[Patch v5 6/8] firmware: qcom: scm: Add support for ARM64 SoCs

Andy Gross
2016-05-13T03:48:17Z

From: Kumar Gala <galak@codeaurora.org>

Add an implementation of the SCM interface that works on ARM64 SoCs. This
is used by things like determine if we have HDCP support or not on the
system.

Signed-off-by: Kumar Gala <galak@codeaurora.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>
---
drivers/firmware/qcom_scm-32.c | 4 +
drivers/firmware/qcom_scm-64.c | 199 +++++++++++++++++++++++++++++++++++++++--
drivers/firmware/qcom_scm.c | 2 +
drivers/firmware/qcom_scm.h | 5 ++
4 files changed, 205 insertions(+), 5 deletions(-)

diff --git a/drivers/firmware/qcom_scm-32.c b/drivers/firmware/qcom_scm-32.c
index e92bf7a..4971b55 100644
--- a/drivers/firmware/qcom_scm-32.c
+++ b/drivers/firmware/qcom_scm-32.c
@@ -420,3 +420,7 @@ int __qcom_scm_hdcp_req(struct device *dev, struct qcom_scm_hdcp_req *req,
return qcom_scm_call(dev, QCOM_SCM_SVC_HDCP, QCOM_SCM_CMD_HDCP,
req, req_cnt * sizeof(*req), resp, sizeof(*resp));
}
+
+void __qcom_scm_init(void)
+{
+}
diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c
index bb6555f..43ed4de 100644
--- a/drivers/firmware/qcom_scm-64.c
+++ b/drivers/firmware/qcom_scm-64.c
@@ -12,7 +12,143 @@

