linux-kernel - [PATCH v2] regulator: qcom_smd: Keep one rpm handle for all vregs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20231227-topic-rpm_vreg_cleanup-v2-1-04c79c4f9166@linaro.org>
Date: Wed, 03 Jan 2024 21:18:37 +0100
From: Konrad Dybcio <konrad.dybcio@...aro.org>
To: Bjorn Andersson <andersson@...nel.org>, 
 Liam Girdwood <lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>
Cc: Marijn Suijten <marijn.suijten@...ainline.org>, 
 linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org, 
 Konrad Dybcio <konrad.dybcio@...aro.org>
Subject: [PATCH v2] regulator: qcom_smd: Keep one rpm handle for all vregs

For no apparent reason (as there's just one RPM per SoC), all vregs
currently store a copy of a pointer to smd_rpm. Introduce a single,
global one to save up on space in each definition.

bloat-o-meter reports:

Total: Before=43944, After=43924, chg -0.05%

plus sizeof(ptr) on every dynamically allocated regulator :)

Signed-off-by: Konrad Dybcio <konrad.dybcio@...aro.org>
---
Changes in v2:
- Remove unused function argument from rpm_regulator_init_vreg kerneldoc
- Do NOT add a mutex around the rpm assignment, talked to Dmitry offline
  and we concluded it makes no sense
- Link to v1: https://lore.kernel.org/r/20231227-topic-rpm_vreg_cleanup-v1-1-949da0864ac5@linaro.org
---
 drivers/regulator/qcom_smd-regulator.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/drivers/regulator/qcom_smd-regulator.c b/drivers/regulator/qcom_smd-regulator.c
index d1be9568025e..5461c03e2aac 100644
--- a/drivers/regulator/qcom_smd-regulator.c
+++ b/drivers/regulator/qcom_smd-regulator.c
@@ -11,11 +11,10 @@
 #include <linux/regulator/of_regulator.h>
 #include <linux/soc/qcom/smd-rpm.h>
 
+struct qcom_smd_rpm *smd_vreg_rpm;
+
 struct qcom_rpm_reg {
 	struct device *dev;
-
-	struct qcom_smd_rpm *rpm;
-
 	u32 type;
 	u32 id;
 
@@ -70,7 +69,7 @@ static int rpm_reg_write_active(struct qcom_rpm_reg *vreg)
 	if (!reqlen)
 		return 0;
 
-	ret = qcom_rpm_smd_write(vreg->rpm, QCOM_SMD_RPM_ACTIVE_STATE,
+	ret = qcom_rpm_smd_write(smd_vreg_rpm, QCOM_SMD_RPM_ACTIVE_STATE,
 				 vreg->type, vreg->id,
 				 req, sizeof(req[0]) * reqlen);
 	if (!ret) {
@@ -1384,14 +1383,13 @@ MODULE_DEVICE_TABLE(of, rpm_of_match);
  * @dev:		Pointer to the top level qcom_smd-regulator PMIC device
  * @node:		Pointer to the individual qcom_smd-regulator resource
  *			device node
- * @rpm:		Pointer to the rpm bus node
  * @pmic_rpm_data:	Pointer to a null-terminated array of qcom_smd-regulator
  *			resources defined for the top level PMIC device
  *
  * Return: 0 on success, errno on failure
  */
 static int rpm_regulator_init_vreg(struct qcom_rpm_reg *vreg, struct device *dev,
-				   struct device_node *node, struct qcom_smd_rpm *rpm,
+				   struct device_node *node,
 				   const struct rpm_regulator_data *pmic_rpm_data)
 {
 	struct regulator_config config = {};
@@ -1409,7 +1407,6 @@ static int rpm_regulator_init_vreg(struct qcom_rpm_reg *vreg, struct device *dev
 	}
 
 	vreg->dev	= dev;
-	vreg->rpm	= rpm;
 	vreg->type	= rpm_data->type;
 	vreg->id	= rpm_data->id;
 
@@ -1440,11 +1437,10 @@ static int rpm_reg_probe(struct platform_device *pdev)
 	const struct rpm_regulator_data *vreg_data;
 	struct device_node *node;
 	struct qcom_rpm_reg *vreg;
-	struct qcom_smd_rpm *rpm;
 	int ret;
 
-	rpm = dev_get_drvdata(pdev->dev.parent);
-	if (!rpm) {
+	smd_vreg_rpm = dev_get_drvdata(pdev->dev.parent);
+	if (!smd_vreg_rpm) {
 		dev_err(&pdev->dev, "Unable to retrieve handle to rpm\n");
 		return -ENODEV;
 	}
@@ -1460,8 +1456,7 @@ static int rpm_reg_probe(struct platform_device *pdev)
 			return -ENOMEM;
 		}
 
-		ret = rpm_regulator_init_vreg(vreg, dev, node, rpm, vreg_data);
-
+		ret = rpm_regulator_init_vreg(vreg, dev, node, vreg_data);
 		if (ret < 0) {
 			of_node_put(node);
 			return ret;

---
base-commit: 0fef202ac2f8e6d9ad21aead648278f1226b9053
change-id: 20231227-topic-rpm_vreg_cleanup-fa095cd528ec

Best regards,
-- 
Konrad Dybcio <konrad.dybcio@...aro.org>