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author | Yinghai Lu <yinghai.lu@sun.com> | 2008-02-06 22:39:45 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-02-06 22:39:45 +0100 |
commit | 20651af9ac60fd6e31360688ad44861a7d05256a (patch) | |
tree | a5081b8ffddf2d2d931c16ae2528fd3679ba9760 /arch/x86/kernel/cpu/mtrr | |
parent | 971a52d66a3e87d4d2f5d3455e62680447cdb8e9 (diff) | |
download | op-kernel-dev-20651af9ac60fd6e31360688ad44861a7d05256a.zip op-kernel-dev-20651af9ac60fd6e31360688ad44861a7d05256a.tar.gz |
x86: fix mttr trimming
Pavel Emelyanov reported that his networking card did not work
and bisected it down to:
"
The commit
093af8d7f0ba3c6be1485973508584ef081e9f93
x86_32: trim memory by updating e820
broke my e1000 card: on loading driver says that
e1000: probe of 0000:04:03.0 failed with error -5
and the interface doesn't appear.
"
on a 32-bit kernel, base will overflow when try to do PAGE_SHIFT,
and highest_addr will always less 4G.
So use pfn instead of address to avoid the overflow when more than
4g RAM is installed on a 32-bit kernel.
Many thanks to Pavel Emelyanov for reporting and testing it.
Bisected-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Tested-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/cpu/mtrr')
-rw-r--r-- | arch/x86/kernel/cpu/mtrr/main.c | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c index 1e27b69..b6e136f 100644 --- a/arch/x86/kernel/cpu/mtrr/main.c +++ b/arch/x86/kernel/cpu/mtrr/main.c @@ -659,7 +659,7 @@ static __init int amd_special_default_mtrr(void) */ int __init mtrr_trim_uncached_memory(unsigned long end_pfn) { - unsigned long i, base, size, highest_addr = 0, def, dummy; + unsigned long i, base, size, highest_pfn = 0, def, dummy; mtrr_type type; u64 trim_start, trim_size; @@ -682,28 +682,27 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn) mtrr_if->get(i, &base, &size, &type); if (type != MTRR_TYPE_WRBACK) continue; - base <<= PAGE_SHIFT; - size <<= PAGE_SHIFT; - if (highest_addr < base + size) - highest_addr = base + size; + if (highest_pfn < base + size) + highest_pfn = base + size; } /* kvm/qemu doesn't have mtrr set right, don't trim them all */ - if (!highest_addr) { + if (!highest_pfn) { printk(KERN_WARNING "WARNING: strange, CPU MTRRs all blank?\n"); WARN_ON(1); return 0; } - if ((highest_addr >> PAGE_SHIFT) < end_pfn) { + if (highest_pfn < end_pfn) { printk(KERN_WARNING "WARNING: BIOS bug: CPU MTRRs don't cover" - " all of memory, losing %LdMB of RAM.\n", - (((u64)end_pfn << PAGE_SHIFT) - highest_addr) >> 20); + " all of memory, losing %luMB of RAM.\n", + (end_pfn - highest_pfn) >> (20 - PAGE_SHIFT)); WARN_ON(1); printk(KERN_INFO "update e820 for mtrr\n"); - trim_start = highest_addr; + trim_start = highest_pfn; + trim_start <<= PAGE_SHIFT; trim_size = end_pfn; trim_size <<= PAGE_SHIFT; trim_size -= trim_start; |