firmware: qcom: scm: Expose secure IO service

The secure IO service provides operations for reading and writing secure
memory from non-secure mode, expose this API through SCM.

Reviewed-by: Stephen Boyd <[e-mail]>
Signed-off-by: Bjorn Andersson <[e-mail]>
Signed-off-by: Andy Gross <[e-mail]>

drivers/firmware/qcom_scm-32.c

···
 {
 	return -ENODEV;
 }
+
+int __qcom_scm_io_readl(struct device *dev, phys_addr_t addr,
+			unsigned int *val)
+{
+	int ret;
+
+	ret = qcom_scm_call_atomic1(QCOM_SCM_SVC_IO, QCOM_SCM_IO_READ, addr);
+	if (ret >= 0)
+		*val = ret;
+
+	return ret < 0 ? ret : 0;
+}
+
+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);
+}

drivers/firmware/qcom_scm-64.c

···
 
 	return ret;
 }
+
+int __qcom_scm_io_readl(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(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(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(dev, QCOM_SCM_SVC_IO, QCOM_SCM_IO_WRITE,
+			     &desc, &res);
+}

drivers/firmware/qcom_scm.c

···
 }
 EXPORT_SYMBOL(qcom_scm_iommu_secure_ptbl_init);
 
+int qcom_scm_io_readl(phys_addr_t addr, unsigned int *val)
+{
+	return __qcom_scm_io_readl(__scm->dev, addr, val);
+}
+EXPORT_SYMBOL(qcom_scm_io_readl);
+
+int qcom_scm_io_writel(phys_addr_t addr, unsigned int val)
+{
+	return __qcom_scm_io_writel(__scm->dev, addr, val);
+}
+EXPORT_SYMBOL(qcom_scm_io_writel);
+
 /**
  * qcom_scm_is_available() - Checks if SCM is available
  */

drivers/firmware/qcom_scm.h

···
 #define QCOM_SCM_CMD_CORE_HOTPLUGGED	0x10
 extern void __qcom_scm_cpu_power_down(u32 flags);
 
+#define QCOM_SCM_SVC_IO			0x5
+#define QCOM_SCM_IO_READ		0x1
+#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);
+
 #define QCOM_SCM_SVC_INFO		0x6
 #define QCOM_IS_CALL_AVAIL_CMD		0x1
 extern int __qcom_scm_is_call_available(struct device *dev, u32 svc_id,

include/linux/qcom_scm.h

···
 extern int qcom_scm_restore_sec_cfg(u32 device_id, u32 spare);
 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);
 #else
 static inline
 int qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus)
···
 static inline int qcom_scm_restore_sec_cfg(u32 device_id, u32 spare) { return -ENODEV; }
 static inline int qcom_scm_iommu_secure_ptbl_size(u32 spare, size_t *size) { return -ENODEV; }
 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; }
 #endif
 #endif