Commit 6873def9 authored by Michael Ellerman's avatar Michael Ellerman Committed by Benjamin Herrenschmidt
Browse files

selftests/powerpc: Move core_busy_loop() into asm 



There is at least one bug in core_busy_loop(), we use r0, but it's
not in the clobber list. We were getting away with this it seems but
that was luck.

It's also fishy to be touching the stack, even if we do it below the
stack pointer. It seems we get away with it, but looking at the
generated code that may just be luck.

So move it into assembler, do all the stack handling by hand. We create
a stack frame to save the non-volatiles in, so we can muck around with
them.

Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 6861b44a

tools/testing/selftests/powerpc/pmu/ebb/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -17,7 +17,7 @@ PROGS := reg_access_test event_attributes_test cycles_test \ 


all: $(PROGS)



$(PROGS): ../../harness.c ../event.c ../lib.c ebb.c ebb_handler.S trace.c

$(PROGS): ../../harness.c ../event.c ../lib.c ebb.c ebb_handler.S trace.c busy_loop.S



instruction_count_test: ../loop.S

tools/testing/selftests/powerpc/pmu/ebb/busy_loop.S

0 → 100644
+271 −0
Original line number Diff line number Diff line 
/*

 * Copyright 2014, Michael Ellerman, IBM Corp.

 * Licensed under GPLv2.

 */



#include <ppc-asm.h>



	.text



FUNC_START(core_busy_loop)

	stdu	%r1, -168(%r1)

	std	r14, 160(%r1)

	std	r15, 152(%r1)

	std	r16, 144(%r1)

	std	r17, 136(%r1)

	std	r18, 128(%r1)

	std	r19, 120(%r1)

	std	r20, 112(%r1)

	std	r21, 104(%r1)

	std	r22, 96(%r1)

	std	r23, 88(%r1)

	std	r24, 80(%r1)

	std	r25, 72(%r1)

	std	r26, 64(%r1)

	std	r27, 56(%r1)

	std	r28, 48(%r1)

	std	r29, 40(%r1)

	std	r30, 32(%r1)

	std	r31, 24(%r1)



	li	 r3, 0x3030

	std	 r3, -96(%r1)

	li	 r4, 0x4040

	std	 r4, -104(%r1)

	li	 r5, 0x5050

	std	 r5, -112(%r1)

	li	 r6, 0x6060

	std	 r6, -120(%r1)

	li	 r7, 0x7070

	std	 r7, -128(%r1)

	li	 r8, 0x0808

	std	 r8, -136(%r1)

	li	 r9, 0x0909

	std	 r9, -144(%r1)

	li	r10, 0x1010

	std	r10, -152(%r1)

	li	r11, 0x1111

	std	r11, -160(%r1)

	li	r14, 0x1414

	std	r14, -168(%r1)

	li	r15, 0x1515

	std	r15, -176(%r1)

	li	r16, 0x1616

	std	r16, -184(%r1)

	li	r17, 0x1717

	std	r17, -192(%r1)

	li	r18, 0x1818

	std	r18, -200(%r1)

	li	r19, 0x1919

	std	r19, -208(%r1)

	li	r20, 0x2020

	std	r20, -216(%r1)

	li	r21, 0x2121

	std	r21, -224(%r1)

	li	r22, 0x2222

	std	r22, -232(%r1)

	li	r23, 0x2323

	std	r23, -240(%r1)

	li	r24, 0x2424

	std	r24, -248(%r1)

	li	r25, 0x2525

	std	r25, -256(%r1)

	li	r26, 0x2626

	std	r26, -264(%r1)

	li	r27, 0x2727

	std	r27, -272(%r1)

	li	r28, 0x2828

	std	r28, -280(%r1)

	li	r29, 0x2929

	std	r29, -288(%r1)

