From 5fc517466dd3d0fc6d2a5180ca6792e60344d8be Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Fri, 10 Jul 2009 09:57:32 -0700 Subject: x86, pat: Keep identity maps consistent with mmaps even when pat_disabled Make reserve_memtype internally take care of pat disabled case and fallback to default return values. Remove the specific pat_disabled checks in track_* routines. Change kernel_map_sync_memtype to sync identity map even when pat_disabled. This change ensures that, even for pat_disabled case, we take care of keeping identity map in sync. Before this patch, in pat disabled case, ioremap() keeps the identity maps in sync and other APIs like pci and /dev/mem mmap don't, which is not a very consistent behavior. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha Signed-off-by: H. Peter Anvin --- arch/x86/mm/pat.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index e6718bb28065..d5af2792d2fd 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -339,6 +339,8 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, 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; } @@ -577,7 +579,7 @@ int kernel_map_sync_memtype(u64 base, unsigned long size, unsigned long flags) { unsigned long id_sz; - if (!pat_enabled || base >= __pa(high_memory)) + if (base >= __pa(high_memory)) return 0; id_sz = (__pa(high_memory) < base + size) ? @@ -677,9 +679,6 @@ int track_pfn_vma_copy(struct vm_area_struct *vma) unsigned long vma_size = vma->vm_end - vma->vm_start; pgprot_t pgprot; - if (!pat_enabled) - return 0; - /* * For now, only handle remap_pfn_range() vmas where * is_linear_pfn_mapping() == TRUE. Handling of @@ -715,9 +714,6 @@ int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot, resource_size_t paddr; unsigned long vma_size = vma->vm_end - vma->vm_start; - if (!pat_enabled) - return 0; - /* * For now, only handle remap_pfn_range() vmas where * is_linear_pfn_mapping() == TRUE. Handling of @@ -743,9 +739,6 @@ void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn, resource_size_t paddr; unsigned long vma_size = vma->vm_end - vma->vm_start; - if (!pat_enabled) - return; - /* * For now, only handle remap_pfn_range() vmas where * is_linear_pfn_mapping() == TRUE. Handling of -- cgit v1.2.3 From 9fd126bc742f74a95d2ba610247712ff05da02fe Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Fri, 10 Jul 2009 09:57:34 -0700 Subject: x86, pat: New i/f for driver to request memtype for IO regions Add new routines to request memtype for IO regions. This will currently be a backend for io_mapping_* routines. But, it can also be made available to drivers directly in future, in case it is needed. reserve interface reserves the memory, makes sure we have a compatible memory type available and keeps the identity map in sync when needed. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/pat.h | 5 +++++ arch/x86/mm/pat.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 54 insertions(+) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/include/asm/pat.h b/arch/x86/include/asm/pat.h index 7af14e512f97..e2c1668dde7a 100644 --- a/arch/x86/include/asm/pat.h +++ b/arch/x86/include/asm/pat.h @@ -19,4 +19,9 @@ extern int free_memtype(u64 start, u64 end); extern int kernel_map_sync_memtype(u64 base, unsigned long size, unsigned long flag); +int io_reserve_memtype(resource_size_t start, resource_size_t end, + unsigned long *type); + +void io_free_memtype(resource_size_t start, resource_size_t end); + #endif /* _ASM_X86_PAT_H */ diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index d5af2792d2fd..82d097ce3091 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -498,6 +498,55 @@ int free_memtype(u64 start, u64 end) } +/** + * 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) +{ + unsigned long req_type = *type; + unsigned long new_type; + int ret; + + WARN_ON_ONCE(iomem_map_sanity_check(start, end - start)); + + ret = reserve_memtype(start, end, req_type, &new_type); + if (ret) + goto out_err; + + if (!is_new_memtype_allowed(req_type, new_type)) + goto out_free; + + if (kernel_map_sync_memtype(start, end - start, 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) { -- cgit v1.2.3 From 335ef896d4c6639849d79367f0fef9abc06d121b Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Fri, 10 Jul 2009 09:57:36 -0700 Subject: x86, pat: Add rbtree to do quick lookup in memtype tracking PAT memtype tracking uses a linear link list to keep track of IO (non-RAM) regions and their memtypes. The code used a last_accessed pointer as a cache to speedup the lookup. As per discussions with H. Peter Anvin a while back, having a rbtree here will avoid bad performances in pathological cases where we may end up with huge linked list. This may not add any noticable performance speedup in normal case as the number of entires in PAT memtype list tend to be ~20-30 range. The patch removes the "cached_entry" logic as with rbtree we have more generic way of speeding up the lookup. With this patch, we use rbtree to do the quick lookup. We still use linked list as the memtype range tracked can be of different sizes and can overlap in different ways. We also keep track of usage counts with linked list. Example: Multiple ioremaps with different sizes uncached-minus @ 0xfffff00000-0xfffff04000 uncached-minus @ 0xfffff02000-0xfffff03000 And one userlevel mmap and the thread forks a new process uncached-minus @ 0xbf453000-0xbf454000 uncached-minus @ 0xbf453000-0xbf454000 Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha Signed-off-by: H. Peter Anvin --- arch/x86/mm/pat.c | 106 +++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 86 insertions(+), 20 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 82d097ce3091..c90f2420f56c 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include @@ -148,11 +149,10 @@ static char *cattr_name(unsigned long flags) * areas). All the aliases have the same cache attributes of course. * Zero attributes are represented as holes. * - * Currently the data structure is a list because the number of mappings - * are expected to be relatively small. If this should be a problem - * it could be changed to a rbtree or similar. + * The data structure is a list that is also organized as an rbtree + * sorted on the start address of memtype range. * - * memtype_lock protects the whole list. + * memtype_lock protects both the linear list and rbtree. */ struct memtype { @@ -160,11 +160,53 @@ struct memtype { 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. @@ -218,9 +260,6 @@ chk_conflict(struct memtype *new, struct memtype *entry, unsigned long *type) return -EBUSY; } -static struct memtype *cached_entry; -static u64 cached_start; - static int pat_pagerange_is_ram(unsigned long start, unsigned long end) { int ram_page = 0, not_rampage = 0; @@ -382,17 +421,19 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, spin_lock(&memtype_lock); - if (cached_entry && start >= cached_start) - entry = cached_entry; - else + entry = memtype_rb_search(&memtype_rbroot, new->start); + if (likely(entry != NULL)) { + /* To work correctly with list_for_each_entry_continue */ + entry = list_entry(entry->nd.prev, struct memtype, nd); + } else { entry = list_entry(&memtype_list, struct memtype, nd); + } /* Search for existing mapping that overlaps the current range */ where = NULL; list_for_each_entry_continue(entry, &memtype_list, nd) { if (end <= entry->start) { where = entry->nd.prev; - cached_entry = list_entry(where, struct memtype, nd); break; } else if (start <= entry->start) { /* end > entry->start */ err = chk_conflict(new, entry, new_type); @@ -400,8 +441,6 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, dprintk("Overlap at 0x%Lx-0x%Lx\n", entry->start, entry->end); where = entry->nd.prev; - cached_entry = list_entry(where, - struct memtype, nd); } break; } else if (start < entry->end) { /* start > entry->start */ @@ -409,8 +448,6 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, if (!err) { dprintk("Overlap at 0x%Lx-0x%Lx\n", entry->start, entry->end); - cached_entry = list_entry(entry->nd.prev, - struct memtype, nd); /* * Move to right position in the linked @@ -438,13 +475,13 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, return err; } - cached_start = start; - 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", @@ -456,7 +493,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, int free_memtype(u64 start, u64 end) { - struct memtype *entry; + struct memtype *entry, *saved_entry; int err = -EINVAL; int is_range_ram; @@ -474,17 +511,46 @@ int free_memtype(u64 start, u64 end) 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(entry, &memtype_list, nd) { if (entry->start == start && entry->end == end) { - if (cached_entry == entry || cached_start == start) - cached_entry = NULL; + 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) { -- cgit v1.2.3 From f58417409603d62f2eb23db4d2cf6853d84a1698 Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Fri, 10 Jul 2009 09:57:38 -0700 Subject: x86, pat: Use page flags to track memtypes of RAM pages Change reserve_ram_pages_type and free_ram_pages_type to use 2 page flags to track UC_MINUS, WC, WB and default types. Previous RAM tracking just tracked WB or NonWB, which was not complete and did not allow tracking of RAM fully and there was no way to get the actual type reserved by looking at the page flags. We use the memtype_lock spinlock for atomicity in dealing with memtype tracking in struct page. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/cacheflush.h | 54 ++++++++++++++++++++++- arch/x86/mm/pat.c | 91 +++++++++++++++++++++------------------ 2 files changed, 102 insertions(+), 43 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h index e55dfc1ad453..b54f6afe7ec4 100644 --- a/arch/x86/include/asm/cacheflush.h +++ b/arch/x86/include/asm/cacheflush.h @@ -43,8 +43,58 @@ static inline void copy_from_user_page(struct vm_area_struct *vma, memcpy(dst, src, len); } -#define PG_non_WB PG_arch_1 -PAGEFLAG(NonWB, non_WB) +#define PG_WC PG_arch_1 +PAGEFLAG(WC, WC) + +#ifdef CONFIG_X86_PAT +/* + * X86 PAT uses page flags WC and Uncached together to keep track of + * memory type of pages that have backing page struct. X86 PAT supports 3 + * different memory types, _PAGE_CACHE_WB, _PAGE_CACHE_WC and + * _PAGE_CACHE_UC_MINUS and fourth state where page's memory type has not + * been changed from its default (value of -1 used to denote this). + * Note we do not support _PAGE_CACHE_UC here. + * + * Caller must hold memtype_lock for atomicity. + */ +static inline unsigned long get_page_memtype(struct page *pg) +{ + if (!PageUncached(pg) && !PageWC(pg)) + return -1; + else if (!PageUncached(pg) && PageWC(pg)) + return _PAGE_CACHE_WC; + else if (PageUncached(pg) && !PageWC(pg)) + return _PAGE_CACHE_UC_MINUS; + else + return _PAGE_CACHE_WB; +} + +static inline void set_page_memtype(struct page *pg, unsigned long memtype) +{ + switch (memtype) { + case _PAGE_CACHE_WC: + ClearPageUncached(pg); + SetPageWC(pg); + break; + case _PAGE_CACHE_UC_MINUS: + SetPageUncached(pg); + ClearPageWC(pg); + break; + case _PAGE_CACHE_WB: + SetPageUncached(pg); + SetPageWC(pg); + break; + default: + case -1: + ClearPageUncached(pg); + ClearPageWC(pg); + break; + } +} +#else +static inline unsigned long get_page_memtype(struct page *pg) { return -1; } +static inline void set_page_memtype(struct page *pg, unsigned long memtype) { } +#endif /* * The set_memory_* API can be used to change various attributes of a virtual diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index c90f2420f56c..1a9d0f07593f 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -288,63 +288,61 @@ static int pat_pagerange_is_ram(unsigned long start, unsigned long end) } /* - * For RAM pages, mark the pages as non WB memory type using - * PageNonWB (PG_arch_1). We allow only one set_memory_uc() or - * set_memory_wc() on a RAM page at a time before marking it as WB again. - * This is ok, because only one driver will be owning the page and - * doing set_memory_*() calls. + * 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 * - * For now, we use PageNonWB to track that the RAM page is being mapped - * as non WB. In future, we will have to use one more flag - * (or some other mechanism in page_struct) to distinguish between - * UC and WC mapping. + * 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, end_pfn; + 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) { - page = pfn_to_page(pfn); - if (page_mapped(page) || PageNonWB(page)) - goto out; + unsigned long type; - SetPageNonWB(page); + 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; + } } - return 0; -out: - end_pfn = pfn; - for (pfn = (start >> PAGE_SHIFT); pfn < end_pfn; ++pfn) { + if (new_type) + *new_type = req_type; + + for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) { page = pfn_to_page(pfn); - ClearPageNonWB(page); + set_page_memtype(page, req_type); } - - return -EINVAL; + return 0; } static int free_ram_pages_type(u64 start, u64 end) { struct page *page; - u64 pfn, end_pfn; + u64 pfn; for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) { page = pfn_to_page(pfn); - if (page_mapped(page) || !PageNonWB(page)) - goto out; - - ClearPageNonWB(page); + set_page_memtype(page, -1); } return 0; - -out: - end_pfn = pfn; - for (pfn = (start >> PAGE_SHIFT); pfn < end_pfn; ++pfn) { - page = pfn_to_page(pfn); - SetPageNonWB(page); - } - return -EINVAL; } /* @@ -405,11 +403,16 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, *new_type = actual_type; is_range_ram = pat_pagerange_is_ram(start, end); - if (is_range_ram == 1) - return reserve_ram_pages_type(start, end, req_type, - new_type); - else if (is_range_ram < 0) + 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) @@ -505,10 +508,16 @@ int free_memtype(u64 start, u64 end) return 0; is_range_ram = pat_pagerange_is_ram(start, end); - if (is_range_ram == 1) - return free_ram_pages_type(start, end); - else if (is_range_ram < 0) + 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); -- cgit v1.2.3 From 637b86e75f4c255a4446bc0b67ce9d914b9d2d42 Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Fri, 10 Jul 2009 09:57:39 -0700 Subject: x86, pat: Add lookup_memtype to get the current memtype of a paddr Add a new routine lookup_memtype() to get the current memtype based on the PAT reserves and frees. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha Signed-off-by: H. Peter Anvin --- arch/x86/mm/pat.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 1a9d0f07593f..71aa6f7246c6 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -573,6 +573,51 @@ unlock_ret: } +/** + * 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 -- cgit v1.2.3 From 1087637616dd5e96d834164ea462aed6159d039b Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Fri, 10 Jul 2009 09:57:40 -0700 Subject: x86, pat: Lookup the protection from memtype list on vm_insert_pfn() Lookup the reserved memtype during vm_insert_pfn and use that memtype for the new mapping. This takes care or handling of vm_insert_pfn() interface in track_pfn_vma*/untrack_pfn_vma. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha Signed-off-by: H. Peter Anvin --- arch/x86/mm/pat.c | 24 +++++++++--------------- 1 file changed, 9 insertions(+), 15 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 71aa6f7246c6..b629f75f73de 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -848,11 +848,6 @@ int track_pfn_vma_copy(struct vm_area_struct *vma) unsigned long vma_size = vma->vm_end - vma->vm_start; pgprot_t pgprot; - /* - * For now, only handle remap_pfn_range() vmas where - * is_linear_pfn_mapping() == TRUE. Handling of - * vm_insert_pfn() is TBD. - */ if (is_linear_pfn_mapping(vma)) { /* * reserve the whole chunk covered by vma. We need the @@ -880,20 +875,24 @@ int track_pfn_vma_copy(struct vm_area_struct *vma) 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; - /* - * For now, only handle remap_pfn_range() vmas where - * is_linear_pfn_mapping() == TRUE. Handling of - * vm_insert_pfn() is TBD. - */ 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; } @@ -908,11 +907,6 @@ void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn, resource_size_t paddr; unsigned long vma_size = vma->vm_end - vma->vm_start; - /* - * For now, only handle remap_pfn_range() vmas where - * is_linear_pfn_mapping() == TRUE. Handling of - * vm_insert_pfn() is TBD. - */ if (is_linear_pfn_mapping(vma)) { /* free the whole chunk starting from vm_pgoff */ paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT; -- cgit v1.2.3 From d886c73cd4cf02a71e1650cbcb6176799d78aac1 Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Fri, 10 Jul 2009 09:57:41 -0700 Subject: x86, pat: Sanity check remap_pfn_range for RAM region Add sanity check for remap_pfn_range of RAM regions using lookup_memtype(). Previously, we did not have anyway to get the type of RAM memory regions as they were tracked using a single bit in page_struct (WB, nonWB). Now we can get the actual type from page struct (WB, WC, UC_MINUS) and make sure the requester gets that type. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha Signed-off-by: H. Peter Anvin --- arch/x86/mm/pat.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index b629f75f73de..a6cace0694a2 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -783,11 +783,29 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, is_ram = pat_pagerange_is_ram(paddr, paddr + size); /* - * reserve_pfn_range() doesn't support RAM pages. Maintain the current - * behavior with RAM pages by returning success. + * 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 != 0) + 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) -- cgit v1.2.3