[RFC PATCH v2 2/4] firmware: qcom: scm: Add support for ARM64 SoCs

Kumar Gala
2015-04-10T20:43:23Z

Add an implementation of the SCM interface that works on ARM64/64-bit SoCs

Signed-off-by: Kumar Gala <galak@codeaurora.org>
---
arch/arm64/Kconfig | 1 +
drivers/firmware/Makefile | 4 +
drivers/firmware/qcom_scm-64.c | 466 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 471 insertions(+)
create mode 100644 drivers/firmware/qcom_scm-64.c

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 610965dd..11e97d8 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -180,6 +180,7 @@ config ARCH_MEDIATEK
config ARCH_QCOM
bool "Qualcomm Platforms"
select PINCTRL
+ select QCOM_SCM
help
This enables support for the ARMv8 based Qualcomm chipsets.

diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 3001f1a..c79751a 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -12,7 +12,11 @@ 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
+ifdef CONFIG_64BIT
+obj-$(CONFIG_QCOM_SCM) += qcom_scm-64.o
+else
obj-$(CONFIG_QCOM_SCM) += qcom_scm-32.o
+endif
CFLAGS_qcom_scm-32.o :=$(call as-instr,.arch_extension sec,-DREQUIRES_SEC=1)

obj-$(CONFIG_GOOGLE_FIRMWARE) += google/
diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c
new file mode 100644
index 0000000..72b75d6
--- /dev/null
+++ b/drivers/firmware/qcom_scm-64.c
@@ -0,0 +1,466 @@
+/* Copyright (c) 2014-2015, The Linux Foundation. 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/cpumask.h>
+#include <linux/delay.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/qcom_scm.h>
+
+#include <asm/cacheflush.h>
+#include <asm/compiler.h>
+#include <asm/smp_plat.h>
+
+#include "qcom_scm.h"
+
+#define QCOM_SCM_SIP_FNID(s, c) (((((s) & 0xFF) << 8) | ((c) & 0xFF)) | 0x02000000)
+
+#define MAX_QCOM_SCM_ARGS 10
+#define MAX_QCOM_SCM_RETS 3
+
+#define QCOM_SCM_ARGS_IMPL(num, a, b, c, d, e, f, g, h, i, j, ...) (\
+ (((a) & 0xff) << 4) | \
+ (((b) & 0xff) << 6) | \
+ (((c) & 0xff) << 8) | \
+ (((d) & 0xff) << 10) | \
+ (((e) & 0xff) << 12) | \
+ (((f) & 0xff) << 14) | \
+ (((g) & 0xff) << 16) | \
+ (((h) & 0xff) << 18) | \
+ (((i) & 0xff) << 20) | \
+ (((j) & 0xff) << 22) | \
+ (num & 0xffff))
+
+#define QCOM_SCM_ARGS(...) QCOM_SCM_ARGS_IMPL(__VA_ARGS__, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)
+
+/**
+ * struct qcom_scm_desc
+ * @arginfo: Metadata describing the arguments in args[]
+ * @args: The array of arguments for the secure syscall
+ * @ret: The values returned by the secure syscall
+ * @extra_arg_buf: The buffer containing extra arguments
+ (that don't fit in available registers)
+ * @x5: The 4rd argument to the secure syscall or physical address of
+ extra_arg_buf
+ */
+struct qcom_scm_desc {
+ u32 arginfo;
+ u64 args[MAX_QCOM_SCM_ARGS];
+ u64 ret[MAX_QCOM_SCM_RETS];
+
+ /* private */
+ void *extra_arg_buf;
+ u64 x5;
+};
+
+
+#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_EBUSY -55
+#define QCOM_SCM_V2_EBUSY -12
+
+static DEFINE_MUTEX(qcom_scm_lock);
+
+#define QCOM_SCM_EBUSY_WAIT_MS 30
+#define QCOM_SCM_EBUSY_MAX_RETRY 20
+
+#define N_EXT_QCOM_SCM_ARGS 7
