts do not get a shadow ring. | 
 | 	 */ | 
 | 	if (type != SC_USER) { | 
 | 		/* | 
 | 		 * Size the shadow ring 1 larger than the number of credits | 
 | 		 * so head == tail can mean empty. | 
 | 		 */ | 
 | 		sc->sr_size = sci->credits + 1; | 
 | 		sc->sr = kzalloc_node(sizeof(union pio_shadow_ring) * | 
 | 				sc->sr_size, GFP_KERNEL, numa); | 
 | 		if (!sc->sr) { | 
 | 			sc_free(sc); | 
 | 			return NULL; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	hfi1_cdbg(PIO, | 
 | 		  "Send context %u(%u) %s group %u credits %u credit_ctrl 0x%llx threshold %u\n", | 
 | 		  sw_index, | 
 | 		  hw_context, | 
 | 		  sc_type_name(type), | 
 | 		  sc->group, | 
 | 		  sc->credits, | 
 | 		  sc->credit_ctrl, | 
 | 		  thresh); | 
 |  | 
 | 	return sc; | 
 | } | 
 |  | 
 | /* free a per-NUMA send context structure */ | 
 | void sc_free(struct send_context *sc) | 
 | { | 
 | 	struct hfi1_devdata *dd; | 
 | 	unsigned long flags; | 
 | 	u32 sw_index; | 
 | 	u32 hw_context; | 
 |  | 
 | 	if (!sc) | 
 | 		return; | 
 |  | 
 | 	sc->flags |= SCF_IN_FREE;	/* ensure no restarts */ | 
 | 	dd = sc->dd; | 
 | 	if (!list_empty(&sc->piowait)) | 
 | 		dd_dev_err(dd, "piowait list not empty!\n"); | 
 | 	sw_index = sc->sw_index; | 
 | 	hw_context = sc->hw_context; | 
 | 	sc_disable(sc);	/* make sure the HW is disabled */ | 
 | 	flush_work(&sc->halt_work); | 
 |  | 
 | 	spin_lock_irqsave(&dd->sc_lock, flags); | 
 | 	dd->send_contexts[sw_index].sc = NULL; | 
 |  | 
 | 	/* clear/disable all registers set in sc_alloc */ | 
 | 	write_kctxt_csr(dd, hw_context, SC(CTRL), 0); | 
 | 	write_kctxt_csr(dd, hw_context, SC(CHECK_ENABLE), 0); | 
 | 	write_kctxt_csr(dd, hw_context, SC(ERR_MASK), 0); | 
 | 	write_kctxt_csr(dd, hw_context, SC(CHECK_PARTITION_KEY), 0); | 
 | 	write_kctxt_csr(dd, hw_context, SC(CHECK_OPCODE), 0); | 
 | 	write_kctxt_csr(dd, hw_context, SC(CREDIT_RETURN_ADDR), 0); | 
 | 	write_kctxt_csr(dd, hw_context, SC(CREDIT_CTRL), 0); | 
 |  | 
 | 	/* release the index and context for re-use */ | 
 | 	sc_hw_free(dd, sw_index, hw_context); | 
 | 	spin_unlock_irqrestore(&dd->sc_lock, flags); | 
 |  | 
 | 	kfree(sc->sr); | 
 | 	free_percpu(sc->buffers_allocated); | 
 | 	kfree(sc); | 
 | } | 
 |  | 
 | /* disable the context */ | 
 | void sc_disable(struct send_context *sc) | 
 | { | 
 | 	u64 reg; | 
 | 	unsigned long flags; | 
 | 	struct pio_buf *pbuf; | 
 |  | 
 | 	if (!sc) | 
 | 		return; | 
 |  | 
 | 	/* do all steps, even if already disabled */ | 
 | 	spin_lock_irqsave(&sc->alloc_lock, flags); | 
 | 	reg = read_kctxt_csr(sc->dd, sc->hw_context, SC(CTRL)); | 
 | 	reg &= ~SC(CTRL_CTXT_ENABLE_SMASK); | 
 | 	sc->flags &= ~SCF_ENABLED; | 
 | 	sc_wait_for_packet_egress(sc, 1); | 
 | 	write_kctxt_csr(sc->dd, sc->hw_context, SC(CTRL), reg); | 
 | 	spin_unlock_irqrestore(&sc->alloc_lock, flags); | 
 |  | 
 | 	/* | 
 | 	 * Flush any waiters.  Once the context is disabled, | 
 | 	 * credit return interrupts are stopped (although there | 
 | 	 * could be one in-process when the context is disabled). | 
 | 	 * Wait one microsecond for any lingering interrupts, then | 
 | 	 * proceed with the flush. | 
 | 	 */ | 
 | 	udelay(1); | 
 | 	spin_lock_irqsave(&sc->release_lock, flags); | 
 | 	if (sc->sr) {	/* this context has a shadow ring */ | 
 | 		while (sc->sr_tail != sc->sr_head) { | 
 | 			pbuf = &sc->sr[sc->sr_tail].pbuf; | 
 | 			if (pbuf->cb) | 
 | 				(*pbuf->cb)(pbuf->arg, PRC_SC_DISABLE); | 
 | 			sc->sr_tail++; | 
 | 			if (sc->sr_tail >= sc->sr_size) | 
 | 				sc->sr_tail = 0; | 
 | 		} | 
 | 	} | 
 | 	spin_unlock_irqrestore(&sc->release_lock, flags); | 
 | } | 
 |  | 
 | /* return SendEgressCtxtStatus.PacketOccupancy */ | 
 | #define packet_occupancy(r) \ | 
 | 	(((r) & SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_PACKET_OCCUPANCY_SMASK)\ | 
 | 	>> SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_PACKET_OCCUPANCY_SHIFT) | 
 |  | 
 | /* is egress halted on the context? */ | 
 | #define egress_halted(r) \ | 
 | 	((r) & SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_HALT_STATUS_SMASK) | 
 |  | 
 | /* wait for packet egress, optionally pause for credit return  */ | 
 | static void sc_wait_for_packet_egress(struct send_context *sc, int pause) | 
 | { | 
 | 	struct hfi1_devdata *dd = sc->dd; | 
 | 	u64 reg = 0; | 
 | 	u64 reg_prev; | 
 | 	u32 loop = 0; | 
 |  | 
 | 	while (1) { | 
 | 		reg_prev = reg; | 
 | 		reg = read_csr(dd, sc->hw_context * 8 + | 
 | 			       SEND_EGRESS_CTXT_STATUS); | 
 | 		/* done if egress is stopped */ | 
 | 		if (egress_halted(reg)) | 
 | 			break; | 
 | 		reg = packet_occupancy(reg); | 
 | 		if (reg == 0) | 
 | 			break; | 
 | 		/* counter is reset if occupancy count changes */ | 
 | 		if (reg != reg_prev) | 
 | 			loop = 0; | 
 | 		if (loop > 50000) { | 
 | 			/* timed out - bounce the link */ | 
 | 			dd_dev_err(dd, | 
 | 				   "%s: context %u(%u) timeout waiting for packets to egress, remaining count %u, bouncing link\n", | 
 | 				   __func__, sc->sw_index, | 
 | 				   sc->hw_context, (u32)reg); | 
 | 			queue_work(dd->pport->hfi1_wq, | 
 | 				   &dd->pport->link_bounce_work); | 
 | 			break; | 
