The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/dev/acpica/acpi_perf.c

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    1 /*-
    2  * Copyright (c) 2003-2005 Nate Lawson (SDG)
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  *
   14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   24  * SUCH DAMAGE.
   25  */
   26 
   27 #include <sys/cdefs.h>
   28 __FBSDID("$FreeBSD: releng/10.4/sys/dev/acpica/acpi_perf.c 246128 2013-01-30 18:01:20Z sbz $");
   29 
   30 #include "opt_acpi.h"
   31 #include <sys/param.h>
   32 #include <sys/kernel.h>
   33 #include <sys/proc.h>
   34 #include <sys/sched.h>
   35 #include <sys/bus.h>
   36 #include <sys/cpu.h>
   37 #include <sys/power.h>
   38 #include <sys/malloc.h>
   39 #include <sys/module.h>
   40 #include <sys/sbuf.h>
   41 #include <sys/pcpu.h>
   42 
   43 #include <machine/bus.h>
   44 #include <machine/resource.h>
   45 #include <sys/rman.h>
   46 
   47 #include <contrib/dev/acpica/include/acpi.h>
   48 
   49 #include <dev/acpica/acpivar.h>
   50 
   51 #include "cpufreq_if.h"
   52 
   53 /*
   54  * Support for ACPI processor performance states (Px) according to
   55  * section 8.3.3 of the ACPI 2.0c specification.
   56  */
   57 
   58 struct acpi_px {
   59         uint32_t         core_freq;
   60         uint32_t         power;
   61         uint32_t         trans_lat;
   62         uint32_t         bm_lat;
   63         uint32_t         ctrl_val;
   64         uint32_t         sts_val;
   65 };
   66 
   67 /* Offsets in struct cf_setting array for storing driver-specific values. */
   68 #define PX_SPEC_CONTROL 0
   69 #define PX_SPEC_STATUS  1
   70 
   71 #define MAX_PX_STATES   16
   72 
   73 struct acpi_perf_softc {
   74         device_t         dev;
   75         ACPI_HANDLE      handle;
   76         struct resource *perf_ctrl;     /* Set new performance state. */
   77         int              perf_ctrl_type; /* Resource type for perf_ctrl. */
   78         struct resource *perf_status;   /* Check that transition succeeded. */
   79         int              perf_sts_type; /* Resource type for perf_status. */
   80         struct acpi_px  *px_states;     /* ACPI perf states. */
   81         uint32_t         px_count;      /* Total number of perf states. */
   82         uint32_t         px_max_avail;  /* Lowest index state available. */
   83         int              px_curr_state; /* Active state index. */
   84         int              px_rid;
   85         int              info_only;     /* Can we set new states? */
   86 };
   87 
   88 #define PX_GET_REG(reg)                                 \
   89         (bus_space_read_4(rman_get_bustag((reg)),       \
   90             rman_get_bushandle((reg)), 0))
   91 #define PX_SET_REG(reg, val)                            \
   92         (bus_space_write_4(rman_get_bustag((reg)),      \
   93             rman_get_bushandle((reg)), 0, (val)))
   94 
   95 #define ACPI_NOTIFY_PERF_STATES         0x80    /* _PSS changed. */
   96 
   97 static void     acpi_perf_identify(driver_t *driver, device_t parent);
   98 static int      acpi_perf_probe(device_t dev);
   99 static int      acpi_perf_attach(device_t dev);
  100 static int      acpi_perf_detach(device_t dev);
  101 static int      acpi_perf_evaluate(device_t dev);
  102 static int      acpi_px_to_set(device_t dev, struct acpi_px *px,
  103                     struct cf_setting *set);
