This patch converts the Qualcomm SCM driver to use the streaming DMA APIs
for communication buffers.

Signed-off-by: Andy Gross <andy.gr...@linaro.org>
---
 drivers/firmware/qcom_scm-32.c | 152 +++++++++++++----------------------------
 drivers/firmware/qcom_scm.c    |   6 +-
 drivers/firmware/qcom_scm.h    |  10 +--
 3 files changed, 58 insertions(+), 110 deletions(-)

diff --git a/drivers/firmware/qcom_scm-32.c b/drivers/firmware/qcom_scm-32.c
index 4388d13..3e71aec 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
  *
@@ -168,7 +129,7 @@ static inline void *qcom_scm_get_response_buffer(const 
struct qcom_scm_response
        return (void *)rsp + le32_to_cpu(rsp->buf_offset);
 }
 
-static u32 smc(u32 cmd_addr)
+static u32 smc(dma_addr_t cmd_addr)
 {
        int context_id;
        register u32 r0 asm("r0") = 1;
@@ -192,51 +153,15 @@ 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
- * @svc_id: service identifier
- * @cmd_id: command identifier
- * @cmd_buf: command buffer
- * @cmd_len: length of the command buffer
- * @resp_buf: response buffer
- * @resp_len: length of the response buffer
+ * @dev:       struct device
+ * @svc_id:    service identifier
+ * @cmd_id:    command identifier
+ * @cmd_buf:   command buffer
+ * @cmd_len:   length of the command buffer
+ * @resp_buf:  response buffer
+ * @resp_len:  length of the response buffer
  *
  * Sends a command to the SCM and waits for the command to finish processing.
  *
@@ -247,42 +172,60 @@ 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) + sizeof(struct qcom_scm_response) +
+                          cmd_len + resp_len;
+       dma_addr_t cmd_phys;
+       u32 offset;
 
-       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);
+       offset = offsetof(struct qcom_scm_command, buf);
+       cmd->buf_offset = cpu_to_le32(offset);
+       cmd->resp_hdr_offset = cpu_to_le32(offset + 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);
 
+       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 + cmd_len + offset,
+                                       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)
+       if (resp_buf) {
+               dma_sync_single_for_cpu(dev, cmd_phys + alloc_len - resp_len,
+                                       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 +380,8 @@ 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 +407,7 @@ 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 +431,27 @@ 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 63a2bfa..9166cbb 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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