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/6.2/sys/dev/acpica/acpi_perf.c 160468 2006-07-18 14:15:04Z bruno $");
   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/acpi.h>
   48 #include <dev/acpica/acpivar.h>
   49 
   50 #include "cpufreq_if.h"
   51 
   52 /*
   53  * Support for ACPI processor performance states (Px) according to
   54  * section 8.3.3 of the ACPI 2.0c specification.
   55  */
   56 
   57 struct acpi_px {
   58         uint32_t         core_freq;
   59         uint32_t         power;
   60         uint32_t         trans_lat;
   61         uint32_t         bm_lat;
   62         uint32_t         ctrl_val;
   63         uint32_t         sts_val;
   64 };
   65 
   66 /* Offsets in struct cf_setting array for storing driver-specific values. */
   67 #define PX_SPEC_CONTROL 0
   68 #define PX_SPEC_STATUS  1
   69 
   70 #define MAX_PX_STATES   16
   71 
   72 struct acpi_perf_softc {
   73         device_t         dev;
   74         ACPI_HANDLE      handle;
   75         struct resource *perf_ctrl;     /* Set new performance state. */
   76         int              perf_ctrl_type; /* Resource type for perf_ctrl. */
   77         struct resource *perf_status;   /* Check that transition succeeded. */
   78         int              perf_sts_type; /* Resource type for perf_status. */
   79         struct acpi_px  *px_states;     /* ACPI perf states. */
   80         uint32_t         px_count;      /* Total number of perf states. */
   81         uint32_t         px_max_avail;  /* Lowest index state available. */
   82         int              px_curr_state; /* Active state index. */
   83         int              px_rid;
   84         int              info_only;     /* Can we set new states? */
   85 };
   86 
   87 #define PX_GET_REG(reg)                                 \
   88         (bus_space_read_4(rman_get_bustag((reg)),       \
   89             rman_get_bushandle((reg)), 0))
   90 #define PX_SET_REG(reg, val)                            \
   91         (bus_space_write_4(rman_get_bustag((reg)),      \
   92             rman_get_bushandle((reg)), 0, (val)))
   93 
   94 #define ACPI_NOTIFY_PERF_STATES         0x80    /* _PSS changed. */
   95 
   96 static void     acpi_perf_identify(driver_t *driver, device_t parent);
   97 static int      acpi_perf_probe(device_t dev);
   98 static int      acpi_perf_attach(device_t dev);
   99 static int      acpi_perf_detach(device_t dev);
  100 static int      acpi_perf_evaluate(device_t dev);
  101 static int      acpi_px_to_set(device_t dev, struct acpi_px *px,
  102                     struct cf_setting *set);
  103 static void     acpi_px_available(struct acpi_perf_softc *sc);
  104 static void     acpi_px_startup(void *arg);
  105 static void     acpi_px_notify(ACPI_HANDLE h, UINT32 notify, void *context);
  106 static int      acpi_px_settings(device_t dev, struct cf_setting *sets,
  107                     int *count);
  108 static int      acpi_px_set(device_t dev, const struct cf_setting *set);
  109 static int      acpi_px_get(device_t dev, struct cf_setting *set);
  110 static int      acpi_px_type(device_t dev, int *type);
  111 
  112 static device_method_t acpi_perf_methods[] = {
  113         /* Device interface */
  114         DEVMETHOD(device_identify,      acpi_perf_identify),
  115         DEVMETHOD(device_probe,         acpi_perf_probe),
  116         DEVMETHOD(device_attach,        acpi_perf_attach),
  117         DEVMETHOD(device_detach,        acpi_perf_detach),
  118 
  119         /* cpufreq interface */
  120         DEVMETHOD(cpufreq_drv_set,      acpi_px_set),
  121         DEVMETHOD(cpufreq_drv_get,      acpi_px_get),
  122         DEVMETHOD(cpufreq_drv_type,     acpi_px_type),
  123         DEVMETHOD(cpufreq_drv_settings, acpi_px_settings),
  124         {0, 0}
  125 };
  126 
  127 static driver_t acpi_perf_driver = {
  128         "acpi_perf",
  129         acpi_perf_methods,
  130         sizeof(struct acpi_perf_softc),
  131 };
  132 
  133 static devclass_t acpi_perf_devclass;
  134 DRIVER_MODULE(acpi_perf, cpu, acpi_perf_driver, acpi_perf_devclass, 0, 0);
  135 MODULE_DEPEND(acpi_perf, acpi, 1, 1, 1);
  136 
  137 MALLOC_DEFINE(M_ACPIPERF, "acpi_perf", "ACPI Performance states");
  138 
  139 static void
  140 acpi_perf_identify(driver_t *driver, device_t parent)
  141 {
  142         ACPI_HANDLE handle;
  143         device_t dev;
  144 
  145         /* Make sure we're not being doubly invoked. */
  146         if (device_find_child(parent, "acpi_perf", -1) != NULL)
  147                 return;
  148 
  149         /* Get the handle for the Processor object and check for perf states. */
  150         handle = acpi_get_handle(parent);
  151         if (handle == NULL)
  152                 return;
  153         if (ACPI_FAILURE(AcpiEvaluateObject(handle, "_PSS", NULL, NULL)))
  154                 return;
  155 
  156         /*
  157          * Add a child to every CPU that has the right methods.  In future
  158          * versions of the ACPI spec, CPUs can have different settings.
