Le 05/11/2020 à 15:34, Nicholas Piggin a écrit :
This also moves the 32s DABR match to C.

Is there a real benefit doing this ?


Similar to the previous patch this makes interrupt handler function
types more regular so they can be wrapped with the next patch.

bad_page_fault and do_break are not performance critical.

Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
  arch/powerpc/include/asm/bug.h             |  2 +-
  arch/powerpc/include/asm/debug.h           |  3 +--
  arch/powerpc/kernel/entry_32.S             | 14 ++++----------
  arch/powerpc/kernel/exceptions-64e.S       |  3 +--
  arch/powerpc/kernel/exceptions-64s.S       |  3 +--
  arch/powerpc/kernel/head_8xx.S             |  5 ++---
  arch/powerpc/kernel/process.c              |  7 +++----
  arch/powerpc/kernel/traps.c                |  2 +-
  arch/powerpc/mm/book3s64/hash_utils.c      |  4 ++--
  arch/powerpc/mm/book3s64/slb.c             |  2 +-
  arch/powerpc/mm/fault.c                    | 14 +++++++-------
  arch/powerpc/platforms/8xx/machine_check.c |  2 +-
  12 files changed, 25 insertions(+), 36 deletions(-)

diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h
index 2fa0cf6c6011..4af6c3835eb2 100644
--- a/arch/powerpc/include/asm/bug.h
+++ b/arch/powerpc/include/asm/bug.h
@@ -113,7 +113,7 @@
  struct pt_regs;
  extern long do_page_fault(struct pt_regs *);
  extern long hash__do_page_fault(struct pt_regs *);
-extern void bad_page_fault(struct pt_regs *, unsigned long, int);
+extern void bad_page_fault(struct pt_regs *, int);

