sparc64: Add 16GB hugepage support
v5 cover sparc64: Add 16GB hugepage support
SPARC architecture supports 16G hugepages but the kernel did not support these. This patch series adds support for it and also cleanes up some page walk/alloc functions.
Patch 1/3: Core changes needed to add 16G hugepage support: To map a
single 16G hugepage, two PUD entries are used. Each PUD entry maps 8G portion of a 16G page. This page table encoding scheme is same as that used for hugepages at PMD level (8M, 256M and 2G pages) where each PMD entry points successively to 8M regions within a page. No page table entries below the PUD level are allocated for 16G hugepage since those are not required.
TSB entries for a 16G page are created at every 4M boundary since the HUGE_TSB is used for these pages which is configured with page size of 4M. When walking page tables (on a TSB miss), bits [32:22] are transferred from vaddr to PUD to resolve addresses at 4M boundary. The resolved address mapping is then stored in HUGE_TSB.
Patch 2/3: get_user_pages() etc. are used for direct IO. These
functions were not aware of hugepages at the PUD level and would try to continue walking page tables beyond the PUD level. Since 16G hugepages have page tables allocated till PUD level only, these accesses would result in invalid access. This patch adds the case for PUD huge pages to these functions.
Patch 3/3: Patch 1 added the case of PUD entry being huge in page
table walk and alloc functions. This new case further increased nesting in these functions and made them harder to follow. This patch flattens these functions for better readability.
Changelog v5 vs v4:
- Checking at PUD level for hugepage entry during page table walk is patched out if 16GB hugepages are not being used.
Changelog v4 vs v3:
- Added cover letter (patch 0/4) for patch series.
Changelog v3 vs v2:
- Fixed email headers so the subject shows up correctly.
Changelog v2 vs v1:
- Remove redundant brgez,pn (Bob Picco)
- Remove unncessary label rename from 700 to 701 (Rob Gardner)
- Add patch description (Paul)
- Add 16G case to get_user_pages()
Nitin Gupta (3):
sparc64: Support huge PUD case in get_user_pages
sparc64: Add 16GB hugepage support
sparc64: Cleanup hugepage table walk functions
arch/sparc/include/asm/hugetlb.h | 7 +++ arch/sparc/include/asm/page_64.h | 3 +- arch/sparc/include/asm/pgtable_64.h | 20 ++++++- arch/sparc/include/asm/tsb.h | 36 +++++++++++++ arch/sparc/kernel/tsb.S | 2 +- arch/sparc/kernel/vmlinux.lds.S | 5 ++ arch/sparc/mm/gup.c | 45 +++++++++++++++- arch/sparc/mm/hugetlbpage.c | 102 +++++++++++++++++++++--------------- arch/sparc/mm/init_64.c | 54 ++++++++++++++++--- 9 files changed, 220 insertions(+), 54 deletions(-)
Signature · 1 line
2.9.2
PATCH v5 1/3 sparc64: Support huge PUD case in get_user_pages
get_user_pages() is used to do direct IO. It already handles the case where the address range is backed by PMD huge pages. This patch now adds the case where the range could be backed by PUD huge pages.
--- arch/sparc/include/asm/pgtable_64.h | 15 +++++++++++-- arch/sparc/mm/gup.c | 45 ++++++++++++++++++++++++++++++++++++- 2 files changed, 57 insertions(+), 3 deletions(-)
arch/sparc/include/asm/pgtable_64.h +13 -2
@@ -687,6 +687,8 @@ static inline unsigned long pmd_write(pmd_t pmd)return pte_write (pte); } +#define pud_write (pud) pte_write(__pte(pud_val(pud))) +#ifdef CONFIG_TRANSPARENT_HUGEPAGE static inline unsigned long pmd_dirty (pmd_t pmd) {
@@ -823,9 +825,18 @@ static inline unsigned long __pmd_page(pmd_t pmd)return ((unsigned long )__va (pfn <<PAGE_SHIFT )); } + +static inline unsigned long pud_page_vaddr (pud_t pud) +{ +pte_t pte =__pte (pud_val (pud)); +unsigned long pfn; + + pfn =pte_pfn (pte); + +return ((unsigned long )__va (pfn <<PAGE_SHIFT )); +} +#define pmd_page (pmd) virt_to_page((void *)__pmd_page(pmd)) -#define pud_page_vaddr (pud) \ - ((unsigned long) __va(pud_val(pud)))#define pud_page (pud) virt_to_page((void *)pud_page_vaddr(pud))#define pmd_clear (pmdp) (pmd_val(*(pmdp)) = 0UL)#define pud_present (pud) (pud_val(pud) != 0U)
arch/sparc/mm/gup.c +44 -1
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Signature · 1 line
2.9.2
PATCH v5 2/3 sparc64: Add 16GB hugepage support
In reply to Nitin GuptaAdds support for 16GB hugepage size. To use this page size use kernel parameters as:
default_hugepageszG hugepageszG hugepages
Testing:
Tested with the stream benchmark which allocates 48G of arrays backed by 16G hugepages and does RW operation on them in parallel.
