[PATCH] arm64/panic: Unify all three existing notifier blocks

Anshuman Khandual
2020-06-16T03:10:43Z

Currently there are three different registered panic notifier blocks. This
unifies all of them into a single one i.e arm64_panic_block, hence reducing
code duplication and required calling sequence during panic. This preserves
the existing dump sequence.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
Applies on 5.8-rc1.

arch/arm64/include/asm/cpufeature.h | 1 +
arch/arm64/include/asm/memory.h | 1 +
arch/arm64/kernel/cpufeature.c | 15 +--------------
arch/arm64/kernel/setup.c | 24 ++++++++++++++----------
arch/arm64/mm/init.c | 18 +-----------------
5 files changed, 18 insertions(+), 41 deletions(-)

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 5d1f4ae42799..e375529ca9fc 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -774,6 +774,7 @@ static inline unsigned int get_vmid_bits(u64 mmfr1)
}

u32 get_kvm_ipa_limit(void);
+void dump_cpu_features(void);

#endif /* __ASSEMBLY__ */

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index a1871bb32bb1..2a88cb734d06 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -322,6 +322,7 @@ static inline void *phys_to_virt(phys_addr_t x)
__is_lm_address(__addr) && pfn_valid(virt_to_pfn(__addr)); \
})

+void dump_mem_limit(void);
#endif /* !ASSEMBLY */

/*
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 2270eda9a7fb..756775f4b7d4 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -119,24 +119,11 @@ static inline void finalize_system_capabilities(void)
static_branch_enable(&arm64_const_caps_ready);
}

-static int dump_cpu_hwcaps(struct notifier_block *self, unsigned long v, void *p)
+void dump_cpu_features(void)
{
/* file-wide pr_fmt adds "CPU features: " prefix */
pr_emerg("0x%*pb\n", ARM64_NCAPS, &cpu_hwcaps);
- return 0;
-}
-
-static struct notifier_block cpu_hwcaps_notifier = {
- .notifier_call = dump_cpu_hwcaps
-};
-
-static int __init register_cpu_hwcaps_dumper(void)
-{
- atomic_notifier_chain_register(&panic_notifier_list,
- &cpu_hwcaps_notifier);
- return 0;
}
-__initcall(register_cpu_hwcaps_dumper);

DEFINE_STATIC_KEY_ARRAY_FALSE(cpu_hwcap_keys, ARM64_NCAPS);
EXPORT_SYMBOL(cpu_hwcap_keys);
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 93b3844cf442..312b19263cb7 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -400,11 +400,7 @@ static int __init topology_init(void)
}
subsys_initcall(topology_init);

-/*
- * Dump out kernel offset information on panic.
- */
-static int dump_kernel_offset(struct notifier_block *self, unsigned long v,
- void *p)
+void dump_kernel_offset(void)
{
const unsigned long offset = kaslr_offset();

@@ -415,17 +411,25 @@ static int dump_kernel_offset(struct notifier_block *self, unsigned long v,
} else {
pr_emerg("Kernel Offset: disabled\n");
}
+}
+
+static int arm64_panic_block_dump(struct notifier_block *self,
+ unsigned long v, void *p)
+{
+ dump_kernel_offset();
+ dump_cpu_features();
+ dump_mem_limit();
return 0;
}

-static struct notifier_block kernel_offset_notifier = {
- .notifier_call = dump_kernel_offset
+static struct notifier_block arm64_panic_block = {
+ .notifier_call = arm64_panic_block_dump
};

-static int __init register_kernel_offset_dumper(void)
+static int __init register_arm64_panic_block(void)
{
atomic_notifier_chain_register(&panic_notifier_list,
- &kernel_offset_notifier);
+ &arm64_panic_block);
return 0;
}
-__initcall(register_kernel_offset_dumper);
+__initcall(register_arm64_panic_block);
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index e631e6425165..b88ef04033de 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -558,27 +558,11 @@ void free_initmem(void)
unmap_kernel_range((u64)__init_begin, (u64)(__init_end - __init_begin));
}

-/*
- * Dump out memory limit information on panic.
- */
-static int dump_mem_limit(struct notifier_block *self, unsigned long v, void *p)
+void dump_mem_limit(void)
{
if (memory_limit != PHYS_ADDR_MAX) {
pr_emerg("Memory Limit: %llu MB\n", memory_limit >> 20);
} else {
pr_emerg("Memory Limit: none\n");
}
- return 0;
-}
-
-static struct notifier_block mem_limit_notifier = {
- .notifier_call = dump_mem_limit,
-};
-
-static int __init register_mem_limit_dumper(void)
-{
- atomic_notifier_chain_register(&panic_notifier_list,
- &mem_limit_notifier);
- return 0;
}
-__initcall(register_mem_limit_dumper);
--
2.20.1