From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Ravi Bangoria <ravi.bangoria@linux.ibm.com>,
mpe@ellerman.id.au, mikey@neuling.org
Cc: apopple@linux.ibm.com, paulus@samba.org, npiggin@gmail.com,
naveen.n.rao@linux.vnet.ibm.com, peterz@infradead.org,
jolsa@kernel.org, oleg@redhat.com, fweisbec@gmail.com,
mingo@kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 03/15] powerpc/watchpoint: Introduce function to get nr watchpoints dynamically
Date: Tue, 17 Mar 2020 11:21:39 +0100 [thread overview]
Message-ID: <53b8bf54-200f-6f37-5870-e641b35f373c@c-s.fr> (raw)
In-Reply-To: <20200309085806.155823-4-ravi.bangoria@linux.ibm.com>
Le 09/03/2020 à 09:57, Ravi Bangoria a écrit :
> So far we had only one watchpoint, so we have hardcoded HBP_NUM to 1.
> But future Power architecture 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: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
> ---
> arch/powerpc/include/asm/cputable.h | 6 +++++-
> arch/powerpc/include/asm/hw_breakpoint.h | 2 ++
> arch/powerpc/include/asm/processor.h | 2 +-
> arch/powerpc/kernel/hw_breakpoint.c | 2 +-
> arch/powerpc/kernel/process.c | 6 ++++++
> 5 files changed, 15 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
> index 40a4d3c6fd99..c67b94f3334c 100644
> --- a/arch/powerpc/include/asm/cputable.h
> +++ b/arch/powerpc/include/asm/cputable.h
> @@ -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__ */
>
> diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
> index f2f8d8aa8e3b..741c4f7573c4 100644
> --- a/arch/powerpc/include/asm/hw_breakpoint.h
> +++ b/arch/powerpc/include/asm/hw_breakpoint.h
> @@ -43,6 +43,8 @@ struct arch_hw_breakpoint {
> #define DABR_MAX_LEN 8
> #define DAWR_MAX_LEN 512
>
> +extern int nr_wp_slots(void);
'extern' keyword is unneeded and irrelevant here. Please remove it. Even
checkpatch is unhappy
(https://openpower.xyz/job/snowpatch/job/snowpatch-linux-checkpatch/12172//artifact/linux/checkpatch.log)
> +
> #ifdef CONFIG_HAVE_HW_BREAKPOINT
> #include <linux/kdebug.h>
> #include <asm/reg.h>
> diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
> index 8387698bd5b6..666b2825278c 100644
> --- a/arch/powerpc/include/asm/processor.h
> +++ b/arch/powerpc/include/asm/processor.h
> @@ -176,7 +176,7 @@ 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
> diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
> index d0854320bb50..e68798cee3fa 100644
> --- a/arch/powerpc/kernel/hw_breakpoint.c
> +++ b/arch/powerpc/kernel/hw_breakpoint.c
> @@ -38,7 +38,7 @@ 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 */
> }
>
> diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
> index 110db94cdf3c..6d4b029532e2 100644
> --- a/arch/powerpc/kernel/process.c
> +++ b/arch/powerpc/kernel/process.c
> @@ -835,6 +835,12 @@ static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
> return true;
> }
>
> +/* Returns total number of data breakpoints available. */
> +int nr_wp_slots(void)
> +{
> + return HBP_NUM_MAX;
> +}
> +
This is not worth a global function. At least it should be a static
function located in hw_breakpoint.c. But it would be even better to have
it as a static inline in asm/hw_breakpoint.h
Christophe