+#define FIRST_EXT_ARG_IDX 3
+#define SMC_ATOMIC_SYSCALL 31
+#define N_REGISTER_ARGS (MAX_QCOM_SCM_ARGS - N_EXT_QCOM_SCM_ARGS + 1)
+#define SMC64_MASK 0x40000000
+#define SMC_ATOMIC_MASK 0x80000000
+#define IS_CALL_AVAIL_CMD 1
+
+#define R0_STR "x0"
+#define R1_STR "x1"
+#define R2_STR "x2"
+#define R3_STR "x3"
+#define R4_STR "x4"
+#define R5_STR "x5"
+
+static int qcom_scm_remap_error(int 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;
+ case QCOM_SCM_EBUSY:
+ return QCOM_SCM_EBUSY;
+ case QCOM_SCM_V2_EBUSY:
+ return QCOM_SCM_V2_EBUSY;
+ }
+ return -EINVAL;
+}
+
+int __qcom_scm_call_armv8_64(u64 x0, u64 x1, u64 x2, u64 x3, u64 x4, u64 x5,
+ u64 *ret1, u64 *ret2, u64 *ret3)
+{
+ register u64 r0 asm("r0") = x0;
+ register u64 r1 asm("r1") = x1;
+ register u64 r2 asm("r2") = x2;
+ register u64 r3 asm("r3") = x3;
+ register u64 r4 asm("r4") = x4;
+ register u64 r5 asm("r5") = x5;
+
+ do {
+ asm volatile(
+ __asmeq("%0", R0_STR)
+ __asmeq("%1", R1_STR)
+ __asmeq("%2", R2_STR)
+ __asmeq("%3", R3_STR)
+ __asmeq("%4", R0_STR)
+ __asmeq("%5", R1_STR)
+ __asmeq("%6", R2_STR)
+ __asmeq("%7", R3_STR)
+ __asmeq("%8", R4_STR)
+ __asmeq("%9", R5_STR)
+#ifdef REQUIRES_SEC
+ ".arch_extension sec\n"
+#endif
+ "smc #0\n"
+ : "=r" (r0), "=r" (r1), "=r" (r2), "=r" (r3)
+ : "r" (r0), "r" (r1), "r" (r2), "r" (r3), "r" (r4),
+ "r" (r5)
+ : "x6", "x7", "x8", "x9", "x10", "x11", "x12", "x13",
+ "x14", "x15", "x16", "x17");
+ } while (r0 == QCOM_SCM_INTERRUPTED);
+
+ if (ret1)
+ *ret1 = r1;
+ if (ret2)
+ *ret2 = r2;
+ if (ret3)
+ *ret3 = r3;
+
+ return r0;
+}
+
+int __qcom_scm_call_armv8_32(u32 w0, u32 w1, u32 w2, u32 w3, u32 w4, u32 w5,
+ u64 *ret1, u64 *ret2, u64 *ret3)
+{
+ register u32 r0 asm("r0") = w0;
+ register u32 r1 asm("r1") = w1;
+ register u32 r2 asm("r2") = w2;
+ register u32 r3 asm("r3") = w3;
+ register u32 r4 asm("r4") = w4;
+ register u32 r5 asm("r5") = w5;
+
+ do {
+ asm volatile(
+ __asmeq("%0", R0_STR)
+ __asmeq("%1", R1_STR)
+ __asmeq("%2", R2_STR)
+ __asmeq("%3", R3_STR)
+ __asmeq("%4", R0_STR)
+ __asmeq("%5", R1_STR)
+ __asmeq("%6", R2_STR)
+ __asmeq("%7", R3_STR)
+ __asmeq("%8", R4_STR)
+ __asmeq("%9", R5_STR)
+#ifdef REQUIRES_SEC
+ ".arch_extension sec\n"
+#endif
+ "smc #0\n"
+ : "=r" (r0), "=r" (r1), "=r" (r2), "=r" (r3)
+ : "r" (r0), "r" (r1), "r" (r2), "r" (r3), "r" (r4),
+ "r" (r5)
+ : "x6", "x7", "x8", "x9", "x10", "x11", "x12", "x13",
+ "x14", "x15", "x16", "x17");
+
+ } while (r0 == QCOM_SCM_INTERRUPTED);
+
+ if (ret1)
+ *ret1 = r1;
+ if (ret2)
+ *ret2 = r2;
+ if (ret3)
+ *ret3 = r3;
+
+ return r0;
+}
+
+struct qcom_scm_extra_arg {
+ union {
+ u32 args32[N_EXT_QCOM_SCM_ARGS];
+ u64 args64[N_EXT_QCOM_SCM_ARGS];
+ };
+};
+
+static enum qcom_scm_interface_version {
+ QCOM_SCM_UNKNOWN,
+ QCOM_SCM_LEGACY,
+ QCOM_SCM_ARMV8_32,
+ QCOM_SCM_ARMV8_64,
+} qcom_scm_version = QCOM_SCM_UNKNOWN;
+
+/* This will be set to specify SMC32 or SMC64 */
+static u32 qcom_scm_version_mask;
+
+/*
+ * If there are more than N_REGISTER_ARGS, allocate a buffer and place
+ * the additional arguments in it. The extra argument buffer will be
+ * pointed to by X5.
