FreeBSD/Linux Kernel Cross Reference
sys/dev/psci/psci.c

     /*-
      * Copyright (c) 2014 Robin Randhawa
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
      *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     */
    
    /*
     * This implements support for ARM's Power State Co-ordination Interface
     * [PSCI]. The implementation adheres to version 0.2 of the PSCI specification
     * but also supports v0.1. PSCI standardizes operations such as system reset, CPU
     * on/off/suspend. PSCI requires a compliant firmware implementation.
     *
     * The PSCI specification used for this implementation is available at:
     *
     * <http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0022b/index.html>.
     *
     * TODO:
     * - Add support for remaining PSCI calls [this implementation only
     *   supports get_version, system_reset and cpu_on].
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include "opt_acpi.h"
    #include "opt_platform.h"
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/bus.h>
    #include <sys/eventhandler.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    #include <sys/reboot.h>
    
    #include <machine/bus.h>
    #include <machine/machdep.h>
    
    #ifdef DEV_ACPI
    #include <contrib/dev/acpica/include/acpi.h>
    #include <dev/acpica/acpivar.h>
    #endif
    
    #ifdef FDT
    #include <dev/fdt/fdt_common.h>
    #include <dev/ofw/openfirm.h>
    #include <dev/ofw/ofw_bus.h>
    #include <dev/ofw/ofw_bus_subr.h>
    #endif
    
    #include <dev/psci/psci.h>
    
    struct psci_softc {
            device_t        dev;
    
            uint32_t        psci_version;
            uint32_t        psci_fnids[PSCI_FN_MAX];
    };
    
    #ifdef FDT
    static int psci_v0_1_init(device_t dev, int default_version);
    #endif
    static int psci_v0_2_init(device_t dev, int default_version);
    
    struct psci_softc *psci_softc = NULL;
    bool psci_present;
    
    #ifdef __arm__
    #define USE_ACPI        0
    #define USE_FDT         1
    #elif defined(__aarch64__)
    #define USE_ACPI        (arm64_bus_method == ARM64_BUS_ACPI)
    #define USE_FDT         (arm64_bus_method == ARM64_BUS_FDT)
    #else
    #error Unknown architecture
    #endif
    
    #ifdef FDT
   struct psci_init_def {
           int             default_version;
           psci_initfn_t   psci_init;
   };
   
   static struct psci_init_def psci_v1_0_init_def = {
           .default_version = (1 << 16) | 0,
           .psci_init = psci_v0_2_init
   };
   
   static struct psci_init_def psci_v0_2_init_def = {
           .default_version = (0 << 16) | 2,
           .psci_init = psci_v0_2_init
   };
   
   static struct psci_init_def psci_v0_1_init_def = {
           .default_version = (0 << 16) | 1,
           .psci_init = psci_v0_1_init
   };
   
   static struct ofw_compat_data compat_data[] = {
           {"arm,psci-1.0",        (uintptr_t)&psci_v1_0_init_def},
           {"arm,psci-0.2",        (uintptr_t)&psci_v0_2_init_def},
           {"arm,psci",            (uintptr_t)&psci_v0_1_init_def},
           {NULL,                  0}
   };
   #endif
   
   static int psci_attach(device_t, psci_initfn_t, int);
   static void psci_shutdown(void *, int);
   
   static int psci_find_callfn(psci_callfn_t *);
   static int psci_def_callfn(register_t, register_t, register_t, register_t,
           register_t, register_t, register_t, register_t,
           struct arm_smccc_res *res);
   
   psci_callfn_t psci_callfn = psci_def_callfn;
   
   static void
   psci_init(void *dummy)
   {
           psci_callfn_t new_callfn;
   
           if (psci_find_callfn(&new_callfn) != PSCI_RETVAL_SUCCESS) {
                   printf("No PSCI/SMCCC call function found\n");
                   return;
           }
   
           psci_callfn = new_callfn;
           psci_present = true;
   }
   /* This needs to be before cpu_mp at SI_SUB_CPU, SI_ORDER_THIRD */
   SYSINIT(psci_start, SI_SUB_CPU, SI_ORDER_FIRST, psci_init, NULL);
   
   static int
   psci_def_callfn(register_t a __unused, register_t b __unused,
       register_t c __unused, register_t d __unused,
       register_t e __unused, register_t f __unused,
       register_t g __unused, register_t h __unused,
       struct arm_smccc_res *res __unused)
   {
   
           panic("No PSCI/SMCCC call function set");
   }
   
   #ifdef FDT
   static int psci_fdt_probe(device_t dev);
   static int psci_fdt_attach(device_t dev);
   
   static device_method_t psci_fdt_methods[] = {
           DEVMETHOD(device_probe,     psci_fdt_probe),
           DEVMETHOD(device_attach,    psci_fdt_attach),
   
