[Patch v6 05/10] firmware: qcom: scm: Convert to streaming DMA APIS

Andy Gross
2016-06-03T23:25:25Z

This patch converts the Qualcomm SCM driver to use the streaming DMA APIs
for communication buffers. This is being done so that the
secure_flush_area call can be removed. Using the DMA APIs will also make
the SCM32 symmetric to the coming SCM64 code.

Signed-off-by: Andy Gross <andy.gross-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
drivers/firmware/qcom_scm-32.c | 143 +++++++++++++----------------------------
drivers/firmware/qcom_scm.c | 6 +-
drivers/firmware/qcom_scm.h | 10 +--
3 files changed, 53 insertions(+), 106 deletions(-)

diff --git a/drivers/firmware/qcom_scm-32.c b/drivers/firmware/qcom_scm-32.c
index 4388d13..83a9351 100644
--- a/drivers/firmware/qcom_scm-32.c
+++ b/drivers/firmware/qcom_scm-32.c
@@ -23,8 +23,7 @@
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/qcom_scm.h>
-
-#include <asm/cacheflush.h>
+#include <linux/dma-mapping.h>

#include "qcom_scm.h"

@@ -97,44 +96,6 @@ struct qcom_scm_response {
};

/**
- * alloc_qcom_scm_command() - Allocate an SCM command
- * @cmd_size: size of the command buffer
- * @resp_size: size of the response buffer
- *
- * Allocate an SCM command, including enough room for the command
- * and response headers as well as the command and response buffers.
- *
- * Returns a valid &qcom_scm_command on success or %NULL if the allocation fails.
- */
-static struct qcom_scm_command *alloc_qcom_scm_command(size_t cmd_size, size_t resp_size)
-{
- struct qcom_scm_command *cmd;
- size_t len = sizeof(*cmd) + sizeof(struct qcom_scm_response) + cmd_size +
- resp_size;
- u32 offset;
-
- cmd = kzalloc(PAGE_ALIGN(len), GFP_KERNEL);
- if (cmd) {
- cmd->len = cpu_to_le32(len);
- offset = offsetof(struct qcom_scm_command, buf);
- cmd->buf_offset = cpu_to_le32(offset);
- cmd->resp_hdr_offset = cpu_to_le32(offset + cmd_size);
- }
- return cmd;
-}
-
-/**
- * free_qcom_scm_command() - Free an SCM command
- * @cmd: command to free
- *
- * Free an SCM command.
- */
-static inline void free_qcom_scm_command(struct qcom_scm_command *cmd)
-{
- kfree(cmd);
-}
-
-/**
* qcom_scm_command_to_response() - Get a pointer to a qcom_scm_response
* @cmd: command
*
@@ -192,45 +153,9 @@ static u32 smc(u32 cmd_addr)
return r0;
}

-static int __qcom_scm_call(const struct qcom_scm_command *cmd)
-{
- int ret;
- u32 cmd_addr = virt_to_phys(cmd);
-
- /*
- * Flush the command buffer so that the secure world sees
- * the correct data.
- */
- secure_flush_area(cmd, cmd->len);
-
- ret = smc(cmd_addr);
- if (ret < 0)
- ret = qcom_scm_remap_error(ret);
-
- return ret;
-}
-
-static void qcom_scm_inv_range(unsigned long start, unsigned long end)
-{
- u32 cacheline_size, ctr;
-
- asm volatile("mrc p15, 0, %0, c0, c0, 1" : "=r" (ctr));
- cacheline_size = 4 << ((ctr >> 16) & 0xf);
-
- start = round_down(start, cacheline_size);
- end = round_up(end, cacheline_size);
- outer_inv_range(start, end);
- while (start < end) {
- asm ("mcr p15, 0, %0, c7, c6, 1" : : "r" (start)
- : "memory");
- start += cacheline_size;
- }
- dsb();
- isb();
-}
-
/**
* qcom_scm_call() - Send an SCM command
+ * @dev: struct device
* @svc_id: service identifier
* @cmd_id: command identifier
* @cmd_buf: command buffer
@@ -247,42 +172,59 @@ static void qcom_scm_inv_range(unsigned long start, unsigned long end)
* and response buffers is taken care of by qcom_scm_call; however, callers are
* responsible for any other cached buffers passed over to the secure world.
*/
-static int qcom_scm_call(u32 svc_id, u32 cmd_id, const void *cmd_buf,
- size_t cmd_len, void *resp_buf, size_t resp_len)
+static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id,
+ const void *cmd_buf, size_t cmd_len, void *resp_buf,
+ size_t resp_len)
{
int ret;
struct qcom_scm_command *cmd;
struct qcom_scm_response *rsp;
- unsigned long start, end;
+ size_t alloc_len = sizeof(*cmd) + cmd_len + sizeof(*rsp) + resp_len;
+ dma_addr_t cmd_phys;