  159          * We probe this child now so that other devices that depend
  160          * on it (i.e., for info about supported states) will see it.
  161          */
  162         if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_perf", -1)) != NULL)
  163                 device_probe_and_attach(dev);
  164         else
  165                 device_printf(parent, "add acpi_perf child failed\n");
  166 }
  167 
  168 static int
  169 acpi_perf_probe(device_t dev)
  170 {
  171         ACPI_HANDLE handle;
  172         ACPI_OBJECT *pkg;
  173         struct resource *res;
  174         ACPI_BUFFER buf;
  175         int error, rid, type;
  176 
  177         if (resource_disabled("acpi_perf", 0))
  178                 return (ENXIO);
  179 
  180         /*
  181          * Check the performance state registers.  If they are of type
  182          * "functional fixed hardware", we attach quietly since we will
  183          * only be providing information on settings to other drivers.
  184          */
  185         error = ENXIO;
  186         handle = acpi_get_handle(dev);
  187         buf.Pointer = NULL;
  188         buf.Length = ACPI_ALLOCATE_BUFFER;
  189         if (ACPI_FAILURE(AcpiEvaluateObject(handle, "_PCT", NULL, &buf)))
  190                 return (error);
  191         pkg = (ACPI_OBJECT *)buf.Pointer;
  192         if (ACPI_PKG_VALID(pkg, 2)) {
  193                 rid = 0;
  194                 error = acpi_PkgGas(dev, pkg, 0, &type, &rid, &res);
  195                 switch (error) {
  196                 case 0:
  197                         bus_release_resource(dev, type, rid, res);
  198                         bus_delete_resource(dev, type, rid);
  199                         device_set_desc(dev, "ACPI CPU Frequency Control");
  200                         break;
  201                 case EOPNOTSUPP:
  202                         device_quiet(dev);
  203                         error = 0;
  204                         break;
  205                 }
  206         }
  207         AcpiOsFree(buf.Pointer);
  208 
  209         return (error);
  210 }
  211 
  212 static int
  213 acpi_perf_attach(device_t dev)
  214 {
  215         struct acpi_perf_softc *sc;
  216 
  217         sc = device_get_softc(dev);
  218         sc->dev = dev;
  219         sc->handle = acpi_get_handle(dev);
  220         sc->px_max_avail = 0;
  221         sc->px_curr_state = CPUFREQ_VAL_UNKNOWN;
  222         if (acpi_perf_evaluate(dev) != 0)
  223                 return (ENXIO);
  224         AcpiOsQueueForExecution(OSD_PRIORITY_LO, acpi_px_startup, NULL);
  225         if (!sc->info_only)
  226                 cpufreq_register(dev);
  227 
  228         return (0);
  229 }
  230 
  231 static int
  232 acpi_perf_detach(device_t dev)
  233 {
  234         /* TODO: teardown registers, remove notify handler. */
  235         return (ENXIO);
  236 }
  237 
  238 /* Probe and setup any valid performance states (Px). */
  239 static int
  240 acpi_perf_evaluate(device_t dev)
  241 {
  242         struct acpi_perf_softc *sc;
  243         ACPI_BUFFER buf;
  244         ACPI_OBJECT *pkg, *res;
  245         ACPI_STATUS status;
  246         int count, error, i, j;
  247         static int once = 1;
  248         uint32_t *p;
  249 
  250         /* Get the control values and parameters for each state. */
  251         error = ENXIO;
  252         sc = device_get_softc(dev);
  253         buf.Pointer = NULL;
  254         buf.Length = ACPI_ALLOCATE_BUFFER;
  255         status = AcpiEvaluateObject(sc->handle, "_PSS", NULL, &buf);
  256         if (ACPI_FAILURE(status))
  257                 return (ENXIO);
  258 
  259         pkg = (ACPI_OBJECT *)buf.Pointer;
  260         if (!ACPI_PKG_VALID(pkg, 1)) {
  261                 device_printf(dev, "invalid top level _PSS package\n");
  262                 goto out;
  263         }
  264         sc->px_count = pkg->Package.Count;
  265 
  266         sc->px_states = malloc(sc->px_count * sizeof(struct acpi_px),
  267             M_ACPIPERF, M_WAITOK | M_ZERO);
  268         if (sc->px_states == NULL)
  269                 goto out;
  270 
  271         /*
  272          * Each state is a package of {CoreFreq, Power, TransitionLatency,
  273          * BusMasterLatency, ControlVal, StatusVal}, sorted from highest
  274          * performance to lowest.
