From e67a807f3d9a82fa91817871f1c0e2e04da993b8 Mon Sep 17 00:00:00 2001 From: Liang Li Date: Fri, 30 Apr 2010 18:01:51 +0800 Subject: [PATCH] x86: Fix 'reservetop=' functionality When specifying the 'reservetop=0xbadc0de' kernel parameter, the kernel will stop booting due to a early_ioremap bug that relates to commit 8827247ff. The root cause of boot failure problem is the value of 'slot_virt[i]' was initialized in setup_arch->early_ioremap_init(). But later in setup_arch, the function 'parse_early_param' will modify 'FIXADDR_TOP' when 'reservetop=0xbadc0de' being specified. The simplest fix might be use __fix_to_virt(idx0) to get updated value of 'FIXADDR_TOP' in '__early_ioremap' instead of reference old value from slot_virt[slot] directly. Changelog since v0: -v1: When reservetop being handled then FIXADDR_TOP get adjusted, Hence check prev_map then re-initialize slot_virt and PMD based on new FIXADDR_TOP. -v2: place fixup_early_ioremap hence call early_ioremap_init in reserve_top_address to re-initialize slot_virt and corresponding PMD when parse_reservertop -v3: move fixup_early_ioremap out of reserve_top_address to make sure other clients of reserve_top_address like xen/lguest won't broken Signed-off-by: Liang Li Tested-by: Konrad Rzeszutek Wilk Acked-by: Yinghai Lu Acked-by: Jeremy Fitzhardinge Cc: Wang Chen Cc: "H. Peter Anvin" Cc: Andrew Morton LKML-Reference: <1272621711-8683-1-git-send-email-liang.li@windriver.com> [ fixed three small cleanliness details in fixup_early_ioremap() ] Signed-off-by: Ingo Molnar --- arch/x86/include/asm/io.h | 1 + arch/x86/mm/ioremap.c | 14 ++++++++++++++ arch/x86/mm/pgtable_32.c | 1 + 3 files changed, 16 insertions(+) diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index a1dcfa3ab17d..30a3e9776123 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -347,6 +347,7 @@ extern void __iomem *early_ioremap(resource_size_t phys_addr, extern void __iomem *early_memremap(resource_size_t phys_addr, unsigned long size); extern void early_iounmap(void __iomem *addr, unsigned long size); +extern void fixup_early_ioremap(void); #define IO_SPACE_LIMIT 0xffff diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 5eb1ba74a3a9..12e4d2d3c110 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -448,6 +448,20 @@ static inline void __init early_clear_fixmap(enum fixed_addresses idx) static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata; static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata; +void __init fixup_early_ioremap(void) +{ + int i; + + for (i = 0; i < FIX_BTMAPS_SLOTS; i++) { + if (prev_map[i]) { + WARN_ON(1); + break; + } + } + + early_ioremap_init(); +} + static int __init check_early_ioremap_leak(void) { int count = 0; diff --git a/arch/x86/mm/pgtable_32.c b/arch/x86/mm/pgtable_32.c index 1a8faf09afed..26eadaa60e6c 100644 --- a/arch/x86/mm/pgtable_32.c +++ b/arch/x86/mm/pgtable_32.c @@ -128,6 +128,7 @@ static int __init parse_reservetop(char *arg) address = memparse(arg, &arg); reserve_top_address(address); + fixup_early_ioremap(); return 0; } early_param("reservetop", parse_reservetop);