diff mbox series

[v4,20/21] firmware: qcom_scm: Refactor code to support multiple download mode

Message ID 1687955688-20809-21-git-send-email-quic_mojha@quicinc.com (mailing list archive)
State Handled Elsewhere
Headers show
Series [v4,01/21] docs: qcom: Add qualcomm minidump guide | expand

Commit Message

Mukesh Ojha June 28, 2023, 12:34 p.m. UTC
Currently on Qualcomm SoC, download_mode is enabled if
CONFIG_QCOM_SCM_DOWNLOAD_MODE_DEFAULT is selected.

Refactor the code such that it supports multiple download
modes and drop CONFIG_QCOM_SCM_DOWNLOAD_MODE_DEFAULT config
instead, give interface to set the download mode from
module parameter.

Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com>
---
 drivers/firmware/Kconfig    | 11 ---------
 drivers/firmware/qcom_scm.c | 56 +++++++++++++++++++++++++++++++++++++++------
 2 files changed, 49 insertions(+), 18 deletions(-)

Comments

Pavan Kondeti June 30, 2023, 5:25 a.m. UTC | #1
On Wed, Jun 28, 2023 at 06:04:47PM +0530, Mukesh Ojha wrote:
> Currently on Qualcomm SoC, download_mode is enabled if
> CONFIG_QCOM_SCM_DOWNLOAD_MODE_DEFAULT is selected.
> 
> Refactor the code such that it supports multiple download
> modes and drop CONFIG_QCOM_SCM_DOWNLOAD_MODE_DEFAULT config
> instead, give interface to set the download mode from
> module parameter.
> 
> Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com>
> ---
>  drivers/firmware/Kconfig    | 11 ---------
>  drivers/firmware/qcom_scm.c | 56 +++++++++++++++++++++++++++++++++++++++------
>  2 files changed, 49 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
> index b59e3041fd62..ff7e9f330559 100644
> --- a/drivers/firmware/Kconfig
> +++ b/drivers/firmware/Kconfig
> @@ -215,17 +215,6 @@ config MTK_ADSP_IPC
>  config QCOM_SCM
>  	tristate
>  
> -config QCOM_SCM_DOWNLOAD_MODE_DEFAULT
> -	bool "Qualcomm download mode enabled by default"
> -	depends on QCOM_SCM
> -	help
> -	  A device with "download mode" enabled will upon an unexpected
> -	  warm-restart enter a special debug mode that allows the user to
> -	  "download" memory content over USB for offline postmortem analysis.
> -	  The feature can be enabled/disabled on the kernel command line.
> -
> -	  Say Y here to enable "download mode" by default.
> -
>  config SYSFB
>  	bool
>  	select BOOT_VESA_SUPPORT
> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> index a9ff77d16c42..946cb0f76a17 100644
> --- a/drivers/firmware/qcom_scm.c
> +++ b/drivers/firmware/qcom_scm.c
> @@ -18,13 +18,13 @@
>  #include <linux/of_irq.h>
>  #include <linux/of_platform.h>
>  #include <linux/clk.h>
> +#include <linux/kstrtox.h>
>  #include <linux/reset-controller.h>
>  #include <linux/arm-smccc.h>
>  
>  #include "qcom_scm.h"
>  
> -static bool download_mode = IS_ENABLED(CONFIG_QCOM_SCM_DOWNLOAD_MODE_DEFAULT);
> -module_param(download_mode, bool, 0);
> +static u32 download_mode;
>  
>  #define SCM_HAS_CORE_CLK	BIT(0)
>  #define SCM_HAS_IFACE_CLK	BIT(1)
> @@ -82,6 +82,11 @@ static const char * const qcom_scm_convention_names[] = {
>  	[SMC_CONVENTION_LEGACY] = "smc legacy",
>  };
>  
> +static const char * const download_mode_name[] = {
> +	[QCOM_DOWNLOAD_NODUMP]	 = "off",
> +	[QCOM_DOWNLOAD_FULLDUMP] = "full",
> +};
> +
>  static struct qcom_scm *__scm;
>  
>  static int qcom_scm_clk_enable(void)
> @@ -442,8 +447,9 @@ static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
>  	return qcom_scm_call_atomic(__scm->dev, &desc, NULL);
>  }
>  
> -static void qcom_scm_set_download_mode(bool enable)
> +static void qcom_scm_set_download_mode(u32 download_mode)
>  {
> +	bool enable = !!download_mode;
>  	bool avail;
>  	int val;
>  	int ret = 0;
> @@ -454,7 +460,7 @@ static void qcom_scm_set_download_mode(bool enable)
>  	if (avail) {
>  		ret = __qcom_scm_set_dload_mode(__scm->dev, enable);
>  	} else if (__scm->dload_mode_addr) {
> -		val = (enable ? QCOM_DOWNLOAD_FULLDUMP : QCOM_DOWNLOAD_NODUMP);
> +		val = download_mode;
>  		val <<= QCOM_DOWNLOAD_MODE_SHIFT;
>  		ret = qcom_scm_io_update_field(__scm->dload_mode_addr,
>  				QCOM_DOWNLOAD_MODE_MASK, val);
> @@ -1425,6 +1431,42 @@ static irqreturn_t qcom_scm_irq_handler(int irq, void *data)
>  	return IRQ_HANDLED;
>  }
>  
> +static int get_download_mode(char *buffer, const struct kernel_param *kp)
> +{
> +	if (download_mode >= ARRAY_SIZE(download_mode_name))
> +		return sysfs_emit(buffer, "unknown mode\n");
> +
> +	return sysfs_emit(buffer, "%s\n", download_mode_name[download_mode]);
> +}
> +
> +static int set_download_mode(const char *val, const struct kernel_param *kp)
> +{
> +	u32 old = download_mode;
> +	int ret;
> +
> +	ret = sysfs_match_string(download_mode_name, val);
> +	if (ret < 0) {
> +		download_mode = old;
> +		pr_err("qcom_scm: unknown download mode: %s\n", val);
> +		return -EINVAL;
> +	}

