Re: [PATCH v2 05/16] powerpc/watchpoint: Provide DAWR number to set_dawr

[Christophe Leroy]

Le 01/04/2020 à 08:12, Ravi Bangoria a écrit :

Introduce new parameter 'nr' to set_dawr() which indicates which DAWR
should be programed.

Signed-off-by: Ravi Bangoria <ravi.bango...@linux.ibm.com>
---
  arch/powerpc/include/asm/hw_breakpoint.h |  4 ++--
  arch/powerpc/kernel/dawr.c               | 15 ++++++++++-----
  arch/powerpc/kernel/process.c            |  2 +-
  3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/include/asm/hw_breakpoint.h 
b/arch/powerpc/include/asm/hw_breakpoint.h
index 518b41eef924..62549007c87a 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h
@@ -104,10 +104,10 @@ static inline bool dawr_enabled(void)
  {
        return dawr_force_enable;
  }
-int set_dawr(struct arch_hw_breakpoint *brk);
+int set_dawr(struct arch_hw_breakpoint *brk, int nr);

Wondering if it wouldn't make more sense to have nr as first argument.

Christophe

  #else
  static inline bool dawr_enabled(void) { return false; }
-static inline int set_dawr(struct arch_hw_breakpoint *brk) { return -1; }
+static inline int set_dawr(struct arch_hw_breakpoint *brk, int nr) { return 
-1; }
  #endif

#endif /* __KERNEL__ */

diff --git a/arch/powerpc/kernel/dawr.c b/arch/powerpc/kernel/dawr.c
index e91b613bf137..311e51ee09f4 100644
--- a/arch/powerpc/kernel/dawr.c
+++ b/arch/powerpc/kernel/dawr.c
@@ -16,7 +16,7 @@
  bool dawr_force_enable;
  EXPORT_SYMBOL_GPL(dawr_force_enable);

-int set_dawr(struct arch_hw_breakpoint *brk)

+int set_dawr(struct arch_hw_breakpoint *brk, int nr)
  {
        unsigned long dawr, dawrx, mrd;

@@ -39,15 +39,20 @@ int set_dawr(struct arch_hw_breakpoint *brk)

        if (ppc_md.set_dawr)
                return ppc_md.set_dawr(dawr, dawrx);

- mtspr(SPRN_DAWR0, dawr);

-       mtspr(SPRN_DAWRX0, dawrx);
+       if (nr == 0) {
+               mtspr(SPRN_DAWR0, dawr);
+               mtspr(SPRN_DAWRX0, dawrx);
+       } else {
+               mtspr(SPRN_DAWR1, dawr);
+               mtspr(SPRN_DAWRX1, dawrx);
+       }

return 0;

  }

static void set_dawr_cb(void *info)

  {
-       set_dawr(info);
+       set_dawr(info, 0);
  }

static ssize_t dawr_write_file_bool(struct file *file,

@@ -60,7 +65,7 @@ static ssize_t dawr_write_file_bool(struct file *file,
        /* Send error to user if they hypervisor won't allow us to write DAWR */
        if (!dawr_force_enable &&
            firmware_has_feature(FW_FEATURE_LPAR) &&
-           set_dawr(&null_brk) != H_SUCCESS)
+           set_dawr(&null_brk, 0) != H_SUCCESS)
                return -ENODEV;

rc = debugfs_write_file_bool(file, user_buf, count, ppos);

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 110db94cdf3c..b548a584e465 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -799,7 +799,7 @@ void __set_breakpoint(struct arch_hw_breakpoint *brk)

if (dawr_enabled())

                // Power8 or later
-               set_dawr(brk);
+               set_dawr(brk, 0);
        else if (IS_ENABLED(CONFIG_PPC_8xx))
                set_breakpoint_8xx(brk);
        else if (!cpu_has_feature(CPU_FTR_ARCH_207S))