From 2639b9826197192b5775035fe3721badb575f4bd Mon Sep 17 00:00:00 2001 From: Wen Congyang Date: Sat, 3 Nov 2012 11:42:05 +1100 Subject: [PATCH] x86: make 'mem=' option work for efi platform Current mem boot option only can work for non efi environments. If the user specifies add_efi_memmap, it cannot work for efi environment. In the efi environment, we call e820_add_region() to add the memory map. So we can modify __e820_add_region() and the mem boot option can work for an efi environment. Signed-off-by: Wen Congyang Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: Matt Fleming Signed-off-by: Andrew Morton --- arch/x86/kernel/e820.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index df06ade26bef..b15b3419756c 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -47,6 +47,7 @@ unsigned long pci_mem_start = 0xaeedbabe; #ifdef CONFIG_PCI EXPORT_SYMBOL(pci_mem_start); #endif +static u64 mem_limit = ~0ULL; /* * This function checks if any part of the range is mapped @@ -119,6 +120,20 @@ static void __init __e820_add_region(struct e820map *e820x, u64 start, u64 size, return; } + if (start >= mem_limit) { + printk(KERN_ERR "e820: ignoring [mem %#010llx-%#010llx]\n", + (unsigned long long)start, + (unsigned long long)(start + size - 1)); + return; + } + + if (mem_limit - start < size) { + printk(KERN_ERR "e820: ignoring [mem %#010llx-%#010llx]\n", + (unsigned long long)mem_limit, + (unsigned long long)(start + size - 1)); + size = mem_limit - start; + } + e820x->map[x].addr = start; e820x->map[x].size = size; e820x->map[x].type = type; @@ -809,7 +824,7 @@ static int userdef __initdata; /* "mem=nopentium" disables the 4MB page tables. */ static int __init parse_memopt(char *p) { - u64 mem_size; + char *oldp; if (!p) return -EINVAL; @@ -825,11 +840,11 @@ static int __init parse_memopt(char *p) } userdef = 1; - mem_size = memparse(p, &p); + oldp = p; + mem_limit = memparse(p, &p); /* don't remove all of memory when handling "mem={invalid}" param */ - if (mem_size == 0) + if (mem_limit == 0 || p == oldp) return -EINVAL; - e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1); return 0; } @@ -881,6 +896,12 @@ early_param("memmap", parse_memmap_opt); void __init finish_e820_parsing(void) { + if (mem_limit != ~0ULL) { + userdef = 1; + e820_remove_range(mem_limit, ULLONG_MAX - mem_limit, + E820_RAM, 1); + } + if (userdef) { u32 nr = e820.nr_map; -- 2.39.5