diff options
| -rw-r--r-- | arch/x86/kernel/resource.c | 38 |
1 files changed, 37 insertions, 1 deletions
diff --git a/arch/x86/kernel/resource.c b/arch/x86/kernel/resource.c index 407a900da9df..89638af2ff19 100644 --- a/arch/x86/kernel/resource.c +++ b/arch/x86/kernel/resource.c @@ -1,11 +1,47 @@ #include <linux/ioport.h> #include <asm/e820.h> +static void resource_clip(struct resource *res, resource_size_t start, + resource_size_t end) +{ + resource_size_t low = 0, high = 0; + + if (res->end < start || res->start > end) + return; /* no conflict */ + + if (res->start < start) + low = start - res->start; + + if (res->end > end) + high = res->end - end; + + /* Keep the area above or below the conflict, whichever is larger */ + if (low > high) + res->end = start - 1; + else + res->start = end + 1; +} + +static void remove_e820_regions(struct resource *avail) +{ + int i; + struct e820entry *entry; + + for (i = 0; i < e820.nr_map; i++) { + entry = &e820.map[i]; + + resource_clip(avail, entry->addr, + entry->addr + entry->size - 1); + } +} + void arch_remove_reservations(struct resource *avail) { - /* Trim out BIOS area (low 1MB) */ + /* Trim out BIOS area (low 1MB) and E820 regions */ if (avail->flags & IORESOURCE_MEM) { if (avail->start < BIOS_END) avail->start = BIOS_END; + + remove_e820_regions(avail); } } |