[PATCH] powerpc: Replace boot_cpu_count with spinning_secondaries, fix off-by-one cpu wait
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From: Matt Evans <hidden>
Date: 2011-05-26 04:09:12
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
smp_release_cpus() waits for all cpus (including the bootcpu) due to an off-by-one count on boot_cpu_count (which is all CPUs). This patch replaces that with spinning_secondaries (which is all secondary CPUs). Signed-off-by: Matt Evans <redacted> --- arch/powerpc/include/asm/smp.h | 2 +- arch/powerpc/kernel/head_64.S | 2 +- arch/powerpc/kernel/prom.c | 8 ++++++++ arch/powerpc/kernel/setup_32.c | 1 - arch/powerpc/kernel/setup_64.c | 6 +++--- 5 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index 880b8c1..8f01c85 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h@@ -30,7 +30,7 @@ #include <asm/percpu.h> extern int boot_cpuid; -extern int boot_cpu_count; +extern int spinning_secondaries; extern void cpu_die(void);
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index ba50409..3564c49 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S@@ -255,7 +255,7 @@ generic_secondary_common_init: mtctr r23 bctrl -3: LOAD_REG_ADDR(r3, boot_cpu_count) /* Decrement boot_cpu_count */ +3: LOAD_REG_ADDR(r3, spinning_secondaries) /* Decrement spinning_secondaries */ lwarx r4,0,r3 subi r4,r4,1 stwcx. r4,0,r3
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 48aeb55..540e0dc 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c@@ -69,6 +69,7 @@ unsigned long tce_alloc_start, tce_alloc_end; u64 ppc64_rma_size; #endif static phys_addr_t first_memblock_size; +static int __initdata boot_cpu_count; static int __init early_parse_mem(char *p) {
@@ -748,6 +749,13 @@ void __init early_init_devtree(void *params) */ of_scan_flat_dt(early_init_dt_scan_cpus, NULL); +#if defined(CONFIG_SMP) && defined(CONFIG_PPC64) + /* We'll later wait for secondaries to check in; there are + * NCPUS-1 non-boot CPUs :-) + */ + spinning_secondaries = boot_cpu_count - 1; +#endif + DBG(" <- early_init_devtree()\n"); }
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 620d792..1d2fbc9 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c@@ -48,7 +48,6 @@ extern void bootx_init(unsigned long r4, unsigned long phys); int boot_cpuid = -1; EXPORT_SYMBOL_GPL(boot_cpuid); -int __initdata boot_cpu_count; int boot_cpuid_phys; int smp_hw_index[NR_CPUS];
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index a88bf27..0576919 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c@@ -73,7 +73,7 @@ #endif int boot_cpuid = 0; -int __initdata boot_cpu_count; +int __initdata spinning_secondaries; u64 ppc64_pft_size; /* Pick defaults since we might want to patch instructions
@@ -253,11 +253,11 @@ void smp_release_cpus(void) for (i = 0; i < 100000; i++) { mb(); HMT_low(); - if (boot_cpu_count == 0) + if (spinning_secondaries == 0) break; udelay(1); } - DBG("boot_cpu_count = %d\n", boot_cpu_count); + DBG("spinning_secondaries = %d\n", spinning_secondaries); DBG(" <- smp_release_cpus()\n"); }
--
1.7.0.4
0