 | 		} | 
 | 		loop++; | 
 | 		udelay(1); | 
 | 	} | 
 |  | 
 | 	if (pause) | 
 | 		/* Add additional delay to ensure chip returns all credits */ | 
 | 		pause_for_credit_return(dd); | 
 | } | 
 |  | 
 | void sc_wait(struct hfi1_devdata *dd) | 
 | { | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; i < dd->num_send_contexts; i++) { | 
 | 		struct send_context *sc = dd->send_contexts[i].sc; | 
 |  | 
 | 		if (!sc) | 
 | 			continue; | 
 | 		sc_wait_for_packet_egress(sc, 0); | 
 | 	} | 
 | } | 
 |  | 
 | /* | 
 |  * Restart a context after it has been halted due to error. | 
 |  * | 
 |  * If the first step fails - wait for the halt to be asserted, return early. | 
 |  * Otherwise complain about timeouts but keep going. | 
 |  * | 
 |  * It is expected that allocations (enabled flag bit) have been shut off | 
 |  * already (only applies to kernel contexts). | 
 |  */ | 
 | int sc_restart(struct send_context *sc) | 
 | { | 
 | 	struct hfi1_devdata *dd = sc->dd; | 
 | 	u64 reg; | 
 | 	u32 loop; | 
 | 	int count; | 
 |  | 
 | 	/* bounce off if not halted, or being free'd */ | 
 | 	if (!(sc->flags & SCF_HALTED) || (sc->flags & SCF_IN_FREE)) | 
 | 		return -EINVAL; | 
 |  | 
 | 	dd_dev_info(dd, "restarting send context %u(%u)\n", sc->sw_index, | 
 | 		    sc->hw_context); | 
 |  | 
 | 	/* | 
 | 	 * Step 1: Wait for the context to actually halt. | 
 | 	 * | 
 | 	 * The error interrupt is asynchronous to actually setting halt | 
 | 	 * on the context. | 
 | 	 */ | 
 | 	loop = 0; | 
 | 	while (1) { | 
 | 		reg = read_kctxt_csr(dd, sc->hw_context, SC(STATUS)); | 
 | 		if (reg & SC(STATUS_CTXT_HALTED_SMASK)) | 
 | 			break; | 
 | 		if (loop > 100) { | 
 | 			dd_dev_err(dd, "%s: context %u(%u) not halting, skipping\n", | 
 | 				   __func__, sc->sw_index, sc->hw_context); | 
 | 			return -ETIME; | 
 | 		} | 
 | 		loop++; | 
 | 		udelay(1); | 
 | 	} | 
 |  | 
 | 	/* | 
 | 	 * Step 2: Ensure no users are still trying to write to PIO. | 
 | 	 * | 
 | 	 * For kernel contexts, we have already turned off buffer allocation. | 
 | 	 * Now wait for the buffer count to go to zero. | 
 | 	 * | 
 | 	 * For user contexts, the user handling code has cut off write access | 
 | 	 * to the context's PIO pages before calling this routine and will | 
 | 	 * restore write access after this routine returns. | 
 | 	 */ | 
 | 	if (sc->type != SC_USER) { | 
 | 		/* kernel context */ | 
 | 		loop = 0; | 
 | 		while (1) { | 
 | 			count = get_buffers_allocated(sc); | 
 | 			if (count == 0) | 
 | 				break; | 
 | 			if (loop > 100) { | 
 | 				dd_dev_err(dd, | 
 | 					   "%s: context %u(%u) timeout waiting for PIO buffers to zero, remaining %d\n", | 
 | 					   __func__, sc->sw_index, | 
 | 					   sc->hw_context, count); | 
 | 			} | 
 | 			loop++; | 
 | 			udelay(1); | 
 | 		} | 
 | 	} | 
 |  | 
 | 	/* | 
 | 	 * Step 3: Wait for all packets to egress. | 
 | 	 * This is done while disabling the send context | 
 | 	 * | 
 | 	 * Step 4: Disable the context | 
 | 	 * | 
 | 	 * This is a superset of the halt.  After the disable, the | 
 | 	 * errors can be cleared. | 
 | 	 */ | 
 | 	sc_disable(sc); | 
 |  | 
 | 	/* | 
 | 	 * Step 5: Enable the context | 
 | 	 * | 
 | 	 * This enable will clear the halted flag and per-send context | 
 | 	 * error flags. | 
 | 	 */ | 
 | 	return sc_enable(sc); | 
 | } | 
 |  | 
 | /* | 
 |  * PIO freeze processing.  To be called after the TXE block is fully frozen. | 
 |  * Go through all frozen send contexts and disable them.  The contexts are | 
 |  * already stopped by the freeze. | 
 |  */ | 
 | void pio_freeze(struct hfi1_devdata *dd) | 
 | { | 
 | 	struct send_context *sc; | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; i < dd->num_send_contexts; i++) { | 
 | 		sc = dd->send_contexts[i].sc; | 
 | 		/* | 
 | 		 * Don't disable unallocated, unfrozen, or user send contexts. | 
 | 		 * User send contexts will be disabled when the process | 
 | 		 * calls into the driver to reset its context. | 
 | 		 */ | 
 | 		if (!sc || !(sc->flags & SCF_FROZEN) || sc->type == SC_USER) | 
 | 			continue; | 
 |  | 
 | 		/* only need to disable, the context is already stopped */ | 
 | 		sc_disable(sc); | 
 | 	} | 
 | } | 
 |  | 
 | /* | 
 |  * Unfreeze PIO for kernel send contexts.  The precondition for calling this | 
 |  * is that all PIO send contexts have been disabled and the SPC freeze has | 
 |  * been cleared.  Now perform the last step and re-enable each kernel context. | 
 |  * User (PSM) processing will occur when PSM calls into the kernel to | 
 |  * acknowledge the freeze. | 
 |  */ | 
 | void pio_kernel_unfreeze(struct hfi1_devdata *dd) | 
 | { | 
 | 	struct send_context *sc; | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; i < dd->num_send_contexts; i++) { | 
 | 		sc = dd->send_contexts[i].sc; | 
 | 		if (!sc || !(sc->flags & SCF_FROZEN) || sc->type == SC_USER) | 
 | 			continue; | 
 |  | 
 | 		sc_enable(sc);	/* will clear the sc frozen flag */ | 
 | 	} | 
 | } | 
 |  | 
 | /* | 
 |  * Wait for the SendPioInitCtxt.PioInitInProgress bit to clear. | 
 |  * Returns: | 
 |  *	-ETIMEDOUT - if we wait too long | 
