Revert "x86 PAT: remove CPA WARN_ON for zero pte"
This reverts commit 58dab916df
, which
makes my Nehalem come to a nasty crawling almost-halt. It looks like it
turns off caching of regular kernel RAM, with the understandable
slowdown of a few orders of magnitude as a result.
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
647df5189f
commit
b5db0e3865
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@ -555,12 +555,10 @@ repeat:
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if (!pte_val(old_pte)) {
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if (!primary)
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return 0;
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/*
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* Special error value returned, indicating that the mapping
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* did not exist at this address.
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*/
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return -EFAULT;
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WARN(1, KERN_WARNING "CPA: called for zero pte. "
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"vaddr = %lx cpa->vaddr = %lx\n", address,
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*cpa->vaddr);
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return -EINVAL;
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}
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if (level == PG_LEVEL_4K) {
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@ -505,35 +505,6 @@ static inline int range_is_allowed(unsigned long pfn, unsigned long size)
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}
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#endif /* CONFIG_STRICT_DEVMEM */
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/*
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* Change the memory type for the physial address range in kernel identity
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* mapping space if that range is a part of identity map.
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*/
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static int kernel_map_sync_memtype(u64 base, unsigned long size,
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unsigned long flags)
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{
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unsigned long id_sz;
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int ret;
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if (!pat_enabled || base >= __pa(high_memory))
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return 0;
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id_sz = (__pa(high_memory) < base + size) ?
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__pa(high_memory) - base :
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size;
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ret = ioremap_change_attr((unsigned long)__va(base), id_sz, flags);
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/*
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* -EFAULT return means that the addr was not valid and did not have
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* any identity mapping. That case is a success for
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* kernel_map_sync_memtype.
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*/
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if (ret == -EFAULT)
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ret = 0;
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return ret;
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}
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int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
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unsigned long size, pgprot_t *vma_prot)
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{
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@ -584,7 +555,9 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
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if (retval < 0)
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return 0;
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if (kernel_map_sync_memtype(offset, size, flags)) {
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if (((pfn < max_low_pfn_mapped) ||
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(pfn >= (1UL<<(32 - PAGE_SHIFT)) && pfn < max_pfn_mapped)) &&
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ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) {
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free_memtype(offset, offset + size);
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printk(KERN_INFO
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"%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n",
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@ -632,7 +605,7 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot,
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int strict_prot)
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{
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int is_ram = 0;
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int ret;
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int id_sz, ret;
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unsigned long flags;
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unsigned long want_flags = (pgprot_val(*vma_prot) & _PAGE_CACHE_MASK);
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@ -673,7 +646,15 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot,
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flags);
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}
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if (kernel_map_sync_memtype(paddr, size, flags)) {
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/* Need to keep identity mapping in sync */
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if (paddr >= __pa(high_memory))
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return 0;
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id_sz = (__pa(high_memory) < paddr + size) ?
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__pa(high_memory) - paddr :
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size;
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if (ioremap_change_attr((unsigned long)__va(paddr), id_sz, flags) < 0) {
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free_memtype(paddr, paddr + size);
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printk(KERN_ERR
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"%s:%d reserve_pfn_range ioremap_change_attr failed %s "
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