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authorMatt Fleming <matt.fleming@intel.com>2011-11-18 13:09:11 +0000
committerIngo Molnar <mingo@elte.hu>2011-12-09 08:32:26 +0100
commite8c7106280a305e1ff2a3a8a4dfce141469fb039 (patch)
tree576cc6990eb3903aeb8e333019b6442441d0fdcb /arch/x86/include/asm/efi.h
parent2ded6e6a94c98ea453a156748cb7fabaf39a76b9 (diff)
downloadvexpress-lsk-e8c7106280a305e1ff2a3a8a4dfce141469fb039.tar.gz
x86, efi: Calling __pa() with an ioremap()ed address is invalid
If we encounter an efi_memory_desc_t without EFI_MEMORY_WB set in ->attribute we currently call set_memory_uc(), which in turn calls __pa() on a potentially ioremap'd address. On CONFIG_X86_32 this is invalid, resulting in the following oops on some machines: BUG: unable to handle kernel paging request at f7f22280 IP: [<c10257b9>] reserve_ram_pages_type+0x89/0x210 [...] Call Trace: [<c104f8ca>] ? page_is_ram+0x1a/0x40 [<c1025aff>] reserve_memtype+0xdf/0x2f0 [<c1024dc9>] set_memory_uc+0x49/0xa0 [<c19334d0>] efi_enter_virtual_mode+0x1c2/0x3aa [<c19216d4>] start_kernel+0x291/0x2f2 [<c19211c7>] ? loglevel+0x1b/0x1b [<c19210bf>] i386_start_kernel+0xbf/0xc8 A better approach to this problem is to map the memory region with the correct attributes from the start, instead of modifying it after the fact. The uncached case can be handled by ioremap_nocache() and the cached by ioremap_cache(). Despite first impressions, it's not possible to use ioremap_cache() to map all cached memory regions on CONFIG_X86_64 because EFI_RUNTIME_SERVICES_DATA regions really don't like being mapped into the vmalloc space, as detailed in the following bug report, https://bugzilla.redhat.com/show_bug.cgi?id=748516 Therefore, we need to ensure that any EFI_RUNTIME_SERVICES_DATA regions are covered by the direct kernel mapping table on CONFIG_X86_64. To accomplish this we now map E820_RESERVED_EFI regions via the direct kernel mapping with the initial call to init_memory_mapping() in setup_arch(), whereas previously these regions wouldn't be mapped if they were after the last E820_RAM region until efi_ioremap() was called. Doing it this way allows us to delete efi_ioremap() completely. Signed-off-by: Matt Fleming <matt.fleming@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg@redhat.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Huang Ying <huang.ying.caritas@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1321621751-3650-1-git-send-email-matt@console-pimps.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/include/asm/efi.h')
-rw-r--r--arch/x86/include/asm/efi.h5
1 files changed, 0 insertions, 5 deletions
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 7093e4a6a0b..b8d8bfcd44a 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -33,8 +33,6 @@ extern unsigned long asmlinkage efi_call_phys(void *, ...);
#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, type) ioremap_cache(addr, size)
-
#else /* !CONFIG_X86_32 */
extern u64 efi_call0(void *fp);
@@ -84,9 +82,6 @@ extern u64 efi_call6(void *fp, u64 arg1, u64 arg2, u64 arg3,
efi_call6((void *)(efi.systab->runtime->f), (u64)(a1), (u64)(a2), \
(u64)(a3), (u64)(a4), (u64)(a5), (u64)(a6))
-extern void __iomem *efi_ioremap(unsigned long addr, unsigned long size,
- u32 type);
-
#endif /* CONFIG_X86_32 */
extern int add_efi_memmap;