>From code review the EFI memory map handling has a couple of problems:
- The test for _WB memory was reversed so it would set cache able memory
to uncached
- It would always set a wrong uninitialized zero address to uncached
(so I suspect it always set the first few pages in phys memory to uncached,
that is why it may have gone unnoticed)
- It would call set_memory_x() on a fixmap address that it doesn't
handle correctly.
- Some other problems I commented in the code (but was unable to solve
for now)
I changed the ioremaps to set the correct caching attributes
and also corrected the ordering so it looks roughly correct now.
This is an RFC, because I don't have a EFI system to test.
v2: Really fix the use before initialization problem. Thanks Thomas!
Fix compiler warning
Add one pair of brackets.
Cc: [email protected]
Signed-off-by: Andi Kleen <[email protected]>
---
arch/x86/kernel/efi.c | 14 ++++++++------
arch/x86/kernel/efi_64.c | 6 ++++--
include/asm-x86/efi.h | 5 +++--
3 files changed, 15 insertions(+), 10 deletions(-)
Index: linux/arch/x86/kernel/efi.c
===================================================================
--- linux.orig/arch/x86/kernel/efi.c
+++ linux/arch/x86/kernel/efi.c
@@ -423,13 +423,16 @@ void __init efi_enter_virtual_mode(void)
size = md->num_pages << EFI_PAGE_SHIFT;
end = md->phys_addr + size;
- if ((end >> PAGE_SHIFT) <= max_pfn_mapped)
+ /* RED-PEN does not handle overlapped areas */
+ if ((end >> PAGE_SHIFT) <= max_pfn_mapped) {
va = __va(md->phys_addr);
- else
- va = efi_ioremap(md->phys_addr, size);
-
- if (md->attribute & EFI_MEMORY_WB)
- set_memory_uc(md->virt_addr, size);
+ /* RED-PEN spec and ia64 have a lot more flags */
+ if (!(md->attribute & EFI_MEMORY_WB))
+ set_memory_uc((unsigned long)va, size);
+ } else {
+ va = efi_ioremap(md->phys_addr, size,
+ !!(md->attribute & EFI_MEMORY_WB));
+ }
md->virt_addr = (u64) (unsigned long) va;
Index: linux/arch/x86/kernel/efi_64.c
===================================================================
--- linux.orig/arch/x86/kernel/efi_64.c
+++ linux/arch/x86/kernel/efi_64.c
@@ -109,7 +109,8 @@ void __init efi_reserve_bootmem(void)
memmap.nr_map * memmap.desc_size);
}
-void __iomem * __init efi_ioremap(unsigned long phys_addr, unsigned long size)
+void __iomem * __init efi_ioremap(unsigned long phys_addr, unsigned long size,
+ int cache)
{
static unsigned pages_mapped;
unsigned i, pages;
@@ -124,7 +125,8 @@ void __iomem * __init efi_ioremap(unsign
for (i = 0; i < pages; i++) {
__set_fixmap(FIX_EFI_IO_MAP_FIRST_PAGE - pages_mapped,
- phys_addr, PAGE_KERNEL);
+ phys_addr,
+ cache ? PAGE_KERNEL : PAGE_KERNEL_NOCACHE);
phys_addr += PAGE_SIZE;
pages_mapped++;
}
Index: linux/include/asm-x86/efi.h
===================================================================
--- linux.orig/include/asm-x86/efi.h
+++ linux/include/asm-x86/efi.h
@@ -33,7 +33,8 @@ extern unsigned long asmlinkage efi_call
#define efi_call_virt6(f, a1, a2, a3, a4, a5, a6) \
efi_call_virt(f, a1, a2, a3, a4, a5, a6)
-#define efi_ioremap(addr, size) ioremap_cache(addr, size)
+#define efi_ioremap(addr, size, cache) \
+ (cache ? ioremap_cache(addr, size) : ioremap_nocache(addr, size))
#else /* !CONFIG_X86_32 */
@@ -86,7 +87,7 @@ extern u64 efi_call6(void *fp, u64 arg1,
efi_call6((void *)(efi.systab->runtime->f), (u64)(a1), (u64)(a2), \
(u64)(a3), (u64)(a4), (u64)(a5), (u64)(a6))
-extern void *efi_ioremap(unsigned long addr, unsigned long size);
+extern void *efi_ioremap(unsigned long addr, unsigned long size, int cache);
#endif /* CONFIG_X86_32 */