From: Peter Zijlstra <peterz@infradead.org>
To: Will Deacon <will@kernel.org>,
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Nick Piggin <npiggin@gmail.com>,
Peter Zijlstra <peterz@infradead.org>
Cc: linux-arch@vger.kernel.org, linux-sh@vger.kernel.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Yoshinori Sato <ysato@users.sourceforge.jp>,
Rich Felker <dalias@libc.org>,
"David S. Miller" <davem@davemloft.net>,
Helge Deller <deller@gmx.de>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Paul Burton <paulburton@kernel.org>,
Tony Luck <tony.luck@intel.com>,
Richard Henderson <rth@twiddle.net>,
Nick Hu <nickhu@andestech.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
Christoph Hellwig <hch@lst.de>
Subject: [PATCH v2 06/11] mips/tlb: Fix __p*_free_tlb()
Date: Fri, 17 Jul 2020 11:10:11 +0000 [thread overview]
Message-ID: <20200717111349.708289813@infradead.org> (raw)
In-Reply-To: 20200717111005.024867618@infradead.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.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
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
@@ -84,6 +84,7 @@ config MIPS
select HAVE_VIRT_CPU_ACCOUNTING_GEN if 64BIT || !SMP
select IRQ_FORCED_THREADING
select ISA if EISA
+ select MMU_GATHER_RCU_TABLE_FREE
select MODULES_USE_ELF_REL if MODULES
select MODULES_USE_ELF_RELA if MODULES && 64BIT
select PERF_USE_VMALLOC
--- 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 <linux/mm.h>
#include <linux/string.h>
#include <asm/pgalloc.h>
+#include <asm-generic/tlb.h>
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;
+ }
+}
next prev parent reply other threads:[~2020-07-17 11:10 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-17 11:10 [PATCH v2 00/11] Fixup page directory freeing Peter Zijlstra
2020-07-17 11:10 ` [PATCH v2 01/11] asm-generic/tlb: Fix MMU_GATHER_TABLE_FREE Peter Zijlstra
2020-09-21 12:01 ` Will Deacon
2020-07-17 11:10 ` [PATCH v2 02/11] sh/tlb: Fix PGTABLE_LEVELS > 2 Peter Zijlstra
2020-07-17 11:10 ` [PATCH v2 03/11] sh/tlb: Fix __pmd_free_tlb() Peter Zijlstra
2020-07-17 11:10 ` [PATCH v2 04/11] sparc32/tlb: Fix __p*_free_tlb() Peter Zijlstra
2020-07-17 11:10 ` [PATCH v2 05/11] parisc/tlb: " Peter Zijlstra
2020-07-17 11:10 ` Peter Zijlstra [this message]
2020-07-17 11:10 ` [PATCH v2 07/11] ia64/tlb: " Peter Zijlstra
2020-07-17 11:10 ` [PATCH v2 08/11] alpha/tlb: " Peter Zijlstra
2020-07-17 11:10 ` [PATCH v2 09/11] nds32/tlb: " Peter Zijlstra
2020-07-17 11:10 ` [PATCH v2 10/11] riscv/tlb: " Peter Zijlstra
2020-07-17 11:10 ` [PATCH v2 11/11] m68k/tlb: " Peter Zijlstra
2020-07-17 11:22 ` [PATCH v2 00/11] Fixup page directory freeing Peter Zijlstra
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