Orabug: 25362942
--- arch/sparc/include/asm/hugetlb.h | 7 ++++ arch/sparc/include/asm/page_64.h | 3 +- arch/sparc/include/asm/pgtable_64.h | 5 +++ arch/sparc/include/asm/tsb.h | 36 ++++++++++++++++++ arch/sparc/kernel/tsb.S | 2 +- arch/sparc/kernel/vmlinux.lds.S | 5 +++ arch/sparc/mm/hugetlbpage.c | 74 ++++++++++++++++++++++++++----------- arch/sparc/mm/init_64.c | 54 +++++++++++++++++++++++---- 8 files changed, 156 insertions(+), 30 deletions(-)
arch/sparc/include/asm/hugetlb.h +7 -0
@@ -4,6 +4,13 @@#include <asm/page.h> #include <asm-generic/hugetlb.h> +#ifdef CONFIG_HUGETLB_PAGE +struct pud_huge_patch_entry { +unsigned int addr; +unsigned int insn; +}; +extern struct pud_huge_patch_entry __pud_huge_patch, __pud_huge_patch_end; +#endif void set_huge_pte_at (struct mm_struct *mm,unsigned long addr,pte_t *ptep,pte_t pte);
arch/sparc/include/asm/page_64.h +2 -1
@@ -17,6 +17,7 @@#define HPAGE_SHIFT 23#define REAL_HPAGE_SHIFT 22 +#define HPAGE_16GB_SHIFT 34#define HPAGE_2GB_SHIFT 31#define HPAGE_256MB_SHIFT 28#define HPAGE_64K_SHIFT 16
@@ -28,7 +29,7 @@#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA #define REAL_HPAGE_PER_HPAGE (_AC(1,UL) << (HPAGE_SHIFT - REAL_HPAGE_SHIFT)) -#define HUGE_MAX_HSTATE 4 +#define HUGE_MAX_HSTATE 5#endif #ifndef __ASSEMBLY__
arch/sparc/include/asm/pgtable_64.h +5 -0
@@ -414,6 +414,11 @@ static inline bool is_hugetlb_pmd(pmd_t pmd)return !!(pmd_val (pmd) & _PAGE_PMD_HUGE); } +static inline bool is_hugetlb_pud (pud_t pud) +{ +return !!(pud_val (pud) & _PAGE_PUD_HUGE); +} +#ifdef CONFIG_TRANSPARENT_HUGEPAGE static inline pmd_t pmd_mkhuge (pmd_t pmd) {
arch/sparc/include/asm/tsb.h +36 -0
@@ -195,6 +195,41 @@ extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end;nop ; \ 699: +/* PUD has been loaded into REG1, interpret the value, seeing +* if it is a HUGE PUD or a normal one. If it is not valid +* then jump to FAIL_LABEL. If it is a HUGE PUD, and it +* translates to a valid PTE, branch to PTE_LABEL. +* +* We have to propagate bits [32:22] from the virtual address +* to resolve at 4M granularity. +*/ +#if defined(CONFIG_HUGETLB_PAGE ) || defined(CONFIG_TRANSPARENT_HUGEPAGE ) +#define USER_PGTABLE_CHECK_PUD_HUGE (VADDR ,REG1 ,REG2 ,FAIL_LABEL ,PTE_LABEL ) \ +700: ba 700f; \ + nop; \ + .section .pud_huge_patch, "ax"; \ + .word 700b; \ + nop; \ + .previous; \ + brz,pn REG1, FAIL_LABEL; \ + sethi %uhi(_PAGE_PUD_HUGE), REG2; \ + sllx REG2, 32, REG2; \ + andcc REG1, REG2, %g0; \ + be,pt %xcc, 700f; \ + sethi %hi(0x1ffc0000), REG2; \ + sllx REG2, 1, REG2; \ + brgez,pn REG1, FAIL_LABEL; \ + andn REG1, REG2, REG1; \ + and VADDR, REG2, REG2; \ + brlz,pt REG1, PTE_LABEL; \ + or REG1, REG2, REG1; \ +700: +#else +#define USER_PGTABLE_CHECK_PUD_HUGE (VADDR ,REG1 ,REG2 ,FAIL_LABEL ,PTE_LABEL ) \ + brz,pn REG1, FAIL_LABEL; \ + nop; +#endif +/* PMD has been loaded into REG1, interpret the value, seeing * if it is a HUGE PMD or a normal one. If it is not valid * then jump to FAIL_LABEL. If it is a HUGE PMD, and it