#include <linux/io.h>
#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/types.h>
#include <linux/qcom_scm.h>
+#include <linux/arm-smccc.h>
+#include <linux/dma-mapping.h>
+
+#include "qcom_scm.h"
+
+#define QCOM_SCM_FNID(s, c) ((((s) & 0xFF) << 8) | ((c) & 0xFF))
+
+#define MAX_QCOM_SCM_ARGS 10
+#define MAX_QCOM_SCM_RETS 3
+
+#define QCOM_SCM_ARGS_IMPL(num, a, b, c, d, e, f, g, h, i, j, ...) (\
+ (((a) & 0x3) << 4) | \
+ (((b) & 0x3) << 6) | \
+ (((c) & 0x3) << 8) | \
+ (((d) & 0x3) << 10) | \
+ (((e) & 0x3) << 12) | \
+ (((f) & 0x3) << 14) | \
+ (((g) & 0x3) << 16) | \
+ (((h) & 0x3) << 18) | \
+ (((i) & 0x3) << 20) | \
+ (((j) & 0x3) << 22) | \
+ (num & 0xf))
+
+#define QCOM_SCM_ARGS(...) QCOM_SCM_ARGS_IMPL(__VA_ARGS__, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)
+
+/**
+ * struct qcom_scm_desc
+ * @arginfo: Metadata describing the arguments in args[]
+ * @args: The array of arguments for the secure syscall
+ * @res: The values returned by the secure syscall
+ */
+struct qcom_scm_desc {
+ u32 arginfo;
+ u64 args[MAX_QCOM_SCM_ARGS];
+ struct arm_smccc_res res;
+};
+
+static u64 qcom_smccc_convention = -1;
+static DEFINE_MUTEX(qcom_scm_lock);
+
+#define QCOM_SCM_EBUSY_WAIT_MS 30
+#define QCOM_SCM_EBUSY_MAX_RETRY 20
+
+#define N_EXT_QCOM_SCM_ARGS 7
+#define FIRST_EXT_ARG_IDX 3
+#define N_REGISTER_ARGS (MAX_QCOM_SCM_ARGS - N_EXT_QCOM_SCM_ARGS + 1)
+
+/**
+ * qcom_scm_call() - Invoke a syscall in the secure world
+ * @dev: device
+ * @svc_id: service identifier
+ * @cmd_id: command identifier
+ * @desc: Descriptor structure containing arguments and return values
+ *
+ * Sends a command to the SCM and waits for the command to finish processing.
+ * This should *only* be called in pre-emptible context.
+*/
+static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id,
+ struct qcom_scm_desc *desc)
+{
+ int arglen = desc->arginfo & 0xf;
+ int retry_count = 0, i;
+ u32 fn_id = QCOM_SCM_FNID(svc_id, cmd_id);
+ u64 cmd, x5 = desc->args[FIRST_EXT_ARG_IDX];
+ dma_addr_t args_phys = 0;
+ void *args_virt = NULL;
+ size_t alloc_len;
+
+ if (unlikely(arglen > N_REGISTER_ARGS)) {
+ alloc_len = N_EXT_QCOM_SCM_ARGS * sizeof(u64);
+ args_virt = kzalloc(PAGE_ALIGN(alloc_len), GFP_KERNEL);
+
+ if (!args_virt)
+ return qcom_scm_remap_error(-ENOMEM);
+
+ if (qcom_smccc_convention == ARM_SMCCC_SMC_32) {
+ __le32 *args = args_virt;
+
+ for (i = 0; i < N_EXT_QCOM_SCM_ARGS; i++)
+ args[i] = cpu_to_le32(desc->args[i +
+ FIRST_EXT_ARG_IDX]);
+ } else {
+ __le64 *args = args_virt;
+
+ for (i = 0; i < N_EXT_QCOM_SCM_ARGS; i++)
+ args[i] = cpu_to_le64(desc->args[i +
+ FIRST_EXT_ARG_IDX]);
+ }
+
+ args_phys = dma_map_single(dev, args_virt, alloc_len,
+ DMA_TO_DEVICE);
+
+ if (dma_mapping_error(dev, args_phys)) {
+ kfree(args_virt);
+ return qcom_scm_remap_error(-ENOMEM);
+ }
+
+ x5 = args_phys;
+ }
+
+ do {
+ mutex_lock(&qcom_scm_lock);
+
+ cmd = ARM_SMCCC_CALL_VAL(ARM_SMCCC_STD_CALL,
+ qcom_smccc_convention,
+ ARM_SMCCC_OWNER_SIP, fn_id);
+
+ do {
+ arm_smccc_smc(cmd, desc->arginfo, desc->args[0],
+ desc->args[1], desc->args[2], x5, 0, 0,
+ &desc->res);
+ } while (desc->res.a0 == QCOM_SCM_INTERRUPTED);
+
+ mutex_unlock(&qcom_scm_lock);
+
+ if (desc->res.a0 == QCOM_SCM_V2_EBUSY) {
+ if (retry_count++ > QCOM_SCM_EBUSY_MAX_RETRY)
+ break;
+ msleep(QCOM_SCM_EBUSY_WAIT_MS);
+ }
+ } while (desc->res.a0 == QCOM_SCM_V2_EBUSY);
+
+ if (args_virt) {
+ dma_unmap_single(dev, args_phys, alloc_len, DMA_TO_DEVICE);
+ kfree(args_virt);
+ }
+
+ if (desc->res.a0 < 0)
+ return qcom_scm_remap_error(desc->res.a0);
+
+ return 0;
+}

/**
* qcom_scm_set_cold_boot_addr() - Set the cold boot address for cpus
@@ -29,13 +165,15 @@ int __qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus)

/**
* qcom_scm_set_warm_boot_addr() - Set the warm boot address for cpus
+ * @dev: Device pointer
* @entry: Entry point function for the cpus
* @cpus: The cpumask of cpus that will use the entry point
*
* Set the Linux entry point for the SCM to transfer control to when coming
* out of a power down. CPU power down may be executed on cpuidle or hotplug.
*/
-int __qcom_scm_set_warm_boot_addr(void *entry, const cpumask_t *cpus)
+int __qcom_scm_set_warm_boot_addr(struct device *dev, void *entry,
+ const cpumask_t *cpus)
{
return -ENOTSUPP;
}
@@ -52,12 +190,63 @@ void __qcom_scm_cpu_power_down(u32 flags)
{
}

