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authorHugh Dickins <hugh@veritas.com>2006-11-01 05:44:54 +1100
committerPaul Mackerras <paulus@samba.org>2007-10-03 11:48:44 +1000
commit048c8bc90e53bf1f5feec020a7d482da94894e93 (patch)
tree6ca0891ac3320706873006104cde3d4e1039bcfc
parent5669c3cf19fbadaa9120b59914beec8431277efe (diff)
[POWERPC] ppc64: support CONFIG_DEBUG_PREEMPT
Add CONFIG_DEBUG_PREEMPT support to ppc64: it was useful for testing get_paca() preemption. Cheat a little, just use debug_smp_processor_id() in the debug version of get_paca(): it contains all the right checks and reporting, though get_paca() doesn't really use smp_processor_id(). Use local_paca for what might have been called __raw_get_paca(). Silence harmless warnings from io.h and lparcfg.c with local_paca - it is okay for iseries_lparcfg_data to be referencing shared_proc with preemption enabled: all cpus should show the same value for shared_proc. Why do other architectures need TRACE_IRQFLAGS_SUPPORT for DEBUG_PREEMPT? I don't know, ppc64 appears to get along fine without it. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
-rw-r--r--arch/powerpc/kernel/lparcfg.c2
-rw-r--r--include/asm-powerpc/io.h2
-rw-r--r--include/asm-powerpc/paca.h11
-rw-r--r--include/asm-powerpc/percpu.h2
-rw-r--r--include/asm-powerpc/smp.h2
-rw-r--r--lib/Kconfig.debug2
6 files changed, 16 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/lparcfg.c b/arch/powerpc/kernel/lparcfg.c
index 6444eaa30a2f..ff781b2eddec 100644
--- a/arch/powerpc/kernel/lparcfg.c
+++ b/arch/powerpc/kernel/lparcfg.c
@@ -77,7 +77,7 @@ static int iseries_lparcfg_data(struct seq_file *m, void *v)
int processors, max_processors;
unsigned long purr = get_purr();
- shared = (int)(get_lppaca()->shared_proc);
+ shared = (int)(local_paca->lppaca_ptr->shared_proc);
seq_printf(m, "system_active_processors=%d\n",
(int)HvLpConfig_getSystemPhysicalProcessors());
diff --git a/include/asm-powerpc/io.h b/include/asm-powerpc/io.h
index 6805efb2cb6d..affba7052fb6 100644
--- a/include/asm-powerpc/io.h
+++ b/include/asm-powerpc/io.h
@@ -86,7 +86,7 @@ extern unsigned long pci_dram_offset;
*/
#ifdef CONFIG_PPC64
-#define IO_SET_SYNC_FLAG() do { get_paca()->io_sync = 1; } while(0)
+#define IO_SET_SYNC_FLAG() do { local_paca->io_sync = 1; } while(0)
#else
#define IO_SET_SYNC_FLAG()
#endif
diff --git a/include/asm-powerpc/paca.h b/include/asm-powerpc/paca.h
index c6a5b1735666..fcd7b428ed0b 100644
--- a/include/asm-powerpc/paca.h
+++ b/include/asm-powerpc/paca.h
@@ -21,7 +21,18 @@
#include <asm/mmu.h>
register struct paca_struct *local_paca asm("r13");
+
+#if defined(CONFIG_DEBUG_PREEMPT) && defined(CONFIG_SMP)
+extern unsigned int debug_smp_processor_id(void); /* from linux/smp.h */
+/*
+ * Add standard checks that preemption cannot occur when using get_paca():
+ * otherwise the paca_struct it points to may be the wrong one just after.
+ */
+#define get_paca() ((void) debug_smp_processor_id(), local_paca)
+#else
#define get_paca() local_paca
+#endif
+
#define get_lppaca() (get_paca()->lppaca_ptr)
#define get_slb_shadow() (get_paca()->slb_shadow_ptr)
diff --git a/include/asm-powerpc/percpu.h b/include/asm-powerpc/percpu.h
index 73dc8ba4010d..6b229626d3ff 100644
--- a/include/asm-powerpc/percpu.h
+++ b/include/asm-powerpc/percpu.h
@@ -28,7 +28,7 @@
/* var is in discarded region: offset to particular copy we want */
#define per_cpu(var, cpu) (*RELOC_HIDE(&per_cpu__##var, __per_cpu_offset(cpu)))
#define __get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()))
-#define __raw_get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()))
+#define __raw_get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, local_paca->data_offset))
/* A macro to avoid #include hell... */
#define percpu_modcopy(pcpudst, src, size) \
diff --git a/include/asm-powerpc/smp.h b/include/asm-powerpc/smp.h
index d037f50580e2..19102bfc14ca 100644
--- a/include/asm-powerpc/smp.h
+++ b/include/asm-powerpc/smp.h
@@ -45,7 +45,7 @@ void generic_mach_cpu_die(void);
#endif
#ifdef CONFIG_PPC64
-#define raw_smp_processor_id() (get_paca()->paca_index)
+#define raw_smp_processor_id() (local_paca->paca_index)
#define hard_smp_processor_id() (get_paca()->hw_cpu_id)
#else
/* 32-bit */
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 50a94eee4d92..51e2fd0d851c 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -167,7 +167,7 @@ config SLUB_DEBUG_ON
config DEBUG_PREEMPT
bool "Debug preemptible kernel"
- depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
+ depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64)
default y
help
If you say Y here then the kernel will use a debug variant of the