| /* |
| * Handle caching attributes in page tables (PAT) |
| * |
| * Authors: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> |
| * Suresh B Siddha <suresh.b.siddha@intel.com> |
| * |
| * Loosely based on earlier PAT patchset from Eric Biederman and Andi Kleen. |
| */ |
| |
| #include <linux/seq_file.h> |
| #include <linux/bootmem.h> |
| #include <linux/debugfs.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/gfp.h> |
| #include <linux/mm.h> |
| #include <linux/fs.h> |
| #include <linux/rbtree.h> |
| |
| #include <asm/cacheflush.h> |
| #include <asm/processor.h> |
| #include <asm/tlbflush.h> |
| #include <asm/pgtable.h> |
| #include <asm/fcntl.h> |
| #include <asm/e820.h> |
| #include <asm/mtrr.h> |
| #include <asm/page.h> |
| #include <asm/msr.h> |
| #include <asm/pat.h> |
| #include <asm/io.h> |
| |
| #ifdef CONFIG_X86_PAT |
| int __read_mostly pat_enabled = 1; |
| |
| static inline void pat_disable(const char *reason) |
| { |
| pat_enabled = 0; |
| printk(KERN_INFO "%s\n", reason); |
| } |
| |
| static int __init nopat(char *str) |
| { |
| pat_disable("PAT support disabled."); |
| return 0; |
| } |
| early_param("nopat", nopat); |
| #else |
| static inline void pat_disable(const char *reason) |
| { |
| (void)reason; |
| } |
| #endif |
| |
| |
| static int debug_enable; |
| |
| static int __init pat_debug_setup(char *str) |
| { |
| debug_enable = 1; |
| return 0; |
| } |
| __setup("debugpat", pat_debug_setup); |
| |
| #define dprintk(fmt, arg...) \ |
| do { if (debug_enable) printk(KERN_INFO fmt, ##arg); } while (0) |
| |
| |
| static u64 __read_mostly boot_pat_state; |
| |
| enum { |
| PAT_UC = 0, /* uncached */ |
| PAT_WC = 1, /* Write combining */ |
| PAT_WT = 4, /* Write Through */ |
| PAT_WP = 5, /* Write Protected */ |
| PAT_WB = 6, /* Write Back (default) */ |
| PAT_UC_MINUS = 7, /* UC, but can be overriden by MTRR */ |
| }; |
| |
| #define PAT(x, y) ((u64)PAT_ ## y << ((x)*8)) |
| |
| void pat_init(void) |
| { |
| u64 pat; |
| |
| if (!pat_enabled) |
| return; |
| |
| if (!cpu_has_pat) { |
| if (!boot_pat_state) { |
| pat_disable("PAT not supported by CPU."); |
| return; |
| } else { |
| /* |
| * If this happens we are on a secondary CPU, but |
| * switched to PAT on the boot CPU. We have no way to |
| * undo PAT. |
| */ |
| printk(KERN_ERR "PAT enabled, " |
| "but not supported by secondary CPU\n"); |
| BUG(); |
| } |
| } |
| |
| /* Set PWT to Write-Combining. All other bits stay the same */ |
| /* |
| * PTE encoding used in Linux: |
| * PAT |
| * |PCD |
| * ||PWT |
| * ||| |
| * 000 WB _PAGE_CACHE_WB |
| * 001 WC _PAGE_CACHE_WC |
| * 010 UC- _PAGE_CACHE_UC_MINUS |
| * 011 UC _PAGE_CACHE_UC |
| * PAT bit unused |
| */ |
| pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, UC) | |
| PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC); |
| |
| /* Boot CPU check */ |
| if (!boot_pat_state) |
| rdmsrl(MSR_IA32_CR_PAT, boot_pat_state); |
| |
| wrmsrl(MSR_IA32_CR_PAT, pat); |
| printk(KERN_INFO "x86 PAT enabled: cpu %d, old 0x%Lx, new 0x%Lx\n", |
| smp_processor_id(), boot_pat_state, pat); |
| } |
| |
| #undef PAT |
| |
| static char *cattr_name(unsigned long flags) |
| { |
| switch (flags & _PAGE_CACHE_MASK) { |
| case _PAGE_CACHE_UC: return "uncached"; |
| case _PAGE_CACHE_UC_MINUS: return "uncached-minus"; |
| case _PAGE_CACHE_WB: return "write-back"; |
| case _PAGE_CACHE_WC: return "write-combining"; |
| default: return "broken"; |
| } |
| } |
| |
| /* |
