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author | Vineet Gupta <vgupta@synopsys.com> | 2014-07-08 15:13:47 +0200 |
---|---|---|
committer | Vineet Gupta <vgupta@synopsys.com> | 2015-10-17 14:18:18 +0200 |
commit | fe6c1b8611aa3a79a937a5e3b85a16576b6ad159 (patch) | |
tree | 48a4677d99954f7abd084be740fbd9457ca190c7 /arch | |
parent | Documentation/features/vm: pte_special now supported by ARC (diff) | |
download | linux-fe6c1b8611aa3a79a937a5e3b85a16576b6ad159.tar.xz linux-fe6c1b8611aa3a79a937a5e3b85a16576b6ad159.zip |
ARCv2: mm: THP support
MMUv4 in HS38x cores supports Super Pages which are basis for Linux THP
support.
Normal and Super pages can co-exist (ofcourse not overlap) in TLB with a
new bit "SZ" in TLB page desciptor to distinguish between them.
Super Page size is configurable in hardware (4K to 16M), but fixed once
RTL builds.
The exact THP size a Linx configuration will support is a function of:
- MMU page size (typical 8K, RTL fixed)
- software page walker address split between PGD:PTE:PFN (typical
11:8:13, but can be changed with 1 line)
So for above default, THP size supported is 8K * 256 = 2M
Default Page Walker is 2 levels, PGD:PTE:PFN, which in THP regime
reduces to 1 level (as PTE is folded into PGD and canonically referred
to as PMD).
Thus thp PMD accessors are implemented in terms of PTE (just like sparc)
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arc/Kconfig | 4 | ||||
-rw-r--r-- | arch/arc/include/asm/hugepage.h | 77 | ||||
-rw-r--r-- | arch/arc/include/asm/page.h | 1 | ||||
-rw-r--r-- | arch/arc/include/asm/pgtable.h | 16 | ||||
-rw-r--r-- | arch/arc/mm/tlb.c | 81 | ||||
-rw-r--r-- | arch/arc/mm/tlbex.S | 19 |
6 files changed, 192 insertions, 6 deletions
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index 78c0621d5819..5912006391ed 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -76,6 +76,10 @@ config STACKTRACE_SUPPORT config HAVE_LATENCYTOP_SUPPORT def_bool y +config HAVE_ARCH_TRANSPARENT_HUGEPAGE + def_bool y + depends on ARC_MMU_V4 + source "init/Kconfig" source "kernel/Kconfig.freezer" diff --git a/arch/arc/include/asm/hugepage.h b/arch/arc/include/asm/hugepage.h new file mode 100644 index 000000000000..1d0700c32b82 --- /dev/null +++ b/arch/arc/include/asm/hugepage.h @@ -0,0 +1,77 @@ +/* + * Copyright (C) 2013-15 Synopsys, Inc. (www.synopsys.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + + +#ifndef _ASM_ARC_HUGEPAGE_H +#define _ASM_ARC_HUGEPAGE_H + +#include <linux/types.h> +#include <asm-generic/pgtable-nopmd.h> + +static inline pte_t pmd_pte(pmd_t pmd) +{ + return __pte(pmd_val(pmd)); +} + +static inline pmd_t pte_pmd(pte_t pte) +{ + return __pmd(pte_val(pte)); +} + +#define pmd_wrprotect(pmd) pte_pmd(pte_wrprotect(pmd_pte(pmd))) +#define pmd_mkwrite(pmd) pte_pmd(pte_mkwrite(pmd_pte(pmd))) +#define pmd_mkdirty(pmd) pte_pmd(pte_mkdirty(pmd_pte(pmd))) +#define pmd_mkold(pmd) pte_pmd(pte_mkold(pmd_pte(pmd))) +#define pmd_mkyoung(pmd) pte_pmd(pte_mkyoung(pmd_pte(pmd))) +#define pmd_mkhuge(pmd) pte_pmd(pte_mkhuge(pmd_pte(pmd))) +#define pmd_mknotpresent(pmd) pte_pmd(pte_mknotpresent(pmd_pte(pmd))) +#define pmd_mksplitting(pmd) pte_pmd(pte_mkspecial(pmd_pte(pmd))) +#define pmd_mkclean(pmd) pte_pmd(pte_mkclean(pmd_pte(pmd))) + +#define pmd_write(pmd) pte_write(pmd_pte(pmd)) +#define pmd_young(pmd) pte_young(pmd_pte(pmd)) +#define pmd_pfn(pmd) pte_pfn(pmd_pte(pmd)) +#define pmd_dirty(pmd) pte_dirty(pmd_pte(pmd)) +#define pmd_special(pmd) pte_special(pmd_pte(pmd)) + +#define mk_pmd(page, prot) pte_pmd(mk_pte(page, prot)) + +#define pmd_trans_huge(pmd) (pmd_val(pmd) & _PAGE_HW_SZ) +#define pmd_trans_splitting(pmd) (pmd_trans_huge(pmd) && pmd_special(pmd)) + +#define