| Message ID | 20240228065559.3434837-4-samuel.holland@sifive.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 05ab803d1ad8ac505ade77c6bd3f86b1b4ea0dc4 |
| Headers | show |
| Series | riscv: cbo.zero fixes | expand |
On Tue, Feb 27, 2024 at 10:55:35PM -0800, Samuel Holland wrote: > The value of the [ms]envcfg CSR is lost when entering a nonretentive > idle state, so the CSR must be rewritten when resuming the CPU. > > Cc: <stable@vger.kernel.org> # v6.7+ > Fixes: 43c16d51a19b ("RISC-V: Enable cbo.zero in usermode") > Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Cheers, Conor.
On Tue, Feb 27, 2024 at 10:55:35PM -0800, Samuel Holland wrote: > The value of the [ms]envcfg CSR is lost when entering a nonretentive > idle state, so the CSR must be rewritten when resuming the CPU. > > Cc: <stable@vger.kernel.org> # v6.7+ > Fixes: 43c16d51a19b ("RISC-V: Enable cbo.zero in usermode") > Signed-off-by: Samuel Holland <samuel.holland@sifive.com> > --- > > Changes in v4: > - Check for Xlinuxenvcfg instead of Zicboz > > Changes in v3: > - Check for Zicboz instead of the privileged ISA version > > Changes in v2: > - Check for privileged ISA v1.12 instead of the specific CSR > - Use riscv_has_extension_likely() instead of new ALTERNATIVE()s > > arch/riscv/include/asm/suspend.h | 1 + > arch/riscv/kernel/suspend.c | 4 ++++ > 2 files changed, 5 insertions(+) > > diff --git a/arch/riscv/include/asm/suspend.h b/arch/riscv/include/asm/suspend.h > index 02f87867389a..491296a335d0 100644 > --- a/arch/riscv/include/asm/suspend.h > +++ b/arch/riscv/include/asm/suspend.h > @@ -14,6 +14,7 @@ struct suspend_context { > struct pt_regs regs; > /* Saved and restored by high-level functions */ > unsigned long scratch; > + unsigned long envcfg; > unsigned long tvec; > unsigned long ie; > #ifdef CONFIG_MMU > diff --git a/arch/riscv/kernel/suspend.c b/arch/riscv/kernel/suspend.c > index 239509367e42..299795341e8a 100644 > --- a/arch/riscv/kernel/suspend.c > +++ b/arch/riscv/kernel/suspend.c > @@ -15,6 +15,8 @@ > void suspend_save_csrs(struct suspend_context *context) > { > context->scratch = csr_read(CSR_SCRATCH); > + if (riscv_cpu_has_extension_unlikely(smp_processor_id(), RISCV_ISA_EXT_XLINUXENVCFG)) > + context->envcfg = csr_read(CSR_ENVCFG); > context->tvec = csr_read(CSR_TVEC); > context->ie = csr_read(CSR_IE); > > @@ -36,6 +38,8 @@ void suspend_save_csrs(struct suspend_context *context) > void suspend_restore_csrs(struct suspend_context *context) > { > csr_write(CSR_SCRATCH, context->scratch); > + if (riscv_cpu_has_extension_unlikely(smp_processor_id(), RISCV_ISA_EXT_XLINUXENVCFG)) > + csr_write(CSR_ENVCFG, context->envcfg); > csr_write(CSR_TVEC, context->tvec); > csr_write(CSR_IE, context->ie); > > -- > 2.43.1 > Picking _likely vs. _unlikely sometimes feels like flipping a coin, but we'll presumably be increasing the likelihood of xlinuxenvcfg being present as we add more and more envcfg using extensions, so maybe we should use _likely here now, lest we forget to change it someday. But, either way, Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Thanks, drew
diff --git a/arch/riscv/include/asm/suspend.h b/arch/riscv/include/asm/suspend.h index 02f87867389a..491296a335d0 100644 --- a/arch/riscv/include/asm/suspend.h +++ b/arch/riscv/include/asm/suspend.h @@ -14,6 +14,7 @@ struct suspend_context { struct pt_regs regs; /* Saved and restored by high-level functions */ unsigned long scratch; + unsigned long envcfg; unsigned long tvec; unsigned long ie; #ifdef CONFIG_MMU diff --git a/arch/riscv/kernel/suspend.c b/arch/riscv/kernel/suspend.c index 239509367e42..299795341e8a 100644 --- a/arch/riscv/kernel/suspend.c +++ b/arch/riscv/kernel/suspend.c @@ -15,6 +15,8 @@ void suspend_save_csrs(struct suspend_context *context) { context->scratch = csr_read(CSR_SCRATCH); + if (riscv_cpu_has_extension_unlikely(smp_processor_id(), RISCV_ISA_EXT_XLINUXENVCFG)) + context->envcfg = csr_read(CSR_ENVCFG); context->tvec = csr_read(CSR_TVEC); context->ie = csr_read(CSR_IE); @@ -36,6 +38,8 @@ void suspend_save_csrs(struct suspend_context *context) void suspend_restore_csrs(struct suspend_context *context) { csr_write(CSR_SCRATCH, context->scratch); + if (riscv_cpu_has_extension_unlikely(smp_processor_id(), RISCV_ISA_EXT_XLINUXENVCFG)) + csr_write(CSR_ENVCFG, context->envcfg); csr_write(CSR_TVEC, context->tvec); csr_write(CSR_IE, context->ie);
The value of the [ms]envcfg CSR is lost when entering a nonretentive idle state, so the CSR must be rewritten when resuming the CPU. Cc: <stable@vger.kernel.org> # v6.7+ Fixes: 43c16d51a19b ("RISC-V: Enable cbo.zero in usermode") Signed-off-by: Samuel Holland <samuel.holland@sifive.com> --- Changes in v4: - Check for Xlinuxenvcfg instead of Zicboz Changes in v3: - Check for Zicboz instead of the privileged ISA version Changes in v2: - Check for privileged ISA v1.12 instead of the specific CSR - Use riscv_has_extension_likely() instead of new ALTERNATIVE()s arch/riscv/include/asm/suspend.h | 1 + arch/riscv/kernel/suspend.c | 4 ++++ 2 files changed, 5 insertions(+)