| Message ID | 20201102113444.103536-3-nikos.nikoleris@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Add support for configuring the translation granule | expand |
On Mon, Nov 02, 2020 at 11:34:44AM +0000, Nikos Nikoleris wrote: > Now that we can change the translation granule at will, and since > arm64 implementations can support a subset of the architecturally > defined granules, we need to check and warn the user if the configured > granule is not supported. nit: it'd be better for this patch to come before the last patch. > > Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com> > --- > lib/arm64/asm/processor.h | 65 +++++++++++++++++++++++++++++++++++++++ > lib/arm/mmu.c | 3 ++ > 2 files changed, 68 insertions(+) > > diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h > index 02665b8..0eac928 100644 > --- a/lib/arm64/asm/processor.h > +++ b/lib/arm64/asm/processor.h > @@ -117,5 +117,70 @@ static inline u64 get_ctr(void) > > extern u32 dcache_line_size; > > +static inline unsigned long get_id_aa64mmfr0_el1(void) > +{ > + unsigned long mmfr0; > + asm volatile("mrs %0, id_aa64mmfr0_el1" : "=r" (mmfr0)); > + return mmfr0; > +} > + > +/* From arch/arm64/include/asm/cpufeature.h */ > +static inline unsigned int > +cpuid_feature_extract_unsigned_field_width(u64 features, int field, int width) > +{ > + return (u64)(features << (64 - width - field)) >> (64 - width); > +} > + > +#define ID_AA64MMFR0_TGRAN4_SHIFT 28 > +#define ID_AA64MMFR0_TGRAN64_SHIFT 24 > +#define ID_AA64MMFR0_TGRAN16_SHIFT 20 > +#define ID_AA64MMFR0_TGRAN4_SUPPORTED 0x0 > +#define ID_AA64MMFR0_TGRAN64_SUPPORTED 0x0 > +#define ID_AA64MMFR0_TGRAN16_SUPPORTED 0x1 > + > +static inline bool system_supports_64kb_granule(void) > +{ > + u64 mmfr0; > + u32 val; > + > + mmfr0 = get_id_aa64mmfr0_el1(); > + val = cpuid_feature_extract_unsigned_field_width( > + mmfr0, ID_AA64MMFR0_TGRAN4_SHIFT,4); > + > + return val == ID_AA64MMFR0_TGRAN64_SUPPORTED; > +} > + > +static inline bool system_supports_16kb_granule(void) > +{ > + u64 mmfr0; > + u32 val; > + > + mmfr0 = get_id_aa64mmfr0_el1(); > + val = cpuid_feature_extract_unsigned_field_width( > + mmfr0, ID_AA64MMFR0_TGRAN16_SHIFT, 4); > + > + return val == ID_AA64MMFR0_TGRAN16_SUPPORTED; > +} > + > +static inline bool system_supports_4kb_granule(void) > +{ > + u64 mmfr0; > + u32 val; > + > + mmfr0 = get_id_aa64mmfr0_el1(); > + val = cpuid_feature_extract_unsigned_field_width( > + mmfr0, ID_AA64MMFR0_TGRAN4_SHIFT, 4); > + > + return val == ID_AA64MMFR0_TGRAN4_SUPPORTED; > +} > + > +#if PAGE_SIZE == 65536 > +#define system_supports_configured_granule system_supports_64kb_granule > +#elif PAGE_SIZE == 16384 > +#define system_supports_configured_granule system_supports_16kb_granule > +#elif PAGE_SIZE == 4096 > +#define system_supports_configured_granule system_supports_4kb_granule > +#endif > + > #endif /* !__ASSEMBLY__ */ > #endif /* _ASMARM64_PROCESSOR_H_ */ > diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c > index 6d1c75b..51fa745 100644 > --- a/lib/arm/mmu.c > +++ b/lib/arm/mmu.c > @@ -163,6 +163,9 @@ void *setup_mmu(phys_addr_t phys_end) > > #ifdef __aarch64__ > init_alloc_vpage((void*)(4ul << 30)); > + > + assert_msg(system_supports_configured_granule(), > + "Unsupported translation granule %d\n", PAGE_SIZE); ^ needs '%ld' to compile > #endif > > mmu_idmap = alloc_page(); > -- > 2.17.1 > I don't think we need the three separate functions. How