From 3e0e1e9c5a327d4dba8490d83ef55c0564e6e8a7 Mon Sep 17 00:00:00 2001 From: Amerigo Wang Date: Fri, 21 Aug 2009 04:34:45 -0400 Subject: x86: Fix an incorrect argument of reserve_bootmem() This line looks suspicious, because if this is true, then the 'flags' parameter of function reserve_bootmem_generic() will be unused when !CONFIG_NUMA. I don't think this is what we want. Signed-off-by: WANG Cong Cc: Yinghai Lu Cc: akpm@linux-foundation.org LKML-Reference: <20090821083709.5098.52505.sendpatchset@localhost.localdomain> Signed-off-by: Ingo Molnar --- arch/x86/mm/init_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 6176fe8f29e..ea56b8cbb6a 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -796,7 +796,7 @@ int __init reserve_bootmem_generic(unsigned long phys, unsigned long len, return ret; #else - reserve_bootmem(phys, len, BOOTMEM_DEFAULT); + reserve_bootmem(phys, len, flags); #endif if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) { -- cgit v1.2.3 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') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index e6718bb2806..d5af2792d2f 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 279e669b3fc0068cc3509e8e53036999e1e86588 Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Fri, 10 Jul 2009 09:57:33 -0700 Subject: x86, pat: ioremap to follow same PAT restrictions as other PAT users ioremap has this hard-coded check for new type and requested type. That check differs from other PAT users like /dev/mem mmap, remap_pfn_range in only one condition where requested type is UC_MINUS and new type is WC. Under that condition, ioremap fails. But other PAT interfaces succeed with a WC mapping. Change to make ioremap be in sync with other PAT APIs and use the same macro as others. Also changes the error print to KERN_ERR instead of pr_debug. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha Signed-off-by: H. Peter Anvin --- arch/x86/mm/ioremap.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 8a450930834..aeaea8c5b2f 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -228,24 +228,13 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, retval = reserve_memtype(phys_addr, (u64)phys_addr + size, prot_val, &new_prot_val); if (retval) { - pr_debug("Warning: reserve_memtype returned %d\n", retval); + printk(KERN_ERR "ioremap reserve_memtype failed %d\n", retval); return NULL; } if (prot_val != new_prot_val) { - /* - * Do not fallback to certain memory types with certain - * requested type: - * - request is uc-, return cannot be write-back - * - request is uc-, return cannot be write-combine - * - request is write-combine, return cannot be write-back - */ - if ((prot_val == _PAGE_CACHE_UC_MINUS && - (new_prot_val == _PAGE_CACHE_WB || - new_prot_val == _PAGE_CACHE_WC)) || - (prot_val == _PAGE_CACHE_WC && - new_prot_val == _PAGE_CACHE_WB)) { - pr_debug( + if (!is_new_memtype_allowed(prot_val, new_prot_val)) { + printk(KERN_ERR "ioremap error for 0x%llx-0x%llx, requested 0x%lx, got 0x%lx\n", (unsigned long long)phys_addr, (unsigned long long)(phys_addr + size), -- 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/mm/pat.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index d5af2792d2f..82d097ce309 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 9e36fda0b359d2a6ae039c3d7e71a04502a77898 Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Fri, 10 Jul 2009 09:57:35 -0700 Subject: x86, pat: Add PAT reserve free to io_mapping* APIs io_mapping_* interfaces were added, mainly for graphics drivers. Make this interface go through the PAT reserve/free, instead of hardcoding WC mapping. This makes sure that there are no aliases due to unconditional WC setting. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha Signed-off-by: H. Peter Anvin --- arch/x86/mm/iomap_32.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c index fe6f84ca121..84e236ce76b 100644 --- a/arch/x86/mm/iomap_32.c +++ b/arch/x86/mm/iomap_32.c @@ -21,7 +21,7 @@ #include #include -int is_io_mapping_possible(resource_size_t base, unsigned long size) +static int is_io_mapping_possible(resource_size_t base, unsigned long size) { #if !defined(CONFIG_X86_PAE) && defined(CONFIG_PHYS_ADDR_T_64BIT) /* There is no way to map greater than 1 << 32 address without PAE */ @@ -30,7 +30,30 @@ int is_io_mapping_possible(resource_size_t base, unsigned long size) #endif return 1; } -EXPORT_SYMBOL_GPL(is_io_mapping_possible); + +int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot) +{ + unsigned long flag = _PAGE_CACHE_WC; + int ret; + + if (!is_io_mapping_possible(base, size)) + return -EINVAL; + + ret = io_reserve_memtype(base, base + size, &flag); + if (ret) + return ret; + + *prot = __pgprot(__PAGE_KERNEL | flag); + return 0; +} +EXPORT_SYMBOL_GPL(iomap_create_wc); + +void +iomap_free(resource_size_t base, unsigned long size) +{ + io_free_memtype(base, base + size); +} +EXPORT_SYMBOL_GPL(iomap_free); void *kmap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t 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') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 82d097ce309..c90f2420f56 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/mm/pat.c | 91 ++++++++++++++++++++++++++++++------------------------- 1 file changed, 50 insertions(+), 41 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index c90f2420f56..1a9d0f07593 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') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 1a9d0f07593..71aa6f7246c 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') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 71aa6f7246c..b629f75f73d 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') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index b629f75f73d..a6cace0694a 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 From fa526d0d641b5365676a1fb821ce359e217c9b85 Mon Sep 17 00:00:00 2001 From: Jack Steiner Date: Thu, 3 Sep 2009 12:56:02 -0500 Subject: x86, pat: Fix cacheflush address in change_page_attr_set_clr() Fix address passed to cpa_flush_range() when changing page attributes from WB to UC. The address (*addr) is modified by __change_page_attr_set_clr(). The result is that the pages being flushed start at the _end_ of the changed range instead of the beginning. This should be considered for 2.6.30-stable and 2.6.31-stable. Signed-off-by: Jack Steiner Acked-by: Suresh Siddha Signed-off-by: H. Peter Anvin Cc: Stable team --- arch/x86/mm/pageattr.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 7e600c1962d..e245775ec85 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -822,6 +822,7 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages, { struct cpa_data cpa; int ret, cache, checkalias; + unsigned long baddr = 0; /* * Check, if we are requested to change a not supported @@ -853,6 +854,11 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages, */ WARN_ON_ONCE(1); } + /* + * Save address for cache flush. *addr is modified in the call + * to __change_page_attr_set_clr() below. + */ + baddr = *addr; } /* Must avoid aliasing mappings in the highmem code */ @@ -900,7 +906,7 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages, cpa_flush_array(addr, numpages, cache, cpa.flags, pages); } else - cpa_flush_range(*addr, numpages, cache); + cpa_flush_range(baddr, numpages, cache); } else cpa_flush_all(cache); -- cgit v1.2.3 From dcb73bf402e0d5b28ce925dbbe4dab3b00b21eee Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Wed, 16 Sep 2009 14:28:03 -0700 Subject: x86, pat: don't use rb-tree based lookup in reserve_memtype() Recent enhancement of rb-tree based lookup exposed a bug with the lookup mechanism in the reserve_memtype() which ensures that there are no conflicting memtype requests for the memory range. memtype_rb_search() returns an entry which has a start address <= new start address. And from here we traverse the linear linked list to check if there any conflicts with the existing mappings. As the rbtree is based on the start address of the memory range, it is quite possible that we have several overlapped mappings whose start address is much less than new requested start but the end is >= new requested end. This results in conflicting memtype mappings. Same bug exists with the old code which uses cached_entry from where we traverse the linear linked list. But the new rb-tree code exposes this bug fairly easily. For now, don't use the memtype_rb_search() and always start the search from the head of linear linked list in reserve_memtype(). Linear linked list for most of the systems grow's to few 10's of entries(as we track memory type of RAM pages using struct page). So we should be ok for now. We still retain the rbtree and use it to speed up free_memtype() which doesn't have the same bug(as we know what exactly we are searching for in free_memtype). Also use list_for_each_entry_from() in free_memtype() so that we start the search from rb-tree lookup result. Reported-by: Markus Trippelsdorf Signed-off-by: Suresh Siddha Cc: Venkatesh Pallipadi LKML-Reference: <1253136483.4119.12.camel@sbs-t61.sc.intel.com> Signed-off-by: H. Peter Anvin --- arch/x86/mm/pat.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index d2a72abc9de..9b647f67938 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -424,17 +424,9 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, spin_lock(&memtype_lock); - 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) { + list_for_each_entry(entry, &memtype_list, nd) { if (end <= entry->start) { where = entry->nd.prev; break; @@ -532,7 +524,7 @@ int free_memtype(u64 start, u64 end) * in sorted start address */ saved_entry = entry; - list_for_each_entry(entry, &memtype_list, nd) { + 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); -- cgit v1.2.3