firmware: qcom: scm: Split out 32-bit specific SCM code

Split out the 32-bit SCM implementation into its own file to prep for
supporting a 64-bit/ARM64 implementation as well.  We create a simple shim
to ensure both versions conform to the same interface.

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

1 files changed, 480 insertions, 0 deletions

diff --git a/drivers/firmware/qcom_scm-32.c b/drivers/firmware/qcom_scm-32.c
new file mode 100644
index 000000000000..b08b822ebafa
--- /dev/null
+++ b/drivers/firmware/qcom_scm-32.c
@@ -0,0 +1,480 @@
+/* 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>
+
+#include "qcom_scm.h"
+
+#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);
+
+/*
+ * 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);
+}
+
+/**
+ * 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;
+}
+
+/**
+ * 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);
+}