about just doing the following diff? Thanks, drew diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c index 540a1e842d5b..fef62f5a9866 100644 --- a/lib/arm/mmu.c +++ b/lib/arm/mmu.c @@ -160,6 +160,9 @@ void *setup_mmu(phys_addr_t phys_end) #ifdef __aarch64__ init_alloc_vpage((void*)(4ul << 30)); + + assert_msg(system_supports_granule(PAGE_SIZE), + "Unsupported translation granule: %ld\n", PAGE_SIZE); #endif mmu_idmap = alloc_page(); diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h index 02665b84cc7e..dc493d1686bc 100644 --- a/lib/arm64/asm/processor.h +++ b/lib/arm64/asm/processor.h @@ -117,5 +117,21 @@ static inline u64 get_ctr(void) extern u32 dcache_line_size; +static inline unsigned long get_id_aa64mmfr0_el1(void) +{ + unsigned long mmfr0; + asm volatile("mrs %0, id_aa64mmfr0_el1" : "=r" (mmfr0)); + return mmfr0; +} + +static inline bool system_supports_granule(size_t granule) +{ + u64 mmfr0 = get_id_aa64mmfr0_el1(); + + return ((granule == SZ_4K && ((mmfr0 >> 28) & 0xf) == 0) || + (granule == SZ_64K && ((mmfr0 >> 24) & 0xf) == 0) || + (granule == SZ_16K && ((mmfr0 >> 20) & 0xf) == 1)); +} + #endif /* !__ASSEMBLY__ */ #endif /* _ASMARM64_PROCESSOR_H_ */
Hi Drew, On 03/11/2020 10:02, Andrew Jones wrote: > On Mon, Nov 02, 2020 at 11:34:44AM +0000, Nikos Nikoleris wrote: >> Now that we can change the translation granule at will, and since >> arm64 implementations can support a subset of the architecturally >> defined granules, we need to check and warn the user if the configured >> granule is not supported. > > nit: it'd be better for this patch to come before the last patch. > Ack, I will re-order them. >> >> Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com> >> --- >> lib/arm64/asm/processor.h | 65 +++++++++++++++++++++++++++++++++++++++ >> lib/arm/mmu.c | 3 ++ >> 2 files changed, 68 insertions(+) >> >> diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h >> index 02665b8..0eac928 100644 >> --- a/lib/arm64/asm/processor.h >> +++ b/lib/arm64/asm/processor.h >> @@ -117,5 +117,70 @@ static inline u64 get_ctr(void) >> >> extern u32 dcache_line_size; >> >> +static inline unsigned long get_id_aa64mmfr0_el1(void) >> +{ >> + unsigned long mmfr0; >> + asm volatile("mrs %0, id_aa64mmfr0_el1" : "=r" (mmfr0)); >> + return mmfr0; >> +} >> + >> +/* From arch/arm64/include/asm/cpufeature.h */ >> +static inline unsigned int >> +cpuid_feature_extract_unsigned_field_width(u64 features, int field, int width) >> +{ >> + return (u64)(features << (64 - width - field)) >> (64 - width); >> +} >> + >> +#define ID_AA64MMFR0_TGRAN4_SHIFT 28 >> +#define ID_AA64MMFR0_TGRAN64_SHIFT 24 >> +#define ID_AA64MMFR0_TGRAN16_SHIFT 20 >> +#define ID_AA64MMFR0_TGRAN4_SUPPORTED 0x0 >> +#define ID_AA64MMFR0_TGRAN64_SUPPORTED 0x0 >> +#define ID_AA64MMFR0_TGRAN16_SUPPORTED 0x1 >> + >> +static inline bool system_supports_64kb_granule(void) >> +{ >> + u64 mmfr0; >> + u32 val; >> + >> + mmfr0 = get_id_aa64mmfr0_el1(); >> + val = cpuid_feature_extract_unsigned_field_width( >> + mmfr0, ID_AA64MMFR0_TGRAN4_SHIFT,4); >> + >> + return val == ID_AA64MMFR0_TGRAN64_SUPPORTED; >> +} >> + >> +static inline bool system_supports_16kb_granule(void) >> +{ >> + u64 mmfr0; >> + u32 val; >> + >> + mmfr0 = get_id_aa64mmfr0_el1(); >> + val = cpuid_feature_extract_unsigned_field_width( >> + mmfr0, ID_AA64MMFR0_TGRAN16_SHIFT, 4); >> + >> + return val == ID_AA64MMFR0_TGRAN16_SUPPORTED; >> +} >> + >> +static