| * The global memtype list keeps track of memory type for specific |
| * physical memory areas. Conflicting memory types in different |
| * mappings can cause CPU cache corruption. To avoid this we keep track. |
| * |
| * The list is sorted based on starting address and can contain multiple |
| * entries for each address (this allows reference counting for overlapping |
| * areas). All the aliases have the same cache attributes of course. |
| * Zero attributes are represented as holes. |
| * |
| * The data structure is a list that is also organized as an rbtree |
| * sorted on the start address of memtype range. |
| * |
| * memtype_lock protects both the linear list and rbtree. |
| */ |
| |
| struct memtype { |
| u64 start; |
| u64 end; |
| unsigned long type; |
| struct list_head nd; |
| struct rb_node rb; |
| }; |
| |
| static struct rb_root memtype_rbroot = RB_ROOT; |
| static LIST_HEAD(memtype_list); |
| static DEFINE_SPINLOCK(memtype_lock); /* protects memtype list */ |
| |
| static struct memtype *memtype_rb_search(struct rb_root *root, u64 start) |
| { |
| struct rb_node *node = root->rb_node; |
| struct memtype *last_lower = NULL; |
| |
| while (node) { |
| struct memtype *data = container_of(node, struct memtype, rb); |
| |
| if (data->start < start) { |
| last_lower = data; |
| node = node->rb_right; |
| } else if (data->start > start) { |
| node = node->rb_left; |
| } else |
| return data; |
| } |
| |
| /* Will return NULL if there is no entry with its start <= start */ |
| return last_lower; |
| } |
| |
| static void memtype_rb_insert(struct rb_root *root, struct memtype *data) |
| { |
| struct rb_node **new = &(root->rb_node); |
| struct rb_node *parent = NULL; |
| |
| while (*new) { |
| struct memtype *this = container_of(*new, struct memtype, rb); |
| |
| parent = *new; |
| if (data->start <= this->start) |
| new = &((*new)->rb_left); |
| else if (data->start > this->start) |
| new = &((*new)->rb_right); |
| } |
| |
| rb_link_node(&data->rb, parent, new); |
| rb_insert_color(&data->rb, root); |
| } |
| |
| /* |
| * Does intersection of PAT memory type and MTRR memory type and returns |
| * the resulting memory type as PAT understands it. |
| * (Type in pat and mtrr will not have same value) |
| * The intersection is based on "Effective Memory Type" tables in IA-32 |
| * SDM vol 3a |
| */ |
| static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type) |
| { |
| /* |
| * Look for MTRR hint to get the effective type in case where PAT |
| * request is for WB. |
| */ |
| if (req_type == _PAGE_CACHE_WB) { |
| u8 mtrr_type; |
| |
| mtrr_type = mtrr_type_lookup(start, end); |
| if (mtrr_type != MTRR_TYPE_WRBACK) |
| return _PAGE_CACHE_UC_MINUS; |
| |
| return _PAGE_CACHE_WB; |
| } |
| |
| return req_type; |
| } |
| |
| static int |
| chk_conflict(struct memtype *new, struct memtype *entry, unsigned long *type) |
| { |
| if (new->type != entry->type) { |
| if (type) { |
| new->type = entry->type; |
| *type = entry->type; |
| } else |
| goto conflict; |
| } |
| |
| /* check overlaps with more than one entry in the list */ |
| list_for_each_entry_continue(entry, &memtype_list, nd) { |
| if (new->end <= entry->start) |
| break; |
| else if (new->type != entry->type) |
| goto conflict; |
| } |
| return 0; |
| |
| conflict: |
| printk(KERN_INFO "%s:%d conflicting memory types " |
| "%Lx-%Lx %s<->%s\n", current->comm, current->pid, new->start, |
| new->end, cattr_name(new->type), cattr_name(entry->type)); |
| return -EBUSY; |
