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powerpc/ftrace: Refactor ftrace_{regs_}caller

Browse source 
ftrace_caller() and frace_regs_caller() have now a lot in common.

Refactor them using GAS macros.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/9d7df9e4fc98a86051489f61d3c9bc67f92f7e27.1645099283.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2022-02-17 13:01:57 +01:00 committed by Michael Ellerman
parent 9bdb2eec3d
commit 228216716c
1 changed files with 45 additions and 102 deletions
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147
arch/powerpc/kernel/trace/ftrace_mprofile.S
View file

@ -32,7 +32,7 @@
* Our job is to save the register state into a struct pt_regs (on the stack)
* and then arrange for the ftrace function to be called.
*/
_GLOBAL(ftrace_regs_caller)
.macro ftrace_regs_entry allregs
/* Save the original return address in A's stack frame */
#ifdef CONFIG_MPROFILE_KERNEL
PPC_STL r0,LRSAVE(r1)
@ -43,7 +43,7 @@ _GLOBAL(ftrace_regs_caller)
/* Save all gprs to pt_regs */
SAVE_GPR(0, r1)
SAVE_GPRS(2, 11, r1)
SAVE_GPRS(3, 10, r1)
#ifdef CONFIG_PPC64
/* Ok to continue? */
@ -52,17 +52,29 @@ _GLOBAL(ftrace_regs_caller)
beq ftrace_no_trace
#endif
SAVE_GPRS(12, 31, r1)
.if \allregs == 1
SAVE_GPR(2, r1)
SAVE_GPRS(11, 31, r1)
.else
#ifdef CONFIG_LIVEPATCH_64
SAVE_GPR(14, r1)
#endif
.endif
/* Save previous stack pointer (r1) */
addi r8, r1, SWITCH_FRAME_SIZE
PPC_STL r8, GPR1(r1)
.if \allregs == 1
/* Load special regs for save below */
mfmsr r8
mfctr r9
mfxer r10
mfcr r11
.else
/* Clear MSR to flag as ftrace_caller versus frace_regs_caller */
li r8, 0
.endif
/* Get the _mcount() call site out of LR */
mflr r7
@ -96,19 +108,17 @@ _GLOBAL(ftrace_regs_caller)
/* Save special regs */
PPC_STL r8, _MSR(r1)
.if \allregs == 1
PPC_STL r9, _CTR(r1)
PPC_STL r10, _XER(r1)
PPC_STL r11, _CCR(r1)
.endif
/* Load &pt_regs in r6 for call below */
addi r6, r1, STACK_FRAME_OVERHEAD
.endm
/* ftrace_call(r3, r4, r5, r6) */
.globl ftrace_regs_call
ftrace_regs_call:
bl ftrace_stub
nop
.macro ftrace_regs_exit allregs
/* Load ctr with the possibly modified NIP */
PPC_LL r3, _NIP(r1)
mtctr r3
@ -118,7 +128,14 @@ ftrace_regs_call:
#endif
/* Restore gprs */
.if \allregs == 1
REST_GPRS(2, 31, r1)
.else
REST_GPRS(3, 10, r1)
#ifdef CONFIG_LIVEPATCH_64
REST_GPR(14, r1)
#endif
.endif
/* Restore possibly modified LR */
PPC_LL r0, _LINK(r1)
@ -137,6 +154,25 @@ ftrace_regs_call:
bne- livepatch_handler
#endif
bctr /* jump after _mcount site */
.endm
_GLOBAL(ftrace_regs_caller)
ftrace_regs_entry 1
/* ftrace_call(r3, r4, r5, r6) */
.globl ftrace_regs_call
ftrace_regs_call:
bl ftrace_stub
nop
ftrace_regs_exit 1
_GLOBAL(ftrace_caller)
ftrace_regs_entry 0
/* ftrace_call(r3, r4, r5, r6) */
.globl ftrace_call
ftrace_call:
bl ftrace_stub
nop
ftrace_regs_exit 0
_GLOBAL(ftrace_stub)
blr
@ -151,99 +187,6 @@ ftrace_no_trace:
bctr
#endif
_GLOBAL(ftrace_caller)
/* Save the original return address in A's stack frame */
#ifdef CONFIG_MPROFILE_KERNEL
PPC_STL r0, LRSAVE(r1)
#endif
/* Create our stack frame + pt_regs */
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
/* Save previous stack pointer (r1) */
addi r8, r1, SWITCH_FRAME_SIZE
PPC_STL r8, GPR1(r1)
/* Get the _mcount() call site out of LR */
mflr r7
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 */
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)
mr r14, r7 /* remember old NIP */
#endif
/* Calculate ip from nip-4 into r3 for call below */
subi r3, r7, MCOUNT_INSN_SIZE
/* Put the original return address in r4 as parent_ip */
PPC_STL r0, _LINK(r1)
mr r4, r0
/* Clear MSR to flag as ftrace_caller versus frace_regs_caller */
li r8, 0
PPC_STL r8, _MSR(r1)
/* Load &pt_regs in r6 for call below */
addi r6, r1, STACK_FRAME_OVERHEAD
/* ftrace_call(r3, r4, r5, r6) */
.globl ftrace_call
ftrace_call:
bl ftrace_stub
nop
PPC_LL r3, _NIP(r1)
mtctr r3
#ifdef CONFIG_LIVEPATCH_64
cmpd r14, r3 /* has NIP been altered? */
REST_GPR(14, r1)
#endif
/* Restore gprs */
REST_GPRS(3, 10, r1)
#ifdef CONFIG_PPC64
/* Restore callee's TOC */
ld r2, 24(r1)
#endif
/* Restore possibly modified LR */
PPC_LL r0, _LINK(r1)
mtlr r0
/* Pop our stack frame */
addi r1, r1, SWITCH_FRAME_SIZE
#ifdef CONFIG_LIVEPATCH_64
/* Based on the cmpd above, if the NIP was altered handle livepatch */
bne- livepatch_handler
#endif
bctr /* jump after _mcount site */
#ifdef CONFIG_LIVEPATCH_64
/*
* This function runs in the mcount context, between two functions. As