inline bool system_supports_4kb_granule(void) >> +{ >> + u64 mmfr0; >> + u32 val; >> + >> + mmfr0 = get_id_aa64mmfr0_el1(); >> + val = cpuid_feature_extract_unsigned_field_width( >> + mmfr0, ID_AA64MMFR0_TGRAN4_SHIFT, 4); >> + >> + return val == ID_AA64MMFR0_TGRAN4_SUPPORTED; >> +} >> + >> +#if PAGE_SIZE == 65536 >> +#define system_supports_configured_granule system_supports_64kb_granule >> +#elif PAGE_SIZE == 16384 >> +#define system_supports_configured_granule system_supports_16kb_granule >> +#elif PAGE_SIZE == 4096 >> +#define system_supports_configured_granule system_supports_4kb_granule >> +#endif >> + >> #endif /* !__ASSEMBLY__ */ >> #endif /* _ASMARM64_PROCESSOR_H_ */ >> diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c >> index 6d1c75b..51fa745 100644 >> --- a/lib/arm/mmu.c >> +++ b/lib/arm/mmu.c >> @@ -163,6 +163,9 @@ void *setup_mmu(phys_addr_t phys_end) >> >> #ifdef __aarch64__ >> init_alloc_vpage((void*)(4ul << 30)); >> + >> + assert_msg(system_supports_configured_granule(), >> + "Unsupported translation granule %d\n", PAGE_SIZE); > ^ > needs '%ld' to compile >> #endif >> >> mmu_idmap = alloc_page(); >> -- >> 2.17.1 >> > > I don't think we need the three separate functions. How about just > doing the following diff? > Makes sense, I was looking at how we do it in the kernel and got carried away. We don't need to do that much at compile time. Thanks for the review, I will included your suggestions in v3. Thanks, Nikos > Thanks, > drew > > > diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c > index 540a1e842d5b..fef62f5a9866 100644 > --- a/lib/arm/mmu.c > +++ b/lib/arm/mmu.c > @@ -160,6 +160,9 @@ void *setup_mmu(phys_addr_t phys_end) > > #ifdef __aarch64__ > init_alloc_vpage((void*)(4ul << 30)); > + > + assert_msg(system_supports_granule(PAGE_SIZE), > + "Unsupported translation granule: %ld\n", PAGE_SIZE); > #endif > > mmu_idmap = alloc_page(); > diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h > index 02665b84cc7e..dc493d1686bc 100644 > --- a/lib/arm64/asm/processor.h > +++ b/lib/arm64/asm/processor.h > @@ -117,5 +117,21 @@ static inline u64 get_ctr(void) > > extern u32 dcache_line_size; > > +static inline unsigned long get_id_aa64mmfr0_el1(void) > +{ > + unsigned long mmfr0; > + asm volatile("mrs %0, id_aa64mmfr0_el1" : "=r" (mmfr0)); > + return mmfr0; > +} > + > +static inline bool system_supports_granule(size_t granule) > +{ > + u64 mmfr0 = get_id_aa64mmfr0_el1(); > + > + return ((granule == SZ_4K && ((mmfr0 >> 28) & 0xf) == 0) || > + (granule == SZ_64K && ((mmfr0 >> 24) & 0xf) == 0) || > + (granule == SZ_16K && ((mmfr0 >> 20) & 0xf) == 1)); > +} > + > #endif /* !__ASSEMBLY__ */ > #endif /* _ASMARM64_PROCESSOR_H_ */ >
Hi, On 11/3/20 10:02 AM, Andrew Jones wrote: > On Mon, Nov 02, 2020 at 11:34:44AM +0000, Nikos Nikoleris wrote: >> Now that we can change the translation granule at will, and since >> arm64 implementations can support a subset of the architecturally >> defined granules, we need to check and warn the user if the configured >> granule is not supported. > nit: it'd be better for this patch to come before the last patch. > >> Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com> >> --- >> lib/arm64/asm/processor.h | 65 +++++++++++++++++++++++++++++++++++++++ >> lib/arm/mmu.c | 3 ++ >> 2 files changed, 68 insertions(+) >> >> diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h >> index 02665b8..0eac928 