| } |
| |
| static int pat_pagerange_is_ram(unsigned long start, unsigned long end) |
| { |
| int ram_page = 0, not_rampage = 0; |
| unsigned long page_nr; |
| |
| for (page_nr = (start >> PAGE_SHIFT); page_nr < (end >> PAGE_SHIFT); |
| ++page_nr) { |
| /* |
| * For legacy reasons, physical address range in the legacy ISA |
| * region is tracked as non-RAM. This will allow users of |
| * /dev/mem to map portions of legacy ISA region, even when |
| * some of those portions are listed(or not even listed) with |
| * different e820 types(RAM/reserved/..) |
| */ |
| if (page_nr >= (ISA_END_ADDRESS >> PAGE_SHIFT) && |
| page_is_ram(page_nr)) |
| ram_page = 1; |
| else |
| not_rampage = 1; |
| |
| if (ram_page == not_rampage) |
| return -1; |
| } |
| |
| return ram_page; |
| } |
| |
| /* |
| * For RAM pages, we use page flags to mark the pages with appropriate type. |
| * Here we do two pass: |
| * - Find the memtype of all the pages in the range, look for any conflicts |
| * - In case of no conflicts, set the new memtype for pages in the range |
| * |
| * Caller must hold memtype_lock for atomicity. |
| */ |
| static int reserve_ram_pages_type(u64 start, u64 end, unsigned long req_type, |
| unsigned long *new_type) |
| { |
| struct page *page; |
| u64 pfn; |
| |
| if (req_type == _PAGE_CACHE_UC) { |
| /* We do not support strong UC */ |
| WARN_ON_ONCE(1); |
| req_type = _PAGE_CACHE_UC_MINUS; |
| } |
| |
| for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) { |
| unsigned long type; |
| |
| page = pfn_to_page(pfn); |
| type = get_page_memtype(page); |
| if (type != -1) { |
| printk(KERN_INFO "reserve_ram_pages_type failed " |
| "0x%Lx-0x%Lx, track 0x%lx, req 0x%lx\n", |
| start, end, type, req_type); |
| if (new_type) |
| *new_type = type; |
| |
| return -EBUSY; |
| } |
| } |
| |
| if (new_type) |
| *new_type = req_type; |
| |
| for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) { |
| page = pfn_to_page(pfn); |
| set_page_memtype(page, req_type); |
| } |
| return 0; |
| } |
| |
| static int free_ram_pages_type(u64 start, u64 end) |
| { |
| struct page *page; |
| u64 pfn; |
| |
| for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) { |
| page = pfn_to_page(pfn); |
| set_page_memtype(page, -1); |
| } |
| return 0; |
| } |
| |
| /* |
| * req_type typically has one of the: |
| * - _PAGE_CACHE_WB |
| * - _PAGE_CACHE_WC |
| * - _PAGE_CACHE_UC_MINUS |
| * - _PAGE_CACHE_UC |
| * |
| * req_type will have a special case value '-1', when requester want to inherit |
| * the memory type from mtrr (if WB), existing PAT, defaulting to UC_MINUS. |
| * |
| * If new_type is NULL, function will return an error if it cannot reserve the |
| * region with req_type. If new_type is non-NULL, function will return |
| * available type in new_type in case of no error. In case of any error |
| * it will return a negative return value. |
| */ |
| int reserve_memtype(u64 start, u64 end, unsigned long req_type, |
| unsigned long *new_type) |
| { |
| struct memtype *new, *entry; |
| unsigned long actual_type; |
| struct list_head *where; |
| int is_range_ram; |
| int err = 0; |
| |
| BUG_ON(start >= end); /* end is exclusive */ |
| |
| if (!pat_enabled) { |
| /* This is identical to page table setting without PAT */ |
| if (new_type) { |
| if (req_type == -1) |
| *new_type = _PAGE_CACHE_WB; |
| else if (req_type == _PAGE_CACHE_WC) |
| *new_type = _PAGE_CACHE_UC_MINUS; |
| else |
| *new_type = req_type & _PAGE_CACHE_MASK; |
