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-rw-r--r--drivers/soc/qcom/scm.c325
1 files changed, 325 insertions, 0 deletions
diff --git a/drivers/soc/qcom/scm.c b/drivers/soc/qcom/scm.c
new file mode 100644
index 000000000000..0ae8f97dc56e
--- /dev/null
+++ b/drivers/soc/qcom/scm.c
@@ -0,0 +1,325 @@
+/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+
+#include <soc/qcom/scm.h>
+
+#include <asm/outercache.h>
+#include <asm/cacheflush.h>
+
+
+#define SCM_ENOMEM -5
+#define SCM_EOPNOTSUPP -4
+#define SCM_EINVAL_ADDR -3
+#define SCM_EINVAL_ARG -2
+#define SCM_ERROR -1
+#define SCM_INTERRUPTED 1
+
+static DEFINE_MUTEX(scm_lock);
+
+/**
+ * struct scm_command - one SCM command buffer
+ * @len: total available memory for command and response
+ * @buf_offset: start of command buffer
+ * @resp_hdr_offset: start of response buffer
+ * @id: command to be executed
+ * @buf: buffer returned from scm_get_command_buffer()
+ *
+ * An SCM command is laid out in memory as follows:
+ *
+ * ------------------- <--- struct scm_command
+ * | command header |
+ * ------------------- <--- scm_get_command_buffer()
+ * | command buffer |
+ * ------------------- <--- struct scm_response and
+ * | response header | scm_command_to_response()
+ * ------------------- <--- scm_get_response_buffer()
+ * | response buffer |
+ * -------------------
+ *
+ * There can be arbitrary padding between the headers and buffers so
+ * you should always use the appropriate scm_get_*_buffer() routines
+ * to access the buffers in a safe manner.
+ */
+struct scm_command {
+ u32 len;
+ u32 buf_offset;
+ u32 resp_hdr_offset;
+ u32 id;
+ u32 buf[0];
+};
+
+/**
+ * struct scm_response - one SCM response buffer
+ * @len: total available memory for response
+ * @buf_offset: start of response data relative to start of scm_response
+ * @is_complete: indicates if the command has finished processing
+ */
+struct scm_response {
+ u32 len;
+ u32 buf_offset;
+ u32 is_complete;
+};
+
+/**
+ * alloc_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 &scm_command on success or %NULL if the allocation fails.
+ */
+static struct scm_command *alloc_scm_command(size_t cmd_size, size_t resp_size)
+{
+ struct scm_command *cmd;
+ size_t len = sizeof(*cmd) + sizeof(struct scm_response) + cmd_size +
+ resp_size;
+
+ cmd = kzalloc(PAGE_ALIGN(len), GFP_KERNEL);
+ if (cmd) {
+ cmd->len = len;
+ cmd->buf_offset = offsetof(struct scm_command, buf);
+ cmd->resp_hdr_offset = cmd->buf_offset + cmd_size;
+ }
+ return cmd;
+}
+
+/**
+ * free_scm_command() - Free an SCM command
+ * @cmd: command to free
+ *
+ * Free an SCM command.
+ */
+static inline void free_scm_command(struct scm_command *cmd)
+{
+ kfree(cmd);
+}
+
+/**
+ * scm_command_to_response() - Get a pointer to a scm_response
+ * @cmd: command
+ *
+ * Returns a pointer to a response for a command.
+ */
+static inline struct scm_response *scm_command_to_response(
+ const struct scm_command *cmd)
+{
+ return (void *)cmd + cmd->resp_hdr_offset;
+}
+
+/**
+ * scm_get_command_buffer() - Get a pointer to a command buffer
+ * @cmd: command
+ *
+ * Returns a pointer to the command buffer of a command.
+ */
+static inline void *scm_get_command_buffer(const struct scm_command *cmd)
+{
+ return (void *)cmd->buf;
+}
+
+/**
+ * scm_get_response_buffer() - Get a pointer to a response buffer
+ * @rsp: response
+ *
+ * Returns a pointer to a response buffer of a response.