  104 static void     acpi_px_available(struct acpi_perf_softc *sc);
  105 static void     acpi_px_startup(void *arg);
  106 static void     acpi_px_notify(ACPI_HANDLE h, UINT32 notify, void *context);
  107 static int      acpi_px_settings(device_t dev, struct cf_setting *sets,
  108                     int *count);
  109 static int      acpi_px_set(device_t dev, const struct cf_setting *set);
  110 static int      acpi_px_get(device_t dev, struct cf_setting *set);
  111 static int      acpi_px_type(device_t dev, int *type);
  112 
  113 static device_method_t acpi_perf_methods[] = {
  114         /* Device interface */
  115         DEVMETHOD(device_identify,      acpi_perf_identify),
  116         DEVMETHOD(device_probe,         acpi_perf_probe),
  117         DEVMETHOD(device_attach,        acpi_perf_attach),
  118         DEVMETHOD(device_detach,        acpi_perf_detach),
  119 
  120         /* cpufreq interface */
  121         DEVMETHOD(cpufreq_drv_set,      acpi_px_set),
  122         DEVMETHOD(cpufreq_drv_get,      acpi_px_get),
  123         DEVMETHOD(cpufreq_drv_type,     acpi_px_type),
  124         DEVMETHOD(cpufreq_drv_settings, acpi_px_settings),
  125 
  126         DEVMETHOD_END
  127 };
  128 
  129 static driver_t acpi_perf_driver = {
  130         "acpi_perf",
  131         acpi_perf_methods,
  132         sizeof(struct acpi_perf_softc),
  133 };
  134 
  135 static devclass_t acpi_perf_devclass;
  136 DRIVER_MODULE(acpi_perf, cpu, acpi_perf_driver, acpi_perf_devclass, 0, 0);
  137 MODULE_DEPEND(acpi_perf, acpi, 1, 1, 1);
  138 
  139 static MALLOC_DEFINE(M_ACPIPERF, "acpi_perf", "ACPI Performance states");
  140 
  141 static void
  142 acpi_perf_identify(driver_t *driver, device_t parent)
  143 {
  144         ACPI_HANDLE handle;
  145         device_t dev;
  146 
  147         /* Make sure we're not being doubly invoked. */
  148         if (device_find_child(parent, "acpi_perf", -1) != NULL)
  149                 return;
  150 
  151         /* Get the handle for the Processor object and check for perf states. */
  152         handle = acpi_get_handle(parent);
  153         if (handle == NULL)
  154                 return;
  155         if (ACPI_FAILURE(AcpiEvaluateObject(handle, "_PSS", NULL, NULL)))
  156                 return;
  157 
  158         /*
  159          * Add a child to every CPU that has the right methods.  In future
  160          * versions of the ACPI spec, CPUs can have different settings.
  161          * We probe this child now so that other devices that depend
  162          * on it (i.e., for info about supported states) will see it.
  163          */
  164         if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_perf", -1)) != NULL)
  165                 device_probe_and_attach(dev);
  166         else
  167                 device_printf(parent, "add acpi_perf child failed\n");
  168 }
  169 
  170 static int
  171 acpi_perf_probe(device_t dev)
  172 {
  173         ACPI_HANDLE handle;
  174         ACPI_OBJECT *pkg;
  175         struct resource *res;
  176         ACPI_BUFFER buf;
  177         int error, rid, type;
  178 
  179         if (resource_disabled("acpi_perf", 0))
  180                 return (ENXIO);
  181 
  182         /*
  183          * Check the performance state registers.  If they are of type
  184          * "functional fixed hardware", we attach quietly since we will
  185          * only be providing information on settings to other drivers.