| } |
| return 0; |
| } |
| |
| /* Low ISA region is always mapped WB in page table. No need to track */ |
| if (is_ISA_range(start, end - 1)) { |
| if (new_type) |
| *new_type = _PAGE_CACHE_WB; |
| return 0; |
| } |
| |
| /* |
| * Call mtrr_lookup to get the type hint. This is an |
| * optimization for /dev/mem mmap'ers into WB memory (BIOS |
| * tools and ACPI tools). Use WB request for WB memory and use |
| * UC_MINUS otherwise. |
| */ |
| actual_type = pat_x_mtrr_type(start, end, req_type & _PAGE_CACHE_MASK); |
| |
| if (new_type) |
| *new_type = actual_type; |
| |
| is_range_ram = pat_pagerange_is_ram(start, end); |
| if (is_range_ram == 1) { |
| |
| spin_lock(&memtype_lock); |
| err = reserve_ram_pages_type(start, end, req_type, new_type); |
| spin_unlock(&memtype_lock); |
| |
| return err; |
| } else if (is_range_ram < 0) { |
| return -EINVAL; |
| } |
| |
| new = kmalloc(sizeof(struct memtype), GFP_KERNEL); |
| if (!new) |
| return -ENOMEM; |
| |
| new->start = start; |
| new->end = end; |
| new->type = actual_type; |
| |
| spin_lock(&memtype_lock); |
| |
| /* Search for existing mapping that overlaps the current range */ |
| where = NULL; |
| list_for_each_entry(entry, &memtype_list, nd) { |
| if (end <= entry->start) { |
| where = entry->nd.prev; |
| break; |
| } else if (start <= entry->start) { /* end > entry->start */ |
| err = chk_conflict(new, entry, new_type); |
| if (!err) { |
| dprintk("Overlap at 0x%Lx-0x%Lx\n", |
| entry->start, entry->end); |
| where = entry->nd.prev; |
| } |
| break; |
| } else if (start < entry->end) { /* start > entry->start */ |
| err = chk_conflict(new, entry, new_type); |
| if (!err) { |
| dprintk("Overlap at 0x%Lx-0x%Lx\n", |
| entry->start, entry->end); |
| |
| /* |
| * Move to right position in the linked |
| * list to add this new entry |
| */ |
| list_for_each_entry_continue(entry, |
| &memtype_list, nd) { |
| if (start <= entry->start) { |
| where = entry->nd.prev; |
| break; |
| } |
| } |
| } |
| break; |
| } |
| } |
| |
| if (err) { |
| printk(KERN_INFO "reserve_memtype failed 0x%Lx-0x%Lx, " |
| "track %s, req %s\n", |
| start, end, cattr_name(new->type), cattr_name(req_type)); |
| kfree(new); |
| spin_unlock(&memtype_lock); |
| |
| return err; |
| } |
| |
| if (where) |
| list_add(&new->nd, where); |
| else |
| list_add_tail(&new->nd, &memtype_list); |
| |
| memtype_rb_insert(&memtype_rbroot, new); |
| |
| spin_unlock(&memtype_lock); |
| |
| dprintk("reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n", |
| start, end, cattr_name(new->type), cattr_name(req_type), |
| new_type ? cattr_name(*new_type) : "-"); |
| |
| return err; |
| } |
| |
| int free_memtype(u64 start, u64 end) |
| { |
| struct memtype *entry, *saved_entry; |
| int err = -EINVAL; |
| int is_range_ram; |
| |
| if (!pat_enabled) |
| return 0; |
| |
| /* Low ISA region is always mapped WB. No need to track */ |
| if (is_ISA_range(start, end - 1)) |
| return 0; |
| |
| is_range_ram = pat_pagerange_is_ram(start, end); |
| if (is_range_ram == 1) { |
| |
| spin_lock(&memtype_lock); |
| err = free_ram_pages_type(start, end); |
| spin_unlock(&memtype_lock); |
| |
| return err; |
| } else if (is_range_ram < 0) { |
| return -EINVAL; |
| } |
| |
| spin_lock(&memtype_lock); |
| |
| entry = memtype_rb_search(&memtype_rbroot, start); |
| if (unlikely(entry == NULL)) |
| goto unlock_ret; |
| |
| /* |
| * Saved entry points to an entry with start same or less than what |