 |  *	-EIO	   - if there was an error | 
 |  */ | 
 | static int pio_init_wait_progress(struct hfi1_devdata *dd) | 
 | { | 
 | 	u64 reg; | 
 | 	int max, count = 0; | 
 |  | 
 | 	/* max is the longest possible HW init time / delay */ | 
 | 	max = (dd->icode == ICODE_FPGA_EMULATION) ? 120 : 5; | 
 | 	while (1) { | 
 | 		reg = read_csr(dd, SEND_PIO_INIT_CTXT); | 
 | 		if (!(reg & SEND_PIO_INIT_CTXT_PIO_INIT_IN_PROGRESS_SMASK)) | 
 | 			break; | 
 | 		if (count >= max) | 
 | 			return -ETIMEDOUT; | 
 | 		udelay(5); | 
 | 		count++; | 
 | 	} | 
 |  | 
 | 	return reg & SEND_PIO_INIT_CTXT_PIO_INIT_ERR_SMASK ? -EIO : 0; | 
 | } | 
 |  | 
 | /* | 
 |  * Reset all of the send contexts to their power-on state.  Used | 
 |  * only during manual init - no lock against sc_enable needed. | 
 |  */ | 
 | void pio_reset_all(struct hfi1_devdata *dd) | 
 | { | 
 | 	int ret; | 
 |  | 
 | 	/* make sure the init engine is not busy */ | 
 | 	ret = pio_init_wait_progress(dd); | 
 | 	/* ignore any timeout */ | 
 | 	if (ret == -EIO) { | 
 | 		/* clear the error */ | 
 | 		write_csr(dd, SEND_PIO_ERR_CLEAR, | 
 | 			  SEND_PIO_ERR_CLEAR_PIO_INIT_SM_IN_ERR_SMASK); | 
 | 	} | 
 |  | 
 | 	/* reset init all */ | 
 | 	write_csr(dd, SEND_PIO_INIT_CTXT, | 
 | 		  SEND_PIO_INIT_CTXT_PIO_ALL_CTXT_INIT_SMASK); | 
 | 	udelay(2); | 
 | 	ret = pio_init_wait_progress(dd); | 
 | 	if (ret < 0) { | 
 | 		dd_dev_err(dd, | 
 | 			   "PIO send context init %s while initializing all PIO blocks\n", | 
 | 			   ret == -ETIMEDOUT ? "is stuck" : "had an error"); | 
 | 	} | 
 | } | 
 |  | 
 | /* enable the context */ | 
 | int sc_enable(struct send_context *sc) | 
 | { | 
 | 	u64 sc_ctrl, reg, pio; | 
 | 	struct hfi1_devdata *dd; | 
 | 	unsigned long flags; | 
 | 	int ret = 0; | 
 |  | 
 | 	if (!sc) | 
 | 		return -EINVAL; | 
 | 	dd = sc->dd; | 
 |  | 
 | 	/* | 
 | 	 * Obtain the allocator lock to guard against any allocation | 
 | 	 * attempts (which should not happen prior to context being | 
 | 	 * enabled). On the release/disable side we don't need to | 
 | 	 * worry about locking since the releaser will not do anything | 
 | 	 * if the context accounting values have not changed. | 
 | 	 */ | 
 | 	spin_lock_irqsave(&sc->alloc_lock, flags); | 
 | 	sc_ctrl = read_kctxt_csr(dd, sc->hw_context, SC(CTRL)); | 
 | 	if ((sc_ctrl & SC(CTRL_CTXT_ENABLE_SMASK))) | 
 | 		goto unlock; /* already enabled */ | 
 |  | 
 | 	/* IMPORTANT: only clear free and fill if transitioning 0 -> 1 */ | 
 |  | 
 | 	*sc->hw_free = 0; | 
 | 	sc->free = 0; | 
 | 	sc->alloc_free = 0; | 
 | 	sc->fill = 0; | 
 | 	sc->sr_head = 0; | 
 | 	sc->sr_tail = 0; | 
 | 	sc->flags = 0; | 
 | 	/* the alloc lock insures no fast path allocation */ | 
 | 	reset_buffers_allocated(sc); | 
 |  | 
 | 	/* | 
 | 	 * Clear all per-context errors.  Some of these will be set when | 
 | 	 * we are re-enabling after a context halt.  Now that the context | 
 | 	 * is disabled, the halt will not clear until after the PIO init | 
 | 	 * engine runs below. | 
 | 	 */ | 
 | 	reg = read_kctxt_csr(dd, sc->hw_context, SC(ERR_STATUS)); | 
 | 	if (reg) | 
 | 		write_kctxt_csr(dd, sc->hw_context, SC(ERR_CLEAR), reg); | 
 |  | 
 | 	/* | 
 | 	 * The HW PIO initialization engine can handle only one init | 
 | 	 * request at a time. Serialize access to each device's engine. | 
 | 	 */ | 
 | 	spin_lock(&dd->sc_init_lock); | 
 | 	/* | 
 | 	 * Since access to this code block is serialized and | 
 | 	 * each access waits for the initialization to complete | 
 | 	 * before releasing the lock, the PIO initialization engine | 
 | 	 * should not be in use, so we don't have to wait for the | 
 | 	 * InProgress bit to go down. | 
 | 	 */ | 
 | 	pio = ((sc->hw_context & SEND_PIO_INIT_CTXT_PIO_CTXT_NUM_MASK) << | 
 | 	       SEND_PIO_INIT_CTXT_PIO_CTXT_NUM_SHIFT) | | 
 | 		SEND_PIO_INIT_CTXT_PIO_SINGLE_CTXT_INIT_SMASK; | 
 | 	write_csr(dd, SEND_PIO_INIT_CTXT, pio); | 
 | 	/* | 
 | 	 * Wait until the engine is done.  Give the chip the required time | 
 | 	 * so, hopefully, we read the register just once. | 
 | 	 */ | 
 | 	udelay(2); | 
 | 	ret = pio_init_wait_progress(dd); | 
 | 	spin_unlock(&dd->sc_init_lock); | 
 | 	if (ret) { | 
 | 		dd_dev_err(dd, | 
 | 			   "sctxt%u(%u): Context not enabled due to init failure %d\n", | 
 | 			   sc->sw_index, sc->hw_context, ret); | 
 | 		goto unlock; | 
 | 	} | 
 |  | 
 | 	/* | 
 | 	 * All is well. Enable the context. | 
 | 	 */ | 
 | 	sc_ctrl |= SC(CTRL_CTXT_ENABLE_SMASK); | 
 | 	write_kctxt_csr(dd, sc->hw_context, SC(CTRL), sc_ctrl); | 
 | 	/* | 
 | 	 * Read SendCtxtCtrl to force the write out and prevent a timing | 
 | 	 * hazard where a PIO write may reach the context before the enable. | 
 | 	 */ | 
 | 	read_kctxt_csr(dd, sc->hw_context, SC(CTRL)); | 
 | 	sc->flags |= SCF_ENABLED; | 
 |  | 
 | unlock: | 
 | 	spin_unlock_irqrestore(&sc->alloc_lock, flags); | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* force a credit return on the context */ | 
 | void sc_return_credits(struct send_context *sc) | 
 | { | 
 | 	if (!sc) | 
 | 		return; | 
 |  | 
 | 	/* a 0->1 transition schedules a credit return */ | 
