summaryrefslogtreecommitdiffstats
path: root/arch/x86/mm/pat.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/mm/pat.c')
-rw-r--r--arch/x86/mm/pat.c378
1 files changed, 140 insertions, 238 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 06b7a1c90fb..d4585077977 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -26,11 +26,11 @@
#include <asm/io.h>
#ifdef CONFIG_X86_PAT
-int __read_mostly pat_wc_enabled = 1;
+int __read_mostly pat_enabled = 1;
void __cpuinit pat_disable(char *reason)
{
- pat_wc_enabled = 0;
+ pat_enabled = 0;
printk(KERN_INFO "%s\n", reason);
}
@@ -42,6 +42,19 @@ static int __init nopat(char *str)
early_param("nopat", nopat);
#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 {
@@ -53,24 +66,25 @@ enum {
PAT_UC_MINUS = 7, /* UC, but can be overriden by MTRR */
};
-#define PAT(x,y) ((u64)PAT_ ## y << ((x)*8))
+#define PAT(x, y) ((u64)PAT_ ## y << ((x)*8))
void pat_init(void)
{
u64 pat;
- if (!pat_wc_enabled)
+ if (!pat_enabled)
return;
/* Paranoia check. */
- if (!cpu_has_pat) {
- printk(KERN_ERR "PAT enabled, but CPU feature cleared\n");
+ if (!cpu_has_pat && boot_pat_state) {
/*
- * Panic if this happens on the secondary CPU, and we
+ * If this happens we are on a secondary CPU, but
* switched to PAT on the boot CPU. We have no way to
* undo PAT.
- */
- BUG_ON(boot_pat_state);
+ */
+ printk(KERN_ERR "PAT enabled, "
+ "but not supported by secondary CPU\n");
+ BUG();
}
/* Set PWT to Write-Combining. All other bits stay the same */
@@ -86,8 +100,8 @@ void pat_init(void)
* 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);
+ 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)
@@ -103,11 +117,11 @@ void pat_init(void)
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";
+ 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";
}
}
@@ -145,47 +159,50 @@ static DEFINE_SPINLOCK(memtype_lock); /* protects memtype list */
* The intersection is based on "Effective Memory Type" tables in IA-32
* SDM vol 3a
*/
-static int pat_x_mtrr_type(u64 start, u64 end, unsigned long prot,
- unsigned long *ret_prot)
+static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type)
{
- unsigned long pat_type;
- u8 mtrr_type;
-
- pat_type = prot & _PAGE_CACHE_MASK;
- prot &= (~_PAGE_CACHE_MASK);
-
- /*
- * We return the PAT request directly for types where PAT takes
- * precedence with respect to MTRR and for UC_MINUS.
- * Consistency checks with other PAT requests is done later
- * while going through memtype list.
- */
- if (pat_type == _PAGE_CACHE_WC) {
- *ret_prot = prot | _PAGE_CACHE_WC;
- return 0;
- } else if (pat_type == _PAGE_CACHE_UC_MINUS) {
- *ret_prot = prot | _PAGE_CACHE_UC_MINUS;
- return 0;
- } else if (pat_type == _PAGE_CACHE_UC) {
- *ret_prot = prot | _PAGE_CACHE_UC;
- return 0;
- }
-
/*
* Look for MTRR hint to get the effective type in case where PAT
* request is for WB.
