Re: [PATCH v2 2/4] firmware/qcom_scm: Add atomic version of io read/write APIs

From: Bjorn Andersson
Date: Mon Mar 25 2019 - 17:10:02 EST


On Sun 09 Sep 23:25 PDT 2018, Vivek Gautam wrote:

> Add atomic versions of qcom_scm_io_readl/writel to enable
> reading/writing secure registers from atomic context.
>
> Signed-off-by: Vivek Gautam <vivek.gautam@xxxxxxxxxxxxxx>

Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>

Regards,
Bjorn

> ---
> drivers/firmware/qcom_scm-32.c | 12 ++++++++++++
> drivers/firmware/qcom_scm-64.c | 32 ++++++++++++++++++++++++++++++++
> drivers/firmware/qcom_scm.c | 12 ++++++++++++
> drivers/firmware/qcom_scm.h | 4 ++++
> include/linux/qcom_scm.h | 4 ++++
> 5 files changed, 64 insertions(+)
>
> diff --git a/drivers/firmware/qcom_scm-32.c b/drivers/firmware/qcom_scm-32.c
> index 4e24e591ae74..7293e5efad69 100644
> --- a/drivers/firmware/qcom_scm-32.c
> +++ b/drivers/firmware/qcom_scm-32.c
> @@ -627,3 +627,15 @@ int __qcom_scm_io_writel(struct device *dev, phys_addr_t addr, unsigned int val)
> return qcom_scm_call_atomic2(QCOM_SCM_SVC_IO, QCOM_SCM_IO_WRITE,
> addr, val);
> }
> +
> +int __qcom_scm_io_readl_atomic(struct device *dev, phys_addr_t addr,
> + unsigned int *val)
> +{
> + return -ENODEV;
> +}
> +
> +int __qcom_scm_io_writel_atomic(struct device *dev, phys_addr_t addr,
> + unsigned int val)
> +{
> + return -ENODEV;
> +}
> diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c
> index 3a8c867cdf51..6bf55403f6e3 100644
> --- a/drivers/firmware/qcom_scm-64.c
> +++ b/drivers/firmware/qcom_scm-64.c
> @@ -558,3 +558,35 @@ int __qcom_scm_io_writel(struct device *dev, phys_addr_t addr, unsigned int val)
> return qcom_scm_call(dev, QCOM_SCM_SVC_IO, QCOM_SCM_IO_WRITE,
> &desc, &res);
> }
> +
> +int __qcom_scm_io_readl_atomic(struct device *dev, phys_addr_t addr,
> + unsigned int *val)
> +{
> + struct qcom_scm_desc desc = {0};
> + struct arm_smccc_res res;
> + int ret;
> +
> + desc.args[0] = addr;
> + desc.arginfo = QCOM_SCM_ARGS(1);
> +
> + ret = qcom_scm_call_atomic(dev, QCOM_SCM_SVC_IO, QCOM_SCM_IO_READ,
> + &desc, &res);
> + if (ret >= 0)
> + *val = res.a1;
> +
> + return ret < 0 ? ret : 0;
> +}
> +
> +int __qcom_scm_io_writel_atomic(struct device *dev, phys_addr_t addr,
> + unsigned int val)
> +{
> + struct qcom_scm_desc desc = {0};
> + struct arm_smccc_res res;
> +
> + desc.args[0] = addr;
> + desc.args[1] = val;
> + desc.arginfo = QCOM_SCM_ARGS(2);
> +
> + return qcom_scm_call_atomic(dev, QCOM_SCM_SVC_IO, QCOM_SCM_IO_WRITE,
> + &desc, &res);
> +}
> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> index e778af766fae..36da0000b37f 100644
> --- a/drivers/firmware/qcom_scm.c
> +++ b/drivers/firmware/qcom_scm.c
> @@ -365,6 +365,18 @@ int qcom_scm_io_writel(phys_addr_t addr, unsigned int val)
> }
> EXPORT_SYMBOL(qcom_scm_io_writel);
>
> +int qcom_scm_io_readl_atomic(phys_addr_t addr, unsigned int *val)
> +{
> + return __qcom_scm_io_readl_atomic(__scm->dev, addr, val);
> +}
> +EXPORT_SYMBOL(qcom_scm_io_readl_atomic);
> +
> +int qcom_scm_io_writel_atomic(phys_addr_t addr, unsigned int val)
> +{
> + return __qcom_scm_io_writel_atomic(__scm->dev, addr, val);
> +}
> +EXPORT_SYMBOL(qcom_scm_io_writel_atomic);
> +
> static void qcom_scm_set_download_mode(bool enable)
> {
> bool avail;
> diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
> index dcd7f7917fc7..bb176107f51e 100644
> --- a/drivers/firmware/qcom_scm.h
> +++ b/drivers/firmware/qcom_scm.h
> @@ -37,6 +37,10 @@ extern void __qcom_scm_cpu_power_down(u32 flags);
> #define QCOM_SCM_IO_WRITE 0x2
> extern int __qcom_scm_io_readl(struct device *dev, phys_addr_t addr, unsigned int *val);
> extern int __qcom_scm_io_writel(struct device *dev, phys_addr_t addr, unsigned int val);
> +extern int __qcom_scm_io_readl_atomic(struct device *dev, phys_addr_t addr,
> + unsigned int *val);
> +extern int __qcom_scm_io_writel_atomic(struct device *dev, phys_addr_t addr,
> + unsigned int val);
>
> #define QCOM_SCM_SVC_INFO 0x6
> #define QCOM_IS_CALL_AVAIL_CMD 0x1
> diff --git a/include/linux/qcom_scm.h b/include/linux/qcom_scm.h
> index 5d65521260b3..6a5d0c98b328 100644
> --- a/include/linux/qcom_scm.h
> +++ b/include/linux/qcom_scm.h
> @@ -64,6 +64,8 @@ extern int qcom_scm_iommu_secure_ptbl_size(u32 spare, size_t *size);
> extern int qcom_scm_iommu_secure_ptbl_init(u64 addr, u32 size, u32 spare);
> extern int qcom_scm_io_readl(phys_addr_t addr, unsigned int *val);
> extern int qcom_scm_io_writel(phys_addr_t addr, unsigned int val);
> +extern int qcom_scm_io_readl_atomic(phys_addr_t addr, unsigned int *val);
> +extern int qcom_scm_io_writel_atomic(phys_addr_t addr, unsigned int val);
> #else
> static inline
> int qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus)
> @@ -100,5 +102,7 @@ static inline int qcom_scm_iommu_secure_ptbl_size(u32 spare, size_t *size) { ret
> static inline int qcom_scm_iommu_secure_ptbl_init(u64 addr, u32 size, u32 spare) { return -ENODEV; }
> static inline int qcom_scm_io_readl(phys_addr_t addr, unsigned int *val) { return -ENODEV; }
> static inline int qcom_scm_io_writel(phys_addr_t addr, unsigned int val) { return -ENODEV; }
> +static inline int qcom_scm_io_readl_atomic(phys_addr_t addr, unsigned int *val) { return -ENODEV; }
> +static inline int qcom_scm_io_writel_atomic(phys_addr_t addr, unsigned int val) { return -ENODEV; }
> #endif
> #endif
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
>