Commit a6ba44e8 authored by Ravi Bangoria's avatar Ravi Bangoria Committed by Michael Ellerman
Browse files

powerpc/watchpoint: Introduce function to get nr watchpoints dynamically 



So far we had only one watchpoint, so we have hardcoded HBP_NUM to 1.
But Power10 is introducing 2nd DAWR and thus kernel should be able to
dynamically find actual number of watchpoints supported by hw it's
running on. Introduce function for the same. Also convert HBP_NUM macro
to HBP_NUM_MAX, which will now represent maximum number of watchpoints
supported by Powerpc.

Signed-off-by: default avatarRavi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: default avatarMichael Neuling <mikey@neuling.org>
Link: https://lore.kernel.org/r/20200514111741.97993-4-ravi.bangoria@linux.ibm.com
parent 4a4ec228

arch/powerpc/include/asm/cputable.h

+5 −1
Original line number Diff line number Diff line
@@ -614,7 +614,11 @@ enum { 
};

#endif /* __powerpc64__ */



#define HBP_NUM 1

/*

 * Maximum number of hw breakpoint supported on powerpc. Number of

 * breakpoints supported by actual hw might be less than this.

 */

#define HBP_NUM_MAX	1



#endif /* !__ASSEMBLY__ */

arch/powerpc/include/asm/hw_breakpoint.h

+5 −0
Original line number Diff line number Diff line
@@ -43,6 +43,11 @@ struct arch_hw_breakpoint { 
#define DABR_MAX_LEN	8

#define DAWR_MAX_LEN	512



static inline int nr_wp_slots(void)

{

	return HBP_NUM_MAX;

}



#ifdef CONFIG_HAVE_HW_BREAKPOINT

#include <linux/kdebug.h>

#include <asm/reg.h>

arch/powerpc/include/asm/processor.h

+1 −1
Original line number Diff line number Diff line
@@ -180,7 +180,7 @@ struct thread_struct { 
	int		fpexc_mode;	/* floating-point exception mode */

	unsigned int	align_ctl;	/* alignment handling control */

#ifdef CONFIG_HAVE_HW_BREAKPOINT

	struct perf_event *ptrace_bps[HBP_NUM];

	struct perf_event *ptrace_bps[HBP_NUM_MAX];

	/*

	 * Helps identify source of single-step exception and subsequent

	 * hw-breakpoint enablement

arch/powerpc/kernel/hw_breakpoint.c

+1 −1
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ static DEFINE_PER_CPU(struct perf_event *, bp_per_reg); 
int hw_breakpoint_slots(int type)

{

	if (type == TYPE_DATA)

		return HBP_NUM;

		return nr_wp_slots();

	return 0;		/* no instruction breakpoints available */

}

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