[PATCH v2 28/43] powerpc/64e: Call bad_page_fault() from do_page_fault()

[Christophe Leroy]

book3e/64 is the last one calling __bad_page_fault()
from assembly.

Save non volatile registers before calling do_page_fault()
and modify do_page_fault() to call __bad_page_fault()
for all platforms.

Then it can be refactored by the call of bad_page_fault()
which avoids the duplication of the exception table search.

Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
 arch/powerpc/kernel/exceptions-64e.S |  8 +-------
 arch/powerpc/mm/fault.c              | 17 ++++-------------
 2 files changed, 5 insertions(+), 20 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64e.S 
b/arch/powerpc/kernel/exceptions-64e.S
index e8eb9992a270..b60f89078a3f 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -1010,15 +1010,9 @@ storage_fault_common:
        addi    r3,r1,STACK_FRAME_OVERHEAD
        ld      r14,PACA_EXGEN+EX_R14(r13)
        ld      r15,PACA_EXGEN+EX_R15(r13)
+       bl      save_nvgprs
        bl      do_page_fault
-       cmpdi   r3,0
-       bne-    1f
        b       ret_from_except_lite
-1:     bl      save_nvgprs
-       mr      r4,r3
-       addi    r3,r1,STACK_FRAME_OVERHEAD
-       bl      __bad_page_fault
-       b       ret_from_except
 
 /*
  * Alignment exception doesn't fit entirely in the 0x100 bytes so it
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 2e54bac99a22..7bcff3fca110 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -541,24 +541,15 @@ NOKPROBE_SYMBOL(___do_page_fault);
 
 static long __do_page_fault(struct pt_regs *regs)
 {
-       const struct exception_table_entry *entry;
        long err;
 
        err = ___do_page_fault(regs, regs->dar, regs->dsisr);
        if (likely(!err))
-               return err;
-
-       entry = search_exception_tables(regs->nip);
-       if (likely(entry)) {
-               instruction_pointer_set(regs, extable_fixup(entry));
                return 0;
-       } else if (!IS_ENABLED(CONFIG_PPC_BOOK3E_64)) {
-               __bad_page_fault(regs, err);
-               return 0;
-       } else {
-               /* 32 and 64e handle the bad page fault in asm */
-               return err;
-       }
+
+       bad_page_fault(regs, err);
+
+       return 0;
 }
 NOKPROBE_SYMBOL(__do_page_fault);
 
-- 
2.25.0