| Message ID | 20241224123946.97486-1-cuiyunhui@bytedance.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] RISC-V: Enable cbo.clean/flush in usermode | expand |
On Tue, Dec 24, 2024 at 08:39:46PM +0800, Yunhui Cui wrote: > Enabling cbo.clean and cbo.flush in user mode makes it more > convenient to manage the cache state and achieve better performance. > > Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com> > --- > arch/riscv/kernel/cpufeature.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c > index c0916ed318c2..60d180b98f52 100644 > --- a/arch/riscv/kernel/cpufeature.c > +++ b/arch/riscv/kernel/cpufeature.c > @@ -30,6 +30,7 @@ > #define NUM_ALPHA_EXTS ('z' - 'a' + 1) > > static bool any_cpu_has_zicboz; > +static bool any_cpu_has_zicbom; > > unsigned long elf_hwcap __read_mostly; > > @@ -87,6 +88,8 @@ static int riscv_ext_zicbom_validate(const struct riscv_isa_ext_data *data, > pr_err("Zicbom disabled as cbom-block-size present, but is not a power-of-2\n"); > return -EINVAL; > } > + > + any_cpu_has_zicbom = true; > return 0; > } > > @@ -944,6 +947,11 @@ void __init riscv_user_isa_enable(void) > current->thread.envcfg |= ENVCFG_CBZE; > else if (any_cpu_has_zicboz) > pr_warn("Zicboz disabled as it is unavailable on some harts\n"); > + > + if (riscv_has_extension_unlikely(RISCV_ISA_EXT_ZICBOM)) > + current->thread.envcfg |= ENVCFG_CBCFE; > + else if (any_cpu_has_zicbom) > + pr_warn("Zicbom disabled as it is unavailable on some harts\n"); > } > > #ifdef CONFIG_RISCV_ALTERNATIVE > -- > 2.39.2 > This looks good, so Reviewed-by: Andrew Jones <ajones@ventanamicro.com> but, as a separate patch, we should also provide hwprobe support like zicboz has, i.e. add ZICBOM to the IMA ext0 key and add a key for the zicbom block size. And then, as another patch, add a test_zicbom() function to tools/testing/selftests/riscv/hwprobe/cbo.c. Thanks, drew
Hi drew, On Tue, Dec 24, 2024 at 10:11 PM Andrew Jones <ajones@ventanamicro.com> wrote: > > On Tue, Dec 24, 2024 at 08:39:46PM +0800, Yunhui Cui wrote: > > Enabling cbo.clean and cbo.flush in user mode makes it more > > convenient to manage the cache state and achieve better performance. > > > > Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com> > > --- > > arch/riscv/kernel/cpufeature.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c > > index c0916ed318c2..60d180b98f52 100644 > > --- a/arch/riscv/kernel/cpufeature.c > > +++ b/arch/riscv/kernel/cpufeature.c > > @@ -30,6 +30,7 @@ > > #define NUM_ALPHA_EXTS ('z' - 'a' + 1) > > > > static bool any_cpu_has_zicboz; > > +static bool any_cpu_has_zicbom; > > > > unsigned long elf_hwcap __read_mostly; > > > > @@ -87,6 +88,8 @@ static int riscv_ext_zicbom_validate(const struct riscv_isa_ext_data *data, > > pr_err("Zicbom disabled as cbom-block-size present, but is not a power-of-2\n"); > > return -EINVAL; > > } > > + > > + any_cpu_has_zicbom = true; > > return 0; > > } > > > > @@ -944,6 +947,11 @@ void __init riscv_user_isa_enable(void) > > current->thread.envcfg |= ENVCFG_CBZE; > > else if (any_cpu_has_zicboz) > > pr_warn("Zicboz disabled as it is unavailable on some harts\n"); > > + > > + if (riscv_has_extension_unlikely(RISCV_ISA_EXT_ZICBOM)) > > + current->thread.envcfg |= ENVCFG_CBCFE; > > + else if (any_cpu_has_zicbom) > > + pr_warn("Zicbom disabled as it is unavailable on some harts\n"); > > } > > > > #ifdef CONFIG_RISCV_ALTERNATIVE > > -- > > 2.39.2 > > > > This looks good, so > > Reviewed-by: Andrew Jones <ajones@ventanamicro.com> > > but, as a separate patch, we should also provide hwprobe support like > zicboz has, i.e. add ZICBOM to the IMA ext0 key and add a key for the > zicbom block size. And then, as another patch, add a test_zicbom() > function to tools/testing/selftests/riscv/hwprobe/cbo.c. > > Thanks, > drew Thank you for your review. Even though hwprobe doesn't export ZICBOM currently, user-mode workarounds can still be used. Alright, I'll send two patches next to support hwprobe's export of ZICBOM and improve the cbo.c in selftests/. Thanks, Yunhui
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index c0916ed318c2..60d180b98f52 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -30,6 +30,7 @@ #define NUM_ALPHA_EXTS ('z' - 'a' + 1) static bool any_cpu_has_zicboz; +static bool any_cpu_has_zicbom; unsigned long elf_hwcap __read_mostly; @@ -87,6 +88,8 @@ static int riscv_ext_zicbom_validate(const struct riscv_isa_ext_data *data, pr_err("Zicbom disabled as cbom-block-size present, but is not a power-of-2\n"); return -EINVAL; } + + any_cpu_has_zicbom = true; return 0; } @@ -944,6 +947,11 @@ void __init riscv_user_isa_enable(void) current->thread.envcfg |= ENVCFG_CBZE; else if (any_cpu_has_zicboz) pr_warn("Zicboz disabled as it is unavailable on some harts\n"); + + if (riscv_has_extension_unlikely(RISCV_ISA_EXT_ZICBOM)) + current->thread.envcfg |= ENVCFG_CBCFE; + else if (any_cpu_has_zicbom) + pr_warn("Zicbom disabled as it is unavailable on some harts\n"); } #ifdef CONFIG_RISCV_ALTERNATIVE
Enabling cbo.clean and cbo.flush in user mode makes it more convenient to manage the cache state and achieve better performance. Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com> --- arch/riscv/kernel/cpufeature.c | 8 ++++++++ 1 file changed, 8 insertions(+)