+ */
+static int allocate_extra_arg_buffer(struct qcom_scm_desc *desc, gfp_t flags)
+{
+ int i, j;
+ struct qcom_scm_extra_arg *argbuf;
+ int arglen = desc->arginfo & 0xf;
+ size_t argbuflen = PAGE_ALIGN(sizeof(struct qcom_scm_extra_arg));
+
+ desc->x5 = desc->args[FIRST_EXT_ARG_IDX];
+
+ if (likely(arglen <= N_REGISTER_ARGS)) {
+ desc->extra_arg_buf = NULL;
+ return 0;
+ }
+
+ argbuf = kzalloc(argbuflen, flags);
+ if (!argbuf) {
+ pr_err("qcom_scm_call: failed to alloc mem for extended argument buffer\n");
+ return -ENOMEM;
+ }
+
+ desc->extra_arg_buf = argbuf;
+
+ j = FIRST_EXT_ARG_IDX;
+ if (qcom_scm_version == QCOM_SCM_ARMV8_64)
+ for (i = 0; i < N_EXT_QCOM_SCM_ARGS; i++)
+ argbuf->args64[i] = desc->args[j++];
+ else
+ for (i = 0; i < N_EXT_QCOM_SCM_ARGS; i++)
+ argbuf->args32[i] = desc->args[j++];
+ desc->x5 = virt_to_phys(argbuf);
+ __flush_dcache_area(argbuf, argbuflen);
+
+ return 0;
+}
+
+/**
+ * qcom_scm_call() - Invoke a syscall in the secure world
+ * @svc_id: service identifier
+ * @cmd_id: command identifier
+ * @fn_id: The function ID for this syscall
+ * @desc: Descriptor structure containing arguments and return values
+ *
+ * Sends a command to the SCM and waits for the command to finish processing.
+ * This should *only* be called in pre-emptible context.
+ *
+ * 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. An important point that must be noted
+ * is that on ARMV8 architectures, invalidation actually also causes a dirty
+ * cache line to be cleaned (flushed + unset-dirty-bit). Therefore it is of
+ * paramount importance that the buffer be flushed before invoking qcom_scm_call,
+ * even if you don't care about the contents of that buffer.