	li	r30, 0x3030

	li	r31, 0x3131



	li	r3, 0

0:	addi	r3, r3, 1

	cmpwi	r3, 100

	blt	0b



	/* Return 1 (fail) unless we get through all the checks */

	li	r3, 1



	/* Check none of our registers have been corrupted */

	cmpwi	r4,  0x4040

	bne	1f

	cmpwi	r5,  0x5050

	bne	1f

	cmpwi	r6,  0x6060

	bne	1f

	cmpwi	r7,  0x7070

	bne	1f

	cmpwi	r8,  0x0808

	bne	1f

	cmpwi	r9,  0x0909

	bne	1f

	cmpwi	r10, 0x1010

	bne	1f

	cmpwi	r11, 0x1111

	bne	1f

	cmpwi	r14, 0x1414

	bne	1f

	cmpwi	r15, 0x1515

	bne	1f

	cmpwi	r16, 0x1616

	bne	1f

	cmpwi	r17, 0x1717

	bne	1f

	cmpwi	r18, 0x1818

	bne	1f

	cmpwi	r19, 0x1919

	bne	1f

	cmpwi	r20, 0x2020

	bne	1f

	cmpwi	r21, 0x2121

	bne	1f

	cmpwi	r22, 0x2222

	bne	1f

	cmpwi	r23, 0x2323

	bne	1f

	cmpwi	r24, 0x2424

	bne	1f

	cmpwi	r25, 0x2525

	bne	1f

	cmpwi	r26, 0x2626

	bne	1f

	cmpwi	r27, 0x2727

	bne	1f

	cmpwi	r28, 0x2828

	bne	1f

	cmpwi	r29, 0x2929

	bne	1f

	cmpwi	r30, 0x3030

	bne	1f

	cmpwi	r31, 0x3131

	bne	1f



	/* Load junk into all our registers before we reload them from the stack. */

	li	r3,  0xde

	li	r4,  0xad

	li	r5,  0xbe

	li	r6,  0xef

	li	r7,  0xde

	li	r8,  0xad

	li	r9,  0xbe

	li	r10, 0xef

	li	r11, 0xde

	li	r14, 0xad

	li	r15, 0xbe

	li	r16, 0xef

	li	r17, 0xde

	li	r18, 0xad

	li	r19, 0xbe

	li	r20, 0xef

	li	r21, 0xde

	li	r22, 0xad

	li	r23, 0xbe

	li	r24, 0xef

	li	r25, 0xde

	li	r26, 0xad

	li	r27, 0xbe

	li	r28, 0xef

	li	r29, 0xdd



	ld	r3,	-96(%r1)

	cmpwi	r3,  0x3030

	bne	1f

	ld	r4,	-104(%r1)

	cmpwi	r4,  0x4040

	bne	1f

	ld	r5,	-112(%r1)

	cmpwi	r5,  0x5050

	bne	1f

	ld	r6,	-120(%r1)

	cmpwi	r6,  0x6060

	bne	1f

	ld	r7,	-128(%r1)

	cmpwi	r7,  0x7070

	bne	1f

	ld	r8,	-136(%r1)

	cmpwi	r8,  0x0808

	bne	1f

	ld	r9,	-144(%r1)

	cmpwi	r9,  0x0909

	bne	1f

	ld	r10, -152(%r1)

	cmpwi	r10, 0x1010

	bne	1f

	ld	r11, -160(%r1)

	cmpwi	r11, 0x1111

	bne	1f

	ld	r14, -168(%r1)

	cmpwi	r14, 0x1414

	bne	1f

	ld	r15, -176(%r1)

	cmpwi	r15, 0x1515

	bne	1f

	ld	r16, -184(%r1)

	cmpwi	r16, 0x1616

	bne	1f

	ld	r17, -192(%r1)

	cmpwi	r17, 0x1717

	bne	1f

	ld	r18, -200(%r1)

	cmpwi	r18, 0x1818

	bne	1f

	ld	r19, -208(%r1)

	cmpwi	r19, 0x1919

	bne	1f

	ld	r20, -216(%r1)

	cmpwi	r20, 0x2020

	bne	1f

	ld	r21, -224(%r1)

	cmpwi	r21, 0x2121

	bne	1f

	ld	r22, -232(%r1)

	cmpwi	r22, 0x2222

	bne	1f

	ld	r23, -240(%r1)

	cmpwi	r23, 0x2323

	bne	1f

	ld	r24, -248(%r1)

	cmpwi	r24, 0x2424

	bne	1f

	ld	r25, -256(%r1)

	cmpwi	r25, 0x2525

	bne	1f

	ld	r26, -264(%r1)

	cmpwi	r26, 0x2626

	bne	1f

	ld	r27, -272(%r1)

	cmpwi	r27, 0x2727

	bne	1f

	ld	r28, -280(%r1)

	cmpwi	r28, 0x2828

	bne	1f

	ld	r29, -288(%r1)

	cmpwi	r29, 0x2929

	bne	1f



	/* Load 0 (success) to return */

	li	r3, 0



1:	ld	r14, 160(%r1)

	ld	r15, 152(%r1)

	ld	r16, 144(%r1)

	ld	r17, 136(%r1)

	ld	r18, 128(%r1)

	ld	r19, 120(%r1)

	ld	r20, 112(%r1)

	ld	r21, 104(%r1)

	ld	r22, 96(%r1)

	ld	r23, 88(%r1)

	ld	r24, 80(%r1)

	ld	r25, 72(%r1)

	ld	r26, 64(%r1)

	ld	r27, 56(%r1)

	ld	r28, 48(%r1)

	ld	r29, 40(%r1)

	ld	r30, 32(%r1)

	ld	r31, 24(%r1)

	addi	%r1, %r1, 168

	blr

tools/testing/selftests/powerpc/pmu/ebb/ebb.c

+0 −251
Original line number Diff line number Diff line
@@ -335,257 +335,6 @@ void event_leader_ebb_init(struct event *e) 
	e->attr.pinned = 1;