  275          */
  276         count = 0;
  277         for (i = 0; i < sc->px_count; i++) {
  278                 res = &pkg->Package.Elements[i];
  279                 if (!ACPI_PKG_VALID(res, 6)) {
  280                         if (once) {
  281                                 once = 0;
  282                                 device_printf(dev, "invalid _PSS package\n");
  283                         }
  284                         continue;
  285                 }
  286 
  287                 /* Parse the rest of the package into the struct. */
  288                 p = &sc->px_states[count].core_freq;
  289                 for (j = 0; j < 6; j++, p++)
  290                         acpi_PkgInt32(res, j, p);
  291 
  292                 /*
  293                  * Check for some impossible frequencies that some systems
  294                  * use to indicate they don't actually support this Px state.
  295                  */
  296                 if (sc->px_states[count].core_freq == 0 ||
  297                     sc->px_states[count].core_freq == 9999 ||
  298                     sc->px_states[count].core_freq == 0x9999 ||
  299                     sc->px_states[count].core_freq >= 0xffff)
  300                         continue;
  301 
  302                 /* Check for duplicate entries */
  303                 if (count > 0 &&
  304                     sc->px_states[count - 1].core_freq ==
  305                         sc->px_states[count].core_freq)
  306                         continue;
  307 
  308                 count++;
  309         }
  310         sc->px_count = count;
  311 
  312         /* No valid Px state found so give up. */
  313         if (count == 0)
  314                 goto out;
  315         AcpiOsFree(buf.Pointer);
  316 
  317         /* Get the control and status registers (one of each). */
  318         buf.Pointer = NULL;
  319         buf.Length = ACPI_ALLOCATE_BUFFER;
  320         status = AcpiEvaluateObject(sc->handle, "_PCT", NULL, &buf);
  321         if (ACPI_FAILURE(status))
  322                 goto out;
  323 
  324         /* Check the package of two registers, each a Buffer in GAS format. */
  325         pkg = (ACPI_OBJECT *)buf.Pointer;
  326         if (!ACPI_PKG_VALID(pkg, 2)) {
  327                 device_printf(dev, "invalid perf register package\n");
  328                 goto out;
  329         }
  330 
  331         error = acpi_PkgGas(sc->dev, pkg, 0, &sc->perf_ctrl_type, &sc->px_rid,
  332             &sc->perf_ctrl);
  333         if (error) {
  334                 /*
  335                  * If the register is of type FFixedHW, we can only return
  336                  * info, we can't get or set new settings.
