On Tue, Aug 31, 2021 at 02:13:08PM +0200, Thomas Gleixner wrote: > On Tue, Aug 31 2021 at 04:13, Guenter Roeck wrote: > > > Hi, > > > > On Mon, Aug 09, 2021 at 10:12:15AM +0800, Xiaoming Ni wrote: > >> Semaphore is sleeping lock. Add might_sleep() to down*() family > >> (with exception of down_trylock()) to detect atomic context sleep. > >> > >> Previously discussed with Peter Zijlstra, see link: > >> https://lore.kernel.org/lkml/20210806082320.GD22037@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx > >> > >> Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx> > >> Acked-by: Will Deacon <will@xxxxxxxxxx> > > > > This patch results in the following traceback on all arm64 boots with > > EFI BIOS. > > That's what this change was supposed to catch :) > > > The problem is only seen with CONFIG_ACPI_PPTT=y, and thus only on arm64. > > The below should fix this. > > Thanks, > > tglx > --- > Subject: drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION() > From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Date: Tue, 31 Aug 2021 13:48:34 +0200 > > DEFINE_SMP_CALL_CACHE_FUNCTION() was usefel before the CPU hotplug rework > to ensure that the cache related functions are called on the upcoming CPU > because the notifier itself could run on any online CPU. > > The hotplug state machine guarantees that the callbacks are invoked on the > upcoming CPU. So there is no need to have this SMP function call > obfuscation. That indirection was missed when the hotplug notifiers were > converted. > > This also solves the problem of ARM64 init_cache_level() invoking ACPI > functions which take a semaphore in that context. That's invalid as SMP > function calls run with interrupts disabled. Running it just from the > callback in context of the CPU hotplug thread solves this. > > Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx> > Fixes: 8571890e1513 ("arm64: Add support for ACPI based firmware tables") > Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> The warning is no longer seen with this patch applied on top of v5.14-1100-gb91db6a0b52e, and I don't see any new problems on riscv, x86/x86_64, or mips. Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx> Thanks, Guenter > --- > arch/arm64/kernel/cacheinfo.c | 7 ++----- > arch/mips/kernel/cacheinfo.c | 7 ++----- > arch/riscv/kernel/cacheinfo.c | 7 ++----- > arch/x86/kernel/cpu/cacheinfo.c | 7 ++----- > include/linux/cacheinfo.h | 18 ------------------ > 5 files changed, 8 insertions(+), 38 deletions(-) > > --- a/arch/arm64/kernel/cacheinfo.c > +++ b/arch/arm64/kernel/cacheinfo.c > @@ -43,7 +43,7 @@ static void ci_leaf_init(struct cacheinf > this_leaf->type = type; > } > > -static int __init_cache_level(unsigned int cpu) > +int init_cache_level(unsigned int cpu) > { > unsigned int ctype, level, leaves, fw_level; > struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); > @@ -78,7 +78,7 @@ static int __init_cache_level(unsigned i > return 0; > } > > -static int __populate_cache_leaves(unsigned int cpu) > +int populate_cache_leaves(unsigned int cpu) > { > unsigned int level, idx; > enum cache_type type; > @@ -97,6 +97,3 @@ static int __populate_cache_leaves(unsig > } > return 0; > } > - > -DEFINE_SMP_CALL_CACHE_FUNCTION(init_cache_level) > -DEFINE_SMP_CALL_CACHE_FUNCTION(populate_cache_leaves) > --- a/arch/mips/kernel/cacheinfo.c > +++ b/arch/mips/kernel/cacheinfo.c > @@ -17,7 +17,7 @@ do { \ > leaf++; \ > } while (0) > > -static int __init_cache_level(unsigned int cpu) > +int init_cache_level(unsigned int cpu) > { > struct cpuinfo_mips *c = ¤t_cpu_data; > struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); > @@ -74,7 +74,7 @@ static void fill_cpumask_cluster(int cpu > cpumask_set_cpu(cpu1, cpu_map); > } > > -static int __populate_cache_leaves(unsigned int cpu) > +int populate_cache_leaves(unsigned int cpu) > { > struct cpuinfo_mips *c = ¤t_cpu_data; > struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); > @@ -114,6 +114,3 @@ static int __populate_cache_leaves(unsig > > return 0; > } > - > -DEFINE_SMP_CALL_CACHE_FUNCTION(init_cache_level) > -DEFINE_SMP_CALL_CACHE_FUNCTION(populate_cache_leaves) > --- a/arch/riscv/kernel/cacheinfo.c > +++ b/arch/riscv/kernel/cacheinfo.c > @@ -113,7 +113,7 @@ static void fill_cacheinfo(struct cachei > } > } > > -static int __init_cache_level(unsigned int cpu) > +int init_cache_level(unsigned int cpu) > { > struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); > struct device_node *np = of_cpu_device_node_get(cpu); > @@ -155,7 +155,7 @@ static int __init_cache_level(unsigned i > return 0; > } > > -static int __populate_cache_leaves(unsigned int cpu) > +int populate_cache_leaves(unsigned int cpu) > { > struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); > struct cacheinfo *this_leaf = this_cpu_ci->info_list; > @@ -187,6 +187,3 @@ static int __populate_cache_leaves(unsig > > return 0; > } > - > -DEFINE_SMP_CALL_CACHE_FUNCTION(init_cache_level) > -DEFINE_SMP_CALL_CACHE_FUNCTION(populate_cache_leaves) > --- a/arch/x86/kernel/cpu/cacheinfo.c > +++ b/arch/x86/kernel/cpu/cacheinfo.c > @@ -985,7 +985,7 @@ static void ci_leaf_init(struct cacheinf > this_leaf->priv = base->nb; > } > > -static int __init_cache_level(unsigned int cpu) > +int init_cache_level(unsigned int cpu) > { > struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); > > @@ -1014,7 +1014,7 @@ static void get_cache_id(int cpu, struct > id4_regs->id = c->apicid >> index_msb; > } > > -static int __populate_cache_leaves(unsigned int cpu) > +int populate_cache_leaves(unsigned int cpu) > { > unsigned int idx, ret; > struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); > @@ -1033,6 +1033,3 @@ static int __populate_cache_leaves(unsig > > return 0; > } > - > -DEFINE_SMP_CALL_CACHE_FUNCTION(init_cache_level) > -DEFINE_SMP_CALL_CACHE_FUNCTION(populate_cache_leaves) > --- a/include/linux/cacheinfo.h > +++ b/include/linux/cacheinfo.h > @@ -79,24 +79,6 @@ struct cpu_cacheinfo { > bool cpu_map_populated; > }; > > -/* > - * Helpers to make sure "func" is executed on the cpu whose cache > - * attributes are being detected > - */ > -#define DEFINE_SMP_CALL_CACHE_FUNCTION(func) \ > -static inline void _##func(void *ret) \ > -{ \ > - int cpu = smp_processor_id(); \ > - *(int *)ret = __##func(cpu); \ > -} \ > - \ > -int func(unsigned int cpu) \ > -{ \ > - int ret; \ > - smp_call_function_single(cpu, _##func, &ret, true); \ > - return ret; \ > -} > - > struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu); > int init_cache_level(unsigned int cpu); > int populate_cache_leaves(unsigned int cpu);
