Commit 41315494 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/ftrace: Prepare ftrace_64_mprofile.S for reuse by PPC32 



PPC64 mprofile versions and PPC32 are very similar.

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

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/82a732915dc71ee766e31809350939331944006d.1640017960.git.christophe.leroy@csgroup.eu
parent 83021378

arch/powerpc/kernel/trace/ftrace_64_mprofile.S

+51 −22
Original line number Diff line number Diff line
@@ -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 */

	stdu	r1,-SWITCH_FRAME_SIZE(r1)

	PPC_STLU	r1,-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

	stmw	r2, GPR2(r1)

#endif



	/* Save previous stack pointer (r1) */

	addi	r8, 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 */

	mflr	r7

	/* 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

	addi	r3,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 */

	addi    r6, 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

	cmpd	r14, 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)

	mtlr	r0



#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:

	mflr	r3

	mtctr	r3
@@ -136,25 +153,31 @@ ftrace_no_trace: 
	addi	r1, r1, SWITCH_FRAME_SIZE

	mtlr	r0

	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 */

	stdu	r1, -SWITCH_FRAME_SIZE(r1)

	PPC_STLU	r1, -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 */

	mflr	r7

	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 +185,10 @@ _GLOBAL(ftrace_caller) 
	addis	r3, r2, function_trace_op@toc@ha

	addi	r3, 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_64

	SAVE_GPR(14, r1)
@@ -171,7 +198,7 @@ _GLOBAL(ftrace_caller) 
	subi    r3, r7, MCOUNT_INSN_SIZE



	/* Put the original return address in r4 as parent_ip */

	std	r0, _LINK(r1)

	PPC_STL	r0, _LINK(r1)

	mr	r4, r0



	/* Load &pt_regs in r6 for call below */
@@ -183,7 +210,7 @@ ftrace_call: 
	bl	ftrace_stub

	nop



	ld	r3, _NIP(r1)

	PPC_LL	r3, _NIP(r1)

	mtctr	r3

#ifdef CONFIG_LIVEPATCH_64

	cmpd	r14, r3		/* has NIP been altered? */
@@ -193,11 +220,13 @@ ftrace_call: 
	/* Restore gprs */

	REST_GPRS(3, 10, r1)



#ifdef CONFIG_PPC64

	/* Restore callee's TOC */

	ld	r2, 24(r1)

#endif



	/* Restore possibly modified LR */

	ld	r0, _LINK(r1)

	PPC_LL	r0, _LINK(r1)

	mtlr	r0



	/* Pop our stack frame */
@@ -209,7 +238,7 @@ ftrace_call: 
#endif

	bctr			/* jump after _mcount site */



#ifdef CONFIG_LIVEPATCH

#ifdef CONFIG_LIVEPATCH_64

	/*

	 * This function runs in the mcount context, between two functions. As

	 * such it can only clobber registers which are volatile and used in