100644 >> --- a/lib/arm64/asm/processor.h >> +++ b/lib/arm64/asm/processor.h >> @@ -117,5 +117,70 @@ static inline u64 get_ctr(void) >> >> extern u32 dcache_line_size; >> >> +static inline unsigned long get_id_aa64mmfr0_el1(void) >> +{ >> + unsigned long mmfr0; >> + asm volatile("mrs %0, id_aa64mmfr0_el1" : "=r" (mmfr0)); >> + return mmfr0; >> +} >> + >> +/* From arch/arm64/include/asm/cpufeature.h */ >> +static inline unsigned int >> +cpuid_feature_extract_unsigned_field_width(u64 features, int field, int width) >> +{ >> + return (u64)(features << (64 - width - field)) >> (64 - width); >> +} >> + >> +#define ID_AA64MMFR0_TGRAN4_SHIFT 28 >> +#define ID_AA64MMFR0_TGRAN64_SHIFT 24 >> +#define ID_AA64MMFR0_TGRAN16_SHIFT 20 >> +#define ID_AA64MMFR0_TGRAN4_SUPPORTED 0x0 >> +#define ID_AA64MMFR0_TGRAN64_SUPPORTED 0x0 >> +#define ID_AA64MMFR0_TGRAN16_SUPPORTED 0x1 >> + >> +static inline bool system_supports_64kb_granule(void) >> +{ >> + u64 mmfr0; >> + u32 val; >> + >> + mmfr0 = get_id_aa64mmfr0_el1(); >> + val = cpuid_feature_extract_unsigned_field_width( >> + mmfr0, ID_AA64MMFR0_TGRAN4_SHIFT,4); >> + >> + return val == ID_AA64MMFR0_TGRAN64_SUPPORTED; >> +} >> + >> +static inline bool system_supports_16kb_granule(void) >> +{ >> + u64 mmfr0; >> + u32 val; >> + >> + mmfr0 = get_id_aa64mmfr0_el1(); >> + val = cpuid_feature_extract_unsigned_field_width( >> + mmfr0, ID_AA64MMFR0_TGRAN16_SHIFT, 4); >> + >> + return val == ID_AA64MMFR0_TGRAN16_SUPPORTED; >> +} >> + >> +static inline bool system_supports_4kb_granule(void) >> +{ >> + u64 mmfr0; >> + u32 val; >> + >> + mmfr0 = get_id_aa64mmfr0_el1(); >> + val = cpuid_feature_extract_unsigned_field_width( >> + mmfr0, ID_AA64MMFR0_TGRAN4_SHIFT, 4); >> + >> + return val == ID_AA64MMFR0_TGRAN4_SUPPORTED; >> +} >> + >> +#if PAGE_SIZE == 65536 >> +#define system_supports_configured_granule system_supports_64kb_granule >> +#elif PAGE_SIZE == 16384 >> +#define system_supports_configured_granule system_supports_16kb_granule >> +#elif PAGE_SIZE == 4096 >> +#define system_supports_configured_granule system_supports_4kb_granule >> +#endif >> + >> #endif /* !__ASSEMBLY__ */ >> #endif /* _ASMARM64_PROCESSOR_H_ */ >> diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c >> index 6d1c75b..51fa745 100644 >> --- a/lib/arm/mmu.c >> +++ b/lib/arm/mmu.c >> @@ -163,6 +163,9 @@ void *setup_mmu(phys_addr_t phys_end) >> >> #ifdef __aarch64__ >> init_alloc_vpage((void*)(4ul << 30)); >> + >> + assert_msg(system_supports_configured_granule(), >> + "Unsupported translation granule %d\n", PAGE_SIZE); > ^ > needs '%ld' to compile >> #endif >> >> mmu_idmap = alloc_page(); >> -- >> 2.17.1 >> > I don't think we need the three separate functions. How about just > doing the following diff? > > Thanks, > drew > > > diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c > index 540a1e842d5b..fef62f5a9866 100644 > --- a/lib/arm/mmu.c > +++ b/lib/arm/mmu.c > @@ -160,6 +160,9 @@ void *setup_mmu(phys_addr_t phys_end) > > #ifdef __aarch64__ > init_alloc_vpage((void*)(4ul << 30)); > + > + assert_msg(system_supports_granule(PAGE_SIZE), > + "Unsupported translation granule: %ld\n", PAGE_SIZE); > #endif > > mmu_idmap = alloc_page(); > diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h > index 02665b84cc7e..dc493d1686bc 100644 > --- a/lib/arm64/asm/processor.h > +++ b/lib/arm64/asm/processor.h > @@ -117,5 +117,21 @@ static inline u64 get_ctr(void) > > extern u32 