firmware: qcom: scm: Move the scm driver to drivers/firmware

Architectural changes in the ARM Linux kernel tree mandate the eventual
removal of the mach-* directories. Move the scm driver to
drivers/firmware and the scm header to include/linux to support that
removal.

Signed-off-by: Kumar Gala <galak@codeaurora.org>

3 files changed, 350 insertions, 0 deletions

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 41983883cef4..6517132e5d8b 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -132,6 +132,10 @@ config ISCSI_IBFT
           detect iSCSI boot parameters dynamically during system boot, say Y.
           Otherwise, say N.
 
+config QCOM_SCM
+        bool
+        depends on ARM || ARM64
+
 source "drivers/firmware/google/Kconfig"
 source "drivers/firmware/efi/Kconfig"
 
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 5373dc5b6011..3fdd3912709a 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -11,6 +11,8 @@ obj-$(CONFIG_DMIID)		+= dmi-id.o
 obj-$(CONFIG_ISCSI_IBFT_FIND)   += iscsi_ibft_find.o
 obj-$(CONFIG_ISCSI_IBFT)        += iscsi_ibft.o
 obj-$(CONFIG_FIRMWARE_MEMMAP)   += memmap.o
+obj-$(CONFIG_QCOM_SCM)          += qcom_scm.o
+CFLAGS_qcom_scm.o :=$(call as-instr,.arch_extension sec,-DREQUIRES_SEC=1)
 
 obj-$(CONFIG_GOOGLE_FIRMWARE)   += google/
 obj-$(CONFIG_EFI)               += efi/
diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
new file mode 100644
index 000000000000..6e7a72bdb176
--- /dev/null
+++ b/drivers/firmware/qcom_scm.c
@@ -0,0 +1,344 @@
+/* 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 <linux/qcom_scm.h>
+
+#include <asm/outercache.h>
+#include <asm/cacheflush.h>
+
+
+#define QCOM_SCM_ENOMEM         -5
+#define QCOM_SCM_EOPNOTSUPP     -4
+#define QCOM_SCM_EINVAL_ADDR    -3
+#define QCOM_SCM_EINVAL_ARG     -2
+#define QCOM_SCM_ERROR          -1
+#define QCOM_SCM_INTERRUPTED    1
+
+static DEFINE_MUTEX(qcom_scm_lock);
+
+/**
+ * struct qcom_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 qcom_scm_get_command_buffer()
+ *
+ * An SCM command is laid out in memory as follows:
+ *
+ *      ------------------- <--- struct qcom_scm_command
+ *      | command header  |
+ *      ------------------- <--- qcom_scm_get_command_buffer()
+ *      | command buffer  |
+ *      ------------------- <--- struct qcom_scm_response and
+ *      | response header |      qcom_scm_command_to_response()
+ *      ------------------- <--- qcom_scm_get_response_buffer()
+ *      | response buffer |
+ *      -------------------
+ *
+ * There can be arbitrary padding between the headers and buffers so
+ * you should always use the appropriate qcom_scm_get_*_buffer() routines
+ * to access the buffers in a safe manner.
+ */
+struct qcom_scm_command {
+        __le32 len;
+        __le32 buf_offset;
+        __le32 resp_hdr_offset;
+        __le32 id;
+        __le32 buf[0];
+};
+
+/**
+ * struct qcom_scm_response - one SCM response buffer
+ * @len: total available memory for response
+ * @buf_offset: start of response data relative to start of qcom_scm_response
+ * @is_complete: indicates if the command has finished processing
+ */
+struct qcom_scm_response {
+        __le32 len;
+        __le32 buf_offset;
+        __le32 is_complete;
+};
+
+/**
+ * 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
+ *
+ * Returns a pointer to a response for a command.
+ */
+static inline struct qcom_scm_response *qcom_scm_command_to_response(
+                const struct qcom_scm_command *cmd)
+{
+        return (void *)cmd + le32_to_cpu(cmd->resp_hdr_offset);
+}
+
+/**
+ * qcom_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 *qcom_scm_get_command_buffer(const struct qcom_scm_command *cmd)
+{
+        return (void *)cmd->buf;
+}
+
+/**
+ * qcom_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 *qcom_scm_get_response_buffer(const struct qcom_scm_response *rsp)
+{
+        return (void *)rsp + le32_to_cpu(rsp->buf_offset);
+}
+
+static int qcom_scm_remap_error(int err)
+{
+        pr_err("qcom_scm_call failed with error code %d\n", err);
+        switch (err) {
+        case QCOM_SCM_ERROR:
+                return -EIO;
+        case QCOM_SCM_EINVAL_ADDR:
+        case QCOM_SCM_EINVAL_ARG:
+                return -EINVAL;
+        case QCOM_SCM_EOPNOTSUPP:
+                return -EOPNOTSUPP;
+        case QCOM_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 == QCOM_SCM_INTERRUPTED);
+
+        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.
+         */
+        __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 = 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
+ *
+ * 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 qcom_scm_call and invalidated in the cache
+ * immediately after qcom_scm_call returns. Cache maintenance on the command
+ * 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)
+{
+        int ret;
+        struct qcom_scm_command *cmd;
+        struct qcom_scm_response *rsp;
+        unsigned long start, end;
+
+        cmd = alloc_qcom_scm_command(cmd_len, resp_len);
+        if (!cmd)
+                return -ENOMEM;
+
+        cmd->id = cpu_to_le32((svc_id << 10) | cmd_id);
+        if (cmd_buf)
+                memcpy(qcom_scm_get_command_buffer(cmd), cmd_buf, cmd_len);
+
+        mutex_lock(&qcom_scm_lock);
+        ret = __qcom_scm_call(cmd);
+        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));
+        } 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);
+out:
+        free_qcom_scm_command(cmd);
+        return ret;
+}
+
+u32 qcom_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(&qcom_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 == QCOM_SCM_INTERRUPTED);
+
+        version = r1;
+        mutex_unlock(&qcom_scm_lock);
+
+        return version;
+}
+EXPORT_SYMBOL(qcom_scm_get_version);
+
+#define QCOM_SCM_SVC_BOOT                       0x1
+#define QCOM_SCM_BOOT_ADDR                      0x1
+/*
+ * Set the cold/warm boot address for one of the CPU cores.
+ */
+int qcom_scm_set_boot_addr(u32 addr, int flags)
+{
+        struct {
+                __le32 flags;
+                __le32 addr;
+        } cmd;
+
+        cmd.addr = cpu_to_le32(addr);
+        cmd.flags = cpu_to_le32(flags);
+        return qcom_scm_call(QCOM_SCM_SVC_BOOT, QCOM_SCM_BOOT_ADDR,
+                        &cmd, sizeof(cmd), NULL, 0);
+}
+EXPORT_SYMBOL(qcom_scm_set_boot_addr);