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Diffstat (limited to 'arch/powerpc/include/asm/book3s/64/hash-64k.h')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/hash-64k.h | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/hash-64k.h b/arch/powerpc/include/asm/book3s/64/hash-64k.h new file mode 100644 index 000000000..338e62fbe --- /dev/null +++ b/arch/powerpc/include/asm/book3s/64/hash-64k.h @@ -0,0 +1,296 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_POWERPC_BOOK3S_64_HASH_64K_H +#define _ASM_POWERPC_BOOK3S_64_HASH_64K_H + +#define H_PTE_INDEX_SIZE 8 // size: 8B << 8 = 2KB, maps 2^8 x 64KB = 16MB +#define H_PMD_INDEX_SIZE 10 // size: 8B << 10 = 8KB, maps 2^10 x 16MB = 16GB +#define H_PUD_INDEX_SIZE 10 // size: 8B << 10 = 8KB, maps 2^10 x 16GB = 16TB +#define H_PGD_INDEX_SIZE 8 // size: 8B << 8 = 2KB, maps 2^8 x 16TB = 4PB + +/* + * If we store section details in page->flags we can't increase the MAX_PHYSMEM_BITS + * if we increase SECTIONS_WIDTH we will not store node details in page->flags and + * page_to_nid does a page->section->node lookup + * Hence only increase for VMEMMAP. Further depending on SPARSEMEM_EXTREME reduce + * memory requirements with large number of sections. + * 51 bits is the max physical real address on POWER9 + */ +#if defined(CONFIG_SPARSEMEM_VMEMMAP) && defined(CONFIG_SPARSEMEM_EXTREME) +#define H_MAX_PHYSMEM_BITS 51 +#else +#define H_MAX_PHYSMEM_BITS 46 +#endif + +/* + * Each context is 512TB size. SLB miss for first context/default context + * is handled in the hotpath. + */ +#define MAX_EA_BITS_PER_CONTEXT 49 +#define REGION_SHIFT MAX_EA_BITS_PER_CONTEXT + +/* + * We use one context for each MAP area. + */ +#define H_KERN_MAP_SIZE (1UL << MAX_EA_BITS_PER_CONTEXT) + +/* + * Define the address range of the kernel non-linear virtual area + * 2PB + */ +#define H_KERN_VIRT_START ASM_CONST(0xc008000000000000) + +/* + * 64k aligned address free up few of the lower bits of RPN for us + * We steal that here. For more deatils look at pte_pfn/pfn_pte() + */ +#define H_PAGE_COMBO _RPAGE_RPN0 /* this is a combo 4k page */ +#define H_PAGE_4K_PFN _RPAGE_RPN1 /* PFN is for a single 4k page */ +#define H_PAGE_BUSY _RPAGE_RSV1 /* software: PTE & hash are busy */ +#define H_PAGE_HASHPTE _RPAGE_RPN43 /* PTE has associated HPTE */ + +/* memory key bits. */ +#define H_PTE_PKEY_BIT4 _RPAGE_PKEY_BIT4 +#define H_PTE_PKEY_BIT3 _RPAGE_PKEY_BIT3 +#define H_PTE_PKEY_BIT2 _RPAGE_PKEY_BIT2 +#define H_PTE_PKEY_BIT1 _RPAGE_PKEY_BIT1 +#define H_PTE_PKEY_BIT0 _RPAGE_PKEY_BIT0 + +/* + * We need to differentiate between explicit huge page and THP huge + * page, since THP huge page also need to track real subpage details + */ +#define H_PAGE_THP_HUGE H_PAGE_4K_PFN + +/* PTE flags to conserve for HPTE identification */ +#define _PAGE_HPTEFLAGS (H_PAGE_BUSY | H_PAGE_HASHPTE | H_PAGE_COMBO) +/* + * We use a 2K PTE page fragment and another 2K for storing + * real_pte_t hash index + * 8 bytes per each pte entry and another 8 bytes for storing + * slot details. + */ +#define H_PTE_FRAG_SIZE_SHIFT (H_PTE_INDEX_SIZE + 3 + 1) +#define H_PTE_FRAG_NR (PAGE_SIZE >> H_PTE_FRAG_SIZE_SHIFT) + +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLB_PAGE) +#define H_PMD_FRAG_SIZE_SHIFT (H_PMD_INDEX_SIZE + 3 + 1) +#else +#define H_PMD_FRAG_SIZE_SHIFT (H_PMD_INDEX_SIZE + 3) +#endif +#define H_PMD_FRAG_NR (PAGE_SIZE >> H_PMD_FRAG_SIZE_SHIFT) + +#ifndef __ASSEMBLY__ +#include <asm/errno.h> + +/* + * With 64K pages on hash table, we have a special PTE format that + * uses a second "half" of the page table to encode sub-page information + * in order to deal with 64K made of 4K HW pages. Thus we