dcache_line_size; > > +static inline unsigned long get_id_aa64mmfr0_el1(void) > +{ > + unsigned long mmfr0; > + asm volatile("mrs %0, id_aa64mmfr0_el1" : "=r" (mmfr0)); > + return mmfr0; I think we can safely use read_sysreg here, the other functions in this file do. > +} > + > +static inline bool system_supports_granule(size_t granule) > +{ > + u64 mmfr0 = get_id_aa64mmfr0_el1(); > + > + return ((granule == SZ_4K && ((mmfr0 >> 28) & 0xf) == 0) || > + (granule == SZ_64K && ((mmfr0 >> 24) & 0xf) == 0) || > + (granule == SZ_16K && ((mmfr0 >> 20) & 0xf) == 1)); > +} Or we can turn it into a switch statement and keep all the field defines. Either way looks good to me (funny how tgran16 stands out). Thanks, Alex
On Tue, Nov 03, 2020 at 05:03:15PM +0000, Alexandru Elisei wrote: > Hi, > > On 11/3/20 10:02 AM, Andrew Jones wrote: > > On Mon, Nov 02, 2020 at 11:34:44AM +0000, Nikos Nikoleris wrote: > >> Now that we can change the translation granule at will, and since > >> arm64 implementations can support a subset of the architecturally > >> defined granules, we need to check and warn the user if the configured > >> granule is not supported. > > nit: it'd be better for this patch to come before the last patch. > > > >> Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com> > >> --- > >> lib/arm64/asm/processor.h | 65 +++++++++++++++++++++++++++++++++++++++ > >> lib/arm/mmu.c | 3 ++ > >> 2 files changed, 68 insertions(+) > >> > >> diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h > >> index 02665b8..0eac928 100644 > >> --- a/lib/arm64/asm/processor.h > >> +++ b/lib/arm64/asm/processor.h > >> @@ -117,5 +117,70 @@ static inline u64 get_ctr(void) > >> > >> extern u32 dcache_line_size; > >> > >> +static inline unsigned long get_id_aa64mmfr0_el1(void) > >> +{ > >> + unsigned long mmfr0; > >> + asm volatile("mrs %0, id_aa64mmfr0_el1" : "=r" (mmfr0)); > >> + return mmfr0; > >> +} > >> + > >> +/* From arch/arm64/include/asm/cpufeature.h */ > >> +static inline unsigned int > >> +cpuid_feature_extract_unsigned_field_width(u64 features, int field, int width) > >> +{ > >> + return (u64)(features << (64 - width - field)) >> (64 - width); > >> +} > >> + > >> +#define ID_AA64MMFR0_TGRAN4_SHIFT 28 > >> +#define ID_AA64MMFR0_TGRAN64_SHIFT 24 > >> +#define ID_AA64MMFR0_TGRAN16_SHIFT 20 > >> +#define ID_AA64MMFR0_TGRAN4_SUPPORTED 0x0 > >> +#define ID_AA64MMFR0_TGRAN64_SUPPORTED 0x0 > >> +#define ID_AA64MMFR0_TGRAN16_SUPPORTED 0x1 > >> + > >> +static inline bool system_supports_64kb_granule(void) > >> +{ > >> + u64 mmfr0; > >> + u32 val; > >> + > >> + mmfr0 = get_id_aa64mmfr0_el1(); > >> + val = cpuid_feature_extract_unsigned_field_width( > >> + mmfr0, ID_AA64MMFR0_TGRAN4_SHIFT,4); > >> + > >> + return val == ID_AA64MMFR0_TGRAN64_SUPPORTED; > >> +} > >> + > >> +static inline bool system_supports_16kb_granule(void) > >> +{ > >> + u64 mmfr0; > >> + u32 val; > >> + > >> + mmfr0 = get_id_aa64mmfr0_el1(); > >> + val = cpuid_feature_extract_unsigned_field_width( > >> + mmfr0, ID_AA64MMFR0_TGRAN16_SHIFT, 4); > >> + > >> + return val == ID_AA64MMFR0_TGRAN16_SUPPORTED; > >> +} > >> + > >> +static inline bool system_supports_4kb_granule(void) > >> +{ > >> + u64 mmfr0; > >> + u32 val; > >> + > >> + mmfr0 = get_id_aa64mmfr0_el1(); > >> + val = cpuid_feature_extract_unsigned_field_width( > >> + mmfr0, ID_AA64MMFR0_TGRAN4_SHIFT, 4); > >> + > >> + return val == ID_AA64MMFR0_TGRAN4_SUPPORTED; > >> +} > >> + > >> +#if PAGE_SIZE == 65536 > >> +#define system_supports_configured_granule system_supports_64kb_granule > >> +#elif PAGE_SIZE == 16384 > >> +#define system_supports_configured_granule system_supports_16kb_granule > >> +#elif PAGE_SIZE == 4096 > >> +#define system_supports_configured_granule system_supports_4kb_granule > >> +#endif > >> + > >> #endif /* !