minor nit: %s/-EINVAL/ret 

> +
> +	download_mode = ret;
> +	if (__scm)
> +		qcom_scm_set_download_mode(download_mode);
> +
> +	return 0;
> +}
> +
> +static const struct kernel_param_ops download_mode_param_ops = {
> +	.get = get_download_mode,
> +	.set = set_download_mode,
> +};
> +
> +module_param_cb(download_mode, &download_mode_param_ops, NULL, 0644);
> +MODULE_PARM_DESC(download_mode,
> +		"download mode: off/full are acceptable values");
> +

Since we are adding a sysfs file under /sys/module/qcom_scm/ , does it
need to be documented under ABI?

Thanks,
Pavan
Andy Shevchenko June 30, 2023, 9:28 a.m. UTC | #2
On Fri, Jun 30, 2023 at 8:25 AM Pavan Kondeti <quic_pkondeti@quicinc.com> wrote:
> On Wed, Jun 28, 2023 at 06:04:47PM +0530, Mukesh Ojha wrote:

...

> > +static int set_download_mode(const char *val, const struct kernel_param *kp)
> > +{
> > +     u32 old = download_mode;
> > +     int ret;
> > +
> > +     ret = sysfs_match_string(download_mode_name, val);
> > +     if (ret < 0) {

> > +             download_mode = old;

Why is this old variable needed at all?

> > +             pr_err("qcom_scm: unknown download mode: %s\n", val);
> > +             return -EINVAL;
> > +     }
>
> minor nit: %s/-EINVAL/ret
>
> > +     download_mode = ret;
> > +     if (__scm)
> > +             qcom_scm_set_download_mode(download_mode);
> > +
> > +     return 0;
> > +}
diff mbox series

Patch

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index b59e3041fd62..ff7e9f330559 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -215,17 +215,6 @@  config MTK_ADSP_IPC
 config QCOM_SCM
 	tristate
 
-config QCOM_SCM_DOWNLOAD_MODE_DEFAULT
-	bool "Qualcomm download mode enabled by default"
-	depends on QCOM_SCM
-	help
-	  A device with "download mode" enabled will upon an unexpected
-	  warm-restart enter a special debug mode that allows the user to
-	  "download" memory content over USB for offline postmortem analysis.
-	  The feature can be enabled/disabled on the kernel command line.
-
-	  Say Y here to enable "download mode" by default.
-
 config SYSFB
 	bool
 	select BOOT_VESA_SUPPORT
diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index a9ff77d16c42..946cb0f76a17 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -18,13 +18,13 @@ 
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/clk.h>
+#include <linux/kstrtox.h>
 #include <linux/reset-controller.h>
 #include <linux/arm-smccc.h>
 