  186          */
  187         error = ENXIO;
  188         handle = acpi_get_handle(dev);
  189         buf.Pointer = NULL;
  190         buf.Length = ACPI_ALLOCATE_BUFFER;
  191         if (ACPI_FAILURE(AcpiEvaluateObject(handle, "_PCT", NULL, &buf)))
  192                 return (error);
  193         pkg = (ACPI_OBJECT *)buf.Pointer;
  194         if (ACPI_PKG_VALID(pkg, 2)) {
  195                 rid = 0;
  196                 error = acpi_PkgGas(dev, pkg, 0, &type, &rid, &res, 0);
  197                 switch (error) {
  198                 case 0:
  199                         bus_release_resource(dev, type, rid, res);
  200                         bus_delete_resource(dev, type, rid);
  201                         device_set_desc(dev, "ACPI CPU Frequency Control");
  202                         break;
  203                 case EOPNOTSUPP:
  204                         device_quiet(dev);
  205                         error = 0;
  206                         break;
  207                 }
  208         }
  209         AcpiOsFree(buf.Pointer);
  210 
  211         return (error);
  212 }
  213 
  214 static int
  215 acpi_perf_attach(device_t dev)
  216 {
  217         struct acpi_perf_softc *sc;
  218 
  219         sc = device_get_softc(dev);
  220         sc->dev = dev;
  221         sc->handle = acpi_get_handle(dev);
  222         sc->px_max_avail = 0;
  223         sc->px_curr_state = CPUFREQ_VAL_UNKNOWN;
  224         if (acpi_perf_evaluate(dev) != 0)
  225                 return (ENXIO);
  226         AcpiOsExecute(OSL_NOTIFY_HANDLER, acpi_px_startup, NULL);
  227         if (!sc->info_only)
  228                 cpufreq_register(dev);
  229 
  230         return (0);
  231 }
  232 
  233 static int
  234 acpi_perf_detach(device_t dev)
  235 {
  236         /* TODO: teardown registers, remove notify handler. */
  237         return (ENXIO);
  238 }
  239 
  240 /* Probe and setup any valid performance states (Px). */
  241 static int
  242 acpi_perf_evaluate(device_t dev)
  243 {
  244         struct acpi_perf_softc *sc;
  245         ACPI_BUFFER buf;
  246         ACPI_OBJECT *pkg, *res;
  247         ACPI_STATUS status;
  248         int count, error, i, j;
  249         static int once = 1;
  250         uint32_t *p;
  251 
  252         /* Get the control values and parameters for each state. */
  253         error = ENXIO;
  254         sc = device_get_softc(dev);
  255         buf.Pointer = NULL;
  256         buf.Length = ACPI_ALLOCATE_BUFFER;
  257         status = AcpiEvaluateObject(sc->handle, "_PSS", NULL, &buf);
  258         if (ACPI_FAILURE(status))
  259                 return (ENXIO);
  260 
  261         pkg = (ACPI_OBJECT *)buf.Pointer;
  262         if (!ACPI_PKG_VALID(pkg, 1)) {
  263                 device_printf(dev, "invalid top level _PSS package\n");
  264                 goto out;
  265         }
  266         sc->px_count = pkg->Package.Count;
  267 
  268         sc->px_states = malloc(sc->px_count * sizeof(struct acpi_px),
  269             M_ACPIPERF, M_WAITOK | M_ZERO);
  270         if (sc->px_states == NULL)
  271                 goto out;
  272 
  273         /*
  274          * Each state is a package of {CoreFreq, Power, TransitionLatency,
  275          * BusMasterLatency, ControlVal, StatusVal}, sorted from highest
  276          * performance to lowest.
  277          */
  278         count = 0;
  279         for (i = 0; i < sc->px_count; i++) {
  280                 res = &pkg->Package.Elements[i];
  281                 if (!ACPI_PKG_VALID(res, 6)) {
  282                         if (once) {
  283                                 once = 0;
  284                                 device_printf(dev, "invalid _PSS package\n");
  285                         }
  286                         continue;
  287                 }
  288 
  289                 /* Parse the rest of the package into the struct. */
  290                 p = &sc->px_states[count].core_freq;
  291                 for (j = 0; j < 6; j++, p++)
  292                         acpi_PkgInt32(res, j, p);
  293 
  294                 /*
  295                  * Check for some impossible frequencies that some systems
  296                  * use to indicate they don't actually support this Px state.