__ASSEMBLY__ */ > >> #endif /* _ASMARM64_PROCESSOR_H_ */ > >> diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c > >> index 6d1c75b..51fa745 100644 > >> --- a/lib/arm/mmu.c > >> +++ b/lib/arm/mmu.c > >> @@ -163,6 +163,9 @@ void *setup_mmu(phys_addr_t phys_end) > >> > >> #ifdef __aarch64__ > >> init_alloc_vpage((void*)(4ul << 30)); > >> + > >> + assert_msg(system_supports_configured_granule(), > >> + "Unsupported translation granule %d\n", PAGE_SIZE); > > ^ > > needs '%ld' to compile > >> #endif > >> > >> mmu_idmap = alloc_page(); > >> -- > >> 2.17.1 > >> > > I don't think we need the three separate functions. How about just > > doing the following diff? > > > > Thanks, > > drew > > > > > > diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c > > index 540a1e842d5b..fef62f5a9866 100644 > > --- a/lib/arm/mmu.c > > +++ b/lib/arm/mmu.c > > @@ -160,6 +160,9 @@ void *setup_mmu(phys_addr_t phys_end) > > > > #ifdef __aarch64__ > > init_alloc_vpage((void*)(4ul << 30)); > > + > > + assert_msg(system_supports_granule(PAGE_SIZE), > > + "Unsupported translation granule: %ld\n", PAGE_SIZE); > > #endif > > > > mmu_idmap = alloc_page(); > > diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h > > index 02665b84cc7e..dc493d1686bc 100644 > > --- a/lib/arm64/asm/processor.h > > +++ b/lib/arm64/asm/processor.h > > @@ -117,5 +117,21 @@ static inline u64 get_ctr(void) > > > > extern u32 dcache_line_size; > > > > +static inline unsigned long get_id_aa64mmfr0_el1(void) > > +{ > > + unsigned long mmfr0; > > + asm volatile("mrs %0, id_aa64mmfr0_el1" : "=r" (mmfr0)); > > + return mmfr0; > > I think we can safely use read_sysreg here, the other functions in this file do. Agreed > > > +} > > + > > +static inline bool system_supports_granule(size_t granule) > > +{ > > + u64 mmfr0 = get_id_aa64mmfr0_el1(); > > + > > + return ((granule == SZ_4K && ((mmfr0 >> 28) & 0xf) == 0) || > > + (granule == SZ_64K && ((mmfr0 >> 24) & 0xf) == 0) || > > + (granule == SZ_16K && ((mmfr0 >> 20) & 0xf) == 1)); > > +} > > Or we can turn it into a switch statement and keep all the field defines. Either > way looks good to me (funny how tgran16 stands out). > Keeping the defines is probably a good idea. Whether the function uses a switch or an expression like above doesn't matter to me much. Keeping LOC down in the lib/ code is a goal of kvm-unit-tests, but so is readabilty. If the switch looks better, then let's go that way. Thanks, drew
On 03/11/2020 17:36, Andrew Jones wrote: > On Tue, Nov 03, 2020 at 05:03:15PM +0000, Alexandru Elisei wrote: >>> +} >>> + >>> +static inline bool system_supports_granule(size_t granule) >>> +{ >>> + u64 mmfr0 = get_id_aa64mmfr0_el1(); >>> + >>> + return ((granule == SZ_4K && ((mmfr0 >> 28) & 0xf) == 0) || >>> + (granule == SZ_64K && ((mmfr0 >> 24) & 0xf) == 0) || >>> + (granule == SZ_16K && ((mmfr0 >> 20) & 0xf) == 1)); >>> +} >> >> Or we can turn it into a switch statement and keep all the field defines. Either >> way looks good to me (funny how tgran16 stands out). >> > > Keeping the defines is probably a