@@ -242,6 +277,7 @@ extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end; srlx REG2, 64 - PAGE_SHIFT, REG2; \ andn REG2, 0x7, REG2; \ ldxa [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \ +USER_PGTABLE_CHECK_PUD_HUGE (VADDR ,REG1 ,REG2 ,FAIL_LABEL ,800f ) \ brz,pn REG1, FAIL_LABEL; \ sllx VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \ srlx REG2, 64 - PAGE_SHIFT, REG2; \
arch/sparc/kernel/tsb.S +1 -1
@@ -117,7 +117,7 @@ tsb_miss_page_table_walk_sun4v_fastpath: /* Valid PTE is now in %g5. */ #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE) - sethi %uhi(_PAGE_PMD_HUGE), %g7 + sethi %uhi(_PAGE_PMD_HUGE | _PAGE_PUD_HUGE), %g7 sllx %g7, 32, %g7 andcc %g5, %g7, %g0
arch/sparc/kernel/vmlinux.lds.S +5 -0
@@ -154,6 +154,11 @@ SECTIONS *(.get_tick_patch) __get_tick_patch_end = .; } + .pud_huge_patch : { + __pud_huge_patch = .; + *(.pud_huge_patch) + __pud_huge_patch_end = .; + } PERCPU_SECTION(SMP_CACHE_BYTES) #ifdef CONFIG_JUMP_LABEL
arch/sparc/mm/hugetlbpage.c +53 -21
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arch/sparc/mm/init_64.c +47 -7
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Signature · 1 line
2.9.2
PATCH v5 3/3 sparc64: Cleanup hugepage table walk functions
In reply to Nitin GuptaFlatten out nested code structure in huge_pte_offset() and huge_pte_alloc().
--- arch/sparc/mm/hugetlbpage.c | 54 +++++++++++++++++---------------------------- 1 file changed, 20 insertions(+), 34 deletions(-)
arch/sparc/mm/hugetlbpage.c +20 -34
@@ -266,27 +266,19 @@ pte_t *huge_pte_alloc(struct mm_struct *mm,pgd_t *pgd;pud_t *pud;pmd_t *pmd; -pte_t *pte =NULL ; pgd =pgd_offset (mm, addr); pud =pud_alloc (mm, pgd, addr);if (!pud)return NULL ; -if (sz >=PUD_SIZE ) - pte = (pte_t *)pud; -else { - pmd =pmd_alloc (mm, pud, addr); -if (!pmd) -return NULL ; - -if (sz >=PMD_SIZE ) - pte = (pte_t *)pmd; -else - pte =pte_alloc_map (mm, pmd, addr); - } - -return pte; +return (pte_t *)pud; + pmd =pmd_alloc (mm, pud, addr); +if (!pmd) +return NULL ; +if (sz >=PMD_SIZE ) +return (pte_t *)pmd; +return pte_alloc_map (mm, pmd, addr); } pte_t *huge_pte_offset(struct mm_struct *mm,
@@ -295,27 +287,21 @@ pte_t *huge_pte_offset(struct mm_struct *mm,pgd_t *pgd;pud_t *pud;pmd_t *pmd; -pte_t *pte =NULL ; pgd =pgd_offset (mm, addr); -if (!pgd_none (*pgd)) { - pud =pud_offset (pgd, addr); -if (!pud_none (*pud)) { -if (is_hugetlb_pud (*pud)) - pte = (pte_t *)pud; -else { - pmd =pmd_offset (pud, addr); -if (!pmd_none (*pmd)) { -if (is_hugetlb_pmd (*pmd)) - pte = (pte_t *)pmd; -else - pte =pte_offset_map (pmd, addr); - } - } - } - } - -return pte; +if (pgd_none (*pgd)) +return NULL ; + pud =pud_offset (pgd, addr); +if (pud_none (*pud)) +return NULL ; +if (is_hugetlb_pud (*pud)) +return (pte_t *)pud; + pmd =pmd_offset (pud, addr); +if (pmd_none (*pmd)) +return NULL ; +if (is_hugetlb_pmd (*pmd)) +return (pte_t *)pmd; +return pte_offset_map (pmd, addr); } void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
Signature · 1 line
2.9.2