diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2022-12-16 21:59:29 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-17 08:50:31 +0100 |
| commit | 07a5f4e69761e851cf4397cbb2db1228b18b8f83 (patch) | |
| tree | cd44dc623a2939669ca86b06da0a2b9220a4b430 /arch/powerpc/include/asm/paca.h | |
| parent | be2e726fa03af85d797d4d75bdac3c23e70ac36f (diff) | |
| download | linux-07a5f4e69761e851cf4397cbb2db1228b18b8f83.tar.gz | |
powerpc/64: Move paca allocation to early_setup()
[ Upstream commit dc222fa7737212fe0da513e5b8937c156d02225d ] The early paca and boot cpuid dance is complicated and currently does not quite work as expected for boot cpuid != 0 cases. early_init_devtree() currently allocates the paca_ptrs and boot cpuid paca, but until that returns and early_setup() calls setup_paca(), this thread is currently still executing with smp_processor_id() == 0. One problem this causes is the paca_ptrs[smp_processor_id()] pointer is poisoned, so valid_emergency_stack() (any backtrace) and any similar users will crash. Another is that the hardware id which is set here will not be returned by get_hard_smp_processor_id(smp_processor_id()), but it would work correctly for boot_cpuid == 0, which could lead to difficult to reproduce or find bugs. The hard id does not seem to be used by the rest of early_init_devtree(), it just looks like all this code might have been put here to allocate somewhere to store boot CPU hardware id while scanning the devtree. Rearrange things so the hwid is put in a global variable like boot_cpuid, and do all the paca allocation and boot paca setup in the 64-bit early_setup() after we have everything ready to go. The paca_ptrs[0] re-poisoning code in early_setup does not seem to have ever worked, because paca_ptrs[0] was never not-poisoned when boot_cpuid is not 0. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fix build error on 32-bit] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221216115930.2667772-4-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/powerpc/include/asm/paca.h')
| -rw-r--r-- | arch/powerpc/include/asm/paca.h | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h index 09f1790d0ae1..0ab3511a47d7 100644 --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -295,7 +295,6 @@ extern void free_unused_pacas(void); #else /* CONFIG_PPC64 */ -static inline void allocate_paca_ptrs(void) { } static inline void allocate_paca(int cpu) { } static inline void free_unused_pacas(void) { } |