diff options
| -rw-r--r-- | arch/x86/kernel/e820.c | 43 | ||||
| -rw-r--r-- | include/asm-x86/e820.h | 2 |
2 files changed, 30 insertions, 15 deletions
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 3900ff51bc68..22cfd665224c 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -488,26 +488,22 @@ void __init update_e820(void) } /* - * Search for the biggest gap in the low 32 bits of the e820 - * memory space. We pass this space to PCI to assign MMIO resources - * for hotplug or unconfigured devices in. - * Hopefully the BIOS let enough space left. + * Search for a gap in the e820 memory space from start_addr to 2^32. */ -__init void e820_setup_gap(void) +__init int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize, + unsigned long start_addr) { - unsigned long gapstart, gapsize, round; - unsigned long long last; - int i; + unsigned long long last = 0x100000000ull; + int i = e820.nr_map; int found = 0; - last = 0x100000000ull; - gapstart = 0x10000000; - gapsize = 0x400000; - i = e820.nr_map; while (--i >= 0) { unsigned long long start = e820.map[i].addr; unsigned long long end = start + e820.map[i].size; + if (end < start_addr) + continue; + /* * Since "last" is at most 4GB, we know we'll * fit in 32 bits if this condition is true @@ -515,15 +511,32 @@ __init void e820_setup_gap(void) if (last > end) { unsigned long gap = last - end; - if (gap > gapsize) { - gapsize = gap; - gapstart = end; + if (gap >= *gapsize) { + *gapsize = gap; + *gapstart = end; found = 1; } } if (start < last) last = start; } + return found; +} + +/* + * Search for the biggest gap in the low 32 bits of the e820 + * memory space. We pass this space to PCI to assign MMIO resources + * for hotplug or unconfigured devices in. + * Hopefully the BIOS let enough space left. + */ +__init void e820_setup_gap(void) +{ + unsigned long gapstart, gapsize, round; + int found; + + gapstart = 0x10000000; + gapsize = 0x400000; + found = e820_search_gap(&gapstart, &gapsize, 0); #ifdef CONFIG_X86_64 if (!found) { diff --git a/include/asm-x86/e820.h b/include/asm-x86/e820.h index 13fa5a076aa2..f622685c9af8 100644 --- a/include/asm-x86/e820.h +++ b/include/asm-x86/e820.h @@ -71,6 +71,8 @@ extern u64 e820_remove_range(u64 start, u64 size, unsigned old_type, int checktype); extern void update_e820(void); extern void e820_setup_gap(void); +extern int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize, + unsigned long start_addr); struct setup_data; extern void parse_e820_ext(struct setup_data *data, unsigned long pa_data); |