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-rw-r--r--include/asm-generic/Kbuild1
-rw-r--r--include/asm-generic/barrier.h19
-rw-r--r--include/asm-generic/rwonce.h90
-rw-r--r--include/asm-generic/tlb.h55
4 files changed, 132 insertions, 33 deletions
diff --git a/include/asm-generic/Kbuild b/include/asm-generic/Kbuild
index 44ec80e70518..74b0612601dd 100644
--- a/include/asm-generic/Kbuild
+++ b/include/asm-generic/Kbuild
@@ -45,6 +45,7 @@ mandatory-y += pci.h
mandatory-y += percpu.h
mandatory-y += pgalloc.h
mandatory-y += preempt.h
+mandatory-y += rwonce.h
mandatory-y += sections.h
mandatory-y += serial.h
mandatory-y += shmparam.h
diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h
index 2eacaf7d62f6..fec97dc34de7 100644
--- a/include/asm-generic/barrier.h
+++ b/include/asm-generic/barrier.h
@@ -13,7 +13,7 @@
#ifndef __ASSEMBLY__
-#include <linux/compiler.h>
+#include <asm/rwonce.h>
#ifndef nop
#define nop() asm volatile ("nop")
@@ -46,10 +46,6 @@
#define dma_wmb() wmb()
#endif
-#ifndef read_barrier_depends
-#define read_barrier_depends() do { } while (0)
-#endif
-
#ifndef __smp_mb
#define __smp_mb() mb()
#endif
@@ -62,10 +58,6 @@
#define __smp_wmb() wmb()
#endif
-#ifndef __smp_read_barrier_depends
-#define __smp_read_barrier_depends() read_barrier_depends()
-#endif
-
#ifdef CONFIG_SMP
#ifndef smp_mb
@@ -80,10 +72,6 @@
#define smp_wmb() __smp_wmb()
#endif
-#ifndef smp_read_barrier_depends
-#define smp_read_barrier_depends() __smp_read_barrier_depends()
-#endif
-
#else /* !CONFIG_SMP */
#ifndef smp_mb
@@ -98,10 +86,6 @@
#define smp_wmb() barrier()
#endif
-#ifndef smp_read_barrier_depends
-#define smp_read_barrier_depends() do { } while (0)
-#endif
-
#endif /* CONFIG_SMP */
#ifndef __smp_store_mb
@@ -196,7 +180,6 @@ do { \
#define virt_mb() __smp_mb()
#define virt_rmb() __smp_rmb()
#define virt_wmb() __smp_wmb()
-#define virt_read_barrier_depends() __smp_read_barrier_depends()
#define virt_store_mb(var, value) __smp_store_mb(var, value)
#define virt_mb__before_atomic() __smp_mb__before_atomic()
#define virt_mb__after_atomic() __smp_mb__after_atomic()
diff --git a/include/asm-generic/rwonce.h b/include/asm-generic/rwonce.h
new file mode 100644
index 000000000000..8d0a6280e982
--- /dev/null
+++ b/include/asm-generic/rwonce.h
@@ -0,0 +1,90 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Prevent the compiler from merging or refetching reads or writes. The
+ * compiler is also forbidden from reordering successive instances of
+ * READ_ONCE and WRITE_ONCE, but only when the compiler is aware of some
+ * particular ordering. One way to make the compiler aware of ordering is to
+ * put the two invocations of READ_ONCE or WRITE_ONCE in different C
+ * statements.
+ *
+ * These two macros will also work on aggregate data types like structs or
+ * unions.
+ *
+ * Their two major use cases are: (1) Mediating communication between
+ * process-level code and irq/NMI handlers, all running on the same CPU,
+ * and (2) Ensuring that the compiler does not fold, spindle, or otherwise
+ * mutilate accesses that either do not require ordering or that interact
+ * with an explicit memory barrier or atomic instruction that provides the
+ * required ordering.
+ */
+#ifndef __ASM_GENERIC_RWONCE_H
+#define __ASM_GENERIC_RWONCE_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/compiler_types.h>
+#include <linux/kasan-checks.h>
+#include <linux/kcsan-checks.h>
+
+/*
+ * Yes, this permits 64-bit accesses on 32-bit architectures. These will
+ * actually be atomic in some cases (namely Armv7 + LPAE), but for others we
+ * rely on the access being split into 2x32-bit accesses for a 32-bit quantity
+ * (e.g. a virtual address) and a strong prevailing wind.
+ */
+#define compiletime_assert_rwonce_type(t) \
+ compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \
+ "Unsupported access size for {READ,WRITE}_ONCE().")
+
+/*
+ * Use __READ_ONCE() instead of READ_ONCE() if you do not require any
+ * atomicity. Note that this may result in tears!
+ */
+#ifndef __READ_ONCE
+#define __READ_ONCE(x) (*(const volatile __unqual_scalar_typeof(x) *)&(x))
+#endif
+
+#define READ_ONCE(x) \
+({ \
+ compiletime_assert_rwonce_type(x); \
+ __READ_ONCE(x); \
+})
+
+#define __WRITE_ONCE(x, val) \
+do { \
+ *(volatile typeof(x) *)&(x) = (val); \
+} while (0)
+
+#define WRITE_ONCE(x, val) \
+do { \
+ compiletime_assert_rwonce_type(x); \
+ __WRITE_ONCE(x, val); \
+} while (0)
+
+static __no_sanitize_or_inline
+unsigned long __read_once_word_nocheck(const void *addr)
+{
+ return __READ_ONCE(*(unsigned long *)addr);
+}
+
+/*
+ * Use READ_ONCE_NOCHECK() instead of READ_ONCE() if you need to load a
+ * word from memory atomically but without telling KASAN/KCSAN. This is
+ * usually used by unwinding code when walking the stack of a running process.