+ *
+ * Note that cache maintenance on the argument buffer (desc->args) 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, struct qcom_scm_desc *desc)
+{
+ int arglen = desc->arginfo & 0xf;
+ int ret, retry_count = 0;
+ u32 fn_id = QCOM_SCM_SIP_FNID(svc_id, cmd_id);
+ u64 x0;
+
+ ret = allocate_extra_arg_buffer(desc, GFP_KERNEL);
+ if (ret)
+ return ret;
+
+ x0 = fn_id | qcom_scm_version_mask;
+
+ do {
+ mutex_lock(&qcom_scm_lock);
+
+ desc->ret[0] = desc->ret[1] = desc->ret[2] = 0;
+
+ pr_debug("qcom_scm_call: func id %#llx, args: %#x, %#llx, %#llx, %#llx, %#llx\n",
+ x0, desc->arginfo, desc->args[0], desc->args[1],
+ desc->args[2], desc->x5);
+
+ if (qcom_scm_version == QCOM_SCM_ARMV8_64)
+ ret = __qcom_scm_call_armv8_64(x0, desc->arginfo,
+ desc->args[0], desc->args[1],
+ desc->args[2], desc->x5,
+ &desc->ret[0], &desc->ret[1],
+ &desc->ret[2]);
+ else
+ ret = __qcom_scm_call_armv8_32(x0, desc->arginfo,
+ desc->args[0], desc->args[1],
+ desc->args[2], desc->x5,
+ &desc->ret[0], &desc->ret[1],
+ &desc->ret[2]);
+ mutex_unlock(&qcom_scm_lock);
+
+ if (ret == QCOM_SCM_V2_EBUSY)
+ msleep(QCOM_SCM_EBUSY_WAIT_MS);
+ } while (ret == QCOM_SCM_V2_EBUSY && (retry_count++ < QCOM_SCM_EBUSY_MAX_RETRY));
+
+ if (ret < 0)
+ pr_err("qcom_scm_call failed: func id %#llx, arginfo: %#x, args: %#llx, %#llx, %#llx, %#llx, ret: %d, syscall returns: %#llx, %#llx, %#llx\n",
+ x0, desc->arginfo, desc->args[0], desc->args[1],
+ desc->args[2], desc->x5, ret, desc->ret[0],
+ desc->ret[1], desc->ret[2]);
+
+ if (arglen > N_REGISTER_ARGS)
+ kfree(desc->extra_arg_buf);
+ if (ret < 0)
+ return qcom_scm_remap_error(ret);
+ return 0;
+}
+
+/**
+ * qcom_scm_call_atomic() - Invoke a syscall in the secure world
+ *
+ * Similar to qcom_scm_call except that this can be invoked in atomic context.
+ * There is also no retry mechanism implemented. Please ensure that the
+ * secure world syscall can be executed in such a context and can complete
+ * in a timely manner.
+ */
+static int qcom_scm_call_atomic(u32 s, u32 c, struct qcom_scm_desc *desc)
+{
+ int arglen = desc->arginfo & 0xf;
+ int ret;
+ u32 fn_id = QCOM_SCM_SIP_FNID(s, c);
+ u64 x0;
+
+ ret = allocate_extra_arg_buffer(desc, GFP_ATOMIC);
+ if (ret)
+ return ret;
+
+ x0 = fn_id | BIT(SMC_ATOMIC_SYSCALL) | qcom_scm_version_mask;
+
+ pr_debug("qcom_scm_call: func id %#llx, args: %#x, %#llx, %#llx, %#llx, %#llx\n",
+ x0, desc->arginfo, desc->args[0], desc->args[1],
+ desc->args[2], desc->x5);
+
+ if (qcom_scm_version == QCOM_SCM_ARMV8_64)
+ ret = __qcom_scm_call_armv8_64(x0, desc->arginfo, desc->args[0],
+ desc->args[1], desc->args[2],
+ desc->x5, &desc->ret[0],
+ &desc->ret[1], &desc->ret[2]);
+ else
+ ret = __qcom_scm_call_armv8_32(x0, desc->arginfo, desc->args[0],
+ desc->args[1], desc->args[2],