-int __qcom_scm_is_call_available(u32 svc_id, u32 cmd_id)
+int __qcom_scm_is_call_available(struct device *dev, u32 svc_id, u32 cmd_id)
{
- return -ENOTSUPP;
+ int ret;
+ struct qcom_scm_desc desc = {0};
+
+ desc.arginfo = QCOM_SCM_ARGS(1);
+ desc.args[0] = QCOM_SCM_FNID(svc_id, cmd_id) |
+ (ARM_SMCCC_OWNER_SIP << ARM_SMCCC_OWNER_SHIFT);
+
+ ret = qcom_scm_call(dev, QCOM_SCM_SVC_INFO, QCOM_IS_CALL_AVAIL_CMD,
+ &desc);
+
+ return ret ? : desc.res.a1;
}

-int __qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp)
+int __qcom_scm_hdcp_req(struct device *dev, struct qcom_scm_hdcp_req *req,
+ u32 req_cnt, u32 *resp)
{
- return -ENOTSUPP;
+ int ret;
+ struct qcom_scm_desc desc = {0};
+
+ if (req_cnt > QCOM_SCM_HDCP_MAX_REQ_CNT)
+ return -ERANGE;
+
+ desc.args[0] = req[0].addr;
+ desc.args[1] = req[0].val;
+ desc.args[2] = req[1].addr;
+ desc.args[3] = req[1].val;
+ desc.args[4] = req[2].addr;
+ desc.args[5] = req[2].val;
+ desc.args[6] = req[3].addr;
+ desc.args[7] = req[3].val;
+ desc.args[8] = req[4].addr;
+ desc.args[9] = req[4].val;
+ desc.arginfo = QCOM_SCM_ARGS(10);
+
+ ret = qcom_scm_call(dev, QCOM_SCM_SVC_HDCP, QCOM_SCM_CMD_HDCP, &desc);
+ *resp = desc.res.a1;
+
+ return ret;
+}
+
+void __qcom_scm_init(void)
+{
+ u64 cmd;
+ struct arm_smccc_res res;
+ u32 function = QCOM_SCM_FNID(QCOM_SCM_SVC_INFO, QCOM_IS_CALL_AVAIL_CMD);
+
+ /* First try a SMC64 call */
+ cmd = ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, ARM_SMCCC_SMC_64,
+ ARM_SMCCC_OWNER_SIP, function);
+
+ arm_smccc_smc(cmd, QCOM_SCM_ARGS(1), cmd & (~BIT(ARM_SMCCC_TYPE_SHIFT)),
+ 0, 0, 0, 0, 0, &res);
+
+ if (!res.a0 && res.a1)
+ qcom_smccc_convention = ARM_SMCCC_SMC_64;
+ else
+ qcom_smccc_convention = ARM_SMCCC_SMC_32;
}
diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index 23ccec6..475410b3e 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -189,6 +189,8 @@ static int qcom_scm_probe(struct platform_device *pdev)
__scm = scm;
__scm->dev = &pdev->dev;

+ __qcom_scm_init();
+
return 0;
}

diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
index afe6676..0ea55d7 100644
--- a/drivers/firmware/qcom_scm.h
+++ b/drivers/firmware/qcom_scm.h
@@ -38,7 +38,10 @@ extern int __qcom_scm_is_call_available(struct device *dev, u32 svc_id,
extern int __qcom_scm_hdcp_req(struct device *dev,
struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp);

+extern void __qcom_scm_init(void);
+
/* common error codes */
+#define QCOM_SCM_V2_EBUSY -12
#define QCOM_SCM_ENOMEM -5
#define QCOM_SCM_EOPNOTSUPP -4
#define QCOM_SCM_EINVAL_ADDR -3
@@ -58,6 +61,8 @@ static inline int qcom_scm_remap_error(int err)
return -EOPNOTSUPP;
case QCOM_SCM_ENOMEM:
return -ENOMEM;
+ case QCOM_SCM_V2_EBUSY:
+ return -EBUSY;
}
return -EINVAL;
}
--
1.9.1