Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI fixes from Ingo Molnar:
"Three EFI fixes:
- Fix a slow-boot-scrolling regression but making sure we use WC for
EFI earlycon framebuffer mappings on x86
- Fix a mixed EFI mode boot crash
- Disable paging explicitly before entering startup_32() in mixed
mode bootup"
* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/efistub: Disable paging at mixed mode entry
efi/libstub/random: Initialize pointer variables to zero for mixed mode
efi/earlycon: Fix write-combine mapping on x86
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 58a512e..ee60b81 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -244,6 +244,11 @@
leal efi32_config(%ebp), %eax
movl %eax, efi_config(%ebp)
+ /* Disable paging */
+ movl %cr0, %eax
+ btrl $X86_CR0_PG_BIT, %eax
+ movl %eax, %cr0
+
jmp startup_32
SYM_FUNC_END(efi32_stub_entry)
#endif
diff --git a/drivers/firmware/efi/earlycon.c b/drivers/firmware/efi/earlycon.c
index d4077db..5d4f847 100644
--- a/drivers/firmware/efi/earlycon.c
+++ b/drivers/firmware/efi/earlycon.c
@@ -17,7 +17,7 @@
static const struct font_desc *font;
static u32 efi_x, efi_y;
static u64 fb_base;
-static pgprot_t fb_prot;
+static bool fb_wb;
static void *efi_fb;
/*
@@ -33,10 +33,8 @@
if (!earlycon_console || !(earlycon_console->flags & CON_ENABLED))
return 0;
- if (pgprot_val(fb_prot) == pgprot_val(PAGE_KERNEL))
- efi_fb = memremap(fb_base, screen_info.lfb_size, MEMREMAP_WB);
- else
- efi_fb = memremap(fb_base, screen_info.lfb_size, MEMREMAP_WC);
+ efi_fb = memremap(fb_base, screen_info.lfb_size,
+ fb_wb ? MEMREMAP_WB : MEMREMAP_WC);
return efi_fb ? 0 : -ENOMEM;
}
@@ -53,9 +51,12 @@
static __ref void *efi_earlycon_map(unsigned long start, unsigned long len)
{
+ pgprot_t fb_prot;
+
if (efi_fb)
return efi_fb + start;
+ fb_prot = fb_wb ? PAGE_KERNEL : pgprot_writecombine(PAGE_KERNEL);
return early_memremap_prot(fb_base + start, len, pgprot_val(fb_prot));
}
@@ -215,10 +216,7 @@
if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
fb_base |= (u64)screen_info.ext_lfb_base << 32;
- if (opt && !strcmp(opt, "ram"))
- fb_prot = PAGE_KERNEL;
- else
- fb_prot = pgprot_writecombine(PAGE_KERNEL);
+ fb_wb = opt && !strcmp(opt, "ram");
si = &screen_info;
xres = si->lfb_width;
diff --git a/drivers/firmware/efi/libstub/random.c b/drivers/firmware/efi/libstub/random.c
index 35edd7c..97378cf 100644
--- a/drivers/firmware/efi/libstub/random.c
+++ b/drivers/firmware/efi/libstub/random.c
@@ -33,7 +33,7 @@
{
efi_guid_t rng_proto = EFI_RNG_PROTOCOL_GUID;
efi_status_t status;
- struct efi_rng_protocol *rng;
+ struct efi_rng_protocol *rng = NULL;
status = efi_call_early(locate_protocol, &rng_proto, NULL,
(void **)&rng);
@@ -162,8 +162,8 @@
efi_guid_t rng_proto = EFI_RNG_PROTOCOL_GUID;
efi_guid_t rng_algo_raw = EFI_RNG_ALGORITHM_RAW;
efi_guid_t rng_table_guid = LINUX_EFI_RANDOM_SEED_TABLE_GUID;
- struct efi_rng_protocol *rng;
- struct linux_efi_random_seed *seed;
+ struct efi_rng_protocol *rng = NULL;
+ struct linux_efi_random_seed *seed = NULL;
efi_status_t status;
status = efi_call_early(locate_protocol, &rng_proto, NULL,
