102 lines
2.2 KiB
C
102 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/* Test context switching to see if the DSCR SPR is correctly preserved
|
|
* when within a transaction.
|
|
*
|
|
* Note: We assume that the DSCR has been left at the default value (0)
|
|
* for all CPUs.
|
|
*
|
|
* Method:
|
|
*
|
|
* Set a value into the DSCR.
|
|
*
|
|
* Start a transaction, and suspend it (*).
|
|
*
|
|
* Hard loop checking to see if the transaction has become doomed.
|
|
*
|
|
* Now that we *may* have been preempted, record the DSCR and TEXASR SPRS.
|
|
*
|
|
* If the abort was because of a context switch, check the DSCR value.
|
|
* Otherwise, try again.
|
|
*
|
|
* (*) If the transaction is not suspended we can't see the problem because
|
|
* the transaction abort handler will restore the DSCR to it's checkpointed
|
|
* value before we regain control.
|
|
*/
|
|
|
|
#include <inttypes.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <assert.h>
|
|
#include <asm/tm.h>
|
|
|
|
#include "utils.h"
|
|
#include "tm.h"
|
|
#include "../pmu/lib.h"
|
|
|
|
#define SPRN_DSCR 0x03
|
|
|
|
int test_body(void)
|
|
{
|
|
uint64_t rv, dscr1 = 1, dscr2, texasr;
|
|
|
|
SKIP_IF(!have_htm());
|
|
SKIP_IF(htm_is_synthetic());
|
|
|
|
printf("Check DSCR TM context switch: ");
|
|
fflush(stdout);
|
|
for (;;) {
|
|
asm __volatile__ (
|
|
/* set a known value into the DSCR */
|
|
"ld 3, %[dscr1];"
|
|
"mtspr %[sprn_dscr], 3;"
|
|
|
|
"li %[rv], 1;"
|
|
/* start and suspend a transaction */
|
|
"tbegin.;"
|
|
"beq 1f;"
|
|
"tsuspend.;"
|
|
|
|
/* hard loop until the transaction becomes doomed */
|
|
"2: ;"
|
|
"tcheck 0;"
|
|
"bc 4, 0, 2b;"
|
|
|
|
/* record DSCR and TEXASR */
|
|
"mfspr 3, %[sprn_dscr];"
|
|
"std 3, %[dscr2];"
|
|
"mfspr 3, %[sprn_texasr];"
|
|
"std 3, %[texasr];"
|
|
|
|
"tresume.;"
|
|
"tend.;"
|
|
"li %[rv], 0;"
|
|
"1: ;"
|
|
: [rv]"=r"(rv), [dscr2]"=m"(dscr2), [texasr]"=m"(texasr)
|
|
: [dscr1]"m"(dscr1)
|
|
, [sprn_dscr]"i"(SPRN_DSCR), [sprn_texasr]"i"(SPRN_TEXASR)
|
|
: "memory", "r3"
|
|
);
|
|
assert(rv); /* make sure the transaction aborted */
|
|
if ((texasr >> 56) != TM_CAUSE_RESCHED) {
|
|
continue;
|
|
}
|
|
if (dscr2 != dscr1) {
|
|
printf(" FAIL\n");
|
|
return 1;
|
|
} else {
|
|
printf(" OK\n");
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
static int tm_resched_dscr(void)
|
|
{
|
|
return eat_cpu(test_body);
|
|
}
|
|
|
|
int main(int argc, const char *argv[])
|
|
{
|
|
return test_harness(tm_resched_dscr, "tm_resched_dscr");
|
|
}
|