| Message ID | 20221216115930.2667772-4-npiggin@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | dc222fa7737212fe0da513e5b8937c156d02225d |
| Headers | show |
| Series | powerpc: Misc early boot fixes | expand |
Hi Nicholas,
I love your patch! Yet something to improve:
[auto build test ERROR on powerpc/next]
[also build test ERROR on next-20221216]
[cannot apply to powerpc/fixes linus/master v6.1]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Nicholas-Piggin/powerpc-Misc-early-boot-fixes/20221216-200425
base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
patch link: https://lore.kernel.org/r/20221216115930.2667772-4-npiggin%40gmail.com
patch subject: [PATCH 3/4] powerpc/64: Move paca allocation to early_setup()
config: powerpc-allmodconfig
compiler: powerpc-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/914e5943b023f1f74d0c717e29daf3b0199512cc
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Nicholas-Piggin/powerpc-Misc-early-boot-fixes/20221216-200425
git checkout 914e5943b023f1f74d0c717e29daf3b0199512cc
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=powerpc olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
powerpc-linux-ld: arch/powerpc/kernel/prom.o: in function `early_init_dt_scan_cpus':
>> prom.c:(.init.text+0xb3e): undefined reference to `boot_cpu_hwid'
>> powerpc-linux-ld: prom.c:(.init.text+0xb56): undefined reference to `boot_cpu_hwid'
powerpc-linux-ld: prom.c:(.init.text+0xb6a): undefined reference to `boot_cpu_hwid'
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) { } diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h index f63505d74932..6c6cb53d7045 100644 --- a/arch/powerpc/include/asm/smp.h +++ b/arch/powerpc/include/asm/smp.h @@ -26,6 +26,7 @@ #include <asm/percpu.h> extern int boot_cpuid; +extern int boot_cpu_hwid; /* PPC64 only */ extern int spinning_secondaries; extern u32 *cpu_to_phys_id; extern bool coregroup_enabled; diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c index 4f1c920aa13e..b3aa6df872a5 100644 --- a/arch/powerpc/kernel/prom.c +++ b/arch/powerpc/kernel/prom.c @@ -369,9 +369,7 @@ static int __init early_init_dt_scan_cpus(unsigned long node, DBG("boot cpu: logical %d physical %d\n", found, be32_to_cpu(intserv[found_thread])); boot_cpuid = found; - - // Pass the boot CPU's hard CPU id back to our caller - *((u32 *)data) = be32_to_cpu(intserv[found_thread]); + boot_cpu_hwid = be32_to_cpu(intserv[found_thread]); /* * PAPR defines "logical" PVR values for cpus that @@ -755,7 +753,6 @@ static inline void save_fscr_to_task(void) {} void __init early_init_devtree(void *params) { - u32 boot_cpu_hwid; phys_addr_t limit; DBG(" -> early_init_devtree(%px)\n", params); @@ -851,7 +848,7 @@ void __init early_init_devtree(void *params) /* Retrieve CPU related informations from the flat tree * (altivec support, boot CPU ID, ...) */ - of_scan_flat_dt(early_init_dt_scan_cpus, &boot_cpu_hwid); + of_scan_flat_dt(early_init_dt_scan_cpus, NULL); if (boot_cpuid < 0) { printk("Failed to identify boot CPU !\n"); BUG(); @@ -868,11 +865,6 @@ void __init early_init_devtree(void *params) mmu_early_init_devtree(); - // NB. paca is not installed until later in early_setup() - allocate_paca_ptrs(); - allocate_paca(boot_cpuid); - set_hard_smp_processor_id(boot_cpuid, boot_cpu_hwid); - #ifdef CONFIG_PPC_POWERNV /* Scan and build the list of machine check recoverable ranges */ of_scan_flat_dt(early_init_dt_scan_recoverable_ranges, NULL); diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index 6d041993a45d..efb301a4987c 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -86,6 +86,10 @@ EXPORT_SYMBOL(machine_id); int boot_cpuid = -1; EXPORT_SYMBOL_GPL(boot_cpuid); +#ifdef CONFIG_PPC64 +int boot_cpu_hwid = -1; +#endif + /* * These are used in binfmt_elf.c to put aux entries on the stack * for each elf executable being started. diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index e6c8d1e326f7..78d8a105764b 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -385,15 +385,14 @@ void __init early_setup(unsigned long dt_ptr) /* * Do early initialization using the flattened device * tree, such as retrieving the physical memory map or - * calculating/retrieving the hash table size. + * calculating/retrieving the hash table size, discover + * boot_cpuid and boot_cpu_hwid. */ early_init_devtree(__va(dt_ptr)); - /* Now we know the logical id of our boot cpu, setup the paca. */ - if (boot_cpuid != 0) { - /* Poison paca_ptrs[0] again if it's not the boot cpu */ - memset(&paca_ptrs[0], 0x88, sizeof(paca_ptrs[0])); - } + allocate_paca_ptrs(); + allocate_paca(boot_cpuid); + set_hard_smp_processor_id(boot_cpuid, boot_cpu_hwid); fixup_boot_paca(paca_ptrs[boot_cpuid]); setup_paca(paca_ptrs[boot_cpuid]); /* install the paca into registers */ // smp_processor_id() now reports boot_cpuid
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> --- arch/powerpc/include/asm/paca.h | 1 - arch/powerpc/include/asm/smp.h | 1 + arch/powerpc/kernel/prom.c | 12 ++---------- arch/powerpc/kernel/setup-common.c | 4 ++++ arch/powerpc/kernel/setup_64.c | 11 +++++------ 5 files changed, 12 insertions(+), 17 deletions(-)