 | 	write_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE), | 
 | 			SC(CREDIT_FORCE_FORCE_RETURN_SMASK)); | 
 | 	/* | 
 | 	 * Ensure that the write is flushed and the credit return is | 
 | 	 * scheduled. We care more about the 0 -> 1 transition. | 
 | 	 */ | 
 | 	read_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE)); | 
 | 	/* set back to 0 for next time */ | 
 | 	write_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE), 0); | 
 | } | 
 |  | 
 | /* allow all in-flight packets to drain on the context */ | 
 | void sc_flush(struct send_context *sc) | 
 | { | 
 | 	if (!sc) | 
 | 		return; | 
 |  | 
 | 	sc_wait_for_packet_egress(sc, 1); | 
 | } | 
 |  | 
 | /* drop all packets on the context, no waiting until they are sent */ | 
 | void sc_drop(struct send_context *sc) | 
 | { | 
 | 	if (!sc) | 
 | 		return; | 
 |  | 
 | 	dd_dev_info(sc->dd, "%s: context %u(%u) - not implemented\n", | 
 | 		    __func__, sc->sw_index, sc->hw_context); | 
 | } | 
 |  | 
 | /* | 
 |  * Start the software reaction to a context halt or SPC freeze: | 
 |  *	- mark the context as halted or frozen | 
 |  *	- stop buffer allocations | 
 |  * | 
 |  * Called from the error interrupt.  Other work is deferred until | 
 |  * out of the interrupt. | 
 |  */ | 
 | void sc_stop(struct send_context *sc, int flag) | 
 | { | 
 | 	unsigned long flags; | 
 |  | 
 | 	/* mark the context */ | 
 | 	sc->flags |= flag; | 
 |  | 
 | 	/* stop buffer allocations */ | 
 | 	spin_lock_irqsave(&sc->alloc_lock, flags); | 
 | 	sc->flags &= ~SCF_ENABLED; | 
 | 	spin_unlock_irqrestore(&sc->alloc_lock, flags); | 
 | 	wake_up(&sc->halt_wait); | 
 | } | 
 |  | 
 | #define BLOCK_DWORDS (PIO_BLOCK_SIZE / sizeof(u32)) | 
 | #define dwords_to_blocks(x) DIV_ROUND_UP(x, BLOCK_DWORDS) | 
 |  | 
 | /* | 
 |  * The send context buffer "allocator". | 
 |  * | 
 |  * @sc: the PIO send context we are allocating from | 
 |  * @len: length of whole packet - including PBC - in dwords | 
 |  * @cb: optional callback to call when the buffer is finished sending | 
 |  * @arg: argument for cb | 
 |  * | 
 |  * Return a pointer to a PIO buffer if successful, NULL if not enough room. | 
 |  */ | 
 | struct pio_buf *sc_buffer_alloc(struct send_context *sc, u32 dw_len, | 
 | 				pio_release_cb cb, void *arg) | 
 | { | 
 | 	struct pio_buf *pbuf = NULL; | 
 | 	unsigned long flags; | 
 | 	unsigned long avail; | 
 | 	unsigned long blocks = dwords_to_blocks(dw_len); | 
 | 	unsigned long start_fill; | 
 | 	int trycount = 0; | 
 | 	u32 head, next; | 
 |  | 
 | 	spin_lock_irqsave(&sc->alloc_lock, flags); | 
 | 	if (!(sc->flags & SCF_ENABLED)) { | 
 | 		spin_unlock_irqrestore(&sc->alloc_lock, flags); | 
 | 		goto done; | 
 | 	} | 
 |  | 
 | retry: | 
 | 	avail = (unsigned long)sc->credits - (sc->fill - sc->alloc_free); | 
 | 	if (blocks > avail) { | 
 | 		/* not enough room */ | 
 | 		if (unlikely(trycount))	{ /* already tried to get more room */ | 
 | 			spin_unlock_irqrestore(&sc->alloc_lock, flags); | 
 | 			goto done; | 
 | 		} | 
 | 		/* copy from receiver cache line and recalculate */ | 
 | 		sc->alloc_free = ACCESS_ONCE(sc->free); | 
 | 		avail = | 
 | 			(unsigned long)sc->credits - | 
 | 			(sc->fill - sc->alloc_free); | 
 | 		if (blocks > avail) { | 
 | 			/* still no room, actively update */ | 
 | 			spin_unlock_irqrestore(&sc->alloc_lock, flags); | 
 | 			sc_release_update(sc); | 
 | 			spin_lock_irqsave(&sc->alloc_lock, flags); | 
 | 			sc->alloc_free = ACCESS_ONCE(sc->free); | 
 | 			trycount++; | 
 | 			goto retry; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	/* there is enough room */ | 
 |  | 
 | 	preempt_disable(); | 
 | 	this_cpu_inc(*sc->buffers_allocated); | 
 |  | 
 | 	/* read this once */ | 
 | 	head = sc->sr_head; | 
 |  | 
 | 	/* "allocate" the buffer */ | 
 | 	start_fill = sc->fill; | 
 | 	sc->fill += blocks; | 
 |  | 
 | 	/* | 
 | 	 * Fill the parts that the releaser looks at before moving the head. | 
 | 	 * The only necessary piece is the sent_at field.  The credits | 
 | 	 * we have just allocated cannot have been returned yet, so the | 
 | 	 * cb and arg will not be looked at for a "while".  Put them | 
 | 	 * on this side of the memory barrier anyway. | 
 | 	 */ | 
 | 	pbuf = &sc->sr[head].pbuf; | 
 | 	pbuf->sent_at = sc->fill; | 
 | 	pbuf->cb = cb; | 
 | 	pbuf->arg = arg; | 
 | 	pbuf->sc = sc;	/* could be filled in at sc->sr init time */ | 
 | 	/* make sure this is in memory before updating the head */ | 
 |  | 
 | 	/* calculate next head index, do not store */ | 
 | 	next = head + 1; | 
 | 	if (next >= sc->sr_size) | 
 | 		next = 0; | 
 | 	/* | 
 | 	 * update the head - must be last! - the releaser can look at fields | 
 | 	 * in pbuf once we move the head | 
 | 	 */ | 
 | 	smp_wmb(); | 
 | 	sc->sr_head = next; | 
 | 	spin_unlock_irqrestore(&sc->alloc_lock, flags); | 
 |  | 
 | 	/* finish filling in the buffer outside the lock */ | 
 | 	pbuf->start = sc->base_addr + ((start_fill % sc->credits) | 
 | 							* PIO_BLOCK_SIZE); | 
 | 	pbuf->size = sc->credits * PIO_BLOCK_SIZE; | 
 | 	pbuf->end = sc->base_addr + pbuf->size; | 
 | 	pbuf->block_count = blocks; | 
