[v4,4/5] firmware: qcom_scm: Refactor code to support multiple download mode
Commit Message
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 | 59 +++++++++++++++++++++++++++++++++++++++------
2 files changed, 52 insertions(+), 18 deletions(-)
Comments
On Mon, Mar 27, 2023 at 10:11:20PM +0530, Mukesh Ojha wrote:
[..]
> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> index 3c6c5e7..0c94429 100644
> --- a/drivers/firmware/qcom_scm.c
> +++ b/drivers/firmware/qcom_scm.c
> @@ -20,11 +20,11 @@
> #include <linux/clk.h>
> #include <linux/reset-controller.h>
> #include <linux/arm-smccc.h>
> +#include <linux/kstrtox.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)
> @@ -32,6 +32,7 @@ module_param(download_mode, bool, 0);
>
> #define QCOM_DOWNLOAD_MODE_MASK 0x30
> #define QCOM_DOWNLOAD_FULLDUMP 0x1
> +#define QCOM_DOWNLOAD_NODUMP 0x0
>
> struct qcom_scm {
> struct device *dev;
> @@ -440,8 +441,9 @@ 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 ret = 0;
>
> @@ -453,7 +455,7 @@ static void qcom_scm_set_download_mode(bool enable)
> } else if (__scm->dload_mode_addr) {
> ret = qcom_scm_io_update_field(__scm->dload_mode_addr,
> QCOM_DOWNLOAD_MODE_MASK,
> - enable ? QCOM_DOWNLOAD_FULLDUMP : 0);
> + enable ? download_mode : 0);
Afaict, with QCOM_DOWNLOAD_NODUMP as 0, this says:
when download_mode is non-zero, write that value, otherwise write 0
That should be the same as "write download_mode", so you should be able
to drop the enable part.
> } else {
> dev_err(__scm->dev,
> "No available mechanism for setting download mode\n");
> @@ -1419,6 +1421,49 @@ 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)
> +{
> + int len = 0;
> +
> + if (download_mode == QCOM_DOWNLOAD_FULLDUMP)
> + len = sysfs_emit(buffer, "full\n");
> + else if (download_mode == QCOM_DOWNLOAD_NODUMP)
> + len = sysfs_emit(buffer, "off\n");
> +
> + return len;
> +}
> +
> +static int set_download_mode(const char *val, const struct kernel_param *kp)
> +{
> + u32 old = download_mode;
> +
> + if (!strncmp(val, "full", strlen("full"))) {
strcmp loops over the two string until they differ and/or both are
'\0'.
As such, the only thing you achieve by using strncmp(.., T, strlen(T))
is that the code has to iterate over T twice - and you make the code
harder to read.
> + download_mode = QCOM_DOWNLOAD_FULLDUMP;
> + } else if (!strncmp(val, "off", strlen("off"))) {
> + download_mode = QCOM_DOWNLOAD_NODUMP;
> + } else if (kstrtouint(val, 0, &download_mode) ||
> + !(download_mode == 0 || download_mode == 1)) {
> + download_mode = old;
> + pr_err("unknown download mode\n");
This will result in a lone "unknown download mode" line somewhere in the
kernel log, without association to any driver or any indication what the
unknown value was.
pr_err("qcom_scm: unknown download mode: %s\n", val);
Would give both context and let the reader know right there what value
the code wasn't able to match.
Regards,
Bjorn
On 3/27/2023 11:53 PM, Bjorn Andersson wrote:
> On Mon, Mar 27, 2023 at 10:11:20PM +0530, Mukesh Ojha wrote:
> [..]
>> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
>> index 3c6c5e7..0c94429 100644
>> --- a/drivers/firmware/qcom_scm.c
>> +++ b/drivers/firmware/qcom_scm.c
>> @@ -20,11 +20,11 @@
>> #include <linux/clk.h>
>> #include <linux/reset-controller.h>
>> #include <linux/arm-smccc.h>
>> +#include <linux/kstrtox.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)
>> @@ -32,6 +32,7 @@ module_param(download_mode, bool, 0);
>>
>> #define QCOM_DOWNLOAD_MODE_MASK 0x30
>> #define QCOM_DOWNLOAD_FULLDUMP 0x1
>> +#define QCOM_DOWNLOAD_NODUMP 0x0
>>
>> struct qcom_scm {
>> struct device *dev;
>> @@ -440,8 +441,9 @@ 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 ret = 0;
>>
>> @@ -453,7 +455,7 @@ static void qcom_scm_set_download_mode(bool enable)
>> } else if (__scm->dload_mode_addr) {
>> ret = qcom_scm_io_update_field(__scm->dload_mode_addr,
>> QCOM_DOWNLOAD_MODE_MASK,
>> - enable ? QCOM_DOWNLOAD_FULLDUMP : 0);
>> + enable ? download_mode : 0);
>
> Afaict, with QCOM_DOWNLOAD_NODUMP as 0, this says:
>
> when download_mode is non-zero, write that value, otherwise write 0
>
> That should be the same as "write download_mode", so you should be able
> to drop the enable part.