pointless extern

Christophe

  extern void _exception(int, struct pt_regs *, int, unsigned long);
  extern void _exception_pkey(struct pt_regs *, unsigned long, int);
  extern void die(const char *, struct pt_regs *, long);
diff --git a/arch/powerpc/include/asm/debug.h b/arch/powerpc/include/asm/debug.h
index ec57daf87f40..0550eceab3ca 100644
--- a/arch/powerpc/include/asm/debug.h
+++ b/arch/powerpc/include/asm/debug.h
@@ -52,8 +52,7 @@ extern void do_send_trap(struct pt_regs *regs, unsigned long 
address,
                         unsigned long error_code, int brkpt);
  #else
-extern void do_break(struct pt_regs *regs, unsigned long address,
-                    unsigned long error_code);
+void do_break(struct pt_regs *regs);
  #endif
#endif /* _ASM_POWERPC_DEBUG_H */
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 8cdc8bcde703..eb97df234a0c 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -657,10 +657,6 @@ ppc_swapcontext:
        .globl  handle_page_fault
  handle_page_fault:
        addi    r3,r1,STACK_FRAME_OVERHEAD
-#ifdef CONFIG_PPC_BOOK3S_32
-       andis.  r0,r5,DSISR_DABRMATCH@h
-       bne-    handle_dabr_fault
-#endif
        bl      do_page_fault
        cmpwi   r3,0
        beq+    ret_from_except
@@ -668,19 +664,17 @@ handle_page_fault:
        lwz     r0,_TRAP(r1)
        clrrwi  r0,r0,1
        stw     r0,_TRAP(r1)
-       mr      r5,r3
+       mr      r4,r3           /* err arg for bad_page_fault */
        addi    r3,r1,STACK_FRAME_OVERHEAD
-       lwz     r4,_DAR(r1)
+#ifdef CONFIG_PPC_BOOK3S_32
+       blt     handle_dabr_fault
+#endif
        bl      bad_page_fault
        b       ret_from_except_full
#ifdef CONFIG_PPC_BOOK3S_32
        /* We have a data breakpoint exception - handle it */
  handle_dabr_fault:
-       SAVE_NVGPRS(r1)
-       lwz     r0,_TRAP(r1)
-       clrrwi  r0,r0,1
-       stw     r0,_TRAP(r1)
        bl      do_break
        b       ret_from_except_full
  #endif
diff --git a/arch/powerpc/kernel/exceptions-64e.S 
b/arch/powerpc/kernel/exceptions-64e.S
index 25fa7d5a643c..dc728bb1c89a 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -1018,9 +1018,8 @@ storage_fault_common:
        bne-    1f
        b       ret_from_except_lite
  1:    bl      save_nvgprs
-       mr      r5,r3
+       mr      r4,r3
        addi    r3,r1,STACK_FRAME_OVERHEAD
-       ld      r4,_DAR(r1)
        bl      bad_page_fault
        b       ret_from_except
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 1f34cfd1887c..e6558c4d3f81 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2135,8 +2135,7 @@ EXC_COMMON_BEGIN(h_data_storage_common)
        GEN_COMMON h_data_storage
        addi    r3,r1,STACK_FRAME_OVERHEAD
  BEGIN_MMU_FTR_SECTION
-       ld      r4,_DAR(r1)
-       li      r5,SIGSEGV
+       li      r4,SIGSEGV
        bl      bad_page_fault
  MMU_FTR_SECTION_ELSE
        bl      unknown_exception
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 0cd95b633e2b..13eda7154695 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -408,10 +408,9 @@ do_databreakpoint:
        addi    r3,r1,STACK_FRAME_OVERHEAD
        mfspr   r4,SPRN_BAR
        stw     r4,_DAR(r11)
-#ifdef CONFIG_VMAP_STACK
-       lwz     r5,_DSISR(r11)
-#else
+#ifndef CONFIG_VMAP_STACK
        mfspr   r5,SPRN_DSISR
+       stw     r5,_DSISR(r11)
  #endif
        EXC_XFER_STD(0x1c00, do_break)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index d421a2c7f822..0bdd3ed653df 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -660,11 +660,10 @@ static void do_break_handler(struct pt_regs *regs)
        }
  }
-void do_break (struct pt_regs *regs, unsigned long address,
-                   unsigned long error_code)
+void do_break(struct pt_regs *regs)
  {
        current->thread.trap_nr = TRAP_HWBKPT;
-       if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
+       if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, regs->dsisr,
                        11, SIGSEGV) == NOTIFY_STOP)
                return;
@@ -682,7 +681,7 @@ void do_break (struct pt_regs *regs, unsigned long address,
                do_break_handler(regs);
/* Deliver the signal to userspace */
-       force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)address);
+       force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)regs->dar);
  }
  #endif        /* CONFIG_PPC_ADV_DEBUG_REGS */
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 5006dcbe1d9f..902fcbd1a778 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1641,7 +1641,7 @@ void alignment_exception(struct pt_regs *regs)
        if (user_mode(regs))
                _exception(sig, regs, code, regs->dar);
        else
-               bad_page_fault(regs, regs->dar, sig);
+               bad_page_fault(regs, sig);
bail:
        exception_exit(prev_state);
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c 
b/arch/powerpc/mm/book3s64/hash_utils.c
index 0f0bd4af4b2d..731518e7d56f 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -1537,7 +1537,7 @@ long do_hash_fault(struct pt_regs *regs)
         * the access, or panic if there isn't a handler.
         */
        if (unlikely(in_nmi())) {
-               bad_page_fault(regs, ea, SIGSEGV);
+               bad_page_fault(regs, SIGSEGV);
                return 0;
        }
@@ -1576,7 +1576,7 @@ long do_hash_fault(struct pt_regs *regs)
                        else
                                _exception(SIGBUS, regs, BUS_ADRERR, ea);
                } else {
-                       bad_page_fault(regs, ea, SIGBUS);
+                       bad_page_fault(regs, SIGBUS);
                }
                err = 0;
diff --git a/arch/powerpc/mm/book3s64/slb.c b/arch/powerpc/mm/book3s64/slb.c
index cc34d50874c1..ae89ad516247 100644
--- a/arch/powerpc/mm/book3s64/slb.c
+++ b/arch/powerpc/mm/book3s64/slb.c
@@ -898,7 +898,7 @@ void do_bad_slb_fault(struct pt_regs *regs)
                if (user_mode(regs))
                        _exception(SIGSEGV, regs, SEGV_BNDERR, regs->dar);
                else
-                       bad_page_fault(regs, regs->dar, SIGSEGV);
+                       bad_page_fault(regs, SIGSEGV);
        } else if (err == -EINVAL) {
                unrecoverable_exception(regs);
        } else {
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 390a296b16a3..49fbe564ea2b 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -375,7 +375,7 @@ static void sanity_check_fault(bool is_write, bool is_user,
  #elif defined(CONFIG_PPC_BOOK3E_64)
  #define page_fault_is_bad(__err)      ((__err) & DSISR_BAD_FAULT_64S)
  #else
-#define page_fault_is_bad(__err)       ((__err) & DSISR_BAD_FAULT_32S)
+#define page_fault_is_bad(__err)       ((__err) & DSISR_BAD_FAULT_32S | 
DSISR_DABRMATCH)
  #endif
  #endif
@@ -408,7 +408,7 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
                return 0;
if (unlikely(page_fault_is_bad(error_code))) {
-               if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && (error_code & 
DSISR_DABRMATCH))
+               if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (error_code & 
DSISR_DABRMATCH))
                        return -1;
if (is_user) {
@@ -562,14 +562,14 @@ long do_page_fault(struct pt_regs *regs)
        /* 32 and 64e handle errors in their asm code */
        if (unlikely(err)) {
                if (err > 0) {
-                       bad_page_fault(regs, address, err);
+                       bad_page_fault(regs, err);
                        err = 0;
                } else {
                        /*
                         * do_break() may change NV GPRS while handling the
                         * breakpoint. Return -ve to caller to do that.
                         */
-                       do_break(regs, address, error_code);
+                       do_break(regs);
                }
        }
  #endif
@@ -591,14 +591,14 @@ long hash__do_page_fault(struct pt_regs *regs)
        err = __do_page_fault(regs, address, error_code);
        if (unlikely(err)) {
                if (err > 0) {
-                       bad_page_fault(regs, address, err);
+                       bad_page_fault(regs, err);
                        err = 0;
                } else {
                        /*
                         * do_break() may change NV GPRS while handling the
                         * breakpoint. Return -ve to caller to do that.
                         */
-                       do_break(regs, address, error_code);
+                       do_break(regs);
                }
        }
@@ -612,7 +612,7 @@ NOKPROBE_SYMBOL(hash__do_page_fault);
   * It is called from the DSI and ISI handlers in head.S and from some
   * of the procedures in traps.c.
   */
-void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
+void bad_page_fault(struct pt_regs *regs, int sig)
  {
        const struct exception_table_entry *entry;
        int is_write = page_fault_is_write(regs->dsisr);
diff --git a/arch/powerpc/platforms/8xx/machine_check.c 
b/arch/powerpc/platforms/8xx/machine_check.c
index 88dedf38eccd..656365975895 100644
--- a/arch/powerpc/platforms/8xx/machine_check.c
+++ b/arch/powerpc/platforms/8xx/machine_check.c
@@ -26,7 +26,7 @@ int machine_check_8xx(struct pt_regs *regs)
         * to deal with that than having a wart in the mcheck handler.
         * -- BenH
         */
-       bad_page_fault(regs, regs->dar, SIGBUS);
+       bad_page_fault(regs, SIGBUS);
        return 1;
  #else
        return 0;

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