           DEVMETHOD_END
   };
   
   static driver_t psci_fdt_driver = {
           "psci",
           psci_fdt_methods,
           sizeof(struct psci_softc),
   };
   
   EARLY_DRIVER_MODULE(psci, simplebus, psci_fdt_driver, 0, 0,
       BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
   EARLY_DRIVER_MODULE(psci, ofwbus, psci_fdt_driver, 0, 0,
       BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
   
   static psci_callfn_t
   psci_fdt_get_callfn(phandle_t node)
   {
           char method[16];
   
           if ((OF_getprop(node, "method", method, sizeof(method))) > 0) {
                   if (strcmp(method, "hvc") == 0)
                           return (arm_smccc_hvc);
                   else if (strcmp(method, "smc") == 0)
                           return (arm_smccc_smc);
                   else
                           printf("psci: PSCI conduit \"%s\" invalid\n", method);
           } else
                   printf("psci: PSCI conduit not supplied in the device tree\n");
   
           return (NULL);
   }
   
   static int
   psci_fdt_probe(device_t dev)
   {
           const struct ofw_compat_data *ocd;
   
           if (!ofw_bus_status_okay(dev))
                   return (ENXIO);
   
           ocd = ofw_bus_search_compatible(dev, compat_data);
           if (ocd->ocd_str == NULL)
                   return (ENXIO);
   
           device_set_desc(dev, "ARM Power State Co-ordination Interface Driver");
   
           return (BUS_PROBE_SPECIFIC);
   }
   
   static int
   psci_fdt_attach(device_t dev)
   {
           const struct ofw_compat_data *ocd;
           struct psci_init_def *psci_init_def;
   
           ocd = ofw_bus_search_compatible(dev, compat_data);
           psci_init_def = (struct psci_init_def *)ocd->ocd_data;
   
           return (psci_attach(dev, psci_init_def->psci_init,
               psci_init_def->default_version));
   }
   #endif
   
   #ifdef DEV_ACPI
   static void psci_acpi_identify(driver_t *, device_t);
   static int psci_acpi_probe(device_t);
   static int psci_acpi_attach(device_t);
   
   static device_method_t psci_acpi_methods[] = {
           /* Device interface */
           DEVMETHOD(device_identify,      psci_acpi_identify),
           DEVMETHOD(device_probe,         psci_acpi_probe),
           DEVMETHOD(device_attach,        psci_acpi_attach),
   
           DEVMETHOD_END
   };
   
   static driver_t psci_acpi_driver = {
           "psci",
           psci_acpi_methods,
           sizeof(struct psci_softc),
   };
   
   EARLY_DRIVER_MODULE(psci, acpi, psci_acpi_driver, 0, 0,
       BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
   
   static int
   psci_acpi_bootflags(void)
   {
           ACPI_TABLE_FADT *fadt;
           vm_paddr_t physaddr;
           int flags;
   
           physaddr = acpi_find_table(ACPI_SIG_FADT);
           if (physaddr == 0)
                   return (0);
   
           fadt = acpi_map_table(physaddr, ACPI_SIG_FADT);
           if (fadt == NULL) {
                   printf("psci: Unable to map the FADT\n");
                   return (0);
           }
   
           flags = fadt->ArmBootFlags;
   
           acpi_unmap_table(fadt);
           return (flags);
   }
   
   static psci_callfn_t
   psci_acpi_get_callfn(int flags)
   {
   
           if ((flags & ACPI_FADT_PSCI_COMPLIANT) != 0) {
                   if ((flags & ACPI_FADT_PSCI_USE_HVC) != 0)
                           return (arm_smccc_hvc);
                   else
                           return (arm_smccc_smc);
           } else {
                   printf("psci: PSCI conduit not supplied in the device tree\n");
           }
   
           return (NULL);
   }
   
   static void
   psci_acpi_identify(driver_t *driver, device_t parent)
   {
           device_t dev;
           int flags;
   
           flags = psci_acpi_bootflags();
           if ((flags & ACPI_FADT_PSCI_COMPLIANT) != 0) {
                   dev = BUS_ADD_CHILD(parent,
                       BUS_PASS_CPU + BUS_PASS_ORDER_FIRST, "psci", -1);
   
                   if (dev != NULL)
                           acpi_set_private(dev, (void *)(uintptr_t)flags);
           }
   }
   
   static int
   psci_acpi_probe(device_t dev)
   {
           uintptr_t flags;
   
           flags = (uintptr_t)acpi_get_private(dev);
           if ((flags & ACPI_FADT_PSCI_COMPLIANT) == 0)
                   return (ENXIO);
   
           device_set_desc(dev, "ARM Power State Co-ordination Interface Driver");
           return (BUS_PROBE_SPECIFIC);
   }
   
   static int
   psci_acpi_attach(device_t dev)
   {
   
           return (psci_attach(dev, psci_v0_2_init, PSCI_RETVAL_NOT_SUPPORTED));
   }
   #endif
   
   static int
   psci_attach(device_t dev, psci_initfn_t psci_init, int default_version)
   {
           struct psci_softc *sc = device_get_softc(dev);
   
           if (psci_softc != NULL)
                   return (ENXIO);
   
