Messages in this thread | | | Date | Thu, 13 Apr 2023 10:49:52 +0100 | From | Sudeep Holla <> | Subject | Re: [PATCH v3 4/4] cacheinfo: Add use_arch[|_cache]_info field/function |
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On Thu, Apr 13, 2023 at 11:14:34AM +0200, Pierre Gondois wrote: > The cache information can be extracted from either a Device > Tree (DT), the PPTT ACPI table, or arch registers (clidr_el1 > for arm64). > > The clidr_el1 register is used only if DT/ACPI information is not > available. It does not states how caches are shared among CPUs. > > Add a use_arch_cache_info field/function to identify when the > DT/ACPI doesn't provide cache information. Use this information > to assume L1 caches are privates and L2 and higher are shared among > all CPUs. >
I have tentatively merged first 3 patches along with Radu's series(waiting for build tests still before confirming). I am not yet sure on this.
> Signed-off-by: Pierre Gondois <pierre.gondois@arm.com> > --- > drivers/base/cacheinfo.c | 13 ++++++++++++- > include/linux/cacheinfo.h | 10 ++++++++++ > 2 files changed, 22 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c > index 06de9a468958..49dbb4357911 100644 > --- a/drivers/base/cacheinfo.c > +++ b/drivers/base/cacheinfo.c > @@ -40,7 +40,8 @@ static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf, > * For non DT/ACPI systems, assume unique level 1 caches, > * system-wide shared caches for all other levels. > */ > - if (!(IS_ENABLED(CONFIG_OF) || IS_ENABLED(CONFIG_ACPI))) > + if (!(IS_ENABLED(CONFIG_OF) || IS_ENABLED(CONFIG_ACPI)) || > + this_leaf->use_arch_info)
Can't we just use use_arch_cache_info() here ?
> return (this_leaf->level != 1) && (sib_leaf->level != 1); > > if ((sib_leaf->attributes & CACHE_ID) && > @@ -349,6 +350,7 @@ static int cache_shared_cpu_map_setup(unsigned int cpu) > struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); > struct cacheinfo *this_leaf, *sib_leaf; > unsigned int index, sib_index; > + bool use_arch_info = false; > int ret = 0; > > if (this_cpu_ci->cpu_map_populated) > @@ -361,6 +363,12 @@ static int cache_shared_cpu_map_setup(unsigned int cpu) > */ > if (!last_level_cache_is_valid(cpu)) { > ret = cache_setup_properties(cpu); > + if (ret && use_arch_cache_info()) { > + // Possibility to rely on arch specific information. > + use_arch_info = true; > + ret = 0; > + } > + > if (ret) > return ret; > } > @@ -370,6 +378,9 @@ static int cache_shared_cpu_map_setup(unsigned int cpu) > > this_leaf = per_cpu_cacheinfo_idx(cpu, index); > > + if (use_arch_info) > + this_leaf->use_arch_info = true; > + > cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map); > for_each_online_cpu(i) { > struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i); > diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h > index 908e19d17f49..fed675b251a2 100644 > --- a/include/linux/cacheinfo.h > +++ b/include/linux/cacheinfo.h > @@ -66,6 +66,7 @@ struct cacheinfo { > #define CACHE_ALLOCATE_POLICY_MASK \ > (CACHE_READ_ALLOCATE | CACHE_WRITE_ALLOCATE) > #define CACHE_ID BIT(4) > + bool use_arch_info;
Do you see the need to stash this value as it is either globally true or false based on the arch ?
> void *fw_token; > bool disable_sysfs; > void *priv; > @@ -129,4 +130,13 @@ static inline int get_cpu_cacheinfo_id(int cpu, int level) > return -1; > } > > +static inline bool use_arch_cache_info(void) > +{ > +#if defined(CONFIG_ARM64) > + return true; > +#else > + return false; > +#endif > +} > +
Can we just have it as: #ifdef CONFIG_ARM64 #define use_arch_cache_info() (true) #else #define use_arch_cache_info() (false) #endif
> #endif /* _LINUX_CACHEINFO_H */ > -- > 2.25.1 >
-- Regards, Sudeep
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