[PATCH 5.15 125/245] powerpc/pseries/lpar: add missing RTAS retry status handling

Greg Kroah-Hartman
2024-02-27T14:07:56Z

From: Nathan Lynch <nathanl@linux.ibm.com>

[ Upstream commit daa8ab59044610aa8ef2ee45a6c157b5e11635e9 ]

The ibm,get-system-parameter RTAS function may return -2 or 990x,
which indicate that the caller should try again.

pseries_lpar_read_hblkrm_characteristics() ignores this, making it
possible to incorrectly detect TLB block invalidation characteristics
at boot.

Move the RTAS call into a coventional rtas_busy_delay()-based loop.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Fixes: 1211ee61b4a8 ("powerpc/pseries: Read TLB Block Invalidate Characteristics")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-3-26929c8cce78@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/platforms/pseries/lpar.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index fce0237b07155..6c196b9413553 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -1434,22 +1434,22 @@ static inline void __init check_lp_set_hblkrm(unsigned int lp,

void __init pseries_lpar_read_hblkrm_characteristics(void)
{
+ const s32 token = rtas_token("ibm,get-system-parameter");
unsigned char local_buffer[SPLPAR_TLB_BIC_MAXLENGTH];
int call_status, len, idx, bpsize;

if (!firmware_has_feature(FW_FEATURE_BLOCK_REMOVE))
return;

- spin_lock(&rtas_data_buf_lock);
- memset(rtas_data_buf, 0, RTAS_DATA_BUF_SIZE);
- call_status = rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1,
- NULL,
- SPLPAR_TLB_BIC_TOKEN,
- __pa(rtas_data_buf),
- RTAS_DATA_BUF_SIZE);
- memcpy(local_buffer, rtas_data_buf, SPLPAR_TLB_BIC_MAXLENGTH);
- local_buffer[SPLPAR_TLB_BIC_MAXLENGTH - 1] = '\0';
- spin_unlock(&rtas_data_buf_lock);
+ do {
+ spin_lock(&rtas_data_buf_lock);
+ memset(rtas_data_buf, 0, RTAS_DATA_BUF_SIZE);
+ call_status = rtas_call(token, 3, 1, NULL, SPLPAR_TLB_BIC_TOKEN,
+ __pa(rtas_data_buf), RTAS_DATA_BUF_SIZE);
+ memcpy(local_buffer, rtas_data_buf, SPLPAR_TLB_BIC_MAXLENGTH);
+ local_buffer[SPLPAR_TLB_BIC_MAXLENGTH - 1] = '\0';
+ spin_unlock(&rtas_data_buf_lock);
+ } while (rtas_busy_delay(call_status));

if (call_status != 0) {
pr_warn("%s %s Error calling get-system-parameter (0x%x)\n",
--
2.43.0