From: Sergey Matyukevich <sergey.matyukevich@xxxxxxxxxxxxx>
commit e921050022f1f12d5029d1487a7dfc46cde15523 upstream.
This reverts the remaining bits of commit 4bd1d80efb5a ("riscv: mm:
notify remote harts harts about mmu cache updates").
According to bug reports, suggested approach to fix stale TLB entries
is not sufficient. It needs to be replaced by a more robust solution.
Fixes: 4bd1d80efb5a ("riscv: mm: notify remote harts about mmu cache updates")
Reported-by: Zong Li <zong.li@xxxxxxxxxx>
Reported-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
Signed-off-by: Sergey Matyukevich <sergey.matyukevich@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Guo Ren <guoren@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230226150137.1919750-2-geomatsi@xxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/riscv/include/asm/mmu.h | 2 --
arch/riscv/include/asm/tlbflush.h | 18 ------------------
arch/riscv/mm/context.c | 10 ----------
arch/riscv/mm/tlbflush.c | 28 +++++++++++++++++-----------
4 files changed, 17 insertions(+), 41 deletions(-)
--- a/arch/riscv/include/asm/mmu.h
+++ b/arch/riscv/include/asm/mmu.h
@@ -19,8 +19,6 @@ typedef struct {
#ifdef CONFIG_SMP
/* A local icache flush is needed before user execution can resume. */
cpumask_t icache_stale_mask;
- /* A local tlb flush is needed before user execution can resume. */
- cpumask_t tlb_stale_mask;
#endif
} mm_context_t;
--- a/arch/riscv/include/asm/tlbflush.h
+++ b/arch/riscv/include/asm/tlbflush.h
@@ -22,24 +22,6 @@ static inline void local_flush_tlb_page(
{
ALT_FLUSH_TLB_PAGE(__asm__ __volatile__ ("sfence.vma %0" : : "r" (addr) : "memory"));
}
-
-static inline void local_flush_tlb_all_asid(unsigned long asid)
-{
- __asm__ __volatile__ ("sfence.vma x0, %0"
- :
- : "r" (asid)
- : "memory");
-}
-
-static inline void local_flush_tlb_page_asid(unsigned long addr,
- unsigned long asid)
-{
- __asm__ __volatile__ ("sfence.vma %0, %1"
- :
- : "r" (addr), "r" (asid)
- : "memory");
-}
-
#else /* CONFIG_MMU */
#define local_flush_tlb_all() do { } while (0)
#define local_flush_tlb_page(addr) do { } while (0)
--- a/arch/riscv/mm/context.c
+++ b/arch/riscv/mm/context.c
@@ -196,16 +196,6 @@ switch_mm_fast:
if (need_flush_tlb)
local_flush_tlb_all();
-#ifdef CONFIG_SMP
- else {
- cpumask_t *mask = &mm->context.tlb_stale_mask;
-
- if (cpumask_test_cpu(cpu, mask)) {
- cpumask_clear_cpu(cpu, mask);
- local_flush_tlb_all_asid(cntx & asid_mask);
- }
- }
-#endif
}
static void set_mm_noasid(struct mm_struct *mm)
--- a/arch/riscv/mm/tlbflush.c
+++ b/arch/riscv/mm/tlbflush.c
@@ -5,7 +5,23 @@
#include <linux/sched.h>
#include <asm/sbi.h>
#include <asm/mmu_context.h>
-#include <asm/tlbflush.h>
+
+static inline void local_flush_tlb_all_asid(unsigned long asid)
+{
+ __asm__ __volatile__ ("sfence.vma x0, %0"
+ :
+ : "r" (asid)
+ : "memory");
+}
+
+static inline void local_flush_tlb_page_asid(unsigned long addr,
+ unsigned long asid)
+{
+ __asm__ __volatile__ ("sfence.vma %0, %1"
+ :
+ : "r" (addr), "r" (asid)
+ : "memory");
+}
void flush_tlb_all(void)
{
@@ -15,7 +31,6 @@ void flush_tlb_all(void)
static void __sbi_tlb_flush_range(struct mm_struct *mm, unsigned long start,
unsigned long size, unsigned long stride)
{
- struct cpumask *pmask = &mm->context.tlb_stale_mask;
struct cpumask *cmask = mm_cpumask(mm);
unsigned int cpuid;
bool broadcast;
@@ -29,15 +44,6 @@ static void __sbi_tlb_flush_range(struct
if (static_branch_unlikely(&use_asid_allocator)) {
unsigned long asid = atomic_long_read(&mm->context.id);
- /*
- * TLB will be immediately flushed on harts concurrently
- * executing this MM context. TLB flush on other harts
- * is deferred until this MM context migrates there.
- */
- cpumask_setall(pmask);
- cpumask_clear_cpu(cpuid, pmask);
- cpumask_andnot(pmask, pmask, cmask);
-
if (broadcast) {
sbi_remote_sfence_vma_asid(cmask, start, size, asid);
} else if (size <= stride) {
