arm64: psci: factor invocation code to drivers

To enable sharing with arm, move the core PSCI framework code to
drivers/firmware. This results in a minor gain in lines of code, but
this will quickly be amortised by the removal of code currently
duplicated in arch/arm.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 369 insertions, 0 deletions

diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
new file mode 100644
index 000000000000..36e2cea3809b
--- /dev/null
+++ b/drivers/firmware/psci.c
@@ -0,0 +1,369 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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.
+ *
+ * Copyright (C) 2015 ARM Limited
+ */
+
+#define pr_fmt(fmt) "psci: " fmt
+
+#include <linux/errno.h>
+#include <linux/linkage.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/printk.h>
+#include <linux/psci.h>
+#include <linux/reboot.h>
+
+#include <uapi/linux/psci.h>
+
+#include <asm/cputype.h>
+#include <asm/system_misc.h>
+#include <asm/smp_plat.h>
+
+/*
+ * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
+ * calls to its resident CPU, so we must avoid issuing those. We never migrate
+ * a Trusted OS even if it claims to be capable of migration -- doing so will
+ * require cooperation with a Trusted OS driver.
+ */
+static int resident_cpu = -1;
+
+bool psci_tos_resident_on(int cpu)
+{
+        return cpu == resident_cpu;
+}
+
+struct psci_operations psci_ops;
+
+typedef unsigned long (psci_fn)(unsigned long, unsigned long,
+                                unsigned long, unsigned long);
+asmlinkage psci_fn __invoke_psci_fn_hvc;
+asmlinkage psci_fn __invoke_psci_fn_smc;
+static psci_fn *invoke_psci_fn;
+
+enum psci_function {
+        PSCI_FN_CPU_SUSPEND,
+        PSCI_FN_CPU_ON,
+        PSCI_FN_CPU_OFF,
+        PSCI_FN_MIGRATE,
+        PSCI_FN_MAX,
+};
+
+static u32 psci_function_id[PSCI_FN_MAX];
+
+static int psci_to_linux_errno(int errno)
+{
+        switch (errno) {
+        case PSCI_RET_SUCCESS:
+                return 0;
+        case PSCI_RET_NOT_SUPPORTED:
+                return -EOPNOTSUPP;
+        case PSCI_RET_INVALID_PARAMS:
+                return -EINVAL;
+        case PSCI_RET_DENIED:
+                return -EPERM;
+        };
+
+        return -EINVAL;
+}
+
+static u32 psci_get_version(void)
+{
+        return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
+}
+
+static int psci_cpu_suspend(u32 state, unsigned long entry_point)
+{
+        int err;
+        u32 fn;
+
+        fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
+        err = invoke_psci_fn(fn, state, entry_point, 0);
+        return psci_to_linux_errno(err);
+}
+
+static int psci_cpu_off(u32 state)
+{
+        int err;
+        u32 fn;
+
+        fn = psci_function_id[PSCI_FN_CPU_OFF];
+        err = invoke_psci_fn(fn, state, 0, 0);
+        return psci_to_linux_errno(err);
+}
+
+static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
+{
+        int err;
+        u32 fn;
+
+        fn = psci_function_id[PSCI_FN_CPU_ON];
+        err = invoke_psci_fn(fn, cpuid, entry_point, 0);
+        return psci_to_linux_errno(err);
+}
+
+static int psci_migrate(unsigned long cpuid)
+{
+        int err;
+        u32 fn;
+
+        fn = psci_function_id[PSCI_FN_MIGRATE];
+        err = invoke_psci_fn(fn, cpuid, 0, 0);
+        return psci_to_linux_errno(err);
+}
+
+static int psci_affinity_info(unsigned long target_affinity,
+                unsigned long lowest_affinity_level)
+{
+        return invoke_psci_fn(PSCI_0_2_FN64_AFFINITY_INFO, target_affinity,
+                              lowest_affinity_level, 0);
+}
+
+static int psci_migrate_info_type(void)
+{
+        return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
+}
+
+static unsigned long psci_migrate_info_up_cpu(void)
+{
+        return invoke_psci_fn(PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU, 0, 0, 0);
+}
+
+static int get_set_conduit_method(struct device_node *np)
+{
+        const char *method;
+
+        pr_info("probing for conduit method from DT.\n");
+
+        if (of_property_read_string(np, "method", &method)) {
+                pr_warn("missing \"method\" property\n");
+                return -ENXIO;
+        }
+
+        if (!strcmp("hvc", method)) {
+                invoke_psci_fn = __invoke_psci_fn_hvc;
+        } else if (!strcmp("smc", method)) {
+                invoke_psci_fn = __invoke_psci_fn_smc;
+        } else {
+                pr_warn("invalid \"method\" property: %s\n", method);
+                return -EINVAL;
+        }
+        return 0;
+}
+
+static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
+{
+        invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
+}
+
+static void psci_sys_poweroff(void)
+{
+        invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
+}
+
+/*
+ * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
+ * return DENIED (which would be fatal).