+ desc->x5, &desc->ret[0],
+ &desc->ret[1], &desc->ret[2]);
+ if (ret < 0)
+ pr_err("qcom_scm_call failed: func id %#llx, arginfo: %#x, args: %#llx, %#llx, %#llx, %#llx, ret: %d, syscall returns: %#llx, %#llx, %#llx\n",
+ x0, desc->arginfo, desc->args[0], desc->args[1],
+ desc->args[2], desc->x5, ret, desc->ret[0],
+ desc->ret[1], desc->ret[2]);
+
+ if (arglen > N_REGISTER_ARGS)
+ kfree(desc->extra_arg_buf);
+ if (ret < 0)
+ return qcom_scm_remap_error(ret);
+ return ret;
+}
+
+static int qcom_scm_set_boot_addr(void *entry, const cpumask_t *cpus, int flags)
+{
+ struct qcom_scm_desc desc = {0};
+ unsigned int cpu = cpumask_first(cpus);
+ u64 mpidr_el1 = cpu_logical_map(cpu);
+
+ /* For now we assume only a single cpu is set in the mask */
+ WARN_ON(cpumask_weight(cpus) != 1);
+
+ if (mpidr_el1 & ~MPIDR_HWID_BITMASK) {
+ pr_err("CPU%d:Failed to set boot address\n", cpu);
+ return -ENOSYS;
+ }
+
+ desc.args[0] = virt_to_phys(entry);
+ desc.args[1] = BIT(MPIDR_AFFINITY_LEVEL(mpidr_el1, 0));
+ desc.args[2] = BIT(MPIDR_AFFINITY_LEVEL(mpidr_el1, 1));
+ desc.args[3] = BIT(MPIDR_AFFINITY_LEVEL(mpidr_el1, 2));
+ desc.args[4] = ~0ULL;
+ desc.args[5] = QCOM_SCM_FLAG_HLOS | flags;
+ desc.arginfo = QCOM_SCM_ARGS(6);
+
+ return qcom_scm_call(QCOM_SCM_SVC_BOOT, QCOM_SCM_BOOT_ADDR_MC, &desc);
+}
+
+int __qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus)
+{
+ int flags = QCOM_SCM_FLAG_COLDBOOT_MC;
+
+ return qcom_scm_set_boot_addr(entry, cpus, flags);
+}
+
+int __qcom_scm_set_warm_boot_addr(void *entry, const cpumask_t *cpus)
+{
+ int flags = QCOM_SCM_FLAG_WARMBOOT_MC;
+
+ return qcom_scm_set_boot_addr(entry, cpus, flags);
+}
+
+void __qcom_scm_cpu_power_down(u32 flags)
+{
+ struct qcom_scm_desc desc = {0};
+ desc.args[0] = QCOM_SCM_CMD_CORE_HOTPLUGGED |
+ (flags & QCOM_SCM_FLUSH_FLAG_MASK);
+ desc.arginfo = QCOM_SCM_ARGS(1);
+
+ qcom_scm_call_atomic(QCOM_SCM_SVC_BOOT, QCOM_SCM_CMD_TERMINATE_PC, &desc);
+}
+
+#define QCOM_SCM_SVC_INFO 0x6
+static int __init qcom_scm_init(void)
+{
+ int ret;
+ u64 ret1 = 0, x0;
+
+ /* First try a SMC64 call */
+ qcom_scm_version = QCOM_SCM_ARMV8_64;
+ x0 = QCOM_SCM_SIP_FNID(QCOM_SCM_SVC_INFO, IS_CALL_AVAIL_CMD) | SMC_ATOMIC_MASK;
+ ret = __qcom_scm_call_armv8_64(x0 | SMC64_MASK, QCOM_SCM_ARGS(1), x0, 0, 0, 0,
+ &ret1, NULL, NULL);
+ if (ret || !ret1) {
+ /* Try SMC32 call */
+ ret1 = 0;
+ ret = __qcom_scm_call_armv8_32(x0, QCOM_SCM_ARGS(1), x0, 0, 0,
+ 0, &ret1, NULL, NULL);
+ if (ret || !ret1)
+ qcom_scm_version = QCOM_SCM_LEGACY;
+ else
+ qcom_scm_version = QCOM_SCM_ARMV8_32;
+ } else
+ qcom_scm_version_mask = SMC64_MASK;
+
+ pr_debug("qcom_scm_call: qcom_scm version is %x, mask is %x\n",
+ qcom_scm_version, qcom_scm_version_mask);
+
+ return 0;
+}
+early_initcall(qcom_scm_init);