+ */
+static inline void *scm_get_response_buffer(const struct scm_response *rsp)
+{
+ return (void *)rsp + rsp->buf_offset;
+}
+
+static int scm_remap_error(int err)
+{
+ pr_err("scm_call failed with error code %d\n", err);
+ switch (err) {
+ case SCM_ERROR:
+ return -EIO;
+ case SCM_EINVAL_ADDR:
+ case SCM_EINVAL_ARG:
+ return -EINVAL;
+ case SCM_EOPNOTSUPP:
+ return -EOPNOTSUPP;
+ case SCM_ENOMEM:
+ return -ENOMEM;
+ }
+ return -EINVAL;
+}
+
+static u32 smc(u32 cmd_addr)
+{
+ int context_id;
+ register u32 r0 asm("r0") = 1;
+ register u32 r1 asm("r1") = (u32)&context_id;
+ register u32 r2 asm("r2") = cmd_addr;
+ do {
+ asm volatile(
+ __asmeq("%0", "r0")
+ __asmeq("%1", "r0")
+ __asmeq("%2", "r1")
+ __asmeq("%3", "r2")
+#ifdef REQUIRES_SEC
+ ".arch_extension sec\n"
+#endif
+ "smc #0 @ switch to secure world\n"
+ : "=r" (r0)
+ : "r" (r0), "r" (r1), "r" (r2)
+ : "r3");
+ } while (r0 == SCM_INTERRUPTED);
+
+ return r0;
+}
+
+static int __scm_call(const struct 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.
+ */
+ __cpuc_flush_dcache_area((void *)cmd, cmd->len);
+ outer_flush_range(cmd_addr, cmd_addr + cmd->len);
+
+ ret = smc(cmd_addr);
+ if (ret < 0)
+ ret = scm_remap_error(ret);
+
+ return ret;
+}
+
+static void 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();
+}
+
+/**
+ * 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
+ *
+ * Sends a command to the SCM and waits for the command to finish processing.
+ *
+ * A note on cache maintenance:
+ * Note that any buffers that are expected to be accessed by the secure world
+ * must be flushed before invoking scm_call and invalidated in the cache
+ * immediately after scm_call returns. Cache maintenance on the command and
+ * response buffers is taken care of by scm_call; however, callers are
+ * responsible for any other cached buffers passed over to the secure world.
+ */
+int scm_call(u32 svc_id, u32 cmd_id, const void *cmd_buf, size_t cmd_len,
+ void *resp_buf, size_t resp_len)
+{
+ int ret;
+ struct scm_command *cmd;
+ struct scm_response *rsp;
+ unsigned long start, end;
+
+ cmd = alloc_scm_command(cmd_len, resp_len);
+ if (!cmd)
+ return -ENOMEM;
+
+ cmd->id = (svc_id << 10) | cmd_id;
+ if (cmd_buf)
+ memcpy(scm_get_command_buffer(cmd), cmd_buf, cmd_len);
+
+ mutex_lock(&scm_lock);
+ ret = __scm_call(cmd);
+ mutex_unlock(&scm_lock);
+ if (ret)
+ goto out;
+
+ rsp = scm_command_to_response(cmd);
+ start = (unsigned long)rsp;
+
+ do {
+ scm_inv_range(start, start + sizeof(*rsp));
+ } while (!rsp->is_complete);
+
+ end = (unsigned long)scm_get_response_buffer(rsp) + resp_len;
+ scm_inv_range(start, end);
+
+ if (resp_buf)
+ memcpy(resp_buf, scm_get_response_buffer(rsp), resp_len);
+out:
+ free_scm_command(cmd);
+ return ret;
+}
+EXPORT_SYMBOL(scm_call);
+
+u32 scm_get_version(void)
+{
+ int context_id;
+ static u32 version = -1;
+ register u32 r0 asm("r0");
+ register u32 r1 asm("r1");
+
+ if (version != -1)
+ return version;
+
+ mutex_lock(&scm_lock);
+
+ r0 = 0x1 << 8;
+ r1 = (u32)&context_id;
+ do {
+ asm volatile(
+ __asmeq("%0", "r0")
+ __asmeq("%1", "r1")
+ __asmeq("%2", "r0")
+ __asmeq("%3", "r1")
+#ifdef REQUIRES_SEC
+ ".arch_extension sec\n"
+#endif
+ "smc #0 @ switch to secure world\n"
+ : "=r" (r0), "=r" (r1)
+ : "r" (r0), "r" (r1)
+ : "r2", "r3");
+ } while (r0 == SCM_INTERRUPTED);
+
+ version = r1;
+ mutex_unlock(&scm_lock);
+
+ return version;
+}
+EXPORT_SYMBOL(scm_get_version);