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authorSuresh Siddha <suresh.b.siddha@intel.com>2009-02-11 11:20:23 -0800
committerIngo Molnar <mingo@elte.hu>2009-02-12 08:27:27 +0100
commitbe03d9e8022030c16abf534e33e185bfc3d40eef (patch)
tree30e197e7eb3631daa882219d882443e58b30ab1a /arch
parent4f06b0436b2ddbd3b67b10e77098a6862787b3eb (diff)
x86, pat: fix warn_on_once() while mapping 0-1MB range with /dev/mem
Jeff Mahoney reported: > With Suse's hwinfo tool, on -tip: > WARNING: at arch/x86/mm/pat.c:637 reserve_pfn_range+0x5b/0x26d() reserve_pfn_range() is not tracking the memory range below 1MB as non-RAM and as such is inconsistent with similar checks in reserve_memtype() and free_memtype() Rename the pagerange_is_ram() to pat_pagerange_is_ram() and add the "track legacy 1MB region as non RAM" condition. And also, fix reserve_pfn_range() to return -EINVAL, when the pfn range is RAM. This is to be consistent with this API design. Reported-and-tested-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/page.h1
-rw-r--r--arch/x86/mm/ioremap.c19
-rw-r--r--arch/x86/mm/pat.c83
3 files changed, 45 insertions, 58 deletions
diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h
index e9873a2e869..776579119a0 100644
--- a/arch/x86/include/asm/page.h
+++ b/arch/x86/include/asm/page.h
@@ -57,7 +57,6 @@ typedef struct { pgdval_t pgd; } pgd_t;
typedef struct { pgprotval_t pgprot; } pgprot_t;
extern int page_is_ram(unsigned long pagenr);
-extern int pagerange_is_ram(unsigned long start, unsigned long end);
extern int devmem_is_allowed(unsigned long pagenr);
extern void map_devmem(unsigned long pfn, unsigned long size,
pgprot_t vma_prot);
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index af750ab973b..f45d5e29a72 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -134,25 +134,6 @@ int page_is_ram(unsigned long pagenr)
return 0;
}
-int 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) {
- if (page_is_ram(page_nr))
- ram_page = 1;
- else
- not_rampage = 1;
-
- if (ram_page == not_rampage)
- return -1;
- }
-
- return ram_page;
-}
-
/*
* Fix up the linear direct mapping of the kernel to avoid cache attribute
* conflicts.
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 7b61036427d..aebbf67a79d 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -211,6 +211,33 @@ 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
@@ -336,20 +363,12 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
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;
- }
+ 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)
+ return -EINVAL;
new = kmalloc(sizeof(struct memtype), GFP_KERNEL);
if (!new)
@@ -446,19 +465,11 @@ int free_memtype(u64 start, u64 end)
if (is_ISA_range(start, end - 1))
return 0;
- /*
- * 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;
- }
+ 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)
+ return -EINVAL;
spin_lock(&memtype_lock);
list_for_each_entry(entry, &memtype_list, nd) {
@@ -626,17 +637,13 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot,
unsigned long flags;
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)
@@ -693,7 +700,7 @@ 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);
}