 | 	pbuf->qw_written = 0; | 
 | 	pbuf->carry_bytes = 0; | 
 | 	pbuf->carry.val64 = 0; | 
 | done: | 
 | 	return pbuf; | 
 | } | 
 |  | 
 | /* | 
 |  * There are at least two entities that can turn on credit return | 
 |  * interrupts and they can overlap.  Avoid problems by implementing | 
 |  * a count scheme that is enforced by a lock.  The lock is needed because | 
 |  * the count and CSR write must be paired. | 
 |  */ | 
 |  | 
 | /* | 
 |  * Start credit return interrupts.  This is managed by a count.  If already | 
 |  * on, just increment the count. | 
 |  */ | 
 | void sc_add_credit_return_intr(struct send_context *sc) | 
 | { | 
 | 	unsigned long flags; | 
 |  | 
 | 	/* lock must surround both the count change and the CSR update */ | 
 | 	spin_lock_irqsave(&sc->credit_ctrl_lock, flags); | 
 | 	if (sc->credit_intr_count == 0) { | 
 | 		sc->credit_ctrl |= SC(CREDIT_CTRL_CREDIT_INTR_SMASK); | 
 | 		write_kctxt_csr(sc->dd, sc->hw_context, | 
 | 				SC(CREDIT_CTRL), sc->credit_ctrl); | 
 | 	} | 
 | 	sc->credit_intr_count++; | 
 | 	spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags); | 
 | } | 
 |  | 
 | /* | 
 |  * Stop credit return interrupts.  This is managed by a count.  Decrement the | 
 |  * count, if the last user, then turn the credit interrupts off. | 
 |  */ | 
 | void sc_del_credit_return_intr(struct send_context *sc) | 
 | { | 
 | 	unsigned long flags; | 
 |  | 
 | 	WARN_ON(sc->credit_intr_count == 0); | 
 |  | 
 | 	/* lock must surround both the count change and the CSR update */ | 
 | 	spin_lock_irqsave(&sc->credit_ctrl_lock, flags); | 
 | 	sc->credit_intr_count--; | 
 | 	if (sc->credit_intr_count == 0) { | 
 | 		sc->credit_ctrl &= ~SC(CREDIT_CTRL_CREDIT_INTR_SMASK); | 
 | 		write_kctxt_csr(sc->dd, sc->hw_context, | 
 | 				SC(CREDIT_CTRL), sc->credit_ctrl); | 
 | 	} | 
 | 	spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags); | 
 | } | 
 |  | 
 | /* | 
 |  * The caller must be careful when calling this.  All needint calls | 
 |  * must be paired with !needint. | 
 |  */ | 
 | void hfi1_sc_wantpiobuf_intr(struct send_context *sc, u32 needint) | 
 | { | 
 | 	if (needint) | 
 | 		sc_add_credit_return_intr(sc); | 
 | 	else | 
 | 		sc_del_credit_return_intr(sc); | 
 | 	trace_hfi1_wantpiointr(sc, needint, sc->credit_ctrl); | 
 | 	if (needint) { | 
 | 		mmiowb(); | 
 | 		sc_return_credits(sc); | 
 | 	} | 
 | } | 
 |  | 
 | /** | 
 |  * sc_piobufavail - callback when a PIO buffer is available | 
 |  * @sc: the send context | 
 |  * | 
 |  * This is called from the interrupt handler when a PIO buffer is | 
 |  * available after hfi1_verbs_send() returned an error that no buffers were | 
 |  * available. Disable the interrupt if there are no more QPs waiting. | 
 |  */ | 
 | static void sc_piobufavail(struct send_context *sc) | 
 | { | 
 | 	struct hfi1_devdata *dd = sc->dd; | 
 | 	struct hfi1_ibdev *dev = &dd->verbs_dev; | 
 | 	struct list_head *list; | 
 | 	struct rvt_qp *qps[PIO_WAIT_BATCH_SIZE]; | 
 | 	struct rvt_qp *qp; | 
 | 	struct hfi1_qp_priv *priv; | 
 | 	unsigned long flags; | 
 | 	unsigned i, n = 0; | 
 |  | 
 | 	if (dd->send_contexts[sc->sw_index].type != SC_KERNEL && | 
 | 	    dd->send_contexts[sc->sw_index].type != SC_VL15) | 
 | 		return; | 
 | 	list = &sc->piowait; | 
 | 	/* | 
 | 	 * Note: checking that the piowait list is empty and clearing | 
 | 	 * the buffer available interrupt needs to be atomic or we | 
 | 	 * could end up with QPs on the wait list with the interrupt | 
 | 	 * disabled. | 
 | 	 */ | 
 | 	write_seqlock_irqsave(&dev->iowait_lock, flags); | 
 | 	while (!list_empty(list)) { | 
 | 		struct iowait *wait; | 
 |  | 
 | 		if (n == ARRAY_SIZE(qps)) | 
 | 			break; | 
 | 		wait = list_first_entry(list, struct iowait, list); | 
 | 		qp = iowait_to_qp(wait); | 
 | 		priv = qp->priv; | 
 | 		list_del_init(&priv->s_iowait.list); | 
 | 		/* refcount held until actual wake up */ | 
 | 		qps[n++] = qp; | 
 | 	} | 
 | 	/* | 
 | 	 * If there had been waiters and there are more | 
 | 	 * insure that we redo the force to avoid a potential hang. | 
 | 	 */ | 
 | 	if (n) { | 
 | 		hfi1_sc_wantpiobuf_intr(sc, 0); | 
 | 		if (!list_empty(list)) | 
 | 			hfi1_sc_wantpiobuf_intr(sc, 1); | 
 | 	} | 
 | 	write_sequnlock_irqrestore(&dev->iowait_lock, flags); | 
 |  | 
 | 	for (i = 0; i < n; i++) | 
 | 		hfi1_qp_wakeup(qps[i], | 
 | 			       RVT_S_WAIT_PIO | RVT_S_WAIT_PIO_DRAIN); | 
 | } | 
 |  | 
 | /* translate a send credit update to a bit code of reasons */ | 
 | static inline int fill_code(u64 hw_free) | 
 | { | 
 | 	int code = 0; | 
 |  | 
 | 	if (hw_free & CR_STATUS_SMASK) | 
 | 		code |= PRC_STATUS_ERR; | 
 | 	if (hw_free & CR_CREDIT_RETURN_DUE_TO_PBC_SMASK) | 
 | 		code |= PRC_PBC; | 
 | 	if (hw_free & CR_CREDIT_RETURN_DUE_TO_THRESHOLD_SMASK) | 
 | 		code |= PRC_THRESHOLD; | 
 | 	if (hw_free & CR_CREDIT_RETURN_DUE_TO_ERR_SMASK) | 
 | 		code |= PRC_FILL_ERR; | 
 | 	if (hw_free & CR_CREDIT_RETURN_DUE_TO_FORCE_SMASK) | 
 | 		code |= PRC_SC_DISABLE; | 
 | 	return code; | 
 | } | 
 |  | 
 | /* use the jiffies compare to get the wrap right */ | 
 | #define sent_before(a, b) time_before(a, b)	/* a < b */ | 
