[yocto] [PATCH 2/3] x86, efi: Make efi_call_phys_prelog() CONFIG_RELOCATABLE-aware

[Darren Hart]

From: Matt Fleming <matt.flem...@intel.com>

efi_call_phys_prelog() assumes that the kernel was loaded at a
physical address within the first 8MB of ram, usually
0x1000000. However, this isn't the case with a CONFIG_RELOCATABLE=y
kernel which could have been loaded anywhere in the physical address
space.

Replace the hardcoded pgd_index(0) and pgd_index(PAGE_OFFSET) with the
runtime addresses of the kernel in the physical and virtual space,
respectively.

Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Ingo Molnar <mi...@elte.hu>
Cc: "H. Peter Anvin" <h...@zytor.com>
Cc: Matthew Garrett <m...@redhat.com>
Signed-off-by: Matt Fleming <matt.flem...@intel.com>
Integrated-by: Darren Hart <dvh...@linux.intel.com>
---
 arch/x86/platform/efi/efi_32.c |   22 +++++++++++++---------
 1 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c
index 5cab48e..1156e9a 100644
--- a/arch/x86/platform/efi/efi_32.c
+++ b/arch/x86/platform/efi/efi_32.c
@@ -44,8 +44,12 @@ void efi_call_phys_prelog(void)
 {
        unsigned long cr4;
        unsigned long temp;
+       unsigned long phys_addr, virt_addr;
        struct desc_ptr gdt_descr;
 
+       virt_addr = (unsigned long)_text;
+       phys_addr = virt_addr - PAGE_OFFSET;
+
        local_irq_save(efi_rt_eflags);
 
        /*
@@ -57,18 +61,18 @@ void efi_call_phys_prelog(void)
 
        if (cr4 & X86_CR4_PAE) {
                efi_bak_pg_dir_pointer[0].pgd =
-                   swapper_pg_dir[pgd_index(0)].pgd;
-               swapper_pg_dir[0].pgd =
-                   swapper_pg_dir[pgd_index(PAGE_OFFSET)].pgd;
+                   swapper_pg_dir[pgd_index(phys_addr)].pgd;
+               swapper_pg_dir[pgd_index(phys_addr)].pgd =
+                   swapper_pg_dir[pgd_index(virt_addr)].pgd;
        } else {
                efi_bak_pg_dir_pointer[0].pgd =
-                   swapper_pg_dir[pgd_index(0)].pgd;
+                   swapper_pg_dir[pgd_index(phys_addr)].pgd;
                efi_bak_pg_dir_pointer[1].pgd =
-                   swapper_pg_dir[pgd_index(0x400000)].pgd;
-               swapper_pg_dir[pgd_index(0)].pgd =
-                   swapper_pg_dir[pgd_index(PAGE_OFFSET)].pgd;
-               temp = PAGE_OFFSET + 0x400000;
-               swapper_pg_dir[pgd_index(0x400000)].pgd =
+                   swapper_pg_dir[pgd_index(phys_addr + 0x400000)].pgd;
+               swapper_pg_dir[pgd_index(phys_addr)].pgd =
+                   swapper_pg_dir[pgd_index(virt_addr)].pgd;
+               temp = virt_addr + 0x400000;
+               swapper_pg_dir[pgd_index(phys_addr + 0x400000)].pgd =
                    swapper_pg_dir[pgd_index(temp)].pgd;
        }
 
-- 
1.7.6.4

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