diff options
Diffstat (limited to 'kernel/drivers/firmware/qcom_scm.c')
| -rw-r--r-- | kernel/drivers/firmware/qcom_scm.c | 494 |
1 files changed, 494 insertions, 0 deletions
diff --git a/kernel/drivers/firmware/qcom_scm.c b/kernel/drivers/firmware/qcom_scm.c new file mode 100644 index 000000000..994b50fd9 --- /dev/null +++ b/kernel/drivers/firmware/qcom_scm.c @@ -0,0 +1,494 @@ +/* Copyright (c) 2010, Code Aurora Forum. All rights reserved. + * Copyright (C) 2015 Linaro Ltd. + * + * 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 + +#define QCOM_SCM_FLAG_COLDBOOT_CPU0 0x00 +#define QCOM_SCM_FLAG_COLDBOOT_CPU1 0x01 +#define QCOM_SCM_FLAG_COLDBOOT_CPU2 0x08 +#define QCOM_SCM_FLAG_COLDBOOT_CPU3 0x20 + +#define QCOM_SCM_FLAG_WARMBOOT_CPU0 0x04 +#define QCOM_SCM_FLAG_WARMBOOT_CPU1 0x02 +#define QCOM_SCM_FLAG_WARMBOOT_CPU2 0x10 +#define QCOM_SCM_FLAG_WARMBOOT_CPU3 0x40 + +struct qcom_scm_entry { + int flag; + void *entry; +}; + +static struct qcom_scm_entry qcom_scm_wb[] = { + { .flag = QCOM_SCM_FLAG_WARMBOOT_CPU0 }, + { .flag = QCOM_SCM_FLAG_WARMBOOT_CPU1 }, + { .flag = QCOM_SCM_FLAG_WARMBOOT_CPU2 }, + { .flag = QCOM_SCM_FLAG_WARMBOOT_CPU3 }, +}; + +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; +} + +#define SCM_CLASS_REGISTER (0x2 << 8) +#define SCM_MASK_IRQS BIT(5) +#define SCM_ATOMIC(svc, cmd, n) (((((svc) << 10)|((cmd) & 0x3ff)) << 12) | \ + SCM_CLASS_REGISTER | \ + SCM_MASK_IRQS | \ + (n & 0xf)) + +/** + * qcom_scm_call_atomic1() - Send an atomic SCM command with one argument + * @svc_id: service identifier + * @cmd_id: command identifier + * @arg1: first argument + * + * This shall only be used with commands that are guaranteed to be + * uninterruptable, atomic and SMP safe. + */ +static s32 qcom_scm_call_atomic1(u32 svc, u32 cmd, u32 arg1) +{ + int context_id; + + register u32 r0 asm("r0") = SCM_ATOMIC(svc, cmd, 1); + register u32 r1 asm("r1") = (u32)&context_id; + register u32 r2 asm("r2") = arg1; + + 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"); + return r0; +} + +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. + */ +static 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); +} + +/** + * qcom_scm_set_cold_boot_addr() - Set the cold boot address for cpus + * @entry: Entry point function for the cpus + * @cpus: The cpumask of cpus that will use the entry point + * + * Set the cold boot address of the cpus. Any cpu outside the supported + * range would be removed from the cpu present mask. + */ +int qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus) +{ + int flags = 0; + int cpu; + int scm_cb_flags[] = { + QCOM_SCM_FLAG_COLDBOOT_CPU0, + QCOM_SCM_FLAG_COLDBOOT_CPU1, + QCOM_SCM_FLAG_COLDBOOT_CPU2, + QCOM_SCM_FLAG_COLDBOOT_CPU3, + }; + + if (!cpus || (cpus && cpumask_empty(cpus))) + return -EINVAL; + + for_each_cpu(cpu, cpus) { + if (cpu < ARRAY_SIZE(scm_cb_flags)) + flags |= scm_cb_flags[cpu]; + else + set_cpu_present(cpu, false); + } + + return qcom_scm_set_boot_addr(virt_to_phys(entry), flags); +} +EXPORT_SYMBOL(qcom_scm_set_cold_boot_addr); + +/** + * qcom_scm_set_warm_boot_addr() - Set the warm boot address for cpus + * @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 ret; + int flags = 0; + int cpu; + + /* + * Reassign only if we are switching from hotplug entry point + * to cpuidle entry point or vice versa. + */ + for_each_cpu(cpu, cpus) { + if (entry == qcom_scm_wb[cpu].entry) + continue; + flags |= qcom_scm_wb[cpu].flag; + } + + /* No change in entry function */ + if (!flags) + return 0; + + ret = qcom_scm_set_boot_addr(virt_to_phys(entry), flags); + if (!ret) { + for_each_cpu(cpu, cpus) + qcom_scm_wb[cpu].entry = entry; + } + + return ret; +} +EXPORT_SYMBOL(qcom_scm_set_warm_boot_addr); + +#define QCOM_SCM_CMD_TERMINATE_PC 0x2 +#define QCOM_SCM_FLUSH_FLAG_MASK 0x3 + +/** + * qcom_scm_cpu_power_down() - Power down the cpu + * @flags - Flags to flush cache + * + * This is an end point to power down cpu. If there was a pending interrupt, + * the control would return from this function, otherwise, the cpu jumps to the + * warm boot entry point set for this cpu upon reset. + */ +void qcom_scm_cpu_power_down(u32 flags) +{ + qcom_scm_call_atomic1(QCOM_SCM_SVC_BOOT, QCOM_SCM_CMD_TERMINATE_PC, + flags & QCOM_SCM_FLUSH_FLAG_MASK); +} +EXPORT_SYMBOL(qcom_scm_cpu_power_down); |