From 7306006f103567fcf595d23dd741da0b8642f4c5 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Wed, 18 Dec 2013 15:52:13 -0800 Subject: x86, realmode: Pointer walk cleanups, pull out invariant use of __pa() The pointer arithmetic in this function was really bizarre, where in fact all we really wanted was a simple pointer array walk. Use the much more idiomatic construction for that (*ptr++). Factor an invariant use of __pa() out of the relocation loop. At least on 64 bits it seems gcc isn't capable of doing that automatically. Change the scope of a couple of variables to make it extra obvious that they are extremely local temp variables. Signed-off-by: H. Peter Anvin Link: http://lkml.kernel.org/n/tip-rd908t9c8kvcojdabtmm94mb@git.kernel.org --- arch/x86/realmode/init.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c index a44f457e70a1..bad628a620c4 100644 --- a/arch/x86/realmode/init.c +++ b/arch/x86/realmode/init.c @@ -29,12 +29,10 @@ void __init reserve_real_mode(void) void __init setup_real_mode(void) { u16 real_mode_seg; - u32 *rel; + const u32 *rel; u32 count; - u32 *ptr; - u16 *seg; - int i; unsigned char *base; + unsigned long phys_base; struct trampoline_header *trampoline_header; size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob); #ifdef CONFIG_X86_64 @@ -46,23 +44,23 @@ void __init setup_real_mode(void) memcpy(base, real_mode_blob, size); - real_mode_seg = __pa(base) >> 4; + phys_base = __pa(base); + real_mode_seg = phys_base >> 4; + rel = (u32 *) real_mode_relocs; /* 16-bit segment relocations. */ - count = rel[0]; - rel = &rel[1]; - for (i = 0; i < count; i++) { - seg = (u16 *) (base + rel[i]); + count = *rel++; + while (count--) { + u16 *seg = (u16 *) (base + *rel++); *seg = real_mode_seg; } /* 32-bit linear relocations. */ - count = rel[i]; - rel = &rel[i + 1]; - for (i = 0; i < count; i++) { - ptr = (u32 *) (base + rel[i]); - *ptr += __pa(base); + count = *rel++; + while (count--) { + u32 *ptr = (u32 *) (base + *rel++); + *ptr += phys_base; } /* Must be perfomed *after* relocation. */ -- cgit v1.2.3