+ */
+#define READ_ONCE_NOCHECK(x) \
+({ \
+ compiletime_assert(sizeof(x) == sizeof(unsigned long), \
+ "Unsupported access size for READ_ONCE_NOCHECK()."); \
+ (typeof(x))__read_once_word_nocheck(&(x)); \
+})
+
+static __no_kasan_or_inline
+unsigned long read_word_at_a_time(const void *addr)
+{
+ kasan_check_read(addr, 1);
+ return *(unsigned long *)addr;
+}
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_GENERIC_RWONCE_H */
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index 3f1649a8cf55..ef75ec86f865 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -512,6 +512,38 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
}
#endif
+/*
+ * tlb_flush_{pte|pmd|pud|p4d}_range() adjust the tlb->start and tlb->end,
+ * and set corresponding cleared_*.
+ */
+static inline void tlb_flush_pte_range(struct mmu_gather *tlb,
+ unsigned long address, unsigned long size)
+{
+ __tlb_adjust_range(tlb, address, size);
+ tlb->cleared_ptes = 1;
+}
+
+static inline void tlb_flush_pmd_range(struct mmu_gather *tlb,
+ unsigned long address, unsigned long size)
+{
+ __tlb_adjust_range(tlb, address, size);
+ tlb->cleared_pmds = 1;
+}
+
+static inline void tlb_flush_pud_range(struct mmu_gather *tlb,
+ unsigned long address, unsigned long size)
+{
+ __tlb_adjust_range(tlb, address, size);
+ tlb->cleared_puds = 1;
+}
+
+static inline void tlb_flush_p4d_range(struct mmu_gather *tlb,
+ unsigned long address, unsigned long size)
+{
+ __tlb_adjust_range(tlb, address, size);
+ tlb->cleared_p4ds = 1;
+}
+
#ifndef __tlb_remove_tlb_entry
#define __tlb_remove_tlb_entry(tlb, ptep, address) do { } while (0)
#endif
@@ -525,19 +557,17 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
*/
#define tlb_remove_tlb_entry(tlb, ptep, address) \
do { \
- __tlb_adjust_range(tlb, address, PAGE_SIZE); \
- tlb->cleared_ptes = 1; \
+ tlb_flush_pte_range(tlb, address, PAGE_SIZE); \
__tlb_remove_tlb_entry(tlb, ptep, address); \
} while (0)
#define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \
do { \
unsigned long _sz = huge_page_size(h); \
- __tlb_adjust_range(tlb, address, _sz); \
if (_sz == PMD_SIZE) \
- tlb->cleared_pmds = 1; \
+ tlb_flush_pmd_range(tlb, address, _sz); \
else if (_sz == PUD_SIZE) \
- tlb->cleared_puds = 1; \
+ tlb_flush_pud_range(tlb, address, _sz); \
__tlb_remove_tlb_entry(tlb, ptep, address); \
} while (0)
@@ -551,8 +581,7 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
#define tlb_remove_pmd_tlb_entry(tlb, pmdp, address) \
do { \
- __tlb_adjust_range(tlb, address, HPAGE_PMD_SIZE); \
- tlb->cleared_pmds = 1; \
+ tlb_flush_pmd_range(tlb, address, HPAGE_PMD_SIZE); \
__tlb_remove_pmd_tlb_entry(tlb, pmdp, address); \
} while (0)
@@ -566,8 +595,7 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
#define tlb_remove_pud_tlb_entry(tlb, pudp, address) \
do { \
- __tlb_adjust_range(tlb, address, HPAGE_PUD_SIZE); \
- tlb->cleared_puds = 1; \
+ tlb_flush_pud_range(tlb, address, HPAGE_PUD_SIZE); \
__tlb_remove_pud_tlb_entry(tlb, pudp, address); \
} while (0)
@@ -592,9 +620,8 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
#ifndef pte_free_tlb
#define pte_free_tlb(tlb, ptep, address) \
do { \
- __tlb_adjust_range(tlb, address, PAGE_SIZE); \
+ tlb_flush_pmd_range(tlb, address, PAGE_SIZE); \
tlb->freed_tables = 1; \
- tlb->cleared_pmds = 1; \
__pte_free_tlb(tlb, ptep, address); \
} while (0)
#endif
@@ -602,9 +629,8 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
#ifndef pmd_free_tlb
#define pmd_free_tlb(tlb, pmdp, address) \
do { \
- __tlb_adjust_range(tlb, address, PAGE_SIZE); \
+ tlb_flush_pud_range(tlb, address, PAGE_SIZE); \
tlb->freed_tables = 1; \
- tlb->cleared_puds = 1; \
__pmd_free_tlb(tlb, pmdp, address); \
} while (0)
#endif
@@ -612,9 +638,8 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
#ifndef pud_free_tlb
#define pud_free_tlb(tlb, pudp, address) \
do { \
- __tlb_adjust_range(tlb, address, PAGE_SIZE); \
+ tlb_flush_p4d_range(tlb, address, PAGE_SIZE); \
tlb->freed_tables = 1; \
- tlb->cleared_p4ds = 1; \
__pud_free_tlb(tlb, pudp, address); \
} while (0)
#endif
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-23 02:56:40 +0300