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author | Alok Kataria <akataria@vmware.com> | 2008-06-24 18:48:30 (GMT) |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-07-08 11:10:39 (GMT) |
commit | 3381959da5a00ae8289cfbd28b0b6d228f2d1d46 (patch) | |
tree | 6383c6b4cc564f84a07e84fd30622aa661d03c79 /arch/x86/kernel/e820.c | |
parent | c987d12f8455b19b3b057d63bac3de161bd809fc (diff) | |
download | linux-fsl-qoriq-3381959da5a00ae8289cfbd28b0b6d228f2d1d46.tar.xz |
x86: cleanup e820_setup_gap(), add e820_search_gap(), v2
This is a preparatory patch for the next patch in series.
Moves some code from e820_setup_gap to a new function e820_search_gap.
This patch is a part of a bug fix where we walk the ACPI table to calculate
a gap for PCI optional devices.
v1->v2: Patch on top of tip/master.
Fixes a bug introduced in the last patch about the typeof "last".
Also the new function e820_search_gap now returns if we found a gap in
e820_map.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Cc: lenb@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/e820.c')
-rw-r--r-- | arch/x86/kernel/e820.c | 43 |
1 files changed, 28 insertions, 15 deletions
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 3900ff5..22cfd66 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) { |