Messages in this thread Patch in this message |  | | From | sxwjean@me ... | Subject | [RFC PATCH 3/4] powerpc: Optimize register usage for dear register | Date | Mon, 26 Jul 2021 22:30:52 +0800 |
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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.
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); -- 2.30.2
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