- cmd = alloc_qcom_scm_command(cmd_len, resp_len);
+ cmd = kzalloc(PAGE_ALIGN(alloc_len), GFP_KERNEL);
if (!cmd)
return -ENOMEM;

+ cmd->len = cpu_to_le32(alloc_len);
+ cmd->buf_offset = cpu_to_le32(sizeof(*cmd));
+ cmd->resp_hdr_offset = cpu_to_le32(sizeof(*cmd) + cmd_len);
+
cmd->id = cpu_to_le32((svc_id << 10) | cmd_id);
if (cmd_buf)
memcpy(qcom_scm_get_command_buffer(cmd), cmd_buf, cmd_len);

+ rsp = qcom_scm_command_to_response(cmd);
+
+ cmd_phys = dma_map_single(dev, cmd, alloc_len, DMA_TO_DEVICE);
+ if (dma_mapping_error(dev, cmd_phys)) {
+ kfree(cmd);
+ return -ENOMEM;
+ }
+
mutex_lock(&qcom_scm_lock);
- ret = __qcom_scm_call(cmd);
+ ret = smc(cmd_phys);
+ if (ret < 0)
+ ret = qcom_scm_remap_error(ret);
mutex_unlock(&qcom_scm_lock);
if (ret)
goto out;

- rsp = qcom_scm_command_to_response(cmd);
- start = (unsigned long)rsp;
-
do {
- qcom_scm_inv_range(start, start + sizeof(*rsp));
+ dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len,
+ sizeof(*rsp), DMA_FROM_DEVICE);
} while (!rsp->is_complete);

- end = (unsigned long)qcom_scm_get_response_buffer(rsp) + resp_len;
- qcom_scm_inv_range(start, end);
-
- if (resp_buf)
- memcpy(resp_buf, qcom_scm_get_response_buffer(rsp), resp_len);
+ if (resp_buf) {
+ dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len +
+ le32_to_cpu(rsp->buf_offset),
+ resp_len, DMA_FROM_DEVICE);
+ memcpy(resp_buf, qcom_scm_get_response_buffer(rsp),
+ resp_len);
+ }
out:
- free_qcom_scm_command(cmd);
+ dma_unmap_single(dev, cmd_phys, alloc_len, DMA_TO_DEVICE);
+ kfree(cmd);
return ret;
}

@@ -437,7 +379,8 @@ int __qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus)
* 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)
{
int ret;
int flags = 0;
@@ -463,7 +406,7 @@ int __qcom_scm_set_warm_boot_addr(void *entry, const cpumask_t *cpus)

cmd.addr = cpu_to_le32(virt_to_phys(entry));
cmd.flags = cpu_to_le32(flags);
- ret = qcom_scm_call(QCOM_SCM_SVC_BOOT, QCOM_SCM_BOOT_ADDR,
+ ret = qcom_scm_call(dev, QCOM_SCM_SVC_BOOT, QCOM_SCM_BOOT_ADDR,
&cmd, sizeof(cmd), NULL, 0);
if (!ret) {
for_each_cpu(cpu, cpus)
@@ -487,25 +430,27 @@ void __qcom_scm_cpu_power_down(u32 flags)
flags & QCOM_SCM_FLUSH_FLAG_MASK);
}