good idea. Whether the function uses > a switch or an expression like above doesn't matter to me much. Keeping > LOC down in the lib/ code is a goal of kvm-unit-tests, but so is > readabilty. If the switch looks better, then let's go that way. > I liked Drew's version in that it was very concise. The new version will be much longer. If you think it's more readable I'll use that instead. diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h index 02665b8..430ded3 100644 --- a/lib/arm64/asm/processor.h +++ b/lib/arm64/asm/processor.h @@ -117,5 +117,38 @@ static inline u64 get_ctr(void) extern u32 dcache_line_size; +static inline unsigned long get_id_aa64mmfr0_el1(void) +{ + return read_sysreg(id_aa64mmfr0_el1); +} + +#define ID_AA64MMFR0_TGRAN4_SHIFT 28 +#define ID_AA64MMFR0_TGRAN64_SHIFT 24 +#define ID_AA64MMFR0_TGRAN16_SHIFT 20 + +#define ID_AA64MMFR0_TGRAN4_SUPPORTED 0x0 +#define ID_AA64MMFR0_TGRAN64_SUPPORTED 0x0 +#define ID_AA64MMFR0_TGRAN16_SUPPORTED 0x1 + +static inline bool system_supports_granule(size_t granule) +{ + u32 shift; + u32 val; + u64 mmfr0 = get_id_aa64mmfr0_el1(); + if (granule == SZ_4K) { + shift = ID_AA64MMFR0_TGRAN4_SHIFT; + val = ID_AA64MMFR0_TGRAN4_SUPPORTED; + } else if (granule == SZ_16K) { + shift = ID_AA64MMFR0_TGRAN16_SHIFT; + val = ID_AA64MMFR0_TGRAN16_SUPPORTED; + } else { + assert(granule == SZ_64K); + shift = ID_AA64MMFR0_TGRAN64_SHIFT; + val = ID_AA64MMFR0_TGRAN64_SUPPORTED; + } + + return ((mmfr0 >> shift) & 0xf) == val; +} + #endif /* !__ASSEMBLY__ */ #endif /* _ASMARM64_PROCESSOR_H_ */ Thanks, Nikos > Thanks, > drew >
On Tue, Nov 03, 2020 at 06:14:53PM +0000, Nikos Nikoleris wrote: > On 03/11/2020 17:36, Andrew Jones wrote: > > On Tue, Nov 03, 2020 at 05:03:15PM +0000, Alexandru Elisei wrote: > > > > +} > > > > + > > > > +static inline bool system_supports_granule(size_t granule) > > > > +{ > > > > + u64 mmfr0 = get_id_aa64mmfr0_el1(); > > > > + > > > > + return ((granule == SZ_4K && ((mmfr0 >> 28) & 0xf) == 0) || > > > > + (granule == SZ_64K && ((mmfr0 >> 24) & 0xf) == 0) || > > > > + (granule == SZ_16K && ((mmfr0 >> 20) & 0xf) == 1)); > > > > +} > > > > > > Or we can turn it into a switch statement and keep all the field defines. Either > > > way looks good to me (funny how tgran16 stands out). > > > > > > > Keeping the defines is probably a good idea. Whether the function uses > > a switch or an expression like above doesn't matter to me much. Keeping > > LOC down in the lib/ code is a goal of kvm-unit-tests, but so is > > readabilty. If the switch looks better, then let's go that way. > > > > I liked Drew's version in that it was very concise. The new version will be > much longer. If you think it's more readable I'll use that instead. > > diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h > index 02665b8..430ded3 100644 > --- a/lib/arm64/asm/processor.h > +++ b/lib/arm64/asm/processor.h > @@ -117,5 +117,38 @@ static inline u64 get_ctr(void) > > extern u32 dcache_line_size; > > +static inline unsigned long get_id_aa64mmfr0_el1(void) > +{ > + return read_sysreg(id_aa64mmfr0_el1); > +} > + > +#define ID_AA64MMFR0_TGRAN4_SHIFT 28 > +#define ID_AA64MMFR0_TGRAN64_SHIFT 24 > +#define ID_AA64MMFR0_TGRAN16_SHIFT 20 > + > +#define ID_AA64MMFR0_TGRAN4_SUPPORTED 0x0 > +#define ID_AA64MMFR0_TGRAN64_SUPPORTED 0x0 > +#define ID_AA64MMFR0_TGRAN16_SUPPORTED 0x1 > + > +static inline bool system_supports_granule(size_t granule) > +{ > + u32 shift; > + u32 val; > + u64 mmfr0 = get_id_aa64mmfr0_el1(); > + if (granule == SZ_4K) { > + shift = ID_AA64MMFR0_TGRAN4_SHIFT; > + val = ID_AA64MMFR0_TGRAN4_SUPPORTED; > + } else if (granule == SZ_16K) { > + shift = ID_AA64MMFR0_TGRAN16_SHIFT; > + val = ID_AA64MMFR0_TGRAN16_SUPPORTED; > + } else { > + assert(granule == SZ_64K); > + shift = ID_AA64MMFR0_TGRAN64_SHIFT; > + val = ID_AA64MMFR0_TGRAN64_SUPPORTED; > + } > + > + return ((mmfr0 >> shift) & 0xf) == val; > +} > + > #endif /* !