From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: [PATCH 13/17] mips/tlb: Fix __p*_free_tlb() Date: Wed, 11 Dec 2019 13:07:26 +0100 Message-ID: <20191211122956.399804770@infradead.org> References: <20191211120713.360281197@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Sender: linux-kernel-owner@vger.kernel.org To: Will Deacon , "Aneesh Kumar K.V" , Andrew Morton , Nick Piggin , Peter Zijlstra Cc: linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Yoshinori Sato , Rich Felker , "David S. Miller" , Helge Deller , Geert Uytterhoeven , Paul Burton , Tony Luck , Richard Henderson , Nick Hu , Paul Walmsley , Paul Burton List-Id: linux-arch.vger.kernel.org Just like regular pages, page directories need to observe the following order: 1) unhook 2) TLB invalidate 3) free to ensure it is safe against concurrent accesses. MIPS has (thanks to Paul Burton for setting me straight): - HAVE_FAST_GUP, which means we need to consider software walkers (many MIPS also have software TLB-fill, which is a similar software walker). - non-page, page directories, which requires a custom table free. - Mostly IPI-based TLB invalidate, but it wouldn't be MIPS if it didn't also have broadcast TLB invalidate (I6500, GINVT). This means that in generic MIPS needs HAVE_RCU_TABLE_FREE. Cc: Paul Burton Signed-off-by: Peter Zijlstra (Intel) --- arch/mips/Kconfig | 1 + arch/mips/include/asm/pgalloc.h | 13 ++++++------- arch/mips/mm/pgtable.c | 34 ++++++++++++++++++++++++++++++++++ 3 files changed, 41 insertions(+), 7 deletions(-) --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -57,6 +57,7 @@ config MIPS select HAVE_DYNAMIC_FTRACE select HAVE_EXIT_THREAD select HAVE_FAST_GUP + select MMU_GATHER_RCU_TABLE_FREE select HAVE_FTRACE_MCOUNT_RECORD select HAVE_FUNCTION_GRAPH_TRACER select HAVE_FUNCTION_TRACER --- a/arch/mips/include/asm/pgalloc.h +++ b/arch/mips/include/asm/pgalloc.h @@ -41,6 +41,9 @@ static inline void pud_populate(struct m } #endif +extern void __tlb_remove_table(void *table); +extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int idx); + /* * Initialize a new pgd / pmd table with invalid pointers. */ @@ -52,11 +55,7 @@ static inline void pgd_free(struct mm_st free_pages((unsigned long)pgd, PGD_ORDER); } -#define __pte_free_tlb(tlb,pte,address) \ -do { \ - pgtable_pte_page_dtor(pte); \ - tlb_remove_page((tlb), pte); \ -} while (0) +#define __pte_free_tlb(tlb,pte,address) pgtable_free_tlb((tlb), (pte), 0) #ifndef __PAGETABLE_PMD_FOLDED @@ -75,7 +74,7 @@ static inline void pmd_free(struct mm_st free_pages((unsigned long)pmd, PMD_ORDER); } -#define __pmd_free_tlb(tlb, x, addr) pmd_free((tlb)->mm, x) +#define __pmd_free_tlb(tlb, x, addr) pgtable_free_tlb((tlb), (x), 1) #endif @@ -101,7 +100,7 @@ static inline void p4d_populate(struct m set_p4d(p4d, __p4d((unsigned long)pud)); } -#define __pud_free_tlb(tlb, x, addr) pud_free((tlb)->mm, x) +#define __pud_free_tlb(tlb, x, addr) pgtable_free_tlb((tlb), (x), 2) #endif /* __PAGETABLE_PUD_FOLDED */ --- a/arch/mips/mm/pgtable.c +++ b/arch/mips/mm/pgtable.c @@ -7,6 +7,7 @@ #include #include #include +#include pgd_t *pgd_alloc(struct mm_struct *mm) { @@ -23,3 +24,36 @@ pgd_t *pgd_alloc(struct mm_struct *mm) return ret; } EXPORT_SYMBOL_GPL(pgd_alloc); + +#define TLB_IDX_MASK 0x3 + +void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int idx) +{ + unsigned long pgf = (unsigned long)table; + BUG_ON(idx > TLB_IDX_MASK); + BUG_ON(pgf & TLB_IDX_MASK); + pgf |= idx; + tlb_remove_table(tlb, (void *)pgf); +} + +void __tlb_remove_table(void *table) +{ + void *dir = (void *)((unsigned long)table & ~TLB_IDX_MASK); + int idx = (unsigned long)table & TLB_IDX_MASK; + + switch (idx) { +#ifndef __PAGETABLE_PUD_FOLDED + case 2: /* PUD */ + pud_free(NULL, dir); + break; +#endif +#ifndef __PAGETABLE_PMD_FOLDED + case 1: /* PMD */ + pmd_free(NULL, dir); + break; +#endif + case 0: /* PTE */ + pte_free(NULL, dir); + break; + } +} From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([198.137.202.133]:51196 