-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)
{
int ret;
__le32 svc_cmd = cpu_to_le32((svc_id << 10) | cmd_id);
__le32 ret_val = 0;

- ret = qcom_scm_call(QCOM_SCM_SVC_INFO, QCOM_IS_CALL_AVAIL_CMD, &svc_cmd,
- sizeof(svc_cmd), &ret_val, sizeof(ret_val));
+ ret = qcom_scm_call(dev, QCOM_SCM_SVC_INFO, QCOM_IS_CALL_AVAIL_CMD,
+ &svc_cmd, sizeof(svc_cmd), &ret_val,
+ sizeof(ret_val));
if (ret)
return ret;

return le32_to_cpu(ret_val);
}

-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)
{
if (req_cnt > QCOM_SCM_HDCP_MAX_REQ_CNT)
return -ERANGE;

- return qcom_scm_call(QCOM_SCM_SVC_HDCP, QCOM_SCM_CMD_HDCP,
+ return qcom_scm_call(dev, QCOM_SCM_SVC_HDCP, QCOM_SCM_CMD_HDCP,
req, req_cnt * sizeof(*req), resp, sizeof(*resp));
}
diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index c4ec60d..937c64a 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -89,7 +89,7 @@ EXPORT_SYMBOL(qcom_scm_set_cold_boot_addr);
*/
int qcom_scm_set_warm_boot_addr(void *entry, const cpumask_t *cpus)
{
- return __qcom_scm_set_warm_boot_addr(entry, cpus);
+ return __qcom_scm_set_warm_boot_addr(__scm->dev, entry, cpus);
}
EXPORT_SYMBOL(qcom_scm_set_warm_boot_addr);

@@ -119,7 +119,7 @@ bool qcom_scm_hdcp_available(void)
if (ret)
return ret;

- ret = __qcom_scm_is_call_available(QCOM_SCM_SVC_HDCP,
+ ret = __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_HDCP,
QCOM_SCM_CMD_HDCP);

qcom_scm_clk_disable();
@@ -143,7 +143,7 @@ int qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp)
if (ret)
return ret;

- ret = __qcom_scm_hdcp_req(req, req_cnt, resp);
+ ret = __qcom_scm_hdcp_req(__scm->dev, req, req_cnt, resp);
qcom_scm_clk_disable();
return ret;
}
diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
index 7dcc733..afe6676 100644
--- a/drivers/firmware/qcom_scm.h
+++ b/drivers/firmware/qcom_scm.h
@@ -19,7 +19,8 @@
#define QCOM_SCM_FLAG_HLOS 0x01
#define QCOM_SCM_FLAG_COLDBOOT_MC 0x02
#define QCOM_SCM_FLAG_WARMBOOT_MC 0x04
-extern int __qcom_scm_set_warm_boot_addr(void *entry, const cpumask_t *cpus);
+extern int __qcom_scm_set_warm_boot_addr(struct device *dev, void *entry,
+ const cpumask_t *cpus);
extern int __qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus);

#define QCOM_SCM_CMD_TERMINATE_PC 0x2
@@ -29,12 +30,13 @@ extern void __qcom_scm_cpu_power_down(u32 flags);

#define QCOM_SCM_SVC_INFO 0x6
#define QCOM_IS_CALL_AVAIL_CMD 0x1
-extern int __qcom_scm_is_call_available(u32 svc_id, u32 cmd_id);
+extern int __qcom_scm_is_call_available(struct device *dev, u32 svc_id,
+ u32 cmd_id);

#define QCOM_SCM_SVC_HDCP 0x11
#define QCOM_SCM_CMD_HDCP 0x01
-extern int __qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt,
- u32 *resp);
+extern int __qcom_scm_hdcp_req(struct device *dev,
+ struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp);

/* common error codes */
#define QCOM_SCM_ENOMEM -5
--
1.9.1

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