aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/platform/efi/efi_32.c
diff options
context:
space:
mode:
authorIngo Molnar <mingo@kernel.org>2015-03-03 07:48:50 +0100
committerMatt Fleming <matt.fleming@intel.com>2015-04-01 12:46:22 +0100
commit744937b0b12a669f298949c4a810794c59fead98 (patch)
treed7d4082f50f1b56a6844012aaf5ff95690686aa1 /arch/x86/platform/efi/efi_32.c
parent23a0d4e8fa6d3a1d7fb819f79bcc0a3739c30ba9 (diff)
efi: Clean up the efi_call_phys_[prolog|epilog]() save/restore interaction
Currently x86-64 efi_call_phys_prolog() saves into a global variable (save_pgd), and efi_call_phys_epilog() restores the kernel pagetables from that global variable. Change this to a cleaner save/restore pattern where the saving function returns the saved object and the restore function restores that. Apply the same concept to the 32-bit code as well. Plus this approach, as an added bonus, allows us to express the !efi_enabled(EFI_OLD_MEMMAP) situation in a clean fashion as well, via a 'NULL' return value. Cc: Tapasweni Pathak <tapaswenipathak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Diffstat (limited to 'arch/x86/platform/efi/efi_32.c')
-rw-r--r--arch/x86/platform/efi/efi_32.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c
index abecc6e1dc90..ed5b67338294 100644
--- a/arch/x86/platform/efi/efi_32.c
+++ b/arch/x86/platform/efi/efi_32.c
@@ -56,19 +56,24 @@ void __init efi_map_region(efi_memory_desc_t *md)
void __init efi_map_region_fixed(efi_memory_desc_t *md) {}
void __init parse_efi_setup(u64 phys_addr, u32 data_len) {}
-void __init efi_call_phys_prolog(void)
+pgd_t * __init efi_call_phys_prolog(void)
{
struct desc_ptr gdt_descr;
+ pgd_t *save_pgd;
+ /* Current pgd is swapper_pg_dir, we'll restore it later: */
+ save_pgd = swapper_pg_dir;
load_cr3(initial_page_table);
__flush_tlb_all();
gdt_descr.address = __pa(get_cpu_gdt_table(0));
gdt_descr.size = GDT_SIZE - 1;
load_gdt(&gdt_descr);
+
+ return save_pgd;
}
-void __init efi_call_phys_epilog(void)
+void __init efi_call_phys_epilog(pgd_t *save_pgd)
{
struct desc_ptr gdt_descr;
@@ -76,7 +81,7 @@ void __init efi_call_phys_epilog(void)
gdt_descr.size = GDT_SIZE - 1;
load_gdt(&gdt_descr);
- load_cr3(swapper_pg_dir);
+ load_cr3(save_pgd);
__flush_tlb_all();
}

Privacy Policy