}



int core_busy_loop(void)

{

	int rc;



	asm volatile (

		"li  3,  0x3030\n"

		"std 3,  -96(1)\n"

		"li  4,  0x4040\n"

		"std 4,  -104(1)\n"

		"li  5,  0x5050\n"

		"std 5,  -112(1)\n"

		"li  6,  0x6060\n"

		"std 6,  -120(1)\n"

		"li  7,  0x7070\n"

		"std 7,  -128(1)\n"

		"li  8,  0x0808\n"

		"std 8,  -136(1)\n"

		"li  9,  0x0909\n"

		"std 9,  -144(1)\n"

		"li  10, 0x1010\n"

		"std 10, -152(1)\n"

		"li  11, 0x1111\n"

		"std 11, -160(1)\n"

		"li  14, 0x1414\n"

		"std 14, -168(1)\n"

		"li  15, 0x1515\n"

		"std 15, -176(1)\n"

		"li  16, 0x1616\n"

		"std 16, -184(1)\n"

		"li  17, 0x1717\n"

		"std 17, -192(1)\n"

		"li  18, 0x1818\n"

		"std 18, -200(1)\n"

		"li  19, 0x1919\n"

		"std 19, -208(1)\n"

		"li  20, 0x2020\n"

		"std 20, -216(1)\n"

		"li  21, 0x2121\n"

		"std 21, -224(1)\n"

		"li  22, 0x2222\n"

		"std 22, -232(1)\n"

		"li  23, 0x2323\n"

		"std 23, -240(1)\n"

		"li  24, 0x2424\n"

		"std 24, -248(1)\n"

		"li  25, 0x2525\n"

		"std 25, -256(1)\n"

		"li  26, 0x2626\n"

		"std 26, -264(1)\n"

		"li  27, 0x2727\n"

		"std 27, -272(1)\n"

		"li  28, 0x2828\n"

		"std 28, -280(1)\n"

		"li  29, 0x2929\n"

		"std 29, -288(1)\n"

		"li  30, 0x3030\n"

		"li  31, 0x3131\n"



		"li    3,  0\n"

		"0: "

		"addi  3, 3, 1\n"

		"cmpwi 3, 100\n"

		"blt   0b\n"



		/* Return 1 (fail) unless we get through all the checks */

		"li	0, 1\n"



		/* Check none of our registers have been corrupted */

		"cmpwi  4,  0x4040\n"

		"bne	1f\n"

		"cmpwi  5,  0x5050\n"

		"bne	1f\n"

		"cmpwi  6,  0x6060\n"

		"bne	1f\n"

		"cmpwi  7,  0x7070\n"

		"bne	1f\n"

		"cmpwi  8,  0x0808\n"

		"bne	1f\n"

		"cmpwi  9,  0x0909\n"

		"bne	1f\n"

		"cmpwi  10, 0x1010\n"

		"bne	1f\n"

		"cmpwi  11, 0x1111\n"

		"bne	1f\n"

		"cmpwi  14, 0x1414\n"

		"bne	1f\n"

		"cmpwi  15, 0x1515\n"

		"bne	1f\n"

		"cmpwi  16, 0x1616\n"

		"bne	1f\n"

		"cmpwi  17, 0x1717\n"

		"bne	1f\n"

		"cmpwi  18, 0x1818\n"

		"bne	1f\n"

		"cmpwi  19, 0x1919\n"

		"bne	1f\n"

		"cmpwi  20, 0x2020\n"

		"bne	1f\n"

		"cmpwi  21, 0x2121\n"

		"bne	1f\n"

		"cmpwi  22, 0x2222\n"

		"bne	1f\n"

		"cmpwi  23, 0x2323\n"

		"bne	1f\n"

		"cmpwi  24, 0x2424\n"

		"bne	1f\n"

		"cmpwi  25, 0x2525\n"

		"bne	1f\n"

		"cmpwi  26, 0x2626\n"

		"bne	1f\n"

		"cmpwi  27, 0x2727\n"

		"bne	1f\n"

		"cmpwi  28, 0x2828\n"

		"bne	1f\n"

		"cmpwi  29, 0x2929\n"

		"bne	1f\n"

		"cmpwi  30, 0x3030\n"

		"bne	1f\n"

		"cmpwi  31, 0x3131\n"

		"bne	1f\n"



		/* Load junk into all our registers before we reload them from the stack. */

		"li  3,  0xde\n"

		"li  4,  0xad\n"

		"li  5,  0xbe\n"

		"li  6,  0xef\n"

		"li  7,  0xde\n"