| * we searched for. Now go through the list in both directions to look |
| * for the entry that matches with both start and end, with list stored |
| * in sorted start address |
| */ |
| saved_entry = entry; |
| list_for_each_entry_from(entry, &memtype_list, nd) { |
| if (entry->start == start && entry->end == end) { |
| rb_erase(&entry->rb, &memtype_rbroot); |
| list_del(&entry->nd); |
| kfree(entry); |
| err = 0; |
| break; |
| } else if (entry->start > start) { |
| break; |
| } |
| } |
| |
| if (!err) |
| goto unlock_ret; |
| |
| entry = saved_entry; |
| list_for_each_entry_reverse(entry, &memtype_list, nd) { |
| if (entry->start == start && entry->end == end) { |
| rb_erase(&entry->rb, &memtype_rbroot); |
| list_del(&entry->nd); |
| kfree(entry); |
| err = 0; |
| break; |
| } else if (entry->start < start) { |
| break; |
| } |
| } |
| unlock_ret: |
| spin_unlock(&memtype_lock); |
| |
| if (err) { |
| printk(KERN_INFO "%s:%d freeing invalid memtype %Lx-%Lx\n", |
| current->comm, current->pid, start, end); |
| } |
| |
| dprintk("free_memtype request 0x%Lx-0x%Lx\n", start, end); |
| |
| return err; |
| } |
| |
| |
| /** |
| * lookup_memtype - Looksup the memory type for a physical address |
| * @paddr: physical address of which memory type needs to be looked up |
| * |
| * Only to be called when PAT is enabled |
| * |
| * Returns _PAGE_CACHE_WB, _PAGE_CACHE_WC, _PAGE_CACHE_UC_MINUS or |
| * _PAGE_CACHE_UC |
| */ |
| static unsigned long lookup_memtype(u64 paddr) |
| { |
| int rettype = _PAGE_CACHE_WB; |
| struct memtype *entry; |
| |
| if (is_ISA_range(paddr, paddr + PAGE_SIZE - 1)) |
| return rettype; |
| |
| if (pat_pagerange_is_ram(paddr, paddr + PAGE_SIZE)) { |
| struct page *page; |
| spin_lock(&memtype_lock); |
| page = pfn_to_page(paddr >> PAGE_SHIFT); |
| rettype = get_page_memtype(page); |
| spin_unlock(&memtype_lock); |
| /* |
| * -1 from get_page_memtype() implies RAM page is in its |
| * default state and not reserved, and hence of type WB |
| */ |
| if (rettype == -1) |
| rettype = _PAGE_CACHE_WB; |
| |
| return rettype; |
| } |
| |
| spin_lock(&memtype_lock); |
| |
| entry = memtype_rb_search(&memtype_rbroot, paddr); |
| if (entry != NULL) |
| rettype = entry->type; |
| else |
| rettype = _PAGE_CACHE_UC_MINUS; |
| |
| spin_unlock(&memtype_lock); |
| return rettype; |
| } |
| |
| /** |
| * io_reserve_memtype - Request a memory type mapping for a region of memory |
| * @start: start (physical address) of the region |
| * @end: end (physical address) of the region |
| * @type: A pointer to memtype, with requested type. On success, requested |
| * or any other compatible type that was available for the region is returned |
| * |
| * On success, returns 0 |
| * On failure, returns non-zero |
| */ |
| int io_reserve_memtype(resource_size_t start, resource_size_t end, |
| unsigned long *type) |
| { |
| resource_size_t size = end - start; |
| unsigned long req_type = *type; |
| unsigned long new_type; |
| int ret; |
| |
| WARN_ON_ONCE(iomem_map_sanity_check(start, size)); |
| |
| ret = reserve_memtype(start, end, req_type, &new_type); |
| if (ret) |
| goto out_err; |
| |
| if (!is_new_memtype_allowed(start, size, req_type, new_type)) |
| goto out_free; |
| |
| if (kernel_map_sync_memtype(start, size, new_type) < 0) |
| goto out_free; |
| |
| *type = new_type; |
| return 0; |
| |
| out_free: |
| free_memtype(start, end); |
| ret = -EBUSY; |
| out_err: |
| return ret; |
| } |
| |
| /** |
