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Diffstat (limited to 'arch/x86/mm/pat.c')
-rw-r--r--arch/x86/mm/pat.c105
1 files changed, 72 insertions, 33 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 85cbd3cd372..e0ab173b697 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -11,6 +11,7 @@
#include <linux/bootmem.h>
#include <linux/debugfs.h>
#include <linux/kernel.h>
+#include <linux/module.h>
#include <linux/gfp.h>
#include <linux/mm.h>
#include <linux/fs.h>
@@ -211,6 +212,33 @@ chk_conflict(struct memtype *new, struct memtype *entry, unsigned long *type)
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;
+ unsigned long page_nr;
+
+ for (page_nr = (start >> PAGE_SHIFT); page_nr < (end >> PAGE_SHIFT);
+ ++page_nr) {
+ /*
+ * For legacy reasons, physical address range in the legacy ISA
+ * region is tracked as non-RAM. This will allow users of
+ * /dev/mem to map portions of legacy ISA region, even when
+ * some of those portions are listed(or not even listed) with
+ * different e820 types(RAM/reserved/..)
+ */
+ if (page_nr >= (ISA_END_ADDRESS >> PAGE_SHIFT) &&
+ page_is_ram(page_nr))
+ ram_page = 1;
+ else
+ not_rampage = 1;
+
+ if (ram_page == not_rampage)
+ return -1;
+ }
+
+ return ram_page;
+}
+
/*
* For RAM pages, mark the pages as non WB memory type using
* PageNonWB (PG_arch_1). We allow only one set_memory_uc() or
@@ -333,9 +361,13 @@ 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 (new_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);
+ return reserve_ram_pages_type(start, end, req_type,
+ new_type);
else if (is_range_ram < 0)
return -EINVAL;
@@ -347,9 +379,6 @@ 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)
@@ -437,7 +466,7 @@ int free_memtype(u64 start, u64 end)
if (is_ISA_range(start, end - 1))
return 0;
- is_range_ram = pagerange_is_ram(start, end);
+ 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)
@@ -601,39 +630,45 @@ 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);
+ is_ram = pat_pagerange_is_ram(paddr, paddr + size);
- if (is_ram != 0) {
- /*
- * For mapping RAM pages, drivers need to call
- * set_memory_[uc|wc|wb] directly, for reserve and free, before
- * setting up the PTE.
- */
- WARN_ON_ONCE(1);
- return 0;
- }
+ /*
+ * reserve_pfn_range() doesn't support RAM pages.
+ */
+ if (is_ram != 0)
+ return -EINVAL;
ret = reserve_memtype(paddr, paddr + size, want_flags, &flags);
if (ret)
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 */
@@ -666,7 +701,7 @@ static void free_pfn_range(u64 paddr, unsigned long size)
{
int is_ram;
- is_ram = pagerange_is_ram(paddr, paddr + size);
+ is_ram = pat_pagerange_is_ram(paddr, paddr + size);
if (is_ram == 0)
free_memtype(paddr, paddr + size);
}
@@ -689,6 +724,7 @@ 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 +738,8 @@ 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 +747,8 @@ 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 +779,7 @@ 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 +796,14 @@ 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;
}
@@ -831,6 +869,7 @@ pgprot_t pgprot_writecombine(pgprot_t prot)
else
return pgprot_noncached(prot);
}
+EXPORT_SYMBOL_GPL(pgprot_writecombine);
#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT)
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-02 03:03:26 +0000