           KASSERT(psci_init != NULL, ("PSCI init function cannot be NULL"));
           if (psci_init(dev, default_version))
                   return (ENXIO);
   
           psci_softc = sc;
   
           return (0);
   }
   
   static int
   _psci_get_version(struct psci_softc *sc)
   {
           uint32_t fnid;
   
           /* PSCI version wasn't supported in v0.1. */
           fnid = sc->psci_fnids[PSCI_FN_VERSION];
           if (fnid)
                   return (psci_call(fnid, 0, 0, 0));
   
           return (PSCI_RETVAL_NOT_SUPPORTED);
   }
   
   int
   psci_get_version(void)
   {
   
           if (psci_softc == NULL)
                   return (PSCI_RETVAL_NOT_SUPPORTED);
           return (_psci_get_version(psci_softc));
   }
   
   #ifdef FDT
   static int
   psci_fdt_callfn(psci_callfn_t *callfn)
   {
           phandle_t node;
   
           node = ofw_bus_find_compatible(OF_peer(0), "arm,psci-0.2");
           if (node == 0) {
                   node = ofw_bus_find_compatible(OF_peer(0), "arm,psci-1.0");
                   if (node == 0)
                           return (PSCI_MISSING);
           }
   
           *callfn = psci_fdt_get_callfn(node);
           return (0);
   }
   #endif
   
   #ifdef DEV_ACPI
   static int
   psci_acpi_callfn(psci_callfn_t *callfn)
   {
           int flags;
   
           flags = psci_acpi_bootflags();
           if ((flags & ACPI_FADT_PSCI_COMPLIANT) == 0)
                   return (PSCI_MISSING);
   
           *callfn = psci_acpi_get_callfn(flags);
           return (0);
   }
   #endif
   
   static int
   psci_find_callfn(psci_callfn_t *callfn)
   {
           int error;
   
           *callfn = NULL;
   #ifdef FDT
           if (USE_FDT) {
                   error = psci_fdt_callfn(callfn);
                   if (error != 0)
                           return (error);
           }
   #endif
   #ifdef DEV_ACPI
           if (*callfn == NULL && USE_ACPI) {
                   error = psci_acpi_callfn(callfn);
                   if (error != 0)
                           return (error);
           }
   #endif
   
           if (*callfn == NULL)
                   return (PSCI_MISSING);
   
           return (PSCI_RETVAL_SUCCESS);
   }
   
   int32_t
   psci_features(uint32_t psci_func_id)
   {
   
           if (psci_softc == NULL)
                   return (PSCI_RETVAL_NOT_SUPPORTED);
   
           /* The feature flags were added to PSCI 1.0 */
           if (PSCI_VER_MAJOR(psci_softc->psci_version) < 1)
                   return (PSCI_RETVAL_NOT_SUPPORTED);
   
           return (psci_call(PSCI_FNID_FEATURES, psci_func_id, 0, 0));
   }
   
   int
   psci_cpu_on(unsigned long cpu, unsigned long entry, unsigned long context_id)
   {
           uint32_t fnid;
   
           fnid = PSCI_FNID_CPU_ON;
           if (psci_softc != NULL)
                   fnid = psci_softc->psci_fnids[PSCI_FN_CPU_ON];
   
           /* PSCI v0.1 and v0.2 both support cpu_on. */
           return (psci_call(fnid, cpu, entry, context_id));
   }
   
   static void
   psci_shutdown(void *xsc, int howto)
   {
           uint32_t fn = 0;
   
           if (psci_softc == NULL)
                   return;
   
           /* PSCI system_off and system_reset werent't supported in v0.1. */
           if ((howto & RB_POWEROFF) != 0)
                   fn = psci_softc->psci_fnids[PSCI_FN_SYSTEM_OFF];
           else if ((howto & RB_HALT) == 0)
                   fn = psci_softc->psci_fnids[PSCI_FN_SYSTEM_RESET];
   
           if (fn)
                   psci_call(fn, 0, 0, 0);
   
           /* System reset and off do not return. */
   }
   
   void
   psci_reset(void)
   {
   
           psci_shutdown(NULL, 0);
   }
   
   #ifdef FDT
   /* Only support PSCI 0.1 on FDT */
   static int
   psci_v0_1_init(device_t dev, int default_version __unused)
   {
           struct psci_softc *sc = device_get_softc(dev);
           int psci_fn;
           uint32_t psci_fnid;
           phandle_t node;
           int len;
   
