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| author | Nicholas Piggin <npiggin@gmail.com> | 2019-06-10 13:08:18 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-06-19 20:05:09 +1000 |
| commit | d909f9109c301f4e9e41678025c45d719ab8f7d7 (patch) | |
| tree | 23360f2a5319e4738af0843bce9148c49b74ca19 /arch/powerpc/mm | |
| parent | d38153f9ccc9b6b6a27a91559999292c27b72b8c (diff) | |
| download | linux-stable-d909f9109c301f4e9e41678025c45d719ab8f7d7.tar.gz linux-stable-d909f9109c301f4e9e41678025c45d719ab8f7d7.tar.bz2 linux-stable-d909f9109c301f4e9e41678025c45d719ab8f7d7.zip | |
powerpc/64s/radix: Enable HAVE_ARCH_HUGE_VMAP
This sets the HAVE_ARCH_HUGE_VMAP option, and defines the required
page table functions.
This enables huge (2MB and 1GB) ioremap mappings. I don't have a
benchmark for this change, but huge vmap will be used by a later core
kernel change to enable huge vmalloc memory mappings. This improves
cached `git diff` performance by about 5% on a 2-node POWER9 with 32MB
size dentry cache hash.
Profiling git diff dTLB misses with a vanilla kernel:
81.75% git [kernel.vmlinux] [k] __d_lookup_rcu
7.21% git [kernel.vmlinux] [k] strncpy_from_user
1.77% git [kernel.vmlinux] [k] find_get_entry
1.59% git [kernel.vmlinux] [k] kmem_cache_free
40,168 dTLB-miss
0.100342754 seconds time elapsed
With powerpc huge vmalloc:
2,987 dTLB-miss
0.095933138 seconds time elapsed
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/mm')
| -rw-r--r-- | arch/powerpc/mm/book3s64/radix_pgtable.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c index 06a5ff2ee626..8904aa1243d8 100644 --- a/arch/powerpc/mm/book3s64/radix_pgtable.c +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c @@ -1124,6 +1124,106 @@ void radix__ptep_modify_prot_commit(struct vm_area_struct *vma, set_pte_at(mm, addr, ptep, pte); } +int __init arch_ioremap_pud_supported(void) +{ + /* HPT does not cope with large pages in the vmalloc area */ + return radix_enabled(); +} + +int __init arch_ioremap_pmd_supported(void) +{ + return radix_enabled(); +} + +int p4d_free_pud_page(p4d_t *p4d, unsigned long addr) +{ + return 0; +} + +int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot) +{ + pte_t *ptep = (pte_t *)pud; + pte_t new_pud = pfn_pte(__phys_to_pfn(addr), prot); + + if (!radix_enabled()) + return 0; + + set_pte_at(&init_mm, 0 /* radix unused */, ptep, new_pud); + + return 1; +} + +int pud_clear_huge(pud_t *pud) +{ + if (pud_huge(*pud)) { + pud_clear(pud); + return 1; + } + + return 0; +} + +int pud_free_pmd_page(pud_t *pud, unsigned long addr) +{ + pmd_t *pmd; + int i; + + pmd = (pmd_t *)pud_page_vaddr(*pud); + pud_clear(pud); + + flush_tlb_kernel_range(addr, addr + PUD_SIZE); + + for (i = 0; i < PTRS_PER_PMD; i++) { + if (!pmd_none(pmd[i])) { + pte_t *pte; + pte = (pte_t *)pmd_page_vaddr(pmd[i]); + + pte_free_kernel(&init_mm, pte); + } + } + + pmd_free(&init_mm, pmd); + + return 1; +} + +int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot) +{ + pte_t *ptep = (pte_t *)pmd; + pte_t new_pmd = pfn_pte(__phys_to_pfn(addr), prot); + + if (!radix_enabled()) + return 0; + + set_pte_at(&init_mm, 0 /* radix unused */, ptep, new_pmd); + + return 1; +} + +int pmd_clear_huge(pmd_t *pmd) +{ + if (pmd_huge(*pmd)) { + pmd_clear(pmd); + return 1; + } + + return 0; +} + +int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) +{ + pte_t *pte; + + pte = (pte_t *)pmd_page_vaddr(*pmd); + pmd_clear(pmd); + + flush_tlb_kernel_range(addr, addr + PMD_SIZE); + + pte_free_kernel(&init_mm, pte); + + return 1; +} + int radix__ioremap_range(unsigned long ea, phys_addr_t pa, unsigned long size, pgprot_t prot, int nid) { |