x86: fix mttr trimming
Pavel Emelyanov reported that his networking card did not work
and bisected it down to:
"
The commit
093af8d7f0
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>
This commit is contained in:
parent
971a52d66a
commit
20651af9ac
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@ -659,7 +659,7 @@ static __init int amd_special_default_mtrr(void)
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*/
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int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
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{
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unsigned long i, base, size, highest_addr = 0, def, dummy;
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unsigned long i, base, size, highest_pfn = 0, def, dummy;
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mtrr_type type;
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u64 trim_start, trim_size;
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@ -682,28 +682,27 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
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mtrr_if->get(i, &base, &size, &type);
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if (type != MTRR_TYPE_WRBACK)
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continue;
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base <<= PAGE_SHIFT;
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size <<= PAGE_SHIFT;
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if (highest_addr < base + size)
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highest_addr = base + size;
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if (highest_pfn < base + size)
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highest_pfn = base + size;
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}
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/* kvm/qemu doesn't have mtrr set right, don't trim them all */
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if (!highest_addr) {
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if (!highest_pfn) {
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printk(KERN_WARNING "WARNING: strange, CPU MTRRs all blank?\n");
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WARN_ON(1);
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return 0;
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}
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if ((highest_addr >> PAGE_SHIFT) < end_pfn) {
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if (highest_pfn < end_pfn) {
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printk(KERN_WARNING "WARNING: BIOS bug: CPU MTRRs don't cover"
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" all of memory, losing %LdMB of RAM.\n",
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(((u64)end_pfn << PAGE_SHIFT) - highest_addr) >> 20);
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" all of memory, losing %luMB of RAM.\n",
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(end_pfn - highest_pfn) >> (20 - PAGE_SHIFT));
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WARN_ON(1);
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printk(KERN_INFO "update e820 for mtrr\n");
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trim_start = highest_addr;
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trim_start = highest_pfn;
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trim_start <<= PAGE_SHIFT;
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trim_size = end_pfn;
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trim_size <<= PAGE_SHIFT;
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trim_size -= trim_start;
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