  337                  */
  338                 if (error == EOPNOTSUPP) {
  339                         sc->info_only = TRUE;
  340                         error = 0;
  341                 } else
  342                         device_printf(dev, "failed in PERF_CTL attach\n");
  343                 goto out;
  344         }
  345         sc->px_rid++;
  346 
  347         error = acpi_PkgGas(sc->dev, pkg, 1, &sc->perf_sts_type, &sc->px_rid,
  348             &sc->perf_status);
  349         if (error) {
  350                 if (error == EOPNOTSUPP) {
  351                         sc->info_only = TRUE;
  352                         error = 0;
  353                 } else
  354                         device_printf(dev, "failed in PERF_STATUS attach\n");
  355                 goto out;
  356         }
  357         sc->px_rid++;
  358 
  359         /* Get our current limit and register for notifies. */
  360         acpi_px_available(sc);
  361         AcpiInstallNotifyHandler(sc->handle, ACPI_DEVICE_NOTIFY,
  362             acpi_px_notify, sc);
  363         error = 0;
  364 
  365 out:
  366         if (error) {
  367                 if (sc->px_states) {
  368                         free(sc->px_states, M_ACPIPERF);
  369                         sc->px_states = NULL;
  370                 }
  371                 if (sc->perf_ctrl) {
  372                         bus_release_resource(sc->dev, sc->perf_ctrl_type, 0,
  373                             sc->perf_ctrl);
  374                         bus_delete_resource(sc->dev, sc->perf_ctrl_type, 0);
  375                         sc->perf_ctrl = NULL;
  376                 }
  377                 if (sc->perf_status) {
  378                         bus_release_resource(sc->dev, sc->perf_sts_type, 1,
  379                             sc->perf_status);
  380                         bus_delete_resource(sc->dev, sc->perf_sts_type, 1);
  381                         sc->perf_status = NULL;
  382                 }
  383                 sc->px_rid = 0;
  384                 sc->px_count = 0;
  385         }
  386         if (buf.Pointer)
  387                 AcpiOsFree(buf.Pointer);
  388         return (error);
  389 }
  390 
  391 static void
  392 acpi_px_startup(void *arg)
  393 {
  394 
  395         /* Signal to the platform that we are taking over CPU control. */
  396         if (AcpiGbl_FADT->PstateCnt == 0)
  397                 return;
  398         ACPI_LOCK(acpi);
  399         AcpiOsWritePort(AcpiGbl_FADT->SmiCmd, AcpiGbl_FADT->PstateCnt, 8);
  400         ACPI_UNLOCK(acpi);
  401 }
  402 
  403 static void
  404 acpi_px_notify(ACPI_HANDLE h, UINT32 notify, void *context)
  405 {
  406         struct acpi_perf_softc *sc;
  407 
  408         sc = context;
  409         if (notify != ACPI_NOTIFY_PERF_STATES)
  410                 return;
  411 
  412         acpi_px_available(sc);
  413 
  414         /* TODO: Implement notification when frequency changes. */
  415 }
  416 
  417 /*
  418  * Find the highest currently-supported performance state.
  419  * This can be called at runtime (e.g., due to a docking event) at
  420  * the request of a Notify on the processor object.
  421  */
  422 static void
  423 acpi_px_available(struct acpi_perf_softc *sc)
  424 {
  425         ACPI_STATUS status;
  426         struct cf_setting set;
  427 
  428         status = acpi_GetInteger(sc->handle, "_PPC", &sc->px_max_avail);
  429 
  430         /* If the old state is too high, set current state to the new max. */
  431         if (ACPI_SUCCESS(status)) {
  432                 if (sc->px_curr_state != CPUFREQ_VAL_UNKNOWN &&
  433                     sc->px_curr_state > sc->px_max_avail) {
  434                         acpi_px_to_set(sc->dev,
  435                             &sc->px_states[sc->px_max_avail], &set);
  436                         acpi_px_set(sc->dev, &set);
  437                 }
  438         } else
  439                 sc->px_max_avail = 0;
  440 }
  441 
  442 static int
  443 acpi_px_to_set(device_t dev, struct acpi_px *px, struct cf_setting *set)
  444 {
  445 
  446         if (px == NULL || set == NULL)
  447                 return (EINVAL);
  448 
  449         set->freq = px->core_freq;
  450         set->power = px->power;
  451         /* XXX Include BM latency too? */
  452         set->lat = px->trans_lat;
  453         set->volts = CPUFREQ_VAL_UNKNOWN;
  454         set->dev = dev;
  455         set->spec[PX_SPEC_CONTROL] = px->ctrl_val;
  456         set->spec[PX_SPEC_STATUS] = px->sts_val;
  457 
  458         return (0);
  459 }
  460 
  461 static int
  462 acpi_px_settings(device_t dev, struct cf_setting *sets, int *count)
  463 {
  464         struct acpi_perf_softc *sc;
  465         int x, y;
  466 
  467         sc = device_get_softc(dev);
  468         if (sets == NULL || count == NULL)
  469                 return (EINVAL);
  470         if (*count < sc->px_count - sc->px_max_avail)
  471                 return (E2BIG);
  472 
  473         /* Return a list of settings that are currently valid. */
  474         y = 0;
  475         for (x = sc->px_max_avail; x < sc->px_count; x++, y++)
  476                 acpi_px_to_set(dev, &sc->px_states[x], &sets[y]);
  477         *count = sc->px_count - sc->px_max_avail;
  478 
  479         return (0);
  480 }
  481 
  482 static int
  483 acpi_px_set(device_t dev, const struct cf_setting *set)
  484 {
  485         struct acpi_perf_softc *sc;
  486         int i, status, sts_val, tries;
  487 
  488         if (set == NULL)
  489                 return (EINVAL);
  490         sc = device_get_softc(dev);
  491 
  492         /* If we can't set new states, return immediately. */
  493         if (sc->info_only)
  494                 return (ENXIO);
  495 
  496         /* Look up appropriate state, based on frequency. */
  497         for (i = sc->px_max_avail; i < sc->px_count; i++) {
  498                 if (CPUFREQ_CMP(set->freq, sc->px_states[i].core_freq))
  499                         break;
  500         }
  501         if (i == sc->px_count)
  502                 return (EINVAL);
  503 
  504         /* Write the appropriate value to the register. */
  505         PX_SET_REG(sc->perf_ctrl, sc->px_states[i].ctrl_val);
  506 
  507         /*
  508          * Try for up to 10 ms to verify the desired state was selected.
