Messages in this thread | | | Subject | Re: [PATCH 4/5] Powerpc/hw-breakpoint: Optimize disable path | From | Christophe Leroy <> | Date | Tue, 18 Jun 2019 08:31:57 +0200 |
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Le 18/06/2019 à 06:27, Ravi Bangoria a écrit : > Directly setting dawr and dawrx with 0 should be enough to > disable watchpoint. No need to reset individual bits in > variable and then set in hw. > > Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> > --- > arch/powerpc/include/asm/hw_breakpoint.h | 3 ++- > arch/powerpc/kernel/process.c | 12 ++++++++++++ > 2 files changed, 14 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h > index 78202d5fb13a..8acbbdd4a2d5 100644 > --- a/arch/powerpc/include/asm/hw_breakpoint.h > +++ b/arch/powerpc/include/asm/hw_breakpoint.h > @@ -19,6 +19,7 @@ struct arch_hw_breakpoint { > /* Note: Don't change the the first 6 bits below as they are in the same order > * as the dabr and dabrx. > */ > +#define HW_BRK_TYPE_DISABLE 0x00
I'd rather call it HW_BRK_TYPE_NONE
> #define HW_BRK_TYPE_READ 0x01 > #define HW_BRK_TYPE_WRITE 0x02 > #define HW_BRK_TYPE_TRANSLATE 0x04 > @@ -68,7 +69,7 @@ static inline void hw_breakpoint_disable(void) > struct arch_hw_breakpoint brk; > > brk.address = 0; > - brk.type = 0; > + brk.type = HW_BRK_TYPE_DISABLE; > brk.len = 0; > if (ppc_breakpoint_available()) > __set_breakpoint(&brk); > diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c > index f002d2ffff86..265fac9fb3a4 100644 > --- a/arch/powerpc/kernel/process.c > +++ b/arch/powerpc/kernel/process.c > @@ -793,10 +793,22 @@ static inline int set_dabr(struct arch_hw_breakpoint *brk) > return __set_dabr(dabr, dabrx); > } > > +static int disable_dawr(void) > +{ > + if (ppc_md.set_dawr) > + return ppc_md.set_dawr(0, 0); > + > + mtspr(SPRN_DAWRX, 0);
And SPRN_DAWR ?
The above code looks pretty similar to the one at the end of set_dawr(). You should factorise it, for instance
static int __set_dawr(int dawr, int dawrx) { if (ppc_md.set_dawr) return ppc_md.set_dawr(dawr, dawrx); mtspr(SPRN_DAWR, dawr); mtspr(SPRN_DAWRX, dawrx); return 0; }
> + return 0; > +} > + > int set_dawr(struct arch_hw_breakpoint *brk) > { > unsigned long dawr, dawrx, mrd; > > + if (brk->type == HW_BRK_TYPE_DISABLE) > + return disable_dawr();
Then replace by __set_dawr(0, 0);
> + > dawr = brk->address; > > dawrx = (brk->type & HW_BRK_TYPE_RDWR) << (63 - 58); >
And use the new helper at the end of the function too.
Christophe
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