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Diffstat (limited to 'arch/x86/mm/pat.c')
-rw-r--r--arch/x86/mm/pat.c119
1 files changed, 79 insertions, 40 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 85cbd3cd372..9127e31c726 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -30,7 +30,7 @@
#ifdef CONFIG_X86_PAT
int __read_mostly pat_enabled = 1;
-void __cpuinit pat_disable(char *reason)
+void __cpuinit pat_disable(const char *reason)
{
pat_enabled = 0;
printk(KERN_INFO "%s\n", reason);
@@ -42,6 +42,11 @@ static int __init nopat(char *str)
return 0;
}
early_param("nopat", nopat);
+#else
+static inline void pat_disable(const char *reason)
+{
+ (void)reason;
+}
#endif
@@ -78,16 +83,20 @@ void pat_init(void)
if (!pat_enabled)
return;
- /* Paranoia check. */
- if (!cpu_has_pat && boot_pat_state) {
- /*
- * 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();
+ 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 */
@@ -333,11 +342,23 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
req_type & _PAGE_CACHE_MASK);
}
- is_range_ram = 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)
- return -EINVAL;
+ if (new_type)
+ *new_type = actual_type;
+
+ /*
+ * For legacy reasons, some parts of the physical address range in the
+ * legacy 1MB region is treated as non-RAM (even when listed as RAM in
+ * the e820 tables). So we will track the memory attributes of this
+ * legacy 1MB region using the linear memtype_list always.
+ */
+ if (end >= ISA_END_ADDRESS) {
+ is_range_ram = 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)
+ return -EINVAL;
+ }
new = kmalloc(sizeof(struct memtype), GFP_KERNEL);
if (!new)
@@ -347,9 +368,6 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
new->end = end;
new->type = actual_type;
- if (new_type)
- *new_type = actual_type;
-
spin_lock(&memtype_lock);
if (cached_entry && start >= cached_start)
@@ -437,11 +455,19 @@ int free_memtype(u64 start, u64 end)
if (is_ISA_range(start, end - 1))
return 0;
- is_range_ram = pagerange_is_ram(start, end);
- if (is_range_ram == 1)
- return free_ram_pages_type(start, end);
- else if (is_range_ram < 0)
- return -EINVAL;
+ /*
+ * For legacy reasons, some parts of the physical address range in the
+ * legacy 1MB region is treated as non-RAM (even when listed as RAM in
+ * the e820 tables). So we will track the memory attributes of this
+ * legacy 1MB region using the linear memtype_list always.
+ */
+ if (end >= ISA_END_ADDRESS) {
+ is_range_ram = pagerange_is_ram(start, end);
+ if (is_range_ram == 1)
+ return free_ram_pages_type(start, end);
+ else if (is_range_ram < 0)
+ return -EINVAL;
+ }
spin_lock(&memtype_lock);
list_for_each_entry(entry, &memtype_list, nd) {
@@ -601,12 +627,13 @@ void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_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)
+static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot,
+ int strict_prot)
{
int is_ram = 0;
int id_sz, ret;
unsigned long flags;
- unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK);
+ unsigned long want_flags = (pgprot_val(*vma_prot) & _PAGE_CACHE_MASK);
is_ram = pagerange_is_ram(paddr, paddr + size);
@@ -625,15 +652,24 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t vma_prot)
return ret;
if (flags != want_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;
+ if (strict_prot || !is_new_memtype_allowed(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);
}
/* Need to keep identity mapping in sync */
@@ -689,6 +725,7 @@ int track_pfn_vma_copy(struct vm_area_struct *vma)
unsigned long vma_start = vma->vm_start;
unsigned long vma_end = vma->vm_end;
unsigned long vma_size = vma_end - vma_start;
+ pgprot_t pgprot;
if (!pat_enabled)
return 0;
@@ -702,7 +739,8 @@ int track_pfn_vma_copy(struct vm_area_struct *vma)
WARN_ON_ONCE(1);
return -EINVAL;
}
- return reserve_pfn_range(paddr, vma_size, __pgprot(prot));
+ pgprot = __pgprot(prot);
+ return reserve_pfn_range(paddr, vma_size, &pgprot, 1);
}
/* reserve entire vma page by page, using pfn and prot from pte */
@@ -710,7 +748,8 @@ int track_pfn_vma_copy(struct vm_area_struct *vma)
if (follow_phys(vma, vma_start + i, 0, &prot, &paddr))
continue;
- retval = reserve_pfn_range(paddr, PAGE_SIZE, __pgprot(prot));
+ pgprot = __pgprot(prot);
+ retval = reserve_pfn_range(paddr, PAGE_SIZE, &pgprot, 1);
if (retval)
goto cleanup_ret;
}
@@ -741,7 +780,7 @@ cleanup_ret:
* Note that this function can be called with caller trying to map only a
* subrange/page inside the vma.
*/
-int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot,
+int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot,
unsigned long pfn, unsigned long size)
{
int retval = 0;
@@ -758,14 +797,14 @@ int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot,
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);
+ return reserve_pfn_range(paddr, vma_size, prot, 0);
}
/* reserve page by page using pfn and size */
base_paddr = (resource_size_t)pfn << PAGE_SHIFT;
for (i = 0; i < size; i += PAGE_SIZE) {
paddr = base_paddr + i;
- retval = reserve_pfn_range(paddr, PAGE_SIZE, prot);
+ retval = reserve_pfn_range(paddr, PAGE_SIZE, prot, 0);
if (retval)
goto cleanup_ret;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-06 01:36:41 +0000