 |  | 
 | /* | 
 |  * The send context buffer "releaser". | 
 |  */ | 
 | void sc_release_update(struct send_context *sc) | 
 | { | 
 | 	struct pio_buf *pbuf; | 
 | 	u64 hw_free; | 
 | 	u32 head, tail; | 
 | 	unsigned long old_free; | 
 | 	unsigned long free; | 
 | 	unsigned long extra; | 
 | 	unsigned long flags; | 
 | 	int code; | 
 |  | 
 | 	if (!sc) | 
 | 		return; | 
 |  | 
 | 	spin_lock_irqsave(&sc->release_lock, flags); | 
 | 	/* update free */ | 
 | 	hw_free = le64_to_cpu(*sc->hw_free);		/* volatile read */ | 
 | 	old_free = sc->free; | 
 | 	extra = (((hw_free & CR_COUNTER_SMASK) >> CR_COUNTER_SHIFT) | 
 | 			- (old_free & CR_COUNTER_MASK)) | 
 | 				& CR_COUNTER_MASK; | 
 | 	free = old_free + extra; | 
 | 	trace_hfi1_piofree(sc, extra); | 
 |  | 
 | 	/* call sent buffer callbacks */ | 
 | 	code = -1;				/* code not yet set */ | 
 | 	head = ACCESS_ONCE(sc->sr_head);	/* snapshot the head */ | 
 | 	tail = sc->sr_tail; | 
 | 	while (head != tail) { | 
 | 		pbuf = &sc->sr[tail].pbuf; | 
 |  | 
 | 		if (sent_before(free, pbuf->sent_at)) { | 
 | 			/* not sent yet */ | 
 | 			break; | 
 | 		} | 
 | 		if (pbuf->cb) { | 
 | 			if (code < 0) /* fill in code on first user */ | 
 | 				code = fill_code(hw_free); | 
 | 			(*pbuf->cb)(pbuf->arg, code); | 
 | 		} | 
 |  | 
 | 		tail++; | 
 | 		if (tail >= sc->sr_size) | 
 | 			tail = 0; | 
 | 	} | 
 | 	sc->sr_tail = tail; | 
 | 	/* make sure tail is updated before free */ | 
 | 	smp_wmb(); | 
 | 	sc->free = free; | 
 | 	spin_unlock_irqrestore(&sc->release_lock, flags); | 
 | 	sc_piobufavail(sc); | 
 | } | 
 |  | 
 | /* | 
 |  * Send context group releaser.  Argument is the send context that caused | 
 |  * the interrupt.  Called from the send context interrupt handler. | 
 |  * | 
 |  * Call release on all contexts in the group. | 
 |  * | 
 |  * This routine takes the sc_lock without an irqsave because it is only | 
 |  * called from an interrupt handler.  Adjust if that changes. | 
 |  */ | 
 | void sc_group_release_update(struct hfi1_devdata *dd, u32 hw_context) | 
 | { | 
 | 	struct send_context *sc; | 
 | 	u32 sw_index; | 
 | 	u32 gc, gc_end; | 
 |  | 
 | 	spin_lock(&dd->sc_lock); | 
 | 	sw_index = dd->hw_to_sw[hw_context]; | 
 | 	if (unlikely(sw_index >= dd->num_send_contexts)) { | 
 | 		dd_dev_err(dd, "%s: invalid hw (%u) to sw (%u) mapping\n", | 
 | 			   __func__, hw_context, sw_index); | 
 | 		goto done; | 
 | 	} | 
 | 	sc = dd->send_contexts[sw_index].sc; | 
 | 	if (unlikely(!sc)) | 
 | 		goto done; | 
 |  | 
 | 	gc = group_context(hw_context, sc->group); | 
 | 	gc_end = gc + group_size(sc->group); | 
 | 	for (; gc < gc_end; gc++) { | 
 | 		sw_index = dd->hw_to_sw[gc]; | 
 | 		if (unlikely(sw_index >= dd->num_send_contexts)) { | 
 | 			dd_dev_err(dd, | 
 | 				   "%s: invalid hw (%u) to sw (%u) mapping\n", | 
 | 				   __func__, hw_context, sw_index); | 
 | 			continue; | 
 | 		} | 
 | 		sc_release_update(dd->send_contexts[sw_index].sc); | 
 | 	} | 
 | done: | 
 | 	spin_unlock(&dd->sc_lock); | 
 | } | 
 |  | 
 | /* | 
 |  * pio_select_send_context_vl() - select send context | 
 |  * @dd: devdata | 
 |  * @selector: a spreading factor | 
 |  * @vl: this vl | 
 |  * | 
 |  * This function returns a send context based on the selector and a vl. | 
 |  * The mapping fields are protected by RCU | 
 |  */ | 
 | struct send_context *pio_select_send_context_vl(struct hfi1_devdata *dd, | 
 | 						u32 selector, u8 vl) | 
 | { | 
 | 	struct pio_vl_map *m; | 
 | 	struct pio_map_elem *e; | 
 | 	struct send_context *rval; | 
 |  | 
 | 	/* | 
 | 	 * NOTE This should only happen if SC->VL changed after the initial | 
 | 	 * checks on the QP/AH | 
 | 	 * Default will return VL0's send context below | 
 | 	 */ | 
 | 	if (unlikely(vl >= num_vls)) { | 
 | 		rval = NULL; | 
 | 		goto done; | 
 | 	} | 
 |  | 
 | 	rcu_read_lock(); | 
 | 	m = rcu_dereference(dd->pio_map); | 
 | 	if (unlikely(!m)) { | 
 | 		rcu_read_unlock(); | 
 | 		return dd->vld[0].sc; | 
 | 	} | 
 | 	e = m->map[vl & m->mask]; | 
 | 	rval = e->ksc[selector & e->mask]; | 
 | 	rcu_read_unlock(); | 
 |  | 
 | done: | 
 | 	rval = !rval ? dd->vld[0].sc : rval; | 
 | 	return rval; | 
 | } | 
 |  | 
 | /* | 
 |  * pio_select_send_context_sc() - select send context | 
 |  * @dd: devdata | 
 |  * @selector: a spreading factor | 
 |  * @sc5: the 5 bit sc | 
 |  * | 
 |  * This function returns an send context based on the selector and an sc | 
 |  */ | 
 | struct send_context *pio_select_send_context_sc(struct hfi1_devdata *dd, | 
 | 						u32 selector, u8 sc5) | 
 | { | 
 | 	u8 vl = sc_to_vlt(dd, sc5); | 
 |  | 
 | 	return pio_select_send_context_vl(dd, selector, vl); | 
 | } | 
 |  | 
 | /* | 
 |  * Free the indicated map struct | 
 |  */ | 
 | static void pio_map_free(struct pio_vl_map *m) | 
 | { | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; m && i < m->actual_vls; i++) | 
 | 		kfree(m->map[i]); | 
 | 	kfree(m); | 
 | } | 
 |  | 
 | /* | 
 |  * Handle RCU callback | 
 |  */ | 
 | static void pio_map_rcu_callback(struct rcu_head *list) | 
 | { | 
 | 	struct pio_vl_map *m = container_of(list, struct pio_vl_map, list); | 