pfn_pmd(pfn, prot) (__pmd(((pfn) << PAGE_SHIFT) | pgprot_val(prot))) + +static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) +{ + /* + * open-coded pte_modify() with additional retaining of HW_SZ bit + * so that pmd_trans_huge() remains true for this PMD + */ + return __pmd((pmd_val(pmd) & (_PAGE_CHG_MASK | _PAGE_HW_SZ)) | pgprot_val(newprot)); +} + +static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, + pmd_t *pmdp, pmd_t pmd) +{ + *pmdp = pmd; +} + +extern void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr, + pmd_t *pmd); + +#define has_transparent_hugepage() 1 + +/* Generic variants assume pgtable_t is struct page *, hence need for these */ +#define __HAVE_ARCH_PGTABLE_DEPOSIT +extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, + pgtable_t pgtable); + +#define __HAVE_ARCH_PGTABLE_WITHDRAW +extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp); + +#endif diff --git a/arch/arc/include/asm/page.h b/arch/arc/include/asm/page.h index 2994cac1069e..37706837ef75 100644 --- a/arch/arc/include/asm/page.h +++ b/arch/arc/include/asm/page.h @@ -64,6 +64,7 @@ typedef unsigned long pgprot_t; #define pgd_val(x) (x) #define pgprot_val(x) (x) #define __pte(x) (x) +#define __pgd(x) (x) #define __pgprot(x) (x) #define pte_pgprot(x) (x) diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h index 431a83329324..336267f2e9d9 100644 --- a/arch/arc/include/asm/pgtable.h +++ b/arch/arc/include/asm/pgtable.h @@ -83,11 +83,13 @@ #define _PAGE_PRESENT (1<<9) /* TLB entry is valid (H) */ #if (CONFIG_ARC_MMU_VER >= 4) -#define _PAGE_SZ (1<<10) /* Page Size indicator (H) */ +#define _PAGE_HW_SZ (1<<10) /* Page Size indicator (H): 0 normal, 1 super */ #endif #define _PAGE_SHARED_CODE (1<<11) /* Shared Code page with cmn vaddr usable for shared TLB entries (H) */ + +#define _PAGE_UNUSED_BIT (1<<12) #endif /* vmalloc permissions */ @@ -99,6 +101,10 @@ #define _PAGE_CACHEABLE 0 #endif +#ifndef _PAGE_HW_SZ +#define _PAGE_HW_SZ 0 +#endif + /* Defaults for every user page */ #define ___DEF (_PAGE_PRESENT | _PAGE_CACHEABLE) @@ -125,7 +131,7 @@ #define PAGE_KERNEL_NO_CACHE __pgprot(_K_PAGE_PERMS) /* Masks for actual TLB "PD"s */ -#define PTE_BITS_IN_PD0 (_PAGE_GLOBAL | _PAGE_PRESENT) +#define PTE_BITS_IN_PD0 (_PAGE_GLOBAL | _PAGE_PRESENT | _PAGE_HW_SZ) #define PTE_BITS_RWX (_PAGE_EXECUTE | _PAGE_WRITE | _PAGE_READ) #define PTE_BITS_NON_RWX_IN_PD1 (PAGE_MASK | _PAGE_CACHEABLE) @@ -299,6 +305,7 @@ static inline void pmd_set(pmd_t *pmdp, pte_t *ptep) #define PTE_BIT_FUNC(fn, op) \ static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; } +PTE_BIT_FUNC(mknotpresent, &= ~(_PAGE_PRESENT)); PTE_BIT_FUNC(wrprotect, &= ~(_PAGE_WRITE)); PTE_BIT_FUNC(mkwrite, |= (_PAGE_WRITE)); PTE_BIT_FUNC(mkclean, &= ~(_PAGE_DIRTY)); @@ -308,6 +315,7 @@ PTE_BIT_FUNC(mkyoung, |= (_PAGE_ACCESSED)); PTE_BIT_FUNC(exprotect, &= ~(_PAGE_EXECUTE)); PTE_BIT_FUNC(mkexec, |= (_PAGE_EXECUTE)); PTE_BIT_FUNC(mkspecial, |= (_PAGE_SPECIAL)); +PTE_BIT_FUNC(mkhuge, |= (_PAGE_HW_SZ)); #define __HAVE_ARCH_PTE_SPECIAL @@ -381,6 +389,10 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, * remap a physical page `pfn' of size `size' with page protection `prot' * into virtual address `from' */ +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#include <asm/hugepage.h> +#endif + #include <asm-generic/pgtable.h> /* to cope with aliasing VIPT cache */ diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c index 2c7ce8bb7475..eb1bdc40e24f 100644 --- a/arch/arc/mm/tlb.c +++ b/arch/arc/mm/tlb.c @@ -256,6 +256,18 @@ noinline void local_flush_tlb_all(void) write_aux_reg(ARC_REG_TLBCOMMAND, TLBWrite); } + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { + const int stlb_idx = 0x800; + + /* Blank sTLB entry */ + write_aux_reg(ARC_REG_TLBPD0, _PAGE_HW_SZ); + + for (entry = stlb_idx; entry < stlb_idx + 16; entry++) { + write_aux_reg(ARC_REG_TLBINDEX, entry); + write_aux_reg(ARC_REG_TLBCOMMAND, TLBWrite); + } + } + utlb_invalidate(); local_irq_restore(flags); @@ -580,6 +592,75 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long vaddr_unaligned, } } +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + +/* + * MMUv4 in HS38x cores supports Super Pages which are basis for Linux THP + * support. + * + * Normal and Super pages can co-exist (ofcourse not overlap) in TLB with a + * new bit "SZ" in TLB page desciptor to distinguish between them. + * Super Page size is configurable in hardware (4K to 16M), but fixed once + * RTL builds. + * + * The exact THP size a Linx configuration will support is a function of: + * - MMU page size (typical 8K, RTL fixed) + * - software page walker address split between PGD:PTE:PFN (typical + * 11:8:13, but can be changed with 1 line) + * So for above default, THP size supported is 8K * (2^8) = 2M + * + * Default Page Walker is 2 levels, PGD:PTE:PFN, which in THP regime + * reduces to 1 level (as PTE is folded into PGD and canonically referred + * to as PMD). + * Thus THP PMD accessors are implemented in terms of PTE (just like sparc) + */ + +void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr, + pmd_t *pmd) +{ + pte_t pte = __pte(pmd_val(*pmd)); + update_mmu_cache(vma, addr, &pte); +} + +void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, + pgtable_t pgtable) +{ + struct list_head *lh = (struct list_head *) pgtable; + + assert_spin_locked(&mm->page_table_lock); + + /* FIFO */ + if (!pmd_huge_pte(mm, pmdp)) + INIT_LIST_HEAD(lh); + else + list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp)); + pmd_huge_pte(mm, pmdp) = pgtable; +} + +pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) +{ + struct list_head *lh; + pgtable_t pgtable; + + assert_spin_locked(&mm->page_table_lock); + + pgtable = pmd_huge_pte(mm, pmdp); + lh = (struct list_head *) pgtable; + if (list_empty(lh)) + pmd_huge_pte(mm, pmdp) = NULL; + else { + pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next; + list_del(lh); + } + + pte_val(pgtable[0]) = 0; + pte_val(pgtable[1]) = 0; + + return pgtable; +} + +#endif + /* Read the Cache Build Confuration Registers, Decode them and save into * the cpuinfo structure for later use. * No Validation is done here, simply read/convert the BCRs diff --git a/arch/arc/mm/tlbex.S b/arch/arc/mm/tlbex.S index b8b014c6904d..552594897655 100644 --- a/arch/arc/mm/tlbex.S +++ b/arch/arc/mm/tlbex.S @@ -205,10 +205,18 @@ ex_saved_reg1: #endif lsr r0, r2, PGDIR_SHIFT ; Bits for indexing into PGD - ld.as r1, [r1, r0] ; PGD entry corresp to faulting addr - and.f r1, r1, PAGE_MASK ; Ignoring protection and other flags - ; contains Ptr to Page Table - bz.d do_slow_path_pf ; if no Page Table, do page fault + ld.as r3, [r1, r0] ; PGD entry corresp to faulting addr + tst r3, r3 + bz do_slow_path_pf ; if no Page Table, do page fault + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + and.f 0, r3, _PAGE_HW_SZ ; Is this Huge PMD (thp) + add2.nz r1, r1, r0 + bnz.d 2f ; YES: PGD == PMD has THP PTE: stop pgd walk + mov.nz r0, r3 + +#endif + and r1, r3, PAGE_MASK ; Get the PTE entry: The idea is ; (1) x = addr >> PAGE_SHIFT -> masks page-off bits from @fault-addr @@ -219,6 +227,9 @@ ex_saved_reg1: lsr r0, r2, (PAGE_SHIFT - 2) and r0, r0, ( (PTRS_PER_PTE - 1) << 2) ld.aw r0, [r1, r0] ; get PTE and PTE ptr for fault addr + +2: + #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT and.f 0, r0, _PAGE_PRESENT bz 1f |