| * io_free_memtype - Release a memory type mapping for a region of memory |
| * @start: start (physical address) of the region |
| * @end: end (physical address) of the region |
| */ |
| void io_free_memtype(resource_size_t start, resource_size_t end) |
| { |
| free_memtype(start, end); |
| } |
| |
| pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, |
| unsigned long size, pgprot_t vma_prot) |
| { |
| return vma_prot; |
| } |
| |
| #ifdef CONFIG_STRICT_DEVMEM |
| /* This check is done in drivers/char/mem.c in case of STRICT_DEVMEM*/ |
| static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
| { |
| return 1; |
| } |
| #else |
| /* This check is needed to avoid cache aliasing when PAT is enabled */ |
| static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
| { |
| u64 from = ((u64)pfn) << PAGE_SHIFT; |
| u64 to = from + size; |
| u64 cursor = from; |
| |
| if (!pat_enabled) |
| return 1; |
| |
| while (cursor < to) { |
| if (!devmem_is_allowed(pfn)) { |
| printk(KERN_INFO |
| "Program %s tried to access /dev/mem between %Lx->%Lx.\n", |
| current->comm, from, to); |
| return 0; |
| } |
| cursor += PAGE_SIZE; |
| pfn++; |
| } |
| return 1; |
| } |
| #endif /* CONFIG_STRICT_DEVMEM */ |
| |
| int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, |
| unsigned long size, pgprot_t *vma_prot) |
| { |
| unsigned long flags = _PAGE_CACHE_WB; |
| |
| if (!range_is_allowed(pfn, size)) |
| return 0; |
| |
| if (file->f_flags & O_SYNC) { |
| flags = _PAGE_CACHE_UC_MINUS; |
| } |
| |
| #ifdef CONFIG_X86_32 |
| /* |
| * On the PPro and successors, the MTRRs are used to set |
| * memory types for physical addresses outside main memory, |
| * so blindly setting UC or PWT on those pages is wrong. |
| * For Pentiums and earlier, the surround logic should disable |
| * caching for the high addresses through the KEN pin, but |
| * we maintain the tradition of paranoia in this code. |
| */ |
| if (!pat_enabled && |
| !(boot_cpu_has(X86_FEATURE_MTRR) || |
| boot_cpu_has(X86_FEATURE_K6_MTRR) || |
| boot_cpu_has(X86_FEATURE_CYRIX_ARR) || |
| boot_cpu_has(X86_FEATURE_CENTAUR_MCR)) && |
| (pfn << PAGE_SHIFT) >= __pa(high_memory)) { |
| flags = _PAGE_CACHE_UC; |
| } |
| #endif |
| |
| *vma_prot = __pgprot((pgprot_val(*vma_prot) & ~_PAGE_CACHE_MASK) | |
| flags); |
| return 1; |
| } |
| |
| /* |
| * Change the memory type for the physial address range in kernel identity |
| * mapping space if that range is a part of identity map. |
| */ |
| int kernel_map_sync_memtype(u64 base, unsigned long size, unsigned long flags) |
| { |
| unsigned long id_sz; |
| |
| if (base >= __pa(high_memory)) |
| return 0; |
| |
| id_sz = (__pa(high_memory) < base + size) ? |
| __pa(high_memory) - base : |
| size; |
| |
| if (ioremap_change_attr((unsigned long)__va(base), id_sz, flags) < 0) { |
| printk(KERN_INFO |
| "%s:%d ioremap_change_attr failed %s " |
| "for %Lx-%Lx\n", |
| current->comm, current->pid, |
| cattr_name(flags), |
| base, (unsigned long long)(base + size)); |
| return -EINVAL; |
| } |
| return 0; |
| } |
| |
| /* |
| * Internal interface to reserve a range of physical memory with prot. |
| * Reserved non RAM regions only and after successful reserve_memtype, |
| * this func also keeps identity mapping (if any) in sync with this new prot. |
| */ |
| static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, |
| int strict_prot) |
| { |
| int is_ram = 0; |
| int ret; |
| unsigned long want_flags = (pgprot_val(*vma_prot) & _PAGE_CACHE_MASK); |