 |  | 
 | 	pio_map_free(m); | 
 | } | 
 |  | 
 | /* | 
 |  * Set credit return threshold for the kernel send context | 
 |  */ | 
 | static void set_threshold(struct hfi1_devdata *dd, int scontext, int i) | 
 | { | 
 | 	u32 thres; | 
 |  | 
 | 	thres = min(sc_percent_to_threshold(dd->kernel_send_context[scontext], | 
 | 					    50), | 
 | 		    sc_mtu_to_threshold(dd->kernel_send_context[scontext], | 
 | 					dd->vld[i].mtu, | 
 | 					dd->rcd[0]->rcvhdrqentsize)); | 
 | 	sc_set_cr_threshold(dd->kernel_send_context[scontext], thres); | 
 | } | 
 |  | 
 | /* | 
 |  * pio_map_init - called when #vls change | 
 |  * @dd: hfi1_devdata | 
 |  * @port: port number | 
 |  * @num_vls: number of vls | 
 |  * @vl_scontexts: per vl send context mapping (optional) | 
 |  * | 
 |  * This routine changes the mapping based on the number of vls. | 
 |  * | 
 |  * vl_scontexts is used to specify a non-uniform vl/send context | 
 |  * loading. NULL implies auto computing the loading and giving each | 
 |  * VL an uniform distribution of send contexts per VL. | 
 |  * | 
 |  * The auto algorithm computers the sc_per_vl and the number of extra | 
 |  * send contexts. Any extra send contexts are added from the last VL | 
 |  * on down | 
 |  * | 
 |  * rcu locking is used here to control access to the mapping fields. | 
 |  * | 
 |  * If either the num_vls or num_send_contexts are non-power of 2, the | 
 |  * array sizes in the struct pio_vl_map and the struct pio_map_elem are | 
 |  * rounded up to the next highest power of 2 and the first entry is | 
 |  * reused in a round robin fashion. | 
 |  * | 
 |  * If an error occurs the map change is not done and the mapping is not | 
 |  * chaged. | 
 |  * | 
 |  */ | 
 | int pio_map_init(struct hfi1_devdata *dd, u8 port, u8 num_vls, u8 *vl_scontexts) | 
 | { | 
 | 	int i, j; | 
 | 	int extra, sc_per_vl; | 
 | 	int scontext = 1; | 
 | 	int num_kernel_send_contexts = 0; | 
 | 	u8 lvl_scontexts[OPA_MAX_VLS]; | 
 | 	struct pio_vl_map *oldmap, *newmap; | 
 |  | 
 | 	if (!vl_scontexts) { | 
 | 		for (i = 0; i < dd->num_send_contexts; i++) | 
 | 			if (dd->send_contexts[i].type == SC_KERNEL) | 
 | 				num_kernel_send_contexts++; | 
 | 		/* truncate divide */ | 
 | 		sc_per_vl = num_kernel_send_contexts / num_vls; | 
 | 		/* extras */ | 
 | 		extra = num_kernel_send_contexts % num_vls; | 
 | 		vl_scontexts = lvl_scontexts; | 
 | 		/* add extras from last vl down */ | 
 | 		for (i = num_vls - 1; i >= 0; i--, extra--) | 
 | 			vl_scontexts[i] = sc_per_vl + (extra > 0 ? 1 : 0); | 
 | 	} | 
 | 	/* build new map */ | 
 | 	newmap = kzalloc(sizeof(*newmap) + | 
 | 			 roundup_pow_of_two(num_vls) * | 
 | 			 sizeof(struct pio_map_elem *), | 
 | 			 GFP_KERNEL); | 
 | 	if (!newmap) | 
 | 		goto bail; | 
 | 	newmap->actual_vls = num_vls; | 
 | 	newmap->vls = roundup_pow_of_two(num_vls); | 
 | 	newmap->mask = (1 << ilog2(newmap->vls)) - 1; | 
 | 	for (i = 0; i < newmap->vls; i++) { | 
 | 		/* save for wrap around */ | 
 | 		int first_scontext = scontext; | 
 |  | 
 | 		if (i < newmap->actual_vls) { | 
 | 			int sz = roundup_pow_of_two(vl_scontexts[i]); | 
 |  | 
 | 			/* only allocate once */ | 
 | 			newmap->map[i] = kzalloc(sizeof(*newmap->map[i]) + | 
 | 						 sz * sizeof(struct | 
 | 							     send_context *), | 
 | 						 GFP_KERNEL); | 
 | 			if (!newmap->map[i]) | 
 | 				goto bail; | 
 | 			newmap->map[i]->mask = (1 << ilog2(sz)) - 1; | 
 | 			/* | 
 | 			 * assign send contexts and | 
 | 			 * adjust credit return threshold | 
 | 			 */ | 
 | 			for (j = 0; j < sz; j++) { | 
 | 				if (dd->kernel_send_context[scontext]) { | 
 | 					newmap->map[i]->ksc[j] = | 
 | 					dd->kernel_send_context[scontext]; | 
 | 					set_threshold(dd, scontext, i); | 
 | 				} | 
 | 				if (++scontext >= first_scontext + | 
 | 						  vl_scontexts[i]) | 
 | 					/* wrap back to first send context */ | 
 | 					scontext = first_scontext; | 
 | 			} | 
 | 		} else { | 
 | 			/* just re-use entry without allocating */ | 
 | 			newmap->map[i] = newmap->map[i % num_vls]; | 
 | 		} | 
 | 		scontext = first_scontext + vl_scontexts[i]; | 
 | 	} | 
 | 	/* newmap in hand, save old map */ | 
 | 	spin_lock_irq(&dd->pio_map_lock); | 
 | 	oldmap = rcu_dereference_protected(dd->pio_map, | 
 | 					   lockdep_is_held(&dd->pio_map_lock)); | 
 |  | 
 | 	/* publish newmap */ | 
 | 	rcu_assign_pointer(dd->pio_map, newmap); | 
 |  | 
 | 	spin_unlock_irq(&dd->pio_map_lock); | 
 | 	/* success, free any old map after grace period */ | 
 | 	if (oldmap) | 
 | 		call_rcu(&oldmap->list, pio_map_rcu_callback); | 
 | 	return 0; | 
 | bail: | 
 | 	/* free any partial allocation */ | 
 | 	pio_map_free(newmap); | 
 | 	return -ENOMEM; | 
 | } | 
 |  | 
 | void free_pio_map(struct hfi1_devdata *dd) | 
 | { | 
 | 	/* Free PIO map if allocated */ | 
 | 	if (rcu_access_pointer(dd->pio_map)) { | 
 | 		spin_lock_irq(&dd->pio_map_lock); | 
 | 		pio_map_free(rcu_access_pointer(dd->pio_map)); | 
 | 		RCU_INIT_POINTER(dd->pio_map, NULL); | 
 | 		spin_unlock_irq(&dd->pio_map_lock); | 
 | 		synchronize_rcu(); | 
 | 	} | 
