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powerpc/perf/hv-24x7: add missing RTAS retry status handling

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The ibm,get-system-parameter RTAS function may return -2 or 990x,
which indicate that the caller should try again. read_24x7_sys_info()
ignores this, allowing transient failures in reporting processor
module information.

Move the RTAS call into a coventional rtas_busy_delay()-based loop,
along with the parsing of results on success.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Fixes: 8ba2142673 ("powerpc/hv-24x7: Add rtas call in hv-24x7 driver to get processor details")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-2-26929c8cce78@linux.ibm.com
This commit is contained in:
Nathan Lynch 2023-02-10 12:41:50 -06:00 committed by Michael Ellerman
parent 09d1ea72c8
commit cc4b26eab1
1 changed files with 18 additions and 24 deletions
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42
arch/powerpc/perf/hv-24x7.c
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@ -79,9 +79,8 @@ static u32 phys_coresperchip; /* Physical cores per chip */
*/
void read_24x7_sys_info(void)
{
int call_status, len, ntypes;
spin_lock(&rtas_data_buf_lock);
const s32 token = rtas_token("ibm,get-system-parameter");
int call_status;
/*
* Making system parameter: chips and sockets and cores per chip
@ -91,32 +90,27 @@ void read_24x7_sys_info(void)
phys_chipspersocket = 1;
phys_coresperchip = 1;
call_status = rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1,
NULL,
PROCESSOR_MODULE_INFO,
__pa(rtas_data_buf),
RTAS_DATA_BUF_SIZE);
do {
spin_lock(&rtas_data_buf_lock);
call_status = rtas_call(token, 3, 1, NULL, PROCESSOR_MODULE_INFO,
__pa(rtas_data_buf), RTAS_DATA_BUF_SIZE);
if (call_status == 0) {
int ntypes = be16_to_cpup((__be16 *)&rtas_data_buf[2]);
int len = be16_to_cpup((__be16 *)&rtas_data_buf[0]);
if (len >= 8 && ntypes != 0) {
phys_sockets = be16_to_cpup((__be16 *)&rtas_data_buf[4]);
phys_chipspersocket = be16_to_cpup((__be16 *)&rtas_data_buf[6]);
phys_coresperchip = be16_to_cpup((__be16 *)&rtas_data_buf[8]);
}
}
spin_unlock(&rtas_data_buf_lock);
} while (rtas_busy_delay(call_status));
if (call_status != 0) {
pr_err("Error calling get-system-parameter %d\n",
call_status);
} else {
len = be16_to_cpup((__be16 *)&rtas_data_buf[0]);
if (len < 8)
goto out;
ntypes = be16_to_cpup((__be16 *)&rtas_data_buf[2]);
if (!ntypes)
goto out;
phys_sockets = be16_to_cpup((__be16 *)&rtas_data_buf[4]);
phys_chipspersocket = be16_to_cpup((__be16 *)&rtas_data_buf[6]);
phys_coresperchip = be16_to_cpup((__be16 *)&rtas_data_buf[8]);
}
out:
spin_unlock(&rtas_data_buf_lock);
}
/* Domains for which more than one result element are returned for each event. */