| unsigned long flags = want_flags; |
| |
| is_ram = pat_pagerange_is_ram(paddr, paddr + size); |
| |
| /* |
| * reserve_pfn_range() for RAM pages. We do not refcount to keep |
| * track of number of mappings of RAM pages. We can assert that |
| * the type requested matches the type of first page in the range. |
| */ |
| if (is_ram) { |
| if (!pat_enabled) |
| return 0; |
| |
| flags = lookup_memtype(paddr); |
| if (want_flags != flags) { |
| printk(KERN_WARNING |
| "%s:%d map pfn RAM range req %s for %Lx-%Lx, got %s\n", |
| current->comm, current->pid, |
| cattr_name(want_flags), |
| (unsigned long long)paddr, |
| (unsigned long long)(paddr + size), |
| cattr_name(flags)); |
| *vma_prot = __pgprot((pgprot_val(*vma_prot) & |
| (~_PAGE_CACHE_MASK)) | |
| flags); |
| } |
| return 0; |
| } |
| |
| ret = reserve_memtype(paddr, paddr + size, want_flags, &flags); |
| if (ret) |
| return ret; |
| |
| if (flags != want_flags) { |
| if (strict_prot || |
| !is_new_memtype_allowed(paddr, size, want_flags, flags)) { |
| free_memtype(paddr, paddr + size); |
| printk(KERN_ERR "%s:%d map pfn expected mapping type %s" |
| " for %Lx-%Lx, got %s\n", |
| current->comm, current->pid, |
| cattr_name(want_flags), |
| (unsigned long long)paddr, |
| (unsigned long long)(paddr + size), |
| cattr_name(flags)); |
| return -EINVAL; |
| } |
| /* |
| * We allow returning different type than the one requested in |
| * non strict case. |
| */ |
| *vma_prot = __pgprot((pgprot_val(*vma_prot) & |
| (~_PAGE_CACHE_MASK)) | |
| flags); |
| } |
| |
| if (kernel_map_sync_memtype(paddr, size, flags) < 0) { |
| free_memtype(paddr, paddr + size); |
| return -EINVAL; |
| } |
| return 0; |
| } |
| |
| /* |
| * Internal interface to free a range of physical memory. |
| * Frees non RAM regions only. |
| */ |
| static void free_pfn_range(u64 paddr, unsigned long size) |
| { |
| int is_ram; |
| |
| is_ram = pat_pagerange_is_ram(paddr, paddr + size); |
| if (is_ram == 0) |
| free_memtype(paddr, paddr + size); |
| } |
| |
| /* |
| * track_pfn_vma_copy is called when vma that is covering the pfnmap gets |
| * copied through copy_page_range(). |
| * |
| * If the vma has a linear pfn mapping for the entire range, we get the prot |
| * from pte and reserve the entire vma range with single reserve_pfn_range call. |
| */ |
| int track_pfn_vma_copy(struct vm_area_struct *vma) |
| { |
| resource_size_t paddr; |
| unsigned long prot; |
| unsigned long vma_size = vma->vm_end - vma->vm_start; |
| pgprot_t pgprot; |
| |
| if (is_linear_pfn_mapping(vma)) { |
| /* |
| * reserve the whole chunk covered by vma. We need the |
| * starting address and protection from pte. |
| */ |
| if (follow_phys(vma, vma->vm_start, 0, &prot, &paddr)) { |
| WARN_ON_ONCE(1); |
| return -EINVAL; |
| } |
| pgprot = __pgprot(prot); |
| return reserve_pfn_range(paddr, vma_size, &pgprot, 1); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * track_pfn_vma_new is called when a _new_ pfn mapping is being established |
| * for physical range indicated by pfn and size. |
| * |
| * prot is passed in as a parameter for the new mapping. If the vma has a |
| * linear pfn mapping for the entire range reserve the entire vma range with |
| * single reserve_pfn_range call. |
| */ |
| int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot, |
| unsigned long pfn, unsigned long size) |
| { |
| unsigned long flags; |
| resource_size_t paddr; |
| unsigned long vma_size = vma->vm_end - vma->vm_start; |
| |