*/
- mtrr_type = mtrr_type_lookup(start, end);
+ if (req_type == _PAGE_CACHE_WB) {
+ u8 mtrr_type;
+
+ mtrr_type = mtrr_type_lookup(start, end);
+ if (mtrr_type == MTRR_TYPE_UNCACHABLE)
+ return _PAGE_CACHE_UC;
+ if (mtrr_type == MTRR_TYPE_WRCOMB)
+ return _PAGE_CACHE_WC;
+ }
- if (mtrr_type == MTRR_TYPE_UNCACHABLE) {
- *ret_prot = prot | _PAGE_CACHE_UC;
- } else if (mtrr_type == MTRR_TYPE_WRCOMB) {
- *ret_prot = prot | _PAGE_CACHE_WC;
- } else {
- *ret_prot = prot | _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;
}
/*
@@ -198,37 +215,36 @@ static int pat_x_mtrr_type(u64 start, u64 end, unsigned long prot,
* 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 ret_type is NULL, function will return an error if it cannot reserve the
- * region with req_type. If ret_type is non-null, function will return
- * available type in ret_type in case of no error. In case of any error
+ * 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 *ret_type)
+ unsigned long *new_type)
{
- struct memtype *new_entry = NULL;
- struct memtype *parse;
+ struct memtype *new, *entry;
unsigned long actual_type;
+ struct list_head *where;
int err = 0;
- /* Only track when pat_wc_enabled */
- if (!pat_wc_enabled) {
+ BUG_ON(start >= end); /* end is exclusive */
+
+ if (!pat_enabled) {
/* This is identical to page table setting without PAT */
- if (ret_type) {
- if (req_type == -1) {
- *ret_type = _PAGE_CACHE_WB;
- } else {
- *ret_type = req_type;
- }
+ if (new_type) {
+ if (req_type == -1)
+ *new_type = _PAGE_CACHE_WB;
+ 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 (start >= ISA_START_ADDRESS && (end - 1) <= ISA_END_ADDRESS) {
- if (ret_type)
- *ret_type = _PAGE_CACHE_WB;
-
+ if (is_ISA_range(start, end - 1)) {
+ if (new_type)
+ *new_type = _PAGE_CACHE_WB;
return 0;
}
@@ -241,206 +257,92 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
*/
u8 mtrr_type = mtrr_type_lookup(start, end);
- if (mtrr_type == MTRR_TYPE_WRBACK) {
- req_type = _PAGE_CACHE_WB;
+ if (mtrr_type == MTRR_TYPE_WRBACK)
actual_type = _PAGE_CACHE_WB;
- } else {
- req_type = _PAGE_CACHE_UC_MINUS;
+ else
actual_type = _PAGE_CACHE_UC_MINUS;
- }
- } else {
- req_type &= _PAGE_CACHE_MASK;
- err = pat_x_mtrr_type(start, end, req_type, &actual_type);
- }
-
- if (err) {
- if (ret_type)
- *ret_type = actual_type;
-
- return -EINVAL;
- }
+ } else
+ actual_type = pat_x_mtrr_type(start, end,
+ req_type & _PAGE_CACHE_MASK);
- new_entry = kmalloc(sizeof(struct memtype), GFP_KERNEL);
- if (!new_entry)
+ new = kmalloc(sizeof(struct memtype), GFP_KERNEL);
+ if (!new)
return -ENOMEM;
- new_entry->start = start;
- new_entry->end = end;
- new_entry->type = actual_type;
+ new->start = start;
+ new->end = end;
+ new->type = actual_type;
- if (ret_type)
- *ret_type = actual_type;
+ if (new_type)
+ *new_type = actual_type;
spin_lock(&memtype_lock);
/* Search for existing mapping that overlaps the current range */
- list_for_each_entry(parse, &memtype_list, nd) {
- struct memtype *saved_ptr;
-
- if (parse->start >= end) {
- pr_debug("New Entry\n");
- list_add(&new_entry->nd, parse->nd.prev);
- new_entry = NULL;
+ where = NULL;
+ list_for_each_entry(entry, &memtype_list, nd) {
+ if (end <= entry->start) {
+ where = entry->nd.prev;
break;
- }
-
- if (start <= parse->start && end >= parse->start) {
- if (actual_type != parse->type && ret_type) {
- actual_type = parse->type;
- *ret_type = actual_type;
- new_entry->type = actual_type;
- }
-
- if (actual_type != parse->type) {
- printk(
- KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n",
- current->comm, current->pid,
- start, end,
- cattr_name(actual_type),
- cattr_name(parse->type));
- err = -EBUSY;
- 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;
}
-
- saved_ptr = parse;
- /*
- * Check to see whether the request overlaps more
- * than one entry in the list
- */
- list_for_each_entry_continue(parse, &memtype_list, nd) {
- if (end <= parse->start) {
- break;
- }
-
- if (actual_type != parse->type) {
- printk(
- KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n",
- current->comm, current->pid,
- start, end,
- cattr_name(actual_type),
- cattr_name(parse->type));
