Messages in this thread |  | | Subject | Re: [RFC PATCH 3/4] powerpc: Optimize register usage for dear register | From | Christophe Leroy <> | Date | Thu, 5 Aug 2021 12:09:19 +0200 |
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Le 26/07/2021 à 16:30, sxwjean@me.com a écrit : > From: Xiongwei Song <sxwjean@gmail.com> > > Create an anonymous union for dar and dear regsiters, we can reference > dear to get the effective address when CONFIG_4xx=y or CONFIG_BOOKE=y. > Otherwise, reference dar. This makes code more clear.
Same comment here as for patch 1.
> > Signed-off-by: Xiongwei Song <sxwjean@gmail.com> > --- > arch/powerpc/include/asm/ptrace.h | 5 ++++- > arch/powerpc/include/uapi/asm/ptrace.h | 5 ++++- > arch/powerpc/kernel/process.c | 2 +- > arch/powerpc/kernel/ptrace/ptrace.c | 2 ++ > arch/powerpc/kernel/traps.c | 5 ++++- > arch/powerpc/mm/fault.c | 2 +- > 6 files changed, 16 insertions(+), 5 deletions(-) > > diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h > index c252d04b1206..fa725e3238c2 100644 > --- a/arch/powerpc/include/asm/ptrace.h > +++ b/arch/powerpc/include/asm/ptrace.h > @@ -43,7 +43,10 @@ struct pt_regs > unsigned long mq; > #endif > unsigned long trap; > - unsigned long dar; > + union { > + unsigned long dar; > + unsigned long dear; > + }; > union { > unsigned long dsisr; > unsigned long esr; > diff --git a/arch/powerpc/include/uapi/asm/ptrace.h b/arch/powerpc/include/uapi/asm/ptrace.h > index e357288b5f34..9ae150fb4c4b 100644 > --- a/arch/powerpc/include/uapi/asm/ptrace.h > +++ b/arch/powerpc/include/uapi/asm/ptrace.h > @@ -52,7 +52,10 @@ struct pt_regs > unsigned long trap; /* Reason for being here */ > /* N.B. for critical exceptions on 4xx, the dar and dsisr > fields are overloaded to hold srr0 and srr1. */ > - unsigned long dar; /* Fault registers */ > + union { > + unsigned long dar; /* Fault registers */ > + unsigned long dear; > + }; > union { > unsigned long dsisr; /* on Book-S used for DSISR */ > unsigned long esr; /* on 4xx/Book-E used for ESR */ > diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c > index f74af8f9133c..50436b52c213 100644 > --- a/arch/powerpc/kernel/process.c > +++ b/arch/powerpc/kernel/process.c > @@ -1499,7 +1499,7 @@ static void __show_regs(struct pt_regs *regs) > trap == INTERRUPT_DATA_STORAGE || > trap == INTERRUPT_ALIGNMENT) { > if (IS_ENABLED(CONFIG_4xx) || IS_ENABLED(CONFIG_BOOKE)) > - pr_cont("DEAR: "REG" ESR: "REG" ", regs->dar, regs->esr); > + pr_cont("DEAR: "REG" ESR: "REG" ", regs->dear, regs->esr); > else > pr_cont("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr); > } > diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c > index 00789ad2c4a3..969dca8b0718 100644 > --- a/arch/powerpc/kernel/ptrace/ptrace.c > +++ b/arch/powerpc/kernel/ptrace/ptrace.c > @@ -373,6 +373,8 @@ void __init pt_regs_check(void) > offsetof(struct user_pt_regs, trap)); > BUILD_BUG_ON(offsetof(struct pt_regs, dar) != > offsetof(struct user_pt_regs, dar)); > + BUILD_BUG_ON(offsetof(struct pt_regs, dear) != > + offsetof(struct user_pt_regs, dear)); > BUILD_BUG_ON(offsetof(struct pt_regs, dsisr) != > offsetof(struct user_pt_regs, dsisr)); > BUILD_BUG_ON(offsetof(struct pt_regs, esr) != > diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c > index 2164f5705a0b..0796630d3d23 100644 > --- a/arch/powerpc/kernel/traps.c > +++ b/arch/powerpc/kernel/traps.c > @@ -1609,7 +1609,10 @@ DEFINE_INTERRUPT_HANDLER(alignment_exception) > } > bad: > if (user_mode(regs)) > - _exception(sig, regs, code, regs->dar); > + if (IS_ENABLED(CONFIG_4xx) || IS_ENABLED(CONFIG_BOOKE)) > + _exception(sig, regs, code, regs->dear); > + else > + _exception(sig, regs, code, regs->dar); > else > bad_page_fault(regs, sig); > } > diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c > index 62953d4e7c93..3db6b39a1178 100644 > --- a/arch/powerpc/mm/fault.c > +++ b/arch/powerpc/mm/fault.c > @@ -542,7 +542,7 @@ static __always_inline void __do_page_fault(struct pt_regs *regs) > long err; > > if (IS_ENABLED(CONFIG_4xx) || IS_ENABLED(CONFIG_BOOKE)) > - err = ___do_page_fault(regs, regs->dar, regs->esr); > + err = ___do_page_fault(regs, regs->dear, regs->esr); > else > err = ___do_page_fault(regs, regs->dar, regs->dsisr); > >
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