 | 	kfree(dd->kernel_send_context); | 
 | 	dd->kernel_send_context = NULL; | 
 | } | 
 |  | 
 | int init_pervl_scs(struct hfi1_devdata *dd) | 
 | { | 
 | 	int i; | 
 | 	u64 mask, all_vl_mask = (u64)0x80ff; /* VLs 0-7, 15 */ | 
 | 	u64 data_vls_mask = (u64)0x00ff; /* VLs 0-7 */ | 
 | 	u32 ctxt; | 
 | 	struct hfi1_pportdata *ppd = dd->pport; | 
 |  | 
 | 	dd->vld[15].sc = sc_alloc(dd, SC_VL15, | 
 | 				  dd->rcd[0]->rcvhdrqentsize, dd->node); | 
 | 	if (!dd->vld[15].sc) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	hfi1_init_ctxt(dd->vld[15].sc); | 
 | 	dd->vld[15].mtu = enum_to_mtu(OPA_MTU_2048); | 
 |  | 
 | 	dd->kernel_send_context = kzalloc_node(dd->num_send_contexts * | 
 | 					sizeof(struct send_context *), | 
 | 					GFP_KERNEL, dd->node); | 
 | 	if (!dd->kernel_send_context) | 
 | 		goto freesc15; | 
 |  | 
 | 	dd->kernel_send_context[0] = dd->vld[15].sc; | 
 |  | 
 | 	for (i = 0; i < num_vls; i++) { | 
 | 		/* | 
 | 		 * Since this function does not deal with a specific | 
 | 		 * receive context but we need the RcvHdrQ entry size, | 
 | 		 * use the size from rcd[0]. It is guaranteed to be | 
 | 		 * valid at this point and will remain the same for all | 
 | 		 * receive contexts. | 
 | 		 */ | 
 | 		dd->vld[i].sc = sc_alloc(dd, SC_KERNEL, | 
 | 					 dd->rcd[0]->rcvhdrqentsize, dd->node); | 
 | 		if (!dd->vld[i].sc) | 
 | 			goto nomem; | 
 | 		dd->kernel_send_context[i + 1] = dd->vld[i].sc; | 
 | 		hfi1_init_ctxt(dd->vld[i].sc); | 
 | 		/* non VL15 start with the max MTU */ | 
 | 		dd->vld[i].mtu = hfi1_max_mtu; | 
 | 	} | 
 | 	for (i = num_vls; i < INIT_SC_PER_VL * num_vls; i++) { | 
 | 		dd->kernel_send_context[i + 1] = | 
 | 		sc_alloc(dd, SC_KERNEL, dd->rcd[0]->rcvhdrqentsize, dd->node); | 
 | 		if (!dd->kernel_send_context[i + 1]) | 
 | 			goto nomem; | 
 | 		hfi1_init_ctxt(dd->kernel_send_context[i + 1]); | 
 | 	} | 
 |  | 
 | 	sc_enable(dd->vld[15].sc); | 
 | 	ctxt = dd->vld[15].sc->hw_context; | 
 | 	mask = all_vl_mask & ~(1LL << 15); | 
 | 	write_kctxt_csr(dd, ctxt, SC(CHECK_VL), mask); | 
 | 	dd_dev_info(dd, | 
 | 		    "Using send context %u(%u) for VL15\n", | 
 | 		    dd->vld[15].sc->sw_index, ctxt); | 
 |  | 
 | 	for (i = 0; i < num_vls; i++) { | 
 | 		sc_enable(dd->vld[i].sc); | 
 | 		ctxt = dd->vld[i].sc->hw_context; | 
 | 		mask = all_vl_mask & ~(data_vls_mask); | 
 | 		write_kctxt_csr(dd, ctxt, SC(CHECK_VL), mask); | 
 | 	} | 
 | 	for (i = num_vls; i < INIT_SC_PER_VL * num_vls; i++) { | 
 | 		sc_enable(dd->kernel_send_context[i + 1]); | 
 | 		ctxt = dd->kernel_send_context[i + 1]->hw_context; | 
 | 		mask = all_vl_mask & ~(data_vls_mask); | 
 | 		write_kctxt_csr(dd, ctxt, SC(CHECK_VL), mask); | 
 | 	} | 
 |  | 
 | 	if (pio_map_init(dd, ppd->port - 1, num_vls, NULL)) | 
 | 		goto nomem; | 
 | 	return 0; | 
 |  | 
 | nomem: | 
 | 	for (i = 0; i < num_vls; i++) { | 
 | 		sc_free(dd->vld[i].sc); | 
 | 		dd->vld[i].sc = NULL; | 
 | 	} | 
 |  | 
 | 	for (i = num_vls; i < INIT_SC_PER_VL * num_vls; i++) | 
 | 		sc_free(dd->kernel_send_context[i + 1]); | 
 |  | 
 | 	kfree(dd->kernel_send_context); | 
 | 	dd->kernel_send_context = NULL; | 
 |  | 
 | freesc15: | 
 | 	sc_free(dd->vld[15].sc); | 
 | 	return -ENOMEM; | 
 | } | 
 |  | 
 | int init_credit_return(struct hfi1_devdata *dd) | 
 | { | 
 | 	int ret; | 
 | 	int num_numa; | 
 | 	int i; | 
 |  | 
 | 	num_numa = num_online_nodes(); | 
 | 	/* enforce the expectation that the numas are compact */ | 
 | 	for (i = 0; i < num_numa; i++) { | 
 | 		if (!node_online(i)) { | 
 | 			dd_dev_err(dd, "NUMA nodes are not compact\n"); | 
 | 			ret = -EINVAL; | 
 | 			goto done; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	dd->cr_base = kcalloc( | 
 | 		num_numa, | 
 | 		sizeof(struct credit_return_base), | 
 | 		GFP_KERNEL); | 
 | 	if (!dd->cr_base) { | 
 | 		dd_dev_err(dd, "Unable to allocate credit return base\n"); | 
 | 		ret = -ENOMEM; | 
 | 		goto done; | 
 | 	} | 
 | 	for (i = 0; i < num_numa; i++) { | 
 | 		int bytes = TXE_NUM_CONTEXTS * sizeof(struct credit_return); | 
 |  | 
 | 		set_dev_node(&dd->pcidev->dev, i); | 
 | 		dd->cr_base[i].va = dma_zalloc_coherent( | 
 | 					&dd->pcidev->dev, | 
 | 					bytes, | 
 | 					&dd->cr_base[i].dma, | 
 | 					GFP_KERNEL); | 
 | 		if (!dd->cr_base[i].va) { | 
 | 			set_dev_node(&dd->pcidev->dev, dd->node); | 
 | 			dd_dev_err(dd, | 
 | 				   "Unable to allocate credit return DMA range for NUMA %d\n", | 
 | 				   i); | 
 | 			ret = -ENOMEM; | 
 | 			goto done; | 
 | 		} | 
 | 	} | 
 | 	set_dev_node(&dd->pcidev->dev, dd->node); | 
 |  | 
 | 	ret = 0; | 
 | done: | 
 | 	return ret; | 
 | } | 
 |  | 
 | void free_credit_return(struct hfi1_devdata *dd) | 
 | { | 
 | 	int num_numa; | 
 | 	int i; | 
 |  | 
 | 	if (!dd->cr_base) | 
 | 		return; | 
 |  | 
 | 	num_numa = num_online_nodes(); | 
 | 	for (i = 0; i < num_numa; i++) { | 
 | 		if (dd->cr_base[i].va) { | 
 | 			dma_free_coherent(&dd->pcidev->dev, | 
 | 					  TXE_NUM_CONTEXTS * | 
 | 					  sizeof(struct credit_return), | 
 | 					  dd->cr_base[i].va, | 
 | 					  dd->cr_base[i].dma); | 
 | 		} | 
 | 	} | 
 | 	kfree(dd->cr_base); | 
 | 	dd->cr_base = NULL; | 
 | } |