>
>> } else {
>> dev_err(__scm->dev,
>> "No available mechanism for setting download mode\n");
>> @@ -1419,6 +1421,49 @@ 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)
>> +{
>> + int len = 0;
>> +
>> + if (download_mode == QCOM_DOWNLOAD_FULLDUMP)
>> + len = sysfs_emit(buffer, "full\n");
>> + else if (download_mode == QCOM_DOWNLOAD_NODUMP)
>> + len = sysfs_emit(buffer, "off\n");
>> +
>> + return len;
>> +}
>> +
>> +static int set_download_mode(const char *val, const struct kernel_param *kp)
>> +{
>> + u32 old = download_mode;
>> +
>> + if (!strncmp(val, "full", strlen("full"))) {
>
> strcmp loops over the two string until they differ and/or both are
> '\0'.
>
> As such, the only thing you achieve by using strncmp(.., T, strlen(T))
> is that the code has to iterate over T twice - and you make the code
> harder to read.
If we use strcmp, i need to use "full\n" which we would not want to do.
I think, we need to take this hit.
-- Mukesh
>
>> + download_mode = QCOM_DOWNLOAD_FULLDUMP;
>> + } else if (!strncmp(val, "off", strlen("off"))) {
>> + download_mode = QCOM_DOWNLOAD_NODUMP;
>> + } else if (kstrtouint(val, 0, &download_mode) ||
>> + !(download_mode == 0 || download_mode == 1)) {
>> + download_mode = old;
>> + pr_err("unknown download mode\n");
>
> This will result in a lone "unknown download mode" line somewhere in the
> kernel log, without association to any driver or any indication what the
> unknown value was.
>
> pr_err("qcom_scm: unknown download mode: %s\n", val);
>
> Would give both context and let the reader know right there what value
> the code wasn't able to match.
>
> Regards,
> Bjorn
On 28/03/2023 11:18, Mukesh Ojha wrote:
>
>
> On 3/27/2023 11:53 PM, Bjorn Andersson wrote:
>> On Mon, Mar 27, 2023 at 10:11:20PM +0530, Mukesh Ojha wrote:
>> [..]
>>> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
>>> index 3c6c5e7..0c94429 100644
>>> --- a/drivers/firmware/qcom_scm.c
>>> +++ b/drivers/firmware/qcom_scm.c
>>> @@ -20,11 +20,11 @@
>>> #include <linux/clk.h>
>>> #include <linux/reset-controller.h>
>>> #include <linux/arm-smccc.h>
>>> +#include <linux/kstrtox.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)
>>> @@ -32,6 +32,7 @@ module_param(download_mode, bool, 0);
>>> #define QCOM_DOWNLOAD_MODE_MASK 0x30
>>> #define QCOM_DOWNLOAD_FULLDUMP 0x1
>>> +#define QCOM_DOWNLOAD_NODUMP 0x0
>>> struct qcom_scm {
>>> struct device *dev;
>>> @@ -440,8 +441,9 @@ 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 ret = 0;
>>> @@ -453,7 +455,7 @@ static void qcom_scm_set_download_mode(bool enable)
>>> } else if (__scm->dload_mode_addr) {
>>> ret = qcom_scm_io_update_field(__scm->dload_mode_addr,
>>> QCOM_DOWNLOAD_MODE_MASK,
>>> - enable ? QCOM_DOWNLOAD_FULLDUMP : 0);
>>> + enable ? download_mode : 0);
>>
>> Afaict, with QCOM_DOWNLOAD_NODUMP as 0, this says:
>>
>> when download_mode is non-zero, write that value, otherwise write 0
>>
>> That should be the same as "write download_mode", so you should be able
>> to drop the enable part.