  509          * This is longer than the standard says (1 ms) but in some modes,
  510          * systems may take longer to respond.
  511          */
  512         sts_val = sc->px_states[i].sts_val;
  513         for (tries = 0; tries < 1000; tries++) {
  514                 status = PX_GET_REG(sc->perf_status);
  515 
  516                 /*
  517                  * If we match the status or the desired status is 8 bits
  518                  * and matches the relevant bits, assume we succeeded.  It
  519                  * appears some systems (IBM R32) expect byte-wide access
  520                  * even though the standard says the register is 32-bit.
  521                  */
  522                 if (status == sts_val ||
  523                     ((sts_val & ~0xff) == 0 && (status & 0xff) == sts_val))
  524                         break;
  525                 DELAY(10);
  526         }
  527         if (tries == 1000) {
  528                 device_printf(dev, "Px transition to %d failed\n",
  529                     sc->px_states[i].core_freq);
  530                 return (ENXIO);
  531         }
  532         sc->px_curr_state = i;
  533 
  534         return (0);
  535 }
  536 
  537 static int
  538 acpi_px_get(device_t dev, struct cf_setting *set)
  539 {
  540         struct acpi_perf_softc *sc;
  541         uint64_t rate;
  542         int i;
  543         struct pcpu *pc;
  544 
  545         if (set == NULL)
  546                 return (EINVAL);
  547         sc = device_get_softc(dev);
  548 
  549         /* If we can't get new states, return immediately. */
  550         if (sc->info_only)
  551                 return (ENXIO);
  552 
  553         /* If we've set the rate before, use the cached value. */
  554         if (sc->px_curr_state != CPUFREQ_VAL_UNKNOWN) {
  555                 acpi_px_to_set(dev, &sc->px_states[sc->px_curr_state], set);
  556                 return (0);
  557         }
  558 
  559         /* Otherwise, estimate and try to match against our settings. */
  560         pc = cpu_get_pcpu(dev);
  561         if (pc == NULL)
  562                 return (ENXIO);
  563         cpu_est_clockrate(pc->pc_cpuid, &rate);
  564         rate /= 1000000;
  565         for (i = 0; i < sc->px_count; i++) {
  566                 if (CPUFREQ_CMP(sc->px_states[i].core_freq, rate)) {
  567                         sc->px_curr_state = i;
  568                         acpi_px_to_set(dev, &sc->px_states[i], set);
  569                         break;
  570                 }
  571         }
  572 
  573         /* No match, give up. */
  574         if (i == sc->px_count) {
  575                 sc->px_curr_state = CPUFREQ_VAL_UNKNOWN;
  576                 set->freq = CPUFREQ_VAL_UNKNOWN;
  577         }
  578 
  579         return (0);
  580 }
  581 
  582 static int
  583 acpi_px_type(device_t dev, int *type)
  584 {
  585         struct acpi_perf_softc *sc;
  586 
  587         if (type == NULL)
  588                 return (EINVAL);
  589         sc = device_get_softc(dev);
  590 
  591         *type = CPUFREQ_TYPE_ABSOLUTE;
  592         if (sc->info_only)
  593                 *type |= CPUFREQ_FLAG_INFO_ONLY;
  594         return (0);
  595 }

Cache object: 1849260014a1f50eec7cfc2cce677fc2


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