* [PATCH] wifi: ath12k: mark QMI driver event helpers as noinline
@ 2024-10-28 14:08 Jeff Johnson
2024-10-31 14:04 ` Kalle Valo
2024-11-04 15:43 ` Jeff Johnson
0 siblings, 2 replies; 3+ messages in thread
From: Jeff Johnson @ 2024-10-28 14:08 UTC (permalink / raw)
To: ath12k-devel-internal, Kalle Valo, Jeff Johnson,
Nathan Chancellor, Nick Desaulniers, Bill Wendling, Justin Stitt,
Arnd Bergmann
Cc: linux-wireless, ath12k, linux-kernel, llvm, Jeff Johnson
As described in [1], compiling the ath12k driver using clang with
KASAN enabled warns about some functions with excessive stack usage,
with the worst case being:
drivers/net/wireless/ath/ath12k/qmi.c:3546:13: warning: stack frame size (2456) exceeds limit (1024) in 'ath12k_qmi_driver_event_work' [-Wframe-larger-than]
Nathan [2] highlighted work done by Arnd [3] to address similar
issues in other portions of the kernel.
ath12k_qmi_driver_event_work() itself is a pretty lightweight
function, but it dispatches to several other functions which do the
real work:
ath12k_qmi_driver_event_work()
ath12k_qmi_event_server_arrive()
ath12k_qmi_host_cap_send()
ath12k_qmi_event_mem_request()
ath12k_qmi_respond_fw_mem_request()
ath12k_qmi_event_load_bdf()
ath12k_qmi_request_target_cap()
ath12k_qmi_load_bdf_qmi()
ath12k_qmi_wlanfw_m3_info_send()
Mark all of those underlying functions as 'noinline_for_stack' to
prevent them from being inlined in ath12k_qmi_driver_event_work(),
thereby eliminating the excessive stack usage.
Link: https://msgid.link/bc214795-1c51-4cb7-922f-67d6ef98bff2@quicinc.com # [1]
Link: https://msgid.link/20241025223321.GA3647469@thelio-3990X # [2]
Link: https://lore.kernel.org/all/?q=f:arnd@kernel.org+Wframe-larger-than # [3]
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
---
drivers/net/wireless/ath/ath12k/qmi.c | 34 +++++++++++++++++++++++++---------
1 file changed, 25 insertions(+), 9 deletions(-)
diff --git a/drivers/net/wireless/ath/ath12k/qmi.c b/drivers/net/wireless/ath/ath12k/qmi.c
index b93ce9f87f61..d2d9d03c7a28 100644
--- a/drivers/net/wireless/ath/ath12k/qmi.c
+++ b/drivers/net/wireless/ath/ath12k/qmi.c
@@ -2066,7 +2066,9 @@ static void ath12k_host_cap_parse_mlo(struct ath12k_base *ab,
req->mlo_chip_info_valid = 1;
}
-static int ath12k_qmi_host_cap_send(struct ath12k_base *ab)
+/* clang stack usage explodes if this is inlined */
+static noinline_for_stack
+int ath12k_qmi_host_cap_send(struct ath12k_base *ab)
{
struct qmi_wlanfw_host_cap_req_msg_v01 req = {};
struct qmi_wlanfw_host_cap_resp_msg_v01 resp = {};
@@ -2275,7 +2277,9 @@ static int ath12k_qmi_fw_ind_register_send(struct ath12k_base *ab)
return ret;
}
-static int ath12k_qmi_respond_fw_mem_request(struct ath12k_base *ab)
+/* clang stack usage explodes if this is inlined */
+static noinline_for_stack
+int ath12k_qmi_respond_fw_mem_request(struct ath12k_base *ab)
{
struct qmi_wlanfw_respond_mem_req_msg_v01 *req;
struct qmi_wlanfw_respond_mem_resp_msg_v01 resp = {};
@@ -2433,7 +2437,9 @@ static int ath12k_qmi_alloc_target_mem_chunk(struct ath12k_base *ab)
return 0;
}
-static int ath12k_qmi_request_target_cap(struct ath12k_base *ab)
+/* clang stack usage explodes if this is inlined */
+static noinline_for_stack
+int ath12k_qmi_request_target_cap(struct ath12k_base *ab)
{
struct qmi_wlanfw_cap_req_msg_v01 req = {};
struct qmi_wlanfw_cap_resp_msg_v01 resp = {};
@@ -2619,8 +2625,10 @@ static int ath12k_qmi_load_file_target_mem(struct ath12k_base *ab,
return ret;
}
-static int ath12k_qmi_load_bdf_qmi(struct ath12k_base *ab,
- enum ath12k_qmi_bdf_type type)
+/* clang stack usage explodes if this is inlined */
+static noinline_for_stack
+int ath12k_qmi_load_bdf_qmi(struct ath12k_base *ab,
+ enum ath12k_qmi_bdf_type type)
{
struct device *dev = ab->dev;
char filename[ATH12K_QMI_MAX_BDF_FILE_NAME_SIZE];
@@ -2791,7 +2799,9 @@ static int ath12k_qmi_m3_load(struct ath12k_base *ab)
return ret;
}
-static int ath12k_qmi_wlanfw_m3_info_send(struct ath12k_base *ab)
+/* clang stack usage explodes if this is inlined */
+static noinline_for_stack
+int ath12k_qmi_wlanfw_m3_info_send(struct ath12k_base *ab)
{
struct m3_mem_region *m3_mem = &ab->qmi.m3_mem;
struct qmi_wlanfw_m3_info_req_msg_v01 req = {};
@@ -3079,7 +3089,9 @@ ath12k_qmi_driver_event_post(struct ath12k_qmi *qmi,
return 0;
}
-static int ath12k_qmi_event_server_arrive(struct ath12k_qmi *qmi)