  297                  */
  298                 if (sc->px_states[count].core_freq == 0 ||
  299                     sc->px_states[count].core_freq == 9999 ||
  300                     sc->px_states[count].core_freq == 0x9999 ||
  301                     sc->px_states[count].core_freq >= 0xffff)
  302                         continue;
  303 
  304                 /* Check for duplicate entries */
  305                 if (count > 0 &&
  306                     sc->px_states[count - 1].core_freq ==
  307                         sc->px_states[count].core_freq)
  308                         continue;
  309 
  310                 count++;
  311         }
  312         sc->px_count = count;
  313 
  314         /* No valid Px state found so give up. */
  315         if (count == 0)
  316                 goto out;
  317         AcpiOsFree(buf.Pointer);
  318 
  319         /* Get the control and status registers (one of each). */
  320         buf.Pointer = NULL;
  321         buf.Length = ACPI_ALLOCATE_BUFFER;
  322         status = AcpiEvaluateObject(sc->handle, "_PCT", NULL, &buf);
  323         if (ACPI_FAILURE(status))
  324                 goto out;
  325 
  326         /* Check the package of two registers, each a Buffer in GAS format. */
  327         pkg = (ACPI_OBJECT *)buf.Pointer;
  328         if (!ACPI_PKG_VALID(pkg, 2)) {
  329                 device_printf(dev, "invalid perf register package\n");
  330                 goto out;
  331         }
  332 
  333         error = acpi_PkgGas(sc->dev, pkg, 0, &sc->perf_ctrl_type, &sc->px_rid,
  334             &sc->perf_ctrl, 0);
  335         if (error) {
  336                 /*
  337                  * If the register is of type FFixedHW, we can only return
  338                  * info, we can't get or set new settings.
  339                  */
  340                 if (error == EOPNOTSUPP) {
  341                         sc->info_only = TRUE;
  342                         error = 0;
  343                 } else
  344                         device_printf(dev, "failed in PERF_CTL attach\n");
  345                 goto out;
  346         }
  347         sc->px_rid++;
  348 
  349         error = acpi_PkgGas(sc->dev, pkg, 1, &sc->perf_sts_type, &sc->px_rid,
  350             &sc->perf_status, 0);
  351         if (error) {
  352                 if (error == EOPNOTSUPP) {
  353                         sc->info_only = TRUE;
  354                         error = 0;
  355                 } else
  356                         device_printf(dev, "failed in PERF_STATUS attach\n");
  357                 goto out;
  358         }
  359         sc->px_rid++;
  360 
  361         /* Get our current limit and register for notifies. */
  362         acpi_px_available(sc);
  363         AcpiInstallNotifyHandler(sc->handle, ACPI_DEVICE_NOTIFY,
  364             acpi_px_notify, sc);
  365         error = 0;
  366 
  367 out:
  368         if (error) {
  369                 if (sc->px_states) {
  370                         free(sc->px_states, M_ACPIPERF);
  371                         sc->px_states = NULL;
  372                 }
  373                 if (sc->perf_ctrl) {
  374                         bus_release_resource(sc->dev, sc->perf_ctrl_type, 0,
  375                             sc->perf_ctrl);
  376                         bus_delete_resource(sc->dev, sc->perf_ctrl_type, 0);
  377                         sc->perf_ctrl = NULL;
  378                 }
  379                 if (sc->perf_status) {
  380                         bus_release_resource(sc->dev, sc->perf_sts_type, 1,
  381                             sc->perf_status);
  382                         bus_delete_resource(sc->dev, sc->perf_sts_type, 1);
  383                         sc->perf_status = NULL;
  384                 }
  385                 sc->px_rid = 0;
  386                 sc->px_count = 0;
  387         }
  388         if (buf.Pointer)
  389                 AcpiOsFree(buf.Pointer);
  390         return (error);
  391 }
  392 
  393 static void
  394 acpi_px_startup(void *arg)
  395 {
  396 
  397         /* Signal to the platform that we are taking over CPU control. */
  398         if (AcpiGbl_FADT.PstateControl == 0)
  399                 return;
  400         ACPI_LOCK(acpi);
  401         AcpiOsWritePort(AcpiGbl_FADT.SmiCommand, AcpiGbl_FADT.PstateControl, 8);
  402         ACPI_UNLOCK(acpi);
  403 }
  404 
  405 static void
  406 acpi_px_notify(ACPI_HANDLE h, UINT32 notify, void *context)
  407 {
  408         struct acpi_perf_softc *sc;
  409 
  410         sc = context;
  411         if (notify != ACPI_NOTIFY_PERF_STATES)
  412                 return;
  413 
  414         acpi_px_available(sc);
  415 
  416         /* TODO: Implement notification when frequency changes. */
  417 }
  418 
  419 /*
  420  * Find the highest currently-supported performance state.