__ASSEMBLY__ */ > #endif /* _ASMARM64_PROCESSOR_H_ */ > I'm happy with it either way. Thanks, drew
diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h index 02665b8..0eac928 100644 --- a/lib/arm64/asm/processor.h +++ b/lib/arm64/asm/processor.h @@ -117,5 +117,70 @@ static inline u64 get_ctr(void) extern u32 dcache_line_size; +static inline unsigned long get_id_aa64mmfr0_el1(void) +{ + unsigned long mmfr0; + asm volatile("mrs %0, id_aa64mmfr0_el1" : "=r" (mmfr0)); + return mmfr0; +} + +/* From arch/arm64/include/asm/cpufeature.h */ +static inline unsigned int +cpuid_feature_extract_unsigned_field_width(u64 features, int field, int width) +{ + return (u64)(features << (64 - width - field)) >> (64 - width); +} + +#define ID_AA64MMFR0_TGRAN4_SHIFT 28 +#define ID_AA64MMFR0_TGRAN64_SHIFT 24 +#define ID_AA64MMFR0_TGRAN16_SHIFT 20 +#define ID_AA64MMFR0_TGRAN4_SUPPORTED 0x0 +#define ID_AA64MMFR0_TGRAN64_SUPPORTED 0x0 +#define ID_AA64MMFR0_TGRAN16_SUPPORTED 0x1 + +static inline bool system_supports_64kb_granule(void) +{ + u64 mmfr0; + u32 val; + + mmfr0 = get_id_aa64mmfr0_el1(); + val = cpuid_feature_extract_unsigned_field_width( + mmfr0, ID_AA64MMFR0_TGRAN4_SHIFT,4); + + return val == ID_AA64MMFR0_TGRAN64_SUPPORTED; +} + +static inline bool system_supports_16kb_granule(void) +{ + u64 mmfr0; + u32 val; + + mmfr0 = get_id_aa64mmfr0_el1(); + val = cpuid_feature_extract_unsigned_field_width( + mmfr0, ID_AA64MMFR0_TGRAN16_SHIFT, 4); + + return val == ID_AA64MMFR0_TGRAN16_SUPPORTED; +} + +static inline bool system_supports_4kb_granule(void) +{ + u64 mmfr0; + u32 val; + + mmfr0 = get_id_aa64mmfr0_el1(); + val = cpuid_feature_extract_unsigned_field_width( + mmfr0, ID_AA64MMFR0_TGRAN4_SHIFT, 4); + + return val == ID_AA64MMFR0_TGRAN4_SUPPORTED; +} + +#if PAGE_SIZE == 65536 +#define system_supports_configured_granule system_supports_64kb_granule +#elif PAGE_SIZE == 16384 +#define system_supports_configured_granule system_supports_16kb_granule +#elif PAGE_SIZE == 4096 +#define system_supports_configured_granule system_supports_4kb_granule +#endif + #endif /* !__ASSEMBLY__ */ #endif /* _ASMARM64_PROCESSOR_H_ */ diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c index 6d1c75b..51fa745 100644 --- a/lib/arm/mmu.c +++ b/lib/arm/mmu.c @@ -163,6 +163,9 @@ void *setup_mmu(phys_addr_t phys_end) #ifdef __aarch64__ init_alloc_vpage((void*)(4ul << 30)); + + assert_msg(system_supports_configured_granule(), + "Unsupported translation granule %d\n", PAGE_SIZE); #endif mmu_idmap = alloc_page();
Now that we can change the translation granule at will, and since arm64 implementations can support a subset of the architecturally defined granules, we need to check and warn the user if the configured granule is not supported. Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com> --- lib/arm64/asm/processor.h | 65 +++++++++++++++++++++++++++++++++++++++ lib/arm/mmu.c | 3 ++ 2 files changed, 68 insertions(+)