+/* clang stack usage explodes if this is inlined */
+static noinline_for_stack
+int ath12k_qmi_event_server_arrive(struct ath12k_qmi *qmi)
{
struct ath12k_base *ab = qmi->ab;
int ret;
@@ -3101,7 +3113,9 @@ static int ath12k_qmi_event_server_arrive(struct ath12k_qmi *qmi)
return ret;
}
-static int ath12k_qmi_event_mem_request(struct ath12k_qmi *qmi)
+/* clang stack usage explodes if this is inlined */
+static noinline_for_stack
+int ath12k_qmi_event_mem_request(struct ath12k_qmi *qmi)
{
struct ath12k_base *ab = qmi->ab;
int ret;
@@ -3115,7 +3129,9 @@ static int ath12k_qmi_event_mem_request(struct ath12k_qmi *qmi)
return ret;
}
-static int ath12k_qmi_event_load_bdf(struct ath12k_qmi *qmi)
+/* clang stack usage explodes if this is inlined */
+static noinline_for_stack
+int ath12k_qmi_event_load_bdf(struct ath12k_qmi *qmi)
{
struct ath12k_base *ab = qmi->ab;
int ret;
---
base-commit: 8a58dcd8db9c7af1187f0236d71a99cbbe146f6a
change-id: 20241025-ath12k_qmi_driver_event_work-ea9703c44ad7
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] wifi: ath12k: mark QMI driver event helpers as noinline
2024-10-28 14:08 [PATCH] wifi: ath12k: mark QMI driver event helpers as noinline Jeff Johnson
@ 2024-10-31 14:04 ` Kalle Valo
2024-11-04 15:43 ` Jeff Johnson
1 sibling, 0 replies; 3+ messages in thread
From: Kalle Valo @ 2024-10-31 14:04 UTC (permalink / raw)
To: Jeff Johnson
Cc: ath12k-devel-internal, Jeff Johnson, Nathan Chancellor,
Nick Desaulniers, Bill Wendling, Justin Stitt, Arnd Bergmann,
linux-wireless, ath12k, linux-kernel, llvm
Jeff Johnson <quic_jjohnson@quicinc.com> writes:
> As described in [1], compiling the ath12k driver using clang with
> KASAN enabled warns about some functions with excessive stack usage,
> with the worst case being:
>
> drivers/net/wireless/ath/ath12k/qmi.c:3546:13: warning: stack frame size (2456) exceeds limit (1024) in 'ath12k_qmi_driver_event_work' [-Wframe-larger-than]
>
> Nathan [2] highlighted work done by Arnd [3] to address similar
> issues in other portions of the kernel.
>
> ath12k_qmi_driver_event_work() itself is a pretty lightweight
> function, but it dispatches to several other functions which do the
> real work:
> ath12k_qmi_driver_event_work()
> ath12k_qmi_event_server_arrive()
> ath12k_qmi_host_cap_send()
> ath12k_qmi_event_mem_request()
> ath12k_qmi_respond_fw_mem_request()
> ath12k_qmi_event_load_bdf()
> ath12k_qmi_request_target_cap()
> ath12k_qmi_load_bdf_qmi()
> ath12k_qmi_wlanfw_m3_info_send()
>
> Mark all of those underlying functions as 'noinline_for_stack' to
> prevent them from being inlined in ath12k_qmi_driver_event_work(),
> thereby eliminating the excessive stack usage.
>
> Link: https://msgid.link/bc214795-1c51-4cb7-922f-67d6ef98bff2@quicinc.com # [1]
> Link: https://msgid.link/20241025223321.GA3647469@thelio-3990X # [2]
> Link: https://lore.kernel.org/all/?q=f:arnd@kernel.org+Wframe-larger-than # [3]
> Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Acked-by: Kalle Valo <kvalo@kernel.org>
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] wifi: ath12k: mark QMI driver event helpers as noinline
2024-10-28 14:08 [PATCH] wifi: ath12k: mark QMI driver event helpers as noinline Jeff Johnson
2024-10-31 14:04 ` Kalle Valo
@ 2024-11-04 15:43 ` Jeff Johnson
1 sibling, 0 replies; 3+ messages in thread
From: Jeff Johnson @ 2024-11-04 15:43 UTC (permalink / raw)
To: ath12k-devel-internal, Kalle Valo, Jeff Johnson,
Nathan Chancellor, Nick Desaulniers, Bill Wendling, Justin Stitt,
Arnd Bergmann, Jeff Johnson
Cc: linux-wireless, ath12k, linux-kernel, llvm
On Mon, 28 Oct 2024 07:08:40 -0700, Jeff Johnson wrote:
> As described in [1], compiling the ath12k driver using clang with
> KASAN enabled warns about some functions with excessive stack usage,
> with the worst case being:
>
> drivers/net/wireless/ath/ath12k/qmi.c:3546:13: warning: stack frame size (2456) exceeds limit (1024) in 'ath12k_qmi_driver_event_work' [-Wframe-larger-than]
>
> Nathan [2] highlighted work done by Arnd [3] to address similar
> issues in other portions of the kernel.
>
> [...]
Applied, thanks!
[1/1] wifi: ath12k: mark QMI driver event helpers as noinline
commit: 07826419700d4e7429523bbb4e936df6bca19c5e
Best regards,
--
Jeff Johnson <quic_jjohnson@quicinc.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2024-10-31 14:04 ` Kalle Valo
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