  421  * This can be called at runtime (e.g., due to a docking event) at
  422  * the request of a Notify on the processor object.
  423  */
  424 static void
  425 acpi_px_available(struct acpi_perf_softc *sc)
  426 {
  427         ACPI_STATUS status;
  428         struct cf_setting set;
  429 
  430         status = acpi_GetInteger(sc->handle, "_PPC", &sc->px_max_avail);
  431 
  432         /* If the old state is too high, set current state to the new max. */
  433         if (ACPI_SUCCESS(status)) {
  434                 if (sc->px_curr_state != CPUFREQ_VAL_UNKNOWN &&
  435                     sc->px_curr_state > sc->px_max_avail) {
  436                         acpi_px_to_set(sc->dev,
  437                             &sc->px_states[sc->px_max_avail], &set);
  438                         acpi_px_set(sc->dev, &set);
  439                 }
  440         } else
  441                 sc->px_max_avail = 0;
  442 }
  443 
  444 static int
  445 acpi_px_to_set(device_t dev, struct acpi_px *px, struct cf_setting *set)
  446 {
  447 
  448         if (px == NULL || set == NULL)
  449                 return (EINVAL);
  450 
  451         set->freq = px->core_freq;
  452         set->power = px->power;
  453         /* XXX Include BM latency too? */
  454         set->lat = px->trans_lat;
  455         set->volts = CPUFREQ_VAL_UNKNOWN;
  456         set->dev = dev;
  457         set->spec[PX_SPEC_CONTROL] = px->ctrl_val;
  458         set->spec[PX_SPEC_STATUS] = px->sts_val;
  459 
  460         return (0);
  461 }
  462 
  463 static int
  464 acpi_px_settings(device_t dev, struct cf_setting *sets, int *count)
  465 {
  466         struct acpi_perf_softc *sc;
  467         int x, y;
  468 
  469         sc = device_get_softc(dev);
  470         if (sets == NULL || count == NULL)
  471                 return (EINVAL);
  472         if (*count < sc->px_count - sc->px_max_avail)
  473                 return (E2BIG);
  474 
  475         /* Return a list of settings that are currently valid. */
  476         y = 0;
  477         for (x = sc->px_max_avail; x < sc->px_count; x++, y++)
  478                 acpi_px_to_set(dev, &sc->px_states[x], &sets[y]);
  479         *count = sc->px_count - sc->px_max_avail;
  480 
  481         return (0);
  482 }
  483 
  484 static int
  485 acpi_px_set(device_t dev, const struct cf_setting *set)
  486 {
  487         struct acpi_perf_softc *sc;
  488         int i, status, sts_val, tries;
  489 
  490         if (set == NULL)
  491                 return (EINVAL);
  492         sc = device_get_softc(dev);
  493 
  494         /* If we can't set new states, return immediately. */
  495         if (sc->info_only)
  496                 return (ENXIO);
  497 
  498         /* Look up appropriate state, based on frequency. */
  499         for (i = sc->px_max_avail; i < sc->px_count; i++) {
  500                 if (CPUFREQ_CMP(set->freq, sc->px_states[i].core_freq))
  501                         break;
  502         }
  503         if (i == sc->px_count)
  504                 return (EINVAL);
  505 
  506         /* Write the appropriate value to the register. */
  507         PX_SET_REG(sc->perf_ctrl, sc->px_states[i].ctrl_val);
  508 
  509         /*
  510          * Try for up to 10 ms to verify the desired state was selected.