+ */
+static void __init psci_init_migrate(void)
+{
+        unsigned long cpuid;
+        int type, cpu = -1;
+
+        type = psci_ops.migrate_info_type();
+
+        if (type == PSCI_0_2_TOS_MP) {
+                pr_info("Trusted OS migration not required\n");
+                return;
+        }
+
+        if (type == PSCI_RET_NOT_SUPPORTED) {
+                pr_info("MIGRATE_INFO_TYPE not supported.\n");
+                return;
+        }
+
+        if (type != PSCI_0_2_TOS_UP_MIGRATE &&
+            type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
+                pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
+                return;
+        }
+
+        cpuid = psci_migrate_info_up_cpu();
+        if (cpuid & ~MPIDR_HWID_BITMASK) {
+                pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
+                        cpuid);
+                return;
+        }
+
+        cpu = get_logical_index(cpuid);
+        resident_cpu = cpu >= 0 ? cpu : -1;
+
+        pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
+}
+
+static void __init psci_0_2_set_functions(void)
+{
+        pr_info("Using standard PSCI v0.2 function IDs\n");
+        psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN64_CPU_SUSPEND;
+        psci_ops.cpu_suspend = psci_cpu_suspend;
+
+        psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
+        psci_ops.cpu_off = psci_cpu_off;
+
+        psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN64_CPU_ON;
+        psci_ops.cpu_on = psci_cpu_on;
+
+        psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE;
+        psci_ops.migrate = psci_migrate;
+
+        psci_ops.affinity_info = psci_affinity_info;
+
+        psci_ops.migrate_info_type = psci_migrate_info_type;
+
+        arm_pm_restart = psci_sys_reset;
+
+        pm_power_off = psci_sys_poweroff;
+}
+
+/*
+ * Probe function for PSCI firmware versions >= 0.2
+ */
+static int __init psci_probe(void)
+{
+        u32 ver = psci_get_version();
+
+        pr_info("PSCIv%d.%d detected in firmware.\n",
+                        PSCI_VERSION_MAJOR(ver),
+                        PSCI_VERSION_MINOR(ver));
+
+        if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
+                pr_err("Conflicting PSCI version detected.\n");
+                return -EINVAL;
+        }
+
+        psci_0_2_set_functions();
+
+        psci_init_migrate();
+
+        return 0;
+}
+
+typedef int (*psci_initcall_t)(const struct device_node *);
+
+/*
+ * PSCI init function for PSCI versions >=0.2
+ *
+ * Probe based on PSCI PSCI_VERSION function
+ */
+static int __init psci_0_2_init(struct device_node *np)
+{
+        int err;
+
+        err = get_set_conduit_method(np);
+
+        if (err)
+                goto out_put_node;
+        /*
+         * Starting with v0.2, the PSCI specification introduced a call
+         * (PSCI_VERSION) that allows probing the firmware version, so
+         * that PSCI function IDs and version specific initialization
+         * can be carried out according to the specific version reported
+         * by firmware
+         */
+        err = psci_probe();
+
+out_put_node:
+        of_node_put(np);
+        return err;
+}
+
+/*
+ * PSCI < v0.2 get PSCI Function IDs via DT.
+ */
+static int __init psci_0_1_init(struct device_node *np)
+{
+        u32 id;
+        int err;
+
+        err = get_set_conduit_method(np);
+
+        if (err)
+                goto out_put_node;
+
+        pr_info("Using PSCI v0.1 Function IDs from DT\n");
+
+        if (!of_property_read_u32(np, "cpu_suspend", &id)) {
+                psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
+                psci_ops.cpu_suspend = psci_cpu_suspend;
+        }
+
+        if (!of_property_read_u32(np, "cpu_off", &id)) {
+                psci_function_id[PSCI_FN_CPU_OFF] = id;
+                psci_ops.cpu_off = psci_cpu_off;
+        }
+
+        if (!of_property_read_u32(np, "cpu_on", &id)) {
+                psci_function_id[PSCI_FN_CPU_ON] = id;
+                psci_ops.cpu_on = psci_cpu_on;
+        }
+
+        if (!of_property_read_u32(np, "migrate", &id)) {
+                psci_function_id[PSCI_FN_MIGRATE] = id;
+                psci_ops.migrate = psci_migrate;
+        }
+
+out_put_node:
+        of_node_put(np);
+        return err;
+}
+
+static const struct of_device_id psci_of_match[] __initconst = {
+        { .compatible = "arm,psci",     .data = psci_0_1_init},
+        { .compatible = "arm,psci-0.2", .data = psci_0_2_init},
+        {},
+};
+
+int __init psci_dt_init(void)
+{
+        struct device_node *np;
+        const struct of_device_id *matched_np;
+        psci_initcall_t init_fn;
+
+        np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
+
+        if (!np)
+                return -ENODEV;
+
+        init_fn = (psci_initcall_t)matched_np->data;
+        return init_fn(np);
+}
+
+#ifdef CONFIG_ACPI
+/*
+ * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
+ * explicitly clarified in SBBR
+ */
+int __init psci_acpi_init(void)
+{
+        if (!acpi_psci_present()) {
+                pr_info("is not implemented in ACPI.\n");
+                return -EOPNOTSUPP;
+        }
+
+        pr_info("probing for conduit method from ACPI.\n");
+
+        if (acpi_psci_use_hvc())
+                invoke_psci_fn = __invoke_psci_fn_hvc;
+        else
+                invoke_psci_fn = __invoke_psci_fn_smc;
+
+        return psci_probe();
+}
+#endif