- err = -EBUSY;
- break;
- }
- }
-
- if (err) {
- break;
- }
-
- pr_debug("Overlap at 0x%Lx-0x%Lx\n",
- saved_ptr->start, saved_ptr->end);
- /* No conflict. Go ahead and add this new entry */
- list_add(&new_entry->nd, saved_ptr->nd.prev);
- new_entry = NULL;
break;
- }
-
- if (start < parse->end) {
- if (actual_type != parse->type && ret_type) {
- actual_type = parse->type;
- *ret_type = actual_type;
- new_entry->type = actual_type;
- }
-
- if (actual_type != parse->type) {
- printk(
- KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n",
- current->comm, current->pid,
- start, end,
- cattr_name(actual_type),
- cattr_name(parse->type));
- err = -EBUSY;
- break;
- }
-
- saved_ptr = parse;
- /*
- * Check to see whether the request overlaps more
- * than one entry in the list
- */
- list_for_each_entry_continue(parse, &memtype_list, nd) {
- if (end <= parse->start) {
- break;
- }
-
- if (actual_type != parse->type) {
- printk(
- KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n",
- current->comm, current->pid,
- start, end,
- cattr_name(actual_type),
- cattr_name(parse->type));
- err = -EBUSY;
- break;
- }
- }
-
- if (err) {
- 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);
+ where = &entry->nd;
}
-
- pr_debug(KERN_INFO "Overlap at 0x%Lx-0x%Lx\n",
- saved_ptr->start, saved_ptr->end);
- /* No conflict. Go ahead and add this new entry */
- list_add(&new_entry->nd, &saved_ptr->nd);
- new_entry = NULL;
break;
}
}
if (err) {
- printk(KERN_INFO
- "reserve_memtype failed 0x%Lx-0x%Lx, track %s, req %s\n",
- start, end, cattr_name(new_entry->type),
- cattr_name(req_type));
- kfree(new_entry);
+ 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 (new_entry) {
- /* No conflict. Not yet added to the list. Add to the tail */
- list_add_tail(&new_entry->nd, &memtype_list);
- pr_debug("New Entry\n");
- }
-
- if (ret_type) {
- pr_debug(
- "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n",
- start, end, cattr_name(actual_type),
- cattr_name(req_type), cattr_name(*ret_type));
- } else {
- pr_debug(
- "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s\n",
- start, end, cattr_name(actual_type),
- cattr_name(req_type));
- }
+ if (where)
+ list_add(&new->nd, where);
+ else
+ list_add_tail(&new->nd, &memtype_list);
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 *ml;
+ struct memtype *entry;
int err = -EINVAL;
- /* Only track when pat_wc_enabled */
- if (!pat_wc_enabled) {
+ if (!pat_enabled)
return 0;
- }
/* Low ISA region is always mapped WB. No need to track */
- if (start >= ISA_START_ADDRESS && end <= ISA_END_ADDRESS) {
+ if (is_ISA_range(start, end - 1))
return 0;
- }
spin_lock(&memtype_lock);
- list_for_each_entry(ml, &memtype_list, nd) {
- if (ml->start == start && ml->end == end) {
- list_del(&ml->nd);
- kfree(ml);
+ list_for_each_entry(entry, &memtype_list, nd) {
+ if (entry->start == start && entry->end == end) {
+ list_del(&entry->nd);
+ kfree(entry);
err = 0;
break;
}
@@ -452,7 +354,7 @@ int free_memtype(u64 start, u64 end)
current->comm, current->pid, start, end);
}
- pr_debug("free_memtype request 0x%Lx-0x%Lx\n", start, end);
+ dprintk("free_memtype request 0x%Lx-0x%Lx\n", start, end);
return err;
}
@@ -521,12 +423,12 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
* caching for the high addresses through the KEN pin, but
* we maintain the tradition of paranoia in this code.
*/
- if (!pat_wc_enabled &&
- ! ( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability)) &&
- (pfn << PAGE_SHIFT) >= __pa(high_memory)) {
+ 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
@@ -547,8 +449,9 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
if (retval < 0)
return 0;
- if (pfn <= max_pfn_mapped &&
- ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) {
+ if (((pfn < max_low_pfn_mapped) ||
+ (pfn >= (1UL<<(32 - PAGE_SHIFT)) && pfn < max_pfn_mapped)) &&
+ ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) {
free_memtype(offset, offset + size);
printk(KERN_INFO
"%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n",
@@ -586,4 +489,3 @@ void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
free_memtype(addr, addr + size);
}
-