Re: [PATCH v2 12/13] powerpc/ftrace: Prepare ftrace_64_mprofile.S for reuse by PPC32

2022-02-15 Thread Christophe Leroy


Le 14/02/2022 à 18:51, Naveen N. Rao a écrit :
> Christophe Leroy wrote:
>> PPC64 mprofile versions and PPC32 are very similar.
>>
>> Modify PPC64 version so that if can be reused for PPC32.
>>
>> Signed-off-by: Christophe Leroy 
>> ---
>>  .../powerpc/kernel/trace/ftrace_64_mprofile.S | 73 +--
>>  1 file changed, 51 insertions(+), 22 deletions(-)
> 
> While I agree that ppc32 and -mprofile-kernel ftrace code are very 
> similar, I think this patch adds way too many #ifdefs. IMHO, this
> makes the resultant code quite difficult to follow.

Ok, I can introduce some GAS macros for a few of them in a followup patch.

Christophe

Re: [PATCH v2 12/13] powerpc/ftrace: Prepare ftrace_64_mprofile.S for reuse by PPC32

2022-02-14 Thread Naveen N. Rao

Christophe Leroy wrote:

PPC64 mprofile versions and PPC32 are very similar.

Modify PPC64 version so that if can be reused for PPC32.

Signed-off-by: Christophe Leroy 
---
 .../powerpc/kernel/trace/ftrace_64_mprofile.S | 73 +--
 1 file changed, 51 insertions(+), 22 deletions(-)


While I agree that ppc32 and -mprofile-kernel ftrace code are very 
similar, I think this patch adds way too many #ifdefs. IMHO, this

makes the resultant code quite difficult to follow.


- Naveen



diff --git a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S 
b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
index 6071e0122797..56da60e98327 100644
--- a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
+++ b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
@@ -34,13 +34,16 @@
  */
 _GLOBAL(ftrace_regs_caller)
/* Save the original return address in A's stack frame */
-   std r0,LRSAVE(r1)
+#ifdef CONFIG_MPROFILE_KERNEL
+   PPC_STL r0,LRSAVE(r1)
+#endif
 
 	/* Create our stack frame + pt_regs */

-   stdur1,-SWITCH_FRAME_SIZE(r1)
+   PPC_STLUr1,-SWITCH_FRAME_SIZE(r1)
 
 	/* Save all gprs to pt_regs */

SAVE_GPR(0, r1)
+#ifdef CONFIG_PPC64
SAVE_GPRS(2, 11, r1)
 
 	/* Ok to continue? */

@@ -49,10 +52,13 @@ _GLOBAL(ftrace_regs_caller)
beq ftrace_no_trace
 
 	SAVE_GPRS(12, 31, r1)

+#else
+   stmwr2, GPR2(r1)
+#endif
 
 	/* Save previous stack pointer (r1) */

addir8, r1, SWITCH_FRAME_SIZE
-   std r8, GPR1(r1)
+   PPC_STL r8, GPR1(r1)
 
 	/* Load special regs for save below */

mfmsr   r8
@@ -63,10 +69,11 @@ _GLOBAL(ftrace_regs_caller)
/* Get the _mcount() call site out of LR */
mflrr7
/* Save it as pt_regs->nip */
-   std r7, _NIP(r1)
+   PPC_STL r7, _NIP(r1)
/* Save the read LR in pt_regs->link */
-   std r0, _LINK(r1)
+   PPC_STL r0, _LINK(r1)
 
+#ifdef CONFIG_PPC64

/* Save callee's TOC in the ABI compliant location */
std r2, 24(r1)
ld  r2,PACATOC(r13) /* get kernel TOC in r2 */
@@ -74,8 +81,12 @@ _GLOBAL(ftrace_regs_caller)
addis   r3,r2,function_trace_op@toc@ha
addir3,r3,function_trace_op@toc@l
ld  r5,0(r3)
+#else
+   lis r3,function_trace_op@ha
+   lwz r5,function_trace_op@l(r3)
+#endif
 
-#ifdef CONFIG_LIVEPATCH

+#ifdef CONFIG_LIVEPATCH_64
mr  r14,r7  /* remember old NIP */
 #endif
/* Calculate ip from nip-4 into r3 for call below */
@@ -85,10 +96,10 @@ _GLOBAL(ftrace_regs_caller)
mr  r4, r0
 
 	/* Save special regs */

-   std r8, _MSR(r1)
-   std r9, _CTR(r1)
-   std r10, _XER(r1)
-   std r11, _CCR(r1)
+   PPC_STL r8, _MSR(r1)
+   PPC_STL r9, _CTR(r1)
+   PPC_STL r10, _XER(r1)
+   PPC_STL r11, _CCR(r1)
 
 	/* Load &pt_regs in r6 for call below */

addir6, r1 ,STACK_FRAME_OVERHEAD
@@ -100,27 +111,32 @@ ftrace_regs_call:
nop
 
 	/* Load ctr with the possibly modified NIP */

-   ld  r3, _NIP(r1)
+   PPC_LL  r3, _NIP(r1)
mtctr   r3
-#ifdef CONFIG_LIVEPATCH
+#ifdef CONFIG_LIVEPATCH_64
cmpdr14, r3 /* has NIP been altered? */
 #endif
 
 	/* Restore gprs */

-   REST_GPR(0, r1)
+#ifdef CONFIG_PPC64
REST_GPRS(2, 31, r1)
+#else
+   lmw r2, GPR2(r1)
+#endif
 
 	/* Restore possibly modified LR */

-   ld  r0, _LINK(r1)
+   PPC_LL  r0, _LINK(r1)
mtlrr0
 
+#ifdef CONFIG_PPC64

/* Restore callee's TOC */
ld  r2, 24(r1)
+#endif
 
 	/* Pop our stack frame */

addi r1, r1, SWITCH_FRAME_SIZE
 
-#ifdef CONFIG_LIVEPATCH

+#ifdef CONFIG_LIVEPATCH_64
 /* Based on the cmpd above, if the NIP was altered handle livepatch */
bne-livepatch_handler
 #endif
@@ -129,6 +145,7 @@ ftrace_regs_call:
 _GLOBAL(ftrace_stub)
blr
 
+#ifdef CONFIG_PPC64

 ftrace_no_trace:
mflrr3
mtctr   r3
@@ -136,25 +153,31 @@ ftrace_no_trace:
addir1, r1, SWITCH_FRAME_SIZE
mtlrr0
bctr
+#endif
 
 _GLOBAL(ftrace_caller)

/* Save the original return address in A's stack frame */
-   std r0, LRSAVE(r1)
+#ifdef CONFIG_MPROFILE_KERNEL
+   PPC_STL r0, LRSAVE(r1)
+#endif
 
 	/* Create our stack frame + pt_regs */

-   stdur1, -SWITCH_FRAME_SIZE(r1)
+   PPC_STLUr1, -SWITCH_FRAME_SIZE(r1)
 
 	/* Save all gprs to pt_regs */

SAVE_GPRS(3, 10, r1)
 
+#ifdef CONFIG_PPC64

lbz r3, PACA_FTRACE_ENABLED(r13)
cmpdi   r3, 0
beq ftrace_no_trace
+#endif
 
 	/* Get the _mcount() call site out of LR */

mflrr7
-   std r7, _NIP(r1)
+   PPC_STL r7, _NIP(r1)
 
+#ifdef CONFIG_PPC64

/* Save callee's TOC in the ABI compliant location */
std r2, 24(r1)
ld  r2, PACATOC(r13)/* get kernel TOC in r2 */
@@ -162,6 +18