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author | David S. Miller <davem@davemloft.net> | 2010-05-19 10:01:55 +0400 |
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committer | David S. Miller <davem@davemloft.net> | 2010-05-19 10:01:55 +0400 |
commit | 2ec8c6bb5d8f3a62a79f463525054bae1e3d4487 (patch) | |
tree | fa7f8400ac685fb52e96f64997c7c682fc2aa021 /arch/x86/mm/pat.c | |
parent | 7b39f90fabcf9e2af0cd79d0a60440d821e22b56 (diff) | |
parent | 537b60d17894b7c19a6060feae40299d7109d6e7 (diff) | |
download | linux-2ec8c6bb5d8f3a62a79f463525054bae1e3d4487.tar.xz |
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts:
include/linux/mod_devicetable.h
scripts/mod/file2alias.c
Diffstat (limited to 'arch/x86/mm/pat.c')
-rw-r--r-- | arch/x86/mm/pat.c | 239 |
1 files changed, 19 insertions, 220 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index edc8b95afc1a..bbe5502ee1cb 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -30,6 +30,8 @@ #include <asm/pat.h> #include <asm/io.h> +#include "pat_internal.h" + #ifdef CONFIG_X86_PAT int __read_mostly pat_enabled = 1; @@ -53,19 +55,15 @@ static inline void pat_disable(const char *reason) #endif -static int debug_enable; +int pat_debug_enable; static int __init pat_debug_setup(char *str) { - debug_enable = 1; + pat_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 { @@ -132,84 +130,7 @@ void pat_init(void) #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); -} +static DEFINE_SPINLOCK(memtype_lock); /* protects memtype accesses */ /* * Does intersection of PAT memory type and MTRR memory type and returns @@ -237,33 +158,6 @@ static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type) 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; @@ -296,8 +190,6 @@ static int pat_pagerange_is_ram(unsigned long start, unsigned long end) * 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) @@ -364,9 +256,8 @@ static int free_ram_pages_type(u64 start, u64 end) int reserve_memtype(u64 start, u64 end, unsigned long req_type, unsigned long *new_type) { - struct memtype *new, *entry; + struct memtype *new; unsigned long actual_type; - struct list_head *where; int is_range_ram; int err = 0; @@ -404,9 +295,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_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) { @@ -423,42 +312,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_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; - } - } - + err = rbt_memtype_check_insert(new, new_type); if (err) { printk(KERN_INFO "reserve_memtype failed 0x%Lx-0x%Lx, " "track %s, req %s\n", @@ -469,13 +323,6 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, 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", @@ -487,7 +334,6 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, int free_memtype(u64 start, u64 end) { - struct memtype *entry, *saved_entry; int err = -EINVAL; int is_range_ram; @@ -501,9 +347,7 @@ int free_memtype(u64 start, u64 end) 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) { @@ -511,46 +355,7 @@ int free_memtype(u64 start, u64 end) } 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: + err = rbt_memtype_erase(start, end); spin_unlock(&memtype_lock); if (err) { @@ -583,10 +388,8 @@ static unsigned long lookup_memtype(u64 paddr) 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 @@ -599,7 +402,7 @@ static unsigned long lookup_memtype(u64 paddr) spin_lock(&memtype_lock); - entry = memtype_rb_search(&memtype_rbroot, paddr); + entry = rbt_memtype_lookup(paddr); if (entry != NULL) rettype = entry->type; else @@ -936,29 +739,25 @@ 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; + struct memtype *print_entry; + int ret; - print_entry = kmalloc(sizeof(struct memtype), GFP_KERNEL); + print_entry = kzalloc(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; - } + ret = rbt_memtype_copy_nth_element(print_entry, pos); spin_unlock(&memtype_lock); - kfree(print_entry); - return NULL; + if (!ret) { + return print_entry; + } else { + kfree(print_entry); + return NULL; + } } static void *memtype_seq_start(struct seq_file *seq, loff_t *pos) |