Commit 048c8bc9 authored by Hugh Dickins's avatar Hugh Dickins Committed by Paul Mackerras
Browse files

[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: default avatarHugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 5669c3cf

arch/powerpc/kernel/lparcfg.c

+1 −1
Original line number Diff line number Diff line
@@ -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());

include/asm-powerpc/io.h

+1 −1
Original line number Diff line number Diff line
@@ -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

include/asm-powerpc/paca.h

+11 −0
Original line number Diff line number Diff line
@@ -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)

include/asm-powerpc/percpu.h

+1 −1
Original line number Diff line number Diff line
@@ -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)			\

include/asm-powerpc/smp.h

+1 −1
Original line number Diff line number Diff line
@@ -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 */

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