		"li  8,  0xad\n"

		"li  9,  0xbe\n"

		"li  10, 0xef\n"

		"li  11, 0xde\n"

		"li  14, 0xad\n"

		"li  15, 0xbe\n"

		"li  16, 0xef\n"

		"li  17, 0xde\n"

		"li  18, 0xad\n"

		"li  19, 0xbe\n"

		"li  20, 0xef\n"

		"li  21, 0xde\n"

		"li  22, 0xad\n"

		"li  23, 0xbe\n"

		"li  24, 0xef\n"

		"li  25, 0xde\n"

		"li  26, 0xad\n"

		"li  27, 0xbe\n"

		"li  28, 0xef\n"

		"li  29, 0xdd\n"



		"ld     3,  -96(1)\n"

		"cmpwi  3,  0x3030\n"

		"bne	1f\n"

		"ld     4,  -104(1)\n"

		"cmpwi  4,  0x4040\n"

		"bne	1f\n"

		"ld     5,  -112(1)\n"

		"cmpwi  5,  0x5050\n"

		"bne	1f\n"

		"ld     6,  -120(1)\n"

		"cmpwi  6,  0x6060\n"

		"bne	1f\n"

		"ld     7,  -128(1)\n"

		"cmpwi  7,  0x7070\n"

		"bne	1f\n"

		"ld     8,  -136(1)\n"

		"cmpwi  8,  0x0808\n"

		"bne	1f\n"

		"ld     9,  -144(1)\n"

		"cmpwi  9,  0x0909\n"

		"bne	1f\n"

		"ld     10, -152(1)\n"

		"cmpwi  10, 0x1010\n"

		"bne	1f\n"

		"ld     11, -160(1)\n"

		"cmpwi  11, 0x1111\n"

		"bne	1f\n"

		"ld     14, -168(1)\n"

		"cmpwi  14, 0x1414\n"

		"bne	1f\n"

		"ld     15, -176(1)\n"

		"cmpwi  15, 0x1515\n"

		"bne	1f\n"

		"ld     16, -184(1)\n"

		"cmpwi  16, 0x1616\n"

		"bne	1f\n"

		"ld     17, -192(1)\n"

		"cmpwi  17, 0x1717\n"

		"bne	1f\n"

		"ld     18, -200(1)\n"

		"cmpwi  18, 0x1818\n"

		"bne	1f\n"

		"ld     19, -208(1)\n"

		"cmpwi  19, 0x1919\n"

		"bne	1f\n"

		"ld     20, -216(1)\n"

		"cmpwi  20, 0x2020\n"

		"bne	1f\n"

		"ld     21, -224(1)\n"

		"cmpwi  21, 0x2121\n"

		"bne	1f\n"

		"ld     22, -232(1)\n"

		"cmpwi  22, 0x2222\n"

		"bne	1f\n"

		"ld     23, -240(1)\n"

		"cmpwi  23, 0x2323\n"

		"bne	1f\n"

		"ld     24, -248(1)\n"

		"cmpwi  24, 0x2424\n"

		"bne	1f\n"

		"ld     25, -256(1)\n"

		"cmpwi  25, 0x2525\n"

		"bne	1f\n"

		"ld     26, -264(1)\n"

		"cmpwi  26, 0x2626\n"

		"bne	1f\n"

		"ld     27, -272(1)\n"

		"cmpwi  27, 0x2727\n"

		"bne	1f\n"

		"ld     28, -280(1)\n"

		"cmpwi  28, 0x2828\n"

		"bne	1f\n"

		"ld     29, -288(1)\n"

		"cmpwi  29, 0x2929\n"

		"bne	1f\n"



		/* Load 0 (success) to return */

		"li	0, 0\n"



		"1: 	mr %0, 0\n"



		: "=r" (rc)

		: /* no inputs */

		: "3", "4", "5", "6", "7", "8", "9", "10", "11", "14",

		  "15", "16", "17", "18", "19", "20", "21", "22", "23",

		   "24", "25", "26", "27", "28", "29", "30", "31",

		   "memory"

	);



	return rc;

}



int core_busy_loop_with_freeze(void)

{

	int rc;



	mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_FC);

	rc = core_busy_loop();

	mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) |  MMCR0_FC);



	return rc;

}



int ebb_child(union pipe read_pipe, union pipe write_pipe)

{

	struct event event;

tools/testing/selftests/powerpc/pmu/ebb/ebb.h

+0 −1
Original line number Diff line number Diff line
@@ -70,7 +70,6 @@ int ebb_check_mmcr0(void); 
extern u64 sample_period;



int core_busy_loop(void);

int core_busy_loop_with_freeze(void);

int ebb_child(union pipe read_pipe, union pipe write_pipe);

int catch_sigill(void (*func)(void));

void write_pmc1(void);

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