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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/s390/include/asm/tlb.h | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | arch/s390/include/asm/tlb.h | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h new file mode 100644 index 0000000000..383b1f9144 --- /dev/null +++ b/arch/s390/include/asm/tlb.h @@ -0,0 +1,137 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _S390_TLB_H +#define _S390_TLB_H + +/* + * TLB flushing on s390 is complicated. The following requirement + * from the principles of operation is the most arduous: + * + * "A valid table entry must not be changed while it is attached + * to any CPU and may be used for translation by that CPU except to + * (1) invalidate the entry by using INVALIDATE PAGE TABLE ENTRY, + * or INVALIDATE DAT TABLE ENTRY, (2) alter bits 56-63 of a page + * table entry, or (3) make a change by means of a COMPARE AND SWAP + * AND PURGE instruction that purges the TLB." + * + * The modification of a pte of an active mm struct therefore is + * a two step process: i) invalidate the pte, ii) store the new pte. + * This is true for the page protection bit as well. + * The only possible optimization is to flush at the beginning of + * a tlb_gather_mmu cycle if the mm_struct is currently not in use. + * + * Pages used for the page tables is a different story. FIXME: more + */ + +void __tlb_remove_table(void *_table); +static inline void tlb_flush(struct mmu_gather *tlb); +static inline bool __tlb_remove_page_size(struct mmu_gather *tlb, + struct encoded_page *page, + int page_size); + +#define tlb_flush tlb_flush +#define pte_free_tlb pte_free_tlb +#define pmd_free_tlb pmd_free_tlb +#define p4d_free_tlb p4d_free_tlb +#define pud_free_tlb pud_free_tlb + +#include <asm/tlbflush.h> +#include <asm-generic/tlb.h> + +/* + * Release the page cache reference for a pte removed by + * tlb_ptep_clear_flush. In both flush modes the tlb for a page cache page + * has already been freed, so just do free_page_and_swap_cache. + * + * s390 doesn't delay rmap removal, so there is nothing encoded in + * the page pointer. + */ +static inline bool __tlb_remove_page_size(struct mmu_gather *tlb, + struct encoded_page *page, + int page_size) +{ + free_page_and_swap_cache(encoded_page_ptr(page)); + return false; +} + +static inline void tlb_flush(struct mmu_gather *tlb) +{ + __tlb_flush_mm_lazy(tlb->mm); +} + +/* + * pte_free_tlb frees a pte table and clears the CRSTE for the + * page table from the tlb. + */ +static inline void pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, + unsigned long address) +{ + __tlb_adjust_range(tlb, address, PAGE_SIZE); + tlb->mm->context.flush_mm = 1; + tlb->freed_tables = 1; + tlb->cleared_pmds = 1; + /* + * page_table_free_rcu takes care of the allocation bit masks + * of the 2K table fragments in the 4K page table page, + * then calls tlb_remove_table. + */ + page_table_free_rcu(tlb, (unsigned long *) pte, address); +} + +/* + * pmd_free_tlb frees a pmd table and clears the CRSTE for the + * segment table entry from the tlb. + * If the mm uses a two level page table the single pmd is freed + * as the pgd. pmd_free_tlb checks the asce_limit against 2GB + * to avoid the double free of the pmd in this case. + */ +static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd, + unsigned long address) +{ + if (mm_pmd_folded(tlb->mm)) + return; + pagetable_pmd_dtor(virt_to_ptdesc(pmd)); + __tlb_adjust_range(tlb, address, PAGE_SIZE); + tlb->mm->context.flush_mm = 1; + tlb->freed_tables = 1; + tlb->cleared_puds = 1; + tlb_remove_ptdesc(tlb, pmd); +} + +/* + * p4d_free_tlb frees a pud table and clears the CRSTE for the + * region second table entry from the tlb. + * If the mm uses a four level page table the single p4d is freed + * as the pgd. p4d_free_tlb checks the asce_limit against 8PB + * to avoid the double free of the p4d in this case. + */ +static inline void p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d, + unsigned long address) +{ + if (mm_p4d_folded(tlb->mm)) + return; + __tlb_adjust_range(tlb, address, PAGE_SIZE); + tlb->mm->context.flush_mm = 1; + tlb->freed_tables = 1; + tlb_remove_table(tlb, p4d); +} + +/* + * pud_free_tlb frees a pud table and clears the CRSTE for the + * region third table entry from the tlb. + * If the mm uses a three level page table the single pud is freed + * as the pgd. pud_free_tlb checks the asce_limit against 4TB + * to avoid the double free of the pud in this case. + */ +static inline void pud_free_tlb(struct mmu_gather *tlb, pud_t *pud, + unsigned long address) +{ + if (mm_pud_folded(tlb->mm)) + return; + tlb->mm->context.flush_mm = 1; + tlb->freed_tables = 1; + tlb->cleared_p4ds = 1; + tlb_remove_table(tlb, pud); +} + + +#endif /* _S390_TLB_H */ |