blob: 32fcf2b324b1ce25a42acdf8f976beb957bc1a39 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* POWER Data Stream Control Register (DSCR) explicit test
*
* This test modifies the DSCR value using mtspr instruction and
* verifies the change with mfspr instruction. It uses both the
* privilege state SPR and the problem state SPR for this purpose.
*
* When using the privilege state SPR, the instructions such as
* mfspr or mtspr are priviledged and the kernel emulates them
* for us. Instructions using problem state SPR can be exuecuted
* directly without any emulation if the HW supports them. Else
* they also get emulated by the kernel.
*
* Copyright 2012, Anton Blanchard, IBM Corporation.
* Copyright 2015, Anshuman Khandual, IBM Corporation.
*/
#include "dscr.h"
int dscr_explicit(void)
{
unsigned long i, dscr = 0;
SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
srand(getpid());
set_dscr(dscr);
for (i = 0; i < COUNT; i++) {
unsigned long cur_dscr, cur_dscr_usr;
double ret = uniform_deviate(rand());
if (ret < 0.001) {
dscr++;
if (dscr > DSCR_MAX)
dscr = 0;
set_dscr(dscr);
}
cur_dscr = get_dscr();
if (cur_dscr != dscr) {
fprintf(stderr, "Kernel DSCR should be %ld but "
"is %ld\n", dscr, cur_dscr);
return 1;
}
ret = uniform_deviate(rand());
if (ret < 0.001) {
dscr++;
if (dscr > DSCR_MAX)
dscr = 0;
set_dscr_usr(dscr);
}
cur_dscr_usr = get_dscr_usr();
if (cur_dscr_usr != dscr) {
fprintf(stderr, "User DSCR should be %ld but "
"is %ld\n", dscr, cur_dscr_usr);
return 1;
}
}
return 0;
}
int main(int argc, char *argv[])
{
return test_harness(dscr_explicit, "dscr_explicit_test");
}