 #include "qcom_scm.h"
 
-static bool download_mode = IS_ENABLED(CONFIG_QCOM_SCM_DOWNLOAD_MODE_DEFAULT);
-module_param(download_mode, bool, 0);
+static u32 download_mode;
 
 #define SCM_HAS_CORE_CLK	BIT(0)
 #define SCM_HAS_IFACE_CLK	BIT(1)
@@ -82,6 +82,11 @@  static const char * const qcom_scm_convention_names[] = {
 	[SMC_CONVENTION_LEGACY] = "smc legacy",
 };
 
+static const char * const download_mode_name[] = {
+	[QCOM_DOWNLOAD_NODUMP]	 = "off",
+	[QCOM_DOWNLOAD_FULLDUMP] = "full",
+};
+
 static struct qcom_scm *__scm;
 
 static int qcom_scm_clk_enable(void)
@@ -442,8 +447,9 @@  static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
 	return qcom_scm_call_atomic(__scm->dev, &desc, NULL);
 }
 
-static void qcom_scm_set_download_mode(bool enable)
+static void qcom_scm_set_download_mode(u32 download_mode)
 {
+	bool enable = !!download_mode;
 	bool avail;
 	int val;
 	int ret = 0;
@@ -454,7 +460,7 @@  static void qcom_scm_set_download_mode(bool enable)
 	if (avail) {
 		ret = __qcom_scm_set_dload_mode(__scm->dev, enable);
 	} else if (__scm->dload_mode_addr) {
-		val = (enable ? QCOM_DOWNLOAD_FULLDUMP : QCOM_DOWNLOAD_NODUMP);
+		val = download_mode;
 		val <<= QCOM_DOWNLOAD_MODE_SHIFT;
 		ret = qcom_scm_io_update_field(__scm->dload_mode_addr,
 				QCOM_DOWNLOAD_MODE_MASK, val);
@@ -1425,6 +1431,42 @@  static irqreturn_t qcom_scm_irq_handler(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+static int get_download_mode(char *buffer, const struct kernel_param *kp)
+{
+	if (download_mode >= ARRAY_SIZE(download_mode_name))
+		return sysfs_emit(buffer, "unknown mode\n");
+
+	return sysfs_emit(buffer, "%s\n", download_mode_name[download_mode]);
+}
+
+static int set_download_mode(const char *val, const struct kernel_param *kp)
+{
+	u32 old = download_mode;
+	int ret;
+
+	ret = sysfs_match_string(download_mode_name, val);
+	if (ret < 0) {
+		download_mode = old;
+		pr_err("qcom_scm: unknown download mode: %s\n", val);
+		return -EINVAL;
+	}
+
+	download_mode = ret;
+	if (__scm)
+		qcom_scm_set_download_mode(download_mode);
+
+	return 0;
+}
+
+static const struct kernel_param_ops download_mode_param_ops = {
+	.get = get_download_mode,
+	.set = set_download_mode,
+};
+
+module_param_cb(download_mode, &download_mode_param_ops, NULL, 0644);
+MODULE_PARM_DESC(download_mode,
+		"download mode: off/full are acceptable values");
+
 static int qcom_scm_probe(struct platform_device *pdev)
 {
 	struct qcom_scm *scm;
@@ -1518,12 +1560,12 @@  static int qcom_scm_probe(struct platform_device *pdev)
 	__get_convention();
 
 	/*
-	 * If requested enable "download mode", from this point on warmboot
+	 * If "download mode" is requested, from this point on warmboot
 	 * will cause the boot stages to enter download mode, unless
 	 * disabled below by a clean shutdown/reboot.
 	 */
 	if (download_mode)
-		qcom_scm_set_download_mode(true);
+		qcom_scm_set_download_mode(download_mode);
 
 	return 0;
 }
@@ -1531,7 +1573,7 @@  static int qcom_scm_probe(struct platform_device *pdev)
 static void qcom_scm_shutdown(struct platform_device *pdev)
 {
 	/* Clean shutdown, disable download mode to allow normal restart */
-	qcom_scm_set_download_mode(false);
+	qcom_scm_set_download_mode(QCOM_DOWNLOAD_NODUMP);
 }
 
 static const struct of_device_id qcom_scm_dt_match[] = {