>>
>>> } else {
>>> dev_err(__scm->dev,
>>> "No available mechanism for setting download mode\n");
>>> @@ -1419,6 +1421,49 @@ 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)
>>> +{
>>> + int len = 0;
>>> +
>>> + if (download_mode == QCOM_DOWNLOAD_FULLDUMP)
>>> + len = sysfs_emit(buffer, "full\n");
>>> + else if (download_mode == QCOM_DOWNLOAD_NODUMP)
>>> + len = sysfs_emit(buffer, "off\n");
>>> +
>>> + return len;
>>> +}
>>> +
>>> +static int set_download_mode(const char *val, const struct
>>> kernel_param *kp)
>>> +{
>>> + u32 old = download_mode;
>>> +
>>> + if (!strncmp(val, "full", strlen("full"))) {
>>
>> strcmp loops over the two string until they differ and/or both are
>> '\0'.
>>
>> As such, the only thing you achieve by using strncmp(.., T, strlen(T))
>> is that the code has to iterate over T twice - and you make the code
>> harder to read.
>
>
> If we use strcmp, i need to use "full\n" which we would not want to do.
> I think, we need to take this hit.
There is a special helper for the sysfs files. See sysfs_streq().
>
> -- Mukesh
>>
>>> + download_mode = QCOM_DOWNLOAD_FULLDUMP;
>>> + } else if (!strncmp(val, "off", strlen("off"))) {
>>> + download_mode = QCOM_DOWNLOAD_NODUMP;
>>> + } else if (kstrtouint(val, 0, &download_mode) ||
>>> + !(download_mode == 0 || download_mode == 1)) {
>>> + download_mode = old;
>>> + pr_err("unknown download mode\n");
>>
>> This will result in a lone "unknown download mode" line somewhere in the
>> kernel log, without association to any driver or any indication what the
>> unknown value was.
>>
>> pr_err("qcom_scm: unknown download mode: %s\n", val);
>>
>> Would give both context and let the reader know right there what value
>> the code wasn't able to match.
>>
>> Regards,
>> Bjorn
On 3/29/2023 3:44 AM, Dmitry Baryshkov wrote:
> On 28/03/2023 11:18, Mukesh Ojha wrote:
>>
>>
>> On 3/27/2023 11:53 PM, Bjorn Andersson wrote:
>>> On Mon, Mar 27, 2023 at 10:11:20PM +0530, Mukesh Ojha wrote:
>>> [..]
>>>> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
>>>> index 3c6c5e7..0c94429 100644
>>>> --- a/drivers/firmware/qcom_scm.c
>>>> +++ b/drivers/firmware/qcom_scm.c
>>>> @@ -20,11 +20,11 @@
>>>> #include <linux/clk.h>
>>>> #include <linux/reset-controller.h>
>>>> #include <linux/arm-smccc.h>
>>>> +#include <linux/kstrtox.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)
>>>> @@ -32,6 +32,7 @@ module_param(download_mode, bool, 0);
>>>> #define QCOM_DOWNLOAD_MODE_MASK 0x30
>>>> #define QCOM_DOWNLOAD_FULLDUMP 0x1
>>>> +#define QCOM_DOWNLOAD_NODUMP 0x0
>>>> struct qcom_scm {
>>>> struct device *dev;
>>>> @@ -440,8 +441,9 @@ 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 ret = 0;
>>>> @@ -453,7 +455,7 @@ static void qcom_scm_set_download_mode(bool enable)
>>>> } else if (__scm->dload_mode_addr) {
>>>> ret = qcom_scm_io_update_field(__scm->dload_mode_addr,
>>>> QCOM_DOWNLOAD_MODE_MASK,
>>>> - enable ? QCOM_DOWNLOAD_FULLDUMP : 0);
>>>> + enable ? download_mode : 0);
>>>
>>> Afaict, with QCOM_DOWNLOAD_NODUMP as 0, this says:
>>>
>>> when download_mode is non-zero, write that value, otherwise write 0
>>>
>>> That should be the same as "write download_mode", so you should be able
>>> to drop the enable part.
