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Subject[PATCH v4 07/21] powerpc/8xx: DataAccess exception not generated by MPC8xx
Date
DataAccess exception is never generated by MPC8xx so do the job directly where
it is used to avoid an unnecessary branching.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

---
Changes in v2:
- None

Changes in v3:
- arch/powerpc/mm/fault.c uses the vector number, so make sure it understands
the new ones.

Changes in v4:
- Removing the change to mm/fault.c, faking the exception id to make mm/fault
think it comes from DataAccess.

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index a535576..570c1ee 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -219,19 +219,10 @@ MachineCheck:
EXC_XFER_STD(0x200, machine_check_exception)

/* Data access exception.
- * This is "never generated" by the MPC8xx. We jump to it for other
- * translation errors.
+ * This is "never generated" by the MPC8xx.
*/
. = 0x300
DataAccess:
- EXCEPTION_PROLOG
- mfspr r10,SPRN_DSISR
- stw r10,_DSISR(r11)
- mr r5,r10
- mfspr r4,SPRN_DAR
- li r10,0x00f0
- mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */
- EXC_XFER_LITE(0x300, handle_page_fault)

/* Instruction access exception.
* This is "never generated" by the MPC8xx.
@@ -491,7 +482,15 @@ DataTLBError:
beq- FixupDAR /* must be a buggy dcbX, icbi insn. */
DARFixed:/* Return from dcbx instruction bug workaround */
EXCEPTION_EPILOG_0
- b DataAccess
+ EXCEPTION_PROLOG
+ mfspr r10,SPRN_DSISR
+ stw r10,_DSISR(r11)
+ mr r5,r10
+ mfspr r4,SPRN_DAR
+ li r10,0x00f0
+ mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */
+ /* 0x300 is DataAccess exception, needed by bad_page_fault() */
+ EXC_XFER_LITE(0x300, handle_page_fault)

EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_EE)
EXCEPTION(0x1600, Trap_16, unknown_exception, EXC_XFER_EE)
--
2.1.0


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