override the + * generic accessors and iterators here + */ +#define __real_pte __real_pte +static inline real_pte_t __real_pte(pte_t pte, pte_t *ptep, int offset) +{ + real_pte_t rpte; + unsigned long *hidxp; + + rpte.pte = pte; + + /* + * Ensure that we do not read the hidx before we read the PTE. Because + * the writer side is expected to finish writing the hidx first followed + * by the PTE, by using smp_wmb(). pte_set_hash_slot() ensures that. + */ + smp_rmb(); + + hidxp = (unsigned long *)(ptep + offset); + rpte.hidx = *hidxp; + return rpte; +} + +/* + * shift the hidx representation by one-modulo-0xf; i.e hidx 0 is respresented + * as 1, 1 as 2,... , and 0xf as 0. This convention lets us represent a + * invalid hidx 0xf with a 0x0 bit value. PTEs are anyway zero'd when + * allocated. We dont have to zero them gain; thus save on the initialization. + */ +#define HIDX_UNSHIFT_BY_ONE(x) ((x + 0xfUL) & 0xfUL) /* shift backward by one */ +#define HIDX_SHIFT_BY_ONE(x) ((x + 0x1UL) & 0xfUL) /* shift forward by one */ +#define HIDX_BITS(x, index) (x << (index << 2)) +#define BITS_TO_HIDX(x, index) ((x >> (index << 2)) & 0xfUL) +#define INVALID_RPTE_HIDX 0x0UL + +static inline unsigned long __rpte_to_hidx(real_pte_t rpte, unsigned long index) +{ + return HIDX_UNSHIFT_BY_ONE(BITS_TO_HIDX(rpte.hidx, index)); +} + +/* + * Commit the hidx and return PTE bits that needs to be modified. The caller is + * expected to modify the PTE bits accordingly and commit the PTE to memory. + */ +static inline unsigned long pte_set_hidx(pte_t *ptep, real_pte_t rpte, + unsigned int subpg_index, + unsigned long hidx, int offset) +{ + unsigned long *hidxp = (unsigned long *)(ptep + offset); + + rpte.hidx &= ~HIDX_BITS(0xfUL, subpg_index); + *hidxp = rpte.hidx | HIDX_BITS(HIDX_SHIFT_BY_ONE(hidx), subpg_index); + + /* + * Anyone reading PTE must ensure hidx bits are read after reading the + * PTE by using the read-side barrier smp_rmb(). __real_pte() can be + * used for that. + */ + smp_wmb(); + + /* No PTE bits to be modified, return 0x0UL */ + return 0x0UL; +} + +#define __rpte_to_pte(r) ((r).pte) +extern bool __rpte_sub_valid(real_pte_t rpte, unsigned long index); +/* + * Trick: we set __end to va + 64k, which happens works for + * a 16M page as well as we want only one iteration + */ +#define pte_iterate_hashed_subpages(rpte, psize, vpn, index, shift) \ + do { \ + unsigned long __end = vpn + (1UL << (PAGE_SHIFT - VPN_SHIFT)); \ + unsigned __split = (psize == MMU_PAGE_4K || \ + psize == MMU_PAGE_64K_AP); \ + shift = mmu_psize_defs[psize].shift; \ + for (index = 0; vpn < __end; index++, \ + vpn += (1L << (shift - VPN_SHIFT))) { \ + if (!__split || __rpte_sub_valid(rpte, index)) + +#define pte_iterate_hashed_end() } } while(0) + +#define pte_pagesize_index(mm, addr, pte) \ + (((pte) & H_PAGE_COMBO)? MMU_PAGE_4K: MMU_PAGE_64K) + +extern int remap_pfn_range(struct vm_area_struct *, unsigned long addr, + unsigned long pfn, unsigned long size, pgprot_t); +static inline int hash__remap_4k_pfn(struct vm_area_struct *vma, unsigned long addr, + unsigned long pfn, pgprot_t prot) +{ + if (pfn > (PTE_RPN_MASK >> PAGE_SHIFT)) { + WARN(1, "remap_4k_pfn called with wrong pfn value\n"); + return -EINVAL; + } + return remap_pfn_range(vma, addr, pfn, PAGE_SIZE, + __pgprot(pgprot_val(prot) | H_PAGE_4K_PFN)); +} + +#define H_PTE_TABLE_SIZE PTE_FRAG_SIZE +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined (CONFIG_HUGETLB_PAGE) +#define H_PMD_TABLE_SIZE ((sizeof(pmd_t) << PMD_INDEX_SIZE) + \ + (sizeof(unsigned long) << PMD_INDEX_SIZE)) +#else +#define H_PMD_TABLE_SIZE (sizeof(pmd_t) << PMD_INDEX_SIZE) +#endif +#ifdef CONFIG_HUGETLB_PAGE +#define H_PUD_TABLE_SIZE ((sizeof(pud_t) << PUD_INDEX_SIZE) + \ + (sizeof(unsigned long) << PUD_INDEX_SIZE)) +#else +#define H_PUD_TABLE_SIZE (sizeof(pud_t) << PUD_INDEX_SIZE) +#endif +#define H_PGD_TABLE_SIZE (sizeof(pgd_t) << PGD_INDEX_SIZE) + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static inline char *get_hpte_slot_array(pmd_t *pmdp) +{ + /* + * The hpte hindex is stored in the pgtable whose address is in the + * second half of the PMD + * + * Order this load with the test for pmd_trans_huge in the caller + */ + smp_rmb(); + return *(char **)(pmdp + PTRS_PER_PMD); + + +} +/* + * The linux hugepage PMD now include the pmd entries followed by the address + * to the stashed pgtable_t. The stashed pgtable_t contains the hpte bits. + * [ 000 | 1 bit secondary | 3 bit hidx | 1 bit valid]. We use one byte per + * each HPTE entry. With 16MB hugepage and 64K HPTE we need 256 entries and + * with 4K HPTE we need 4096 entries. Both will fit in a 4K pgtable_t. + * + * The top three bits are intentionally left as zero. This memory location + * are also used as normal page PTE pointers. So if we have any pointers + * left around while we collapse a hugepage, we need to make sure + * _PAGE_PRESENT bit of that is zero when we look at them + */ +static inline unsigned int hpte_valid(unsigned char *hpte_slot_array, int index) +{ + return hpte_slot_array[index] & 0x1; +} + +static inline unsigned int hpte_hash_index(unsigned char *hpte_slot_array, + int index) +{ + return hpte_slot_array[index] >> 1; +} + +static inline void mark_hpte_slot_valid(unsigned char *hpte_slot_array, + unsigned int index, unsigned int hidx) +{ + hpte_slot_array[index] = (hidx << 1) | 0x1; +} + +/* + * + * For core kernel code by design pmd_trans_huge is never run on any hugetlbfs + * page. The hugetlbfs page table walking and mangling paths are totally + * separated form the core VM paths and they're differentiated by + * VM_HUGETLB being set on vm_flags well before any pmd_trans_huge could run. + * + * pmd_trans_huge() is defined as false at build time if + * CONFIG_TRANSPARENT_HUGEPAGE=n to optimize away code blocks at build + * time in such case. + * + * For ppc64 we need to differntiate from explicit hugepages from THP, because + * for THP we also track the subpage details at the pmd level. We don't do + * that for explicit huge pages. + * + */ +static inline int hash__pmd_trans_huge(pmd_t pmd) +{ + return !!((pmd_val(pmd) & (_PAGE_PTE | H_PAGE_THP_HUGE | _PAGE_DEVMAP)) == + (_PAGE_PTE | H_PAGE_THP_HUGE)); +} + +static inline int hash__pmd_same(pmd_t pmd_a, pmd_t pmd_b) +{ + return (((pmd_raw(pmd_a) ^ pmd_raw(pmd_b)) & ~cpu_to_be64(_PAGE_HPTEFLAGS)) == 0); +} + +static inline pmd_t hash__pmd_mkhuge(pmd_t pmd) +{ + return __pmd(pmd_val(pmd) | (_PAGE_PTE | H_PAGE_THP_HUGE)); +} + +extern unsigned long hash__pmd_hugepage_update(struct mm_struct *mm, + unsigned long addr, pmd_t *pmdp, + unsigned long clr, unsigned long set); +extern pmd_t hash__pmdp_collapse_flush(struct vm_area_struct *vma, + unsigned long address, pmd_t *pmdp); +extern void hash__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, + pgtable_t pgtable); +extern pgtable_t hash__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp); +extern pmd_t hash__pmdp_huge_get_and_clear(struct mm_struct *mm, + unsigned long addr, pmd_t *pmdp); +extern int hash__has_transparent_hugepage(void); +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +static inline pmd_t hash__pmd_mkdevmap(pmd_t pmd) +{ + return __pmd(pmd_val(pmd) | (_PAGE_PTE | H_PAGE_THP_HUGE | _PAGE_DEVMAP)); +} + +#endif /* __ASSEMBLY__ */ + +#endif /* _ASM_POWERPC_BOOK3S_64_HASH_64K_H */ |