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729345AbfLKMbo (ORCPT ); Wed, 11 Dec 2019 07:31:44 -0500 Message-ID: <20191211122956.399804770@infradead.org> Date: Wed, 11 Dec 2019 13:07:26 +0100 From: Peter Zijlstra Subject: [PATCH 13/17] mips/tlb: Fix __p*_free_tlb() References: <20191211120713.360281197@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-arch-owner@vger.kernel.org List-ID: To: Will Deacon , "Aneesh Kumar K.V" , Andrew Morton , Nick Piggin , Peter Zijlstra Cc: linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Yoshinori Sato , Rich Felker , "David S. Miller" , Helge Deller , Geert Uytterhoeven , Paul Burton , Tony Luck , Richard Henderson , Nick Hu , Paul Walmsley , Paul Burton Message-ID: <20191211120726.WMNp0bxKwWSd43-KfNwYJ61qaAi_owkuYMXkZl1ZNMc@z> Just like regular pages, page directories need to observe the following order: 1) unhook 2) TLB invalidate 3) free to ensure it is safe against concurrent accesses. MIPS has (thanks to Paul Burton for setting me straight): - HAVE_FAST_GUP, which means we need to consider software walkers (many MIPS also have software TLB-fill, which is a similar software walker). - non-page, page directories, which requires a custom table free. - Mostly IPI-based TLB invalidate, but it wouldn't be MIPS if it didn't also have broadcast TLB invalidate (I6500, GINVT). This means that in generic MIPS needs HAVE_RCU_TABLE_FREE. Cc: Paul Burton Signed-off-by: Peter Zijlstra (Intel) --- arch/mips/Kconfig | 1 + arch/mips/include/asm/pgalloc.h | 13 ++++++------- arch/mips/mm/pgtable.c | 34 ++++++++++++++++++++++++++++++++++ 3 files changed, 41 insertions(+), 7 deletions(-) --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -57,6 +57,7 @@ config MIPS select HAVE_DYNAMIC_FTRACE select HAVE_EXIT_THREAD select HAVE_FAST_GUP + select MMU_GATHER_RCU_TABLE_FREE select HAVE_FTRACE_MCOUNT_RECORD select HAVE_FUNCTION_GRAPH_TRACER select HAVE_FUNCTION_TRACER --- a/arch/mips/include/asm/pgalloc.h +++ b/arch/mips/include/asm/pgalloc.h @@ -41,6 +41,9 @@ static inline void pud_populate(struct m } #endif +extern void __tlb_remove_table(void *table); +extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int idx); + /* * Initialize a new pgd / pmd table with invalid pointers. */ @@ -52,11 +55,7 @@ static inline void pgd_free(struct mm_st free_pages((unsigned long)pgd, PGD_ORDER); } -#define __pte_free_tlb(tlb,pte,address) \ -do { \ - pgtable_pte_page_dtor(pte); \ - tlb_remove_page((tlb), pte); \ -} while (0) +#define __pte_free_tlb(tlb,pte,address) pgtable_free_tlb((tlb), (pte), 0) #ifndef __PAGETABLE_PMD_FOLDED @@ -75,7 +74,7 @@ static inline void pmd_free(struct mm_st free_pages((unsigned long)pmd, PMD_ORDER); } -#define __pmd_free_tlb(tlb, x, addr) pmd_free((tlb)->mm, x) +#define __pmd_free_tlb(tlb, x, addr) pgtable_free_tlb((tlb), (x), 1) #endif @@ -101,7 +100,7 @@ static inline void p4d_populate(struct m set_p4d(p4d, __p4d((unsigned long)pud)); } -#define __pud_free_tlb(tlb, x, addr) pud_free((tlb)->mm, x) +#define __pud_free_tlb(tlb, x, addr) pgtable_free_tlb((tlb), (x), 2) #endif /* __PAGETABLE_PUD_FOLDED */ --- a/arch/mips/mm/pgtable.c +++ b/arch/mips/mm/pgtable.c @@ -7,6 +7,7 @@ #include #include #include +#include pgd_t *pgd_alloc(struct mm_struct *mm) { @@ -23,3 +24,36 @@ pgd_t *pgd_alloc(struct mm_struct *mm) return ret; } EXPORT_SYMBOL_GPL(pgd_alloc); + +#define TLB_IDX_MASK 0x3 + +void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int idx) +{ + unsigned long pgf = (unsigned long)table; + BUG_ON(idx > TLB_IDX_MASK); + BUG_ON(pgf & TLB_IDX_MASK); + pgf |= idx; + tlb_remove_table(tlb, (void *)pgf); +} + +void __tlb_remove_table(void *table) +{ + void *dir = (void *)((unsigned long)table & ~TLB_IDX_MASK); + int idx = (unsigned long)table & TLB_IDX_MASK; + + switch (idx) { +#ifndef __PAGETABLE_PUD_FOLDED + case 2: /* PUD */ + pud_free(NULL, dir); + break; +#endif +#ifndef __PAGETABLE_PMD_FOLDED + case 1: /* PMD */ + pmd_free(NULL, dir); + break; +#endif + case 0: /* PTE */ + pte_free(NULL, dir); + break; + } +}