  511          * This is longer than the standard says (1 ms) but in some modes,
  512          * systems may take longer to respond.
  513          */
  514         sts_val = sc->px_states[i].sts_val;
  515         for (tries = 0; tries < 1000; tries++) {
  516                 status = PX_GET_REG(sc->perf_status);
  517 
  518                 /*
  519                  * If we match the status or the desired status is 8 bits
  520                  * and matches the relevant bits, assume we succeeded.  It
  521                  * appears some systems (IBM R32) expect byte-wide access
  522                  * even though the standard says the register is 32-bit.
  523                  */
  524                 if (status == sts_val ||
  525                     ((sts_val & ~0xff) == 0 && (status & 0xff) == sts_val))
  526                         break;
  527                 DELAY(10);
  528         }
  529         if (tries == 1000) {
  530                 device_printf(dev, "Px transition to %d failed\n",
  531                     sc->px_states[i].core_freq);
  532                 return (ENXIO);
  533         }
  534         sc->px_curr_state = i;
  535 
  536         return (0);
  537 }
  538 
  539 static int
  540 acpi_px_get(device_t dev, struct cf_setting *set)
  541 {
  542         struct acpi_perf_softc *sc;
  543         uint64_t rate;
  544         int i;
  545         struct pcpu *pc;
  546 
  547         if (set == NULL)
  548                 return (EINVAL);
  549         sc = device_get_softc(dev);
  550 
  551         /* If we can't get new states, return immediately. */
  552         if (sc->info_only)
  553                 return (ENXIO);
  554 
  555         /* If we've set the rate before, use the cached value. */
  556         if (sc->px_curr_state != CPUFREQ_VAL_UNKNOWN) {
  557                 acpi_px_to_set(dev, &sc->px_states[sc->px_curr_state], set);
  558                 return (0);
  559         }
  560 
  561         /* Otherwise, estimate and try to match against our settings. */
  562         pc = cpu_get_pcpu(dev);
  563         if (pc == NULL)
  564                 return (ENXIO);
  565         cpu_est_clockrate(pc->pc_cpuid, &rate);
  566         rate /= 1000000;
  567         for (i = 0; i < sc->px_count; i++) {
  568                 if (CPUFREQ_CMP(sc->px_states[i].core_freq, rate)) {
  569                         sc->px_curr_state = i;
  570                         acpi_px_to_set(dev, &sc->px_states[i], set);
  571                         break;
  572                 }
  573         }
  574 
  575         /* No match, give up. */
  576         if (i == sc->px_count) {
  577                 sc->px_curr_state = CPUFREQ_VAL_UNKNOWN;
  578                 set->freq = CPUFREQ_VAL_UNKNOWN;
  579         }
  580 
  581         return (0);
  582 }
  583 
  584 static int
  585 acpi_px_type(device_t dev, int *type)
  586 {
  587         struct acpi_perf_softc *sc;
  588 
  589         if (type == NULL)
  590                 return (EINVAL);
  591         sc = device_get_softc(dev);
  592 
  593         *type = CPUFREQ_TYPE_ABSOLUTE;
  594         if (sc->info_only)
  595                 *type |= CPUFREQ_FLAG_INFO_ONLY;
  596         return (0);
  597 }

Cache object: bad4e064bcd356053e3a9150da61eea2


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