           /* Zero out the function ID table - Is this needed ? */
           for (psci_fn = PSCI_FN_VERSION, psci_fnid = PSCI_FNID_VERSION;
               psci_fn < PSCI_FN_MAX; psci_fn++, psci_fnid++)
                   sc->psci_fnids[psci_fn] = 0;
   
           /* PSCI v0.1 doesn't specify function IDs. Get them from DT */
           node = ofw_bus_get_node(dev);
   
           if ((len = OF_getproplen(node, "cpu_suspend")) > 0) {
                   OF_getencprop(node, "cpu_suspend", &psci_fnid, len);
                   sc->psci_fnids[PSCI_FN_CPU_SUSPEND] = psci_fnid;
           }
   
           if ((len = OF_getproplen(node, "cpu_on")) > 0) {
                   OF_getencprop(node, "cpu_on", &psci_fnid, len);
                   sc->psci_fnids[PSCI_FN_CPU_ON] = psci_fnid;
           }
   
           if ((len = OF_getproplen(node, "cpu_off")) > 0) {
                   OF_getencprop(node, "cpu_off", &psci_fnid, len);
                   sc->psci_fnids[PSCI_FN_CPU_OFF] = psci_fnid;
           }
   
           if ((len = OF_getproplen(node, "migrate")) > 0) {
                   OF_getencprop(node, "migrate", &psci_fnid, len);
                   sc->psci_fnids[PSCI_FN_MIGRATE] = psci_fnid;
           }
   
           sc->psci_version = (0 << 16) | 1;
           if (bootverbose)
                   device_printf(dev, "PSCI version 0.1 available\n");
   
           return(0);
   }
   #endif
   
   static int
   psci_v0_2_init(device_t dev, int default_version)
   {
           struct psci_softc *sc = device_get_softc(dev);
           int version;
   
           /* PSCI v0.2 specifies explicit function IDs. */
           sc->psci_fnids[PSCI_FN_VERSION]             = PSCI_FNID_VERSION;
           sc->psci_fnids[PSCI_FN_CPU_SUSPEND]         = PSCI_FNID_CPU_SUSPEND;
           sc->psci_fnids[PSCI_FN_CPU_OFF]             = PSCI_FNID_CPU_OFF;
           sc->psci_fnids[PSCI_FN_CPU_ON]              = PSCI_FNID_CPU_ON;
           sc->psci_fnids[PSCI_FN_AFFINITY_INFO]       = PSCI_FNID_AFFINITY_INFO;
           sc->psci_fnids[PSCI_FN_MIGRATE]             = PSCI_FNID_MIGRATE;
           sc->psci_fnids[PSCI_FN_MIGRATE_INFO_TYPE]   = PSCI_FNID_MIGRATE_INFO_TYPE;
           sc->psci_fnids[PSCI_FN_MIGRATE_INFO_UP_CPU] = PSCI_FNID_MIGRATE_INFO_UP_CPU;
           sc->psci_fnids[PSCI_FN_SYSTEM_OFF]          = PSCI_FNID_SYSTEM_OFF;
           sc->psci_fnids[PSCI_FN_SYSTEM_RESET]        = PSCI_FNID_SYSTEM_RESET;
   
           version = _psci_get_version(sc);
   
           /*
            * U-Boot PSCI implementation doesn't have psci_get_version()
            * method implemented for many boards. In this case, use the version
            * readed from FDT as fallback. No fallback method for ACPI.
            */
           if (version == PSCI_RETVAL_NOT_SUPPORTED) {
                   if (default_version == PSCI_RETVAL_NOT_SUPPORTED)
                           return (1);
   
                   version = default_version;
                   printf("PSCI get_version() function is not implemented, "
                       " assuming v%d.%d\n", PSCI_VER_MAJOR(version),
                       PSCI_VER_MINOR(version));
           }
   
           sc->psci_version = version;
           if ((PSCI_VER_MAJOR(version) == 0 && PSCI_VER_MINOR(version) == 2) ||
               PSCI_VER_MAJOR(version) == 1) {
                   if (bootverbose)
                           device_printf(dev, "PSCI version 0.2 compatible\n");
   
                   /*
                    * We only register this for v0.2 since v0.1 doesn't support
                    * system_reset.
                    */
                   EVENTHANDLER_REGISTER(shutdown_final, psci_shutdown, sc,
                       SHUTDOWN_PRI_LAST);
   
                   return (0);
           }
   
           device_printf(dev, "PSCI version number mismatched with DT\n");
           return (1);
   }

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