next prev parent reply other threads:[~2020-03-17 10:21 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-09 8:57 [PATCH 00/15] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
2020-03-09 8:57 ` [PATCH 01/15] powerpc/watchpoint: Rename current DAWR macros Ravi Bangoria
2020-03-17 10:14 ` Christophe Leroy
2020-03-18 12:40 ` Ravi Bangoria
2020-03-09 8:57 ` [PATCH 02/15] powerpc/watchpoint: Add SPRN macros for second DAWR Ravi Bangoria
2020-03-17 10:16 ` Christophe Leroy
2020-03-18 18:30 ` Segher Boessenkool
2020-03-09 8:57 ` [PATCH 03/15] powerpc/watchpoint: Introduce function to get nr watchpoints dynamically Ravi Bangoria
2020-03-17 10:21 ` Christophe Leroy [this message]
2020-03-18 5:50 ` Ravi Bangoria
2020-03-09 8:57 ` [PATCH 04/15] powerpc/watchpoint/ptrace: Return actual num of available watchpoints Ravi Bangoria
2020-03-09 8:57 ` [PATCH 05/15] powerpc/watchpoint: Provide DAWR number to set_dawr Ravi Bangoria
2020-03-17 10:28 ` Christophe Leroy
2020-03-18 6:18 ` Ravi Bangoria
2020-03-09 8:57 ` [PATCH 06/15] powerpc/watchpoint: Provide DAWR number to __set_breakpoint Ravi Bangoria
2020-03-09 8:57 ` [PATCH 07/15] powerpc/watchpoint: Get watchpoint count dynamically while disabling them Ravi Bangoria
2020-03-17 10:32 ` Christophe Leroy
2020-03-18 6:57 ` Ravi Bangoria
2020-03-26 3:32 ` Ravi Bangoria
2020-03-09 8:57 ` [PATCH 08/15] powerpc/watchpoint: Disable all available watchpoints when !dawr_force_enable Ravi Bangoria
2020-03-17 10:35 ` Christophe Leroy
2020-03-18 7:32 ` Ravi Bangoria
2020-03-09 8:58 ` [PATCH 09/15] powerpc/watchpoint: Convert thread_struct->hw_brk to an array Ravi Bangoria
2020-03-17 10:37 ` Christophe Leroy
2020-03-18 8:36 ` Ravi Bangoria
2020-03-18 8:56 ` Christophe Leroy
2020-03-18 9:22 ` Ravi Bangoria
2020-03-09 8:58 ` [PATCH 10/15] powerpc/watchpoint: Use loop for thread_struct->ptrace_bps Ravi Bangoria
2020-03-17 10:48 ` Christophe Leroy
2020-03-18 9:43 ` Ravi Bangoria
2020-03-09 8:58 ` [PATCH 11/15] powerpc/watchpoint: Introduce is_ptrace_bp() function Ravi Bangoria
2020-03-17 10:49 ` Christophe Leroy
2020-03-09 8:58 ` [PATCH 12/15] powerpc/watchpoint: Prepare handler to handle more than one watcnhpoint Ravi Bangoria
2020-03-17 10:59 ` Christophe Leroy
2020-03-18 11:35 ` Michael Ellerman
2020-03-18 11:44 ` Christophe Leroy
2020-03-18 21:27 ` Segher Boessenkool
2020-03-18 23:36 ` Michael Ellerman
2020-03-18 12:14 ` Ravi Bangoria
2020-03-09 8:58 ` [PATCH 13/15] powerpc/watchpoint: Don't allow concurrent perf and ptrace events Ravi Bangoria
2020-03-17 11:08 ` Christophe Leroy
2020-03-18 12:35 ` Ravi Bangoria
2020-03-09 8:58 ` [PATCH 14/15] powerpc/watchpoint/xmon: Don't allow breakpoint overwriting Ravi Bangoria
2020-03-17 11:10 ` Christophe Leroy
2020-03-18 12:37 ` Ravi Bangoria
2020-03-18 13:31 ` Christophe Leroy
2020-03-09 8:58 ` [PATCH 15/15] powerpc/watchpoint/xmon: Support 2nd dawr Ravi Bangoria
2020-03-17 11:14 ` Christophe Leroy
2020-03-18 12:39 ` Ravi Bangoria
2020-03-16 15:05 ` [PATCH 00/15] powerpc/watchpoint: Preparation for more than one watchpoint Christophe Leroy
2020-03-16 18:43 ` Segher Boessenkool
2020-03-17 5:56 ` Christophe Leroy
2020-03-18 12:52 ` Ravi Bangoria
2020-03-23 13:37 ` Ravi Bangoria
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