5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nathan Lynch nathanl@linux.ibm.com
[ Upstream commit 5d08633e5f6564b60f1cbe09af3af40a74d66431 ]
The ibm,get-system-parameter RTAS function may return -2 or 990x, which indicate that the caller should try again.
lparcfg's parse_system_parameter_string() ignores this, making it possible to intermittently report incorrect SPLPAR characteristics.
Move the RTAS call into a coventional rtas_busy_delay()-based loop.
Signed-off-by: Nathan Lynch nathanl@linux.ibm.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-4-26929c8cce78@l... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/platforms/pseries/lparcfg.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/lparcfg.c b/arch/powerpc/platforms/pseries/lparcfg.c index 19503a8797823..a291b5a94d4da 100644 --- a/arch/powerpc/platforms/pseries/lparcfg.c +++ b/arch/powerpc/platforms/pseries/lparcfg.c @@ -322,6 +322,7 @@ static void parse_mpp_x_data(struct seq_file *m) */ static void parse_system_parameter_string(struct seq_file *m) { + const s32 token = rtas_token("ibm,get-system-parameter"); int call_status;
unsigned char *local_buffer = kmalloc(SPLPAR_MAXLENGTH, GFP_KERNEL); @@ -331,16 +332,15 @@ static void parse_system_parameter_string(struct seq_file *m) return; }
- spin_lock(&rtas_data_buf_lock); - memset(rtas_data_buf, 0, SPLPAR_MAXLENGTH); - call_status = rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1, - NULL, - SPLPAR_CHARACTERISTICS_TOKEN, - __pa(rtas_data_buf), - RTAS_DATA_BUF_SIZE); - memcpy(local_buffer, rtas_data_buf, SPLPAR_MAXLENGTH); - local_buffer[SPLPAR_MAXLENGTH - 1] = '\0'; - spin_unlock(&rtas_data_buf_lock); + do { + spin_lock(&rtas_data_buf_lock); + memset(rtas_data_buf, 0, SPLPAR_MAXLENGTH); + call_status = rtas_call(token, 3, 1, NULL, SPLPAR_CHARACTERISTICS_TOKEN, + __pa(rtas_data_buf), RTAS_DATA_BUF_SIZE); + memcpy(local_buffer, rtas_data_buf, SPLPAR_MAXLENGTH); + local_buffer[SPLPAR_MAXLENGTH - 1] = '\0'; + spin_unlock(&rtas_data_buf_lock); + } while (rtas_busy_delay(call_status));
if (call_status != 0) { printk(KERN_INFO