| Message ID | 20240327045035.368512-2-samuel.holland@sifive.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | riscv: ASID-related and UP-related TLB flush enhancements | expand |
Hi Samuel, On 27/03/2024 05:49, Samuel Holland wrote: > Instruction cache flush IPIs are sent only to CPUs in cpu_online_mask, > so they will not target a CPU until it calls set_cpu_online() earlier in > smp_callin(). As a result, if instruction memory is modified between the > CPU coming out of reset and that point, then its instruction cache may > contain stale data. Therefore, the instruction cache must be flushed > after the set_cpu_online() synchronization point. > > Fixes: 08f051eda33b ("RISC-V: Flush I$ when making a dirty page executable") > Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> > Signed-off-by: Samuel Holland <samuel.holland@sifive.com> > --- > > (no changes since v4) > > Changes in v4: > - New patch for v4 > > arch/riscv/kernel/smpboot.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c > index d41090fc3203..4b3c50da48ba 100644 > --- a/arch/riscv/kernel/smpboot.c > +++ b/arch/riscv/kernel/smpboot.c > @@ -26,7 +26,7 @@ > #include <linux/sched/task_stack.h> > #include <linux/sched/mm.h> > > -#include <asm/cpufeature.h> > +#include <asm/cacheflush.h> > #include <asm/cpu_ops.h> > #include <asm/irq.h> > #include <asm/mmu_context.h> > @@ -234,9 +234,10 @@ asmlinkage __visible void smp_callin(void) > riscv_user_isa_enable(); > > /* > - * Remote TLB flushes are ignored while the CPU is offline, so emit > - * a local TLB flush right now just in case. > + * Remote cache and TLB flushes are ignored while the CPU is offline, > + * so flush them both right now just in case. > */ > + local_flush_icache_all(); > local_flush_tlb_all(); > complete(&cpu_running); > /* This should go into -fixes, would you mind sending this patch on its own? I think it is easier for Palmer. Thanks, Alex
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index d41090fc3203..4b3c50da48ba 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -26,7 +26,7 @@ #include <linux/sched/task_stack.h> #include <linux/sched/mm.h> -#include <asm/cpufeature.h> +#include <asm/cacheflush.h> #include <asm/cpu_ops.h> #include <asm/irq.h> #include <asm/mmu_context.h> @@ -234,9 +234,10 @@ asmlinkage __visible void smp_callin(void) riscv_user_isa_enable(); /* - * Remote TLB flushes are ignored while the CPU is offline, so emit - * a local TLB flush right now just in case. + * Remote cache and TLB flushes are ignored while the CPU is offline, + * so flush them both right now just in case. */ + local_flush_icache_all(); local_flush_tlb_all(); complete(&cpu_running); /*
Instruction cache flush IPIs are sent only to CPUs in cpu_online_mask, so they will not target a CPU until it calls set_cpu_online() earlier in smp_callin(). As a result, if instruction memory is modified between the CPU coming out of reset and that point, then its instruction cache may contain stale data. Therefore, the instruction cache must be flushed after the set_cpu_online() synchronization point. Fixes: 08f051eda33b ("RISC-V: Flush I$ when making a dirty page executable") Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Samuel Holland <samuel.holland@sifive.com> --- (no changes since v4) Changes in v4: - New patch for v4 arch/riscv/kernel/smpboot.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)