>>>
>>>> } else {
>>>> dev_err(__scm->dev,
>>>> "No available mechanism for setting download mode\n");
>>>> @@ -1419,6 +1421,49 @@ 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)
>>>> +{
>>>> + int len = 0;
>>>> +
>>>> + if (download_mode == QCOM_DOWNLOAD_FULLDUMP)
>>>> + len = sysfs_emit(buffer, "full\n");
>>>> + else if (download_mode == QCOM_DOWNLOAD_NODUMP)
>>>> + len = sysfs_emit(buffer, "off\n");
>>>> +
>>>> + return len;
>>>> +}
>>>> +
>>>> +static int set_download_mode(const char *val, const struct
>>>> kernel_param *kp)
>>>> +{
>>>> + u32 old = download_mode;
>>>> +
>>>> + if (!strncmp(val, "full", strlen("full"))) {
>>>
>>> strcmp loops over the two string until they differ and/or both are
>>> '\0'.
>>>
>>> As such, the only thing you achieve by using strncmp(.., T, strlen(T))
>>> is that the code has to iterate over T twice - and you make the code
>>> harder to read.
>>
>>
>> If we use strcmp, i need to use "full\n" which we would not want to do.
>> I think, we need to take this hit.
>
> There is a special helper for the sysfs files. See sysfs_streq().
You are awesome !!
Thanks.
Have applied the change.
-- Mukesh
>
>>
>> -- Mukesh
>>>
>>>> + download_mode = QCOM_DOWNLOAD_FULLDUMP;
>>>> + } else if (!strncmp(val, "off", strlen("off"))) {
>>>> + download_mode = QCOM_DOWNLOAD_NODUMP;
>>>> + } else if (kstrtouint(val, 0, &download_mode) ||
>>>> + !(download_mode == 0 || download_mode == 1)) {
>>>> + download_mode = old;
>>>> + pr_err("unknown download mode\n");
>>>
>>> This will result in a lone "unknown download mode" line somewhere in the
>>> kernel log, without association to any driver or any indication what the
>>> unknown value was.
>>>
>>> pr_err("qcom_scm: unknown download mode: %s\n", val);
>>>
>>> Would give both context and let the reader know right there what value
>>> the code wasn't able to match.
>>>
>>> Regards,
>>> Bjorn
>
@@ -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
@@ -20,11 +20,11 @@
#include <linux/clk.h>
#include <linux/reset-controller.h>
#include <linux/arm-smccc.h>
+#include <linux/kstrtox.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)
@@ -32,6 +32,7 @@ module_param(download_mode, bool, 0);
#define QCOM_DOWNLOAD_MODE_MASK 0x30
#define QCOM_DOWNLOAD_FULLDUMP 0x1
+#define QCOM_DOWNLOAD_NODUMP 0x0
struct qcom_scm {
struct device *dev;
@@ -440,8 +441,9 @@ 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 ret = 0;
@@ -453,7 +455,7 @@ static void qcom_scm_set_download_mode(bool enable)
} else if (__scm->dload_mode_addr) {
ret = qcom_scm_io_update_field(__scm->dload_mode_addr,
QCOM_DOWNLOAD_MODE_MASK,
- enable ? QCOM_DOWNLOAD_FULLDUMP : 0);
+ enable ? download_mode : 0);
} else {
dev_err(__scm->dev,
"No available mechanism for setting download mode\n");
@@ -1419,6 +1421,49 @@ 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)
+{
+ int len = 0;
+
+ if (download_mode == QCOM_DOWNLOAD_FULLDUMP)
+ len = sysfs_emit(buffer, "full\n");
+ else if (download_mode == QCOM_DOWNLOAD_NODUMP)
+ len = sysfs_emit(buffer, "off\n");
+
+ return len;
+}
+
+static int set_download_mode(const char *val, const struct kernel_param *kp)
+{
+ u32 old = download_mode;
+
+ if (!strncmp(val, "full", strlen("full"))) {
+ download_mode = QCOM_DOWNLOAD_FULLDUMP;
+ } else if (!strncmp(val, "off", strlen("off"))) {
+ download_mode = QCOM_DOWNLOAD_NODUMP;
+ } else if (kstrtouint(val, 0, &download_mode) ||
+ !(download_mode == 0 || download_mode == 1)) {
+ download_mode = old;
+ pr_err("unknown download mode\n");
+ return -EINVAL;
+ }
+
+ 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 or 0/1 for existing users");
+
static int qcom_scm_probe(struct platform_device *pdev)
{
struct qcom_scm *scm;
@@ -1512,12 +1557,12 @@ 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;
}
@@ -1525,7 +1570,7 @@ 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[] = {