| if (is_linear_pfn_mapping(vma)) { |
| /* reserve the whole chunk starting from vm_pgoff */ |
| paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT; |
| return reserve_pfn_range(paddr, vma_size, prot, 0); |
| } |
| |
| if (!pat_enabled) |
| return 0; |
| |
| /* for vm_insert_pfn and friends, we set prot based on lookup */ |
| flags = lookup_memtype(pfn << PAGE_SHIFT); |
| *prot = __pgprot((pgprot_val(vma->vm_page_prot) & (~_PAGE_CACHE_MASK)) | |
| flags); |
| |
| return 0; |
| } |
| |
| /* |
| * untrack_pfn_vma is called while unmapping a pfnmap for a region. |
| * untrack can be called for a specific region indicated by pfn and size or |
| * can be for the entire vma (in which case size can be zero). |
| */ |
| void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn, |
| unsigned long size) |
| { |
| resource_size_t paddr; |
| unsigned long vma_size = vma->vm_end - vma->vm_start; |
| |
| if (is_linear_pfn_mapping(vma)) { |
| /* free the whole chunk starting from vm_pgoff */ |
| paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT; |
| free_pfn_range(paddr, vma_size); |
| return; |
| } |
| } |
| |
| pgprot_t pgprot_writecombine(pgprot_t prot) |
| { |
| if (pat_enabled) |
| return __pgprot(pgprot_val(prot) | _PAGE_CACHE_WC); |
| else |
| return pgprot_noncached(prot); |
| } |
| EXPORT_SYMBOL_GPL(pgprot_writecombine); |
| |
| #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT) |
| |
| /* get Nth element of the linked list */ |
| static struct memtype *memtype_get_idx(loff_t pos) |
| { |
| struct memtype *list_node, *print_entry; |
| int i = 1; |
| |
| print_entry = kmalloc(sizeof(struct memtype), GFP_KERNEL); |
| if (!print_entry) |
| return NULL; |
| |
| spin_lock(&memtype_lock); |
| list_for_each_entry(list_node, &memtype_list, nd) { |
| if (pos == i) { |
| *print_entry = *list_node; |
| spin_unlock(&memtype_lock); |
| return print_entry; |
| } |
| ++i; |
| } |
| spin_unlock(&memtype_lock); |
| kfree(print_entry); |
| |
| return NULL; |
| } |
| |
| static void *memtype_seq_start(struct seq_file *seq, loff_t *pos) |
| { |
| if (*pos == 0) { |
| ++*pos; |
| seq_printf(seq, "PAT memtype list:\n"); |
| } |
| |
| return memtype_get_idx(*pos); |
| } |
| |
| static void *memtype_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
| { |
| ++*pos; |
| return memtype_get_idx(*pos); |
| } |
| |
| static void memtype_seq_stop(struct seq_file *seq, void *v) |
| { |
| } |
| |
| static int memtype_seq_show(struct seq_file *seq, void *v) |
| { |
| struct memtype *print_entry = (struct memtype *)v; |
| |
| seq_printf(seq, "%s @ 0x%Lx-0x%Lx\n", cattr_name(print_entry->type), |
| print_entry->start, print_entry->end); |
| kfree(print_entry); |
| |
| return 0; |
| } |
| |
| static const struct seq_operations memtype_seq_ops = { |
| .start = memtype_seq_start, |
| .next = memtype_seq_next, |
| .stop = memtype_seq_stop, |
| .show = memtype_seq_show, |
| }; |
| |
| static int memtype_seq_open(struct inode *inode, struct file *file) |
| { |
| return seq_open(file, &memtype_seq_ops); |
| } |
| |
| static const struct file_operations memtype_fops = { |
| .open = memtype_seq_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release, |
| }; |
| |
| static int __init pat_memtype_list_init(void) |
| { |
| debugfs_create_file("pat_memtype_list", S_IRUSR, arch_debugfs_dir, |
| NULL, &memtype_fops); |
| return 0; |
| } |
| |
| late_initcall(pat_memtype_list_init); |
| |
| #endif /* CONFIG_DEBUG_FS && CONFIG_X86_PAT */ |