2023-10-04 17:26:58

by Mukesh Ojha

[permalink] [raw]
Subject: [PATCH v7 1/3] firmware: qcom_scm: provide a read-modify-write function

It was realized by Srinivas K. that there is a need of
read-modify-write scm exported function so that it can
be used by multiple clients.

Let's introduce qcom_scm_io_update_field() which masks
out the bits and write the passed value to that bit-offset.

Suggested-by: Srinivas Kandagatla <[email protected]>
Signed-off-by: Mukesh Ojha <[email protected]>
Tested-by: Kathiravan Thirumoorthy <[email protected]> # IPQ9574 and IPQ5332
---
drivers/firmware/qcom_scm.c | 20 ++++++++++++++++++++
include/linux/firmware/qcom/qcom_scm.h | 2 ++
2 files changed, 22 insertions(+)

diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index 520de9b5633a..084e4782b88d 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -122,6 +122,7 @@ static const char * const qcom_scm_convention_names[] = {
};

static struct qcom_scm *__scm;
+static DEFINE_SPINLOCK(lock);

static int qcom_scm_clk_enable(void)
{
@@ -481,6 +482,25 @@ static int qcom_scm_disable_sdi(void)
return ret ? : res.result[0];
}

+int qcom_scm_io_update_field(phys_addr_t addr, unsigned int mask, unsigned int val)
+{
+ unsigned int old, new;
+ int ret;
+
+ spin_lock(&lock);
+ ret = qcom_scm_io_readl(addr, &old);
+ if (ret)
+ goto unlock;
+
+ new = (old & ~mask) | (val & mask);
+
+ ret = qcom_scm_io_writel(addr, new);
+unlock:
+ spin_unlock(&lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(qcom_scm_io_update_field);
+
static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
{
struct qcom_scm_desc desc = {
diff --git a/include/linux/firmware/qcom/qcom_scm.h b/include/linux/firmware/qcom/qcom_scm.h
index ccaf28846054..5497eaf9c7b5 100644
--- a/include/linux/firmware/qcom/qcom_scm.h
+++ b/include/linux/firmware/qcom/qcom_scm.h
@@ -82,6 +82,8 @@ bool qcom_scm_pas_supported(u32 peripheral);

int qcom_scm_io_readl(phys_addr_t addr, unsigned int *val);
int qcom_scm_io_writel(phys_addr_t addr, unsigned int val);
+int qcom_scm_io_update_field(phys_addr_t addr, unsigned int mask,
+ unsigned int val);

bool qcom_scm_restore_sec_cfg_available(void);
int qcom_scm_restore_sec_cfg(u32 device_id, u32 spare);
--
2.7.4


2023-10-24 19:59:40

by Dmitry Baryshkov

[permalink] [raw]
Subject: Re: [PATCH v7 1/3] firmware: qcom_scm: provide a read-modify-write function

On Wed, 4 Oct 2023 at 20:26, Mukesh Ojha <[email protected]> wrote:
>
> It was realized by Srinivas K. that there is a need of
> read-modify-write scm exported function so that it can
> be used by multiple clients.
>
> Let's introduce qcom_scm_io_update_field() which masks
> out the bits and write the passed value to that bit-offset.
>
> Suggested-by: Srinivas Kandagatla <[email protected]>
> Signed-off-by: Mukesh Ojha <[email protected]>
> Tested-by: Kathiravan Thirumoorthy <[email protected]> # IPQ9574 and IPQ5332
> ---
> drivers/firmware/qcom_scm.c | 20 ++++++++++++++++++++
> include/linux/firmware/qcom/qcom_scm.h | 2 ++
> 2 files changed, 22 insertions(+)
>
> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> index 520de9b5633a..084e4782b88d 100644
> --- a/drivers/firmware/qcom_scm.c
> +++ b/drivers/firmware/qcom_scm.c
> @@ -122,6 +122,7 @@ static const char * const qcom_scm_convention_names[] = {
> };
>
> static struct qcom_scm *__scm;
> +static DEFINE_SPINLOCK(lock);

Please move the spinlock inside __scm.

>
> static int qcom_scm_clk_enable(void)
> {
> @@ -481,6 +482,25 @@ static int qcom_scm_disable_sdi(void)
> return ret ? : res.result[0];
> }
>
> +int qcom_scm_io_update_field(phys_addr_t addr, unsigned int mask, unsigned int val)

qcom_scm_io_rmw ? qcom_scm_io_update_bits? These might be better names
and they follow the existing function names.

> +{
> + unsigned int old, new;
> + int ret;
> +
> + spin_lock(&lock);
> + ret = qcom_scm_io_readl(addr, &old);
> + if (ret)
> + goto unlock;
> +
> + new = (old & ~mask) | (val & mask);
> +
> + ret = qcom_scm_io_writel(addr, new);
> +unlock:
> + spin_unlock(&lock);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(qcom_scm_io_update_field);
> +
> static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
> {
> struct qcom_scm_desc desc = {
> diff --git a/include/linux/firmware/qcom/qcom_scm.h b/include/linux/firmware/qcom/qcom_scm.h
> index ccaf28846054..5497eaf9c7b5 100644
> --- a/include/linux/firmware/qcom/qcom_scm.h
> +++ b/include/linux/firmware/qcom/qcom_scm.h
> @@ -82,6 +82,8 @@ bool qcom_scm_pas_supported(u32 peripheral);
>
> int qcom_scm_io_readl(phys_addr_t addr, unsigned int *val);
> int qcom_scm_io_writel(phys_addr_t addr, unsigned int val);
> +int qcom_scm_io_update_field(phys_addr_t addr, unsigned int mask,
> + unsigned int val);
>
> bool qcom_scm_restore_sec_cfg_available(void);
> int qcom_scm_restore_sec_cfg(u32 device_id, u32 spare);
> --
> 2.7.4
>


--
With best wishes
Dmitry