[PATCH 6.7 147/162] powerpc/rtas: use correct function name for resetting TCE tables

Greg Kroah-Hartman
2024-03-04T21:33:04Z

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

[ Upstream commit fad87dbd48156ab940538f052f1820f4b6ed2819 ]

The PAPR spec spells the function name as

"ibm,reset-pe-dma-windows"

but in practice firmware uses the singular form:

"ibm,reset-pe-dma-window"

in the device tree. Since we have the wrong spelling in the RTAS
function table, reverse lookups (token -> name) fail and warn:

unexpected failed lookup for token 86
WARNING: CPU: 1 PID: 545 at arch/powerpc/kernel/rtas.c:659 __do_enter_rtas_trace+0x2a4/0x2b4
CPU: 1 PID: 545 Comm: systemd-udevd Not tainted 6.8.0-rc4 #30
Hardware name: IBM,9105-22A POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NL1060_028) hv:phyp pSeries
NIP [c0000000000417f0] __do_enter_rtas_trace+0x2a4/0x2b4
LR [c0000000000417ec] __do_enter_rtas_trace+0x2a0/0x2b4
Call Trace:
__do_enter_rtas_trace+0x2a0/0x2b4 (unreliable)
rtas_call+0x1f8/0x3e0
enable_ddw.constprop.0+0x4d0/0xc84
dma_iommu_dma_supported+0xe8/0x24c
dma_set_mask+0x5c/0xd8
mlx5_pci_init.constprop.0+0xf0/0x46c [mlx5_core]
probe_one+0xfc/0x32c [mlx5_core]
local_pci_probe+0x68/0x12c
pci_call_probe+0x68/0x1ec
pci_device_probe+0xbc/0x1a8
really_probe+0x104/0x570
__driver_probe_device+0xb8/0x224
driver_probe_device+0x54/0x130
__driver_attach+0x158/0x2b0
bus_for_each_dev+0xa8/0x120
driver_attach+0x34/0x48
bus_add_driver+0x174/0x304
driver_register+0x8c/0x1c4
__pci_register_driver+0x68/0x7c
mlx5_init+0xb8/0x118 [mlx5_core]
do_one_initcall+0x60/0x388
do_init_module+0x7c/0x2a4
init_module_from_file+0xb4/0x108
idempotent_init_module+0x184/0x34c
sys_finit_module+0x90/0x114

And oopses are possible when lockdep is enabled or the RTAS
tracepoints are active, since those paths dereference the result of
the lookup.

Use the correct spelling to match firmware's behavior, adjusting the
related constants to match.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Fixes: 8252b88294d2 ("powerpc/rtas: improve function information lookups")
Reported-by: Gaurav Batra <gbatra@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240222-rtas-fix-ibm-reset-pe-dma-window-v1-1-7aaf235ac63c@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/include/asm/rtas.h | 4 ++--
arch/powerpc/kernel/rtas.c | 9 +++++++--
2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
index c697c3c746946..33024a2874a69 100644
--- a/arch/powerpc/include/asm/rtas.h
+++ b/arch/powerpc/include/asm/rtas.h
@@ -68,7 +68,7 @@ enum rtas_function_index {
RTAS_FNIDX__IBM_READ_SLOT_RESET_STATE,
RTAS_FNIDX__IBM_READ_SLOT_RESET_STATE2,
RTAS_FNIDX__IBM_REMOVE_PE_DMA_WINDOW,
- RTAS_FNIDX__IBM_RESET_PE_DMA_WINDOWS,
+ RTAS_FNIDX__IBM_RESET_PE_DMA_WINDOW,
RTAS_FNIDX__IBM_SCAN_LOG_DUMP,
RTAS_FNIDX__IBM_SET_DYNAMIC_INDICATOR,
RTAS_FNIDX__IBM_SET_EEH_OPTION,
@@ -163,7 +163,7 @@ typedef struct {
#define RTAS_FN_IBM_READ_SLOT_RESET_STATE rtas_fn_handle(RTAS_FNIDX__IBM_READ_SLOT_RESET_STATE)
#define RTAS_FN_IBM_READ_SLOT_RESET_STATE2 rtas_fn_handle(RTAS_FNIDX__IBM_READ_SLOT_RESET_STATE2)
#define RTAS_FN_IBM_REMOVE_PE_DMA_WINDOW rtas_fn_handle(RTAS_FNIDX__IBM_REMOVE_PE_DMA_WINDOW)
-#define RTAS_FN_IBM_RESET_PE_DMA_WINDOWS rtas_fn_handle(RTAS_FNIDX__IBM_RESET_PE_DMA_WINDOWS)
+#define RTAS_FN_IBM_RESET_PE_DMA_WINDOW rtas_fn_handle(RTAS_FNIDX__IBM_RESET_PE_DMA_WINDOW)
#define RTAS_FN_IBM_SCAN_LOG_DUMP rtas_fn_handle(RTAS_FNIDX__IBM_SCAN_LOG_DUMP)
#define RTAS_FN_IBM_SET_DYNAMIC_INDICATOR rtas_fn_handle(RTAS_FNIDX__IBM_SET_DYNAMIC_INDICATOR)
#define RTAS_FN_IBM_SET_EEH_OPTION rtas_fn_handle(RTAS_FNIDX__IBM_SET_EEH_OPTION)
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 87d65bdd3ecae..46b9476d75824 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -310,8 +310,13 @@ static struct rtas_function rtas_function_table[] __ro_after_init = {
[RTAS_FNIDX__IBM_REMOVE_PE_DMA_WINDOW] = {
.name = "ibm,remove-pe-dma-window",
},
- [RTAS_FNIDX__IBM_RESET_PE_DMA_WINDOWS] = {
- .name = "ibm,reset-pe-dma-windows",
+ [RTAS_FNIDX__IBM_RESET_PE_DMA_WINDOW] = {
+ /*
+ * Note: PAPR+ v2.13 7.3.31.4.1 spells this as
+ * "ibm,reset-pe-dma-windows" (plural), but RTAS
+ * implementations use the singular form in practice.
+ */
+ .name = "ibm,reset-pe-dma-window",
},
[RTAS_FNIDX__IBM_SCAN_LOG_DUMP] = {
.name = "ibm,scan-log-dump",
--
2.43.0