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[src/trunk]: src/sys/dev/acpi acpi: Add support for ACPI Platform Communicati...



details:   https://anonhg.NetBSD.org/src/rev/d3548874613f
branches:  trunk
changeset: 979107:d3548874613f
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Sun Dec 13 20:27:53 2020 +0000

description:
acpi: Add support for ACPI Platform Communications Channel (PCC).

diffstat:

 sys/dev/acpi/acpi_pcc.c |  389 ++++++++++++++++++++++++++++++++++++++++++++++++
 sys/dev/acpi/acpi_pcc.h |   38 ++++
 sys/dev/acpi/files.acpi |    7 +-
 3 files changed, 433 insertions(+), 1 deletions(-)

diffs (truncated from 456 to 300 lines):

diff -r c14de722a28b -r d3548874613f sys/dev/acpi/acpi_pcc.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/dev/acpi/acpi_pcc.c   Sun Dec 13 20:27:53 2020 +0000
@@ -0,0 +1,389 @@
+/* $NetBSD: acpi_pcc.c,v 1.1 2020/12/13 20:27:53 jmcneill Exp $ */
+
+/*-
+ * Copyright (c) 2020 Jared McNeill <jmcneill%invisible.ca@localhost>
+ * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+ */
+
+/*
+ * Platform Communications Channel (PCC) device driver.
+ */
+
+#include <sys/cdefs.h>
+__KERNEL_RCSID(0, "$NetBSD: acpi_pcc.c,v 1.1 2020/12/13 20:27:53 jmcneill Exp $");
+
+#include <sys/param.h>
+#include <sys/bus.h>
+#include <sys/cpu.h>
+#include <sys/device.h>
+#include <sys/kmem.h>
+
+#include <dev/acpi/acpireg.h>
+#include <dev/acpi/acpivar.h>
+#include <dev/acpi/acpi_pcc.h>
+
+#define        PCC_MEMORY_BARRIER()    membar_sync()
+#if defined(__aarch64__)
+#define        PCC_DMA_BARRIER()       __asm __volatile("dsb sy" ::: "memory")
+#else
+#error PCC_BARRIER not implemented on this platform
+#endif
+
+#define        PCC_SIGNATURE(space_id)         (0x50434300 | (space_id))
+#define        PCC_STATUS_COMMAND_COMPLETE     __BIT(0)
+#define        PCC_STATUS_COMMAND_ERROR        __BIT(2)
+
+struct pcc_register {
+       ACPI_GENERIC_ADDRESS    reg_addr;
+       uint64_t                reg_preserve;
+       uint64_t                reg_set;
+};
+
+struct pcc_subspace {
+       uint8_t                 ss_id;
+       uint8_t                 ss_type;
+       void *                  ss_data;
+       size_t                  ss_len;
+       struct pcc_register     ss_doorbell_reg;
+       uint32_t                ss_latency;
+       uint32_t                ss_turnaround;
+       kmutex_t                ss_lock;
+};
+
+struct pcc_softc {
+       device_t                sc_dev;
+       struct pcc_subspace *   sc_ss;
+       u_int                   sc_nss;
+};
+
+typedef void (*pcc_subspace_callback)(ACPI_SUBTABLE_HEADER *, uint8_t, void *);
+
+static int     pcc_match(device_t, cfdata_t, void *);
+static void    pcc_attach(device_t, device_t, void *);
+
+static uint8_t pcc_subspace_foreach(ACPI_TABLE_PCCT *,
+                                    pcc_subspace_callback, void *);
+static void    pcc_subspace_attach(ACPI_SUBTABLE_HEADER *, uint8_t, void *);
+
+static struct pcc_softc *pcc_softc = NULL;
+
+CFATTACH_DECL_NEW(acpipcc, sizeof(struct pcc_softc),
+    pcc_match, pcc_attach, NULL, NULL);
+
+static int
+pcc_match(device_t parent, cfdata_t cf, void *aux)
+{
+       ACPI_TABLE_HEADER *hdrp = aux;
+
+       return memcmp(hdrp->Signature, ACPI_SIG_PCCT, ACPI_NAMESEG_SIZE) == 0;
+}
+
+static void
+pcc_attach(device_t parent, device_t self, void *aux)
+{
+       struct pcc_softc * const sc = device_private(self);
+       ACPI_TABLE_PCCT *pcct = aux;
+       u_int count;
+
+       if (pcc_softc != NULL) {
+               aprint_error(": Already attached!\n");
+               return;
+       }
+
+       count = pcc_subspace_foreach(pcct, NULL, NULL);
+       if (count == 0) {
+               aprint_error(": No subspaces found!\n");
+               return;
+       }
+
+       aprint_naive("\n");
+       aprint_normal(": Platform Communications Channel, %u subspace%s\n",
+           count, count == 1 ? "" : "s");
+
+       sc->sc_dev = self;
+       sc->sc_nss = count;
+       sc->sc_ss = kmem_zalloc(count * sizeof(*sc->sc_ss), KM_SLEEP);
+       pcc_subspace_foreach(pcct, pcc_subspace_attach, sc);
+
+       pcc_softc = sc;
+}
+
+/*
+ * pcc_subspace_foreach --
+ *
+ *     Find all subspaces defined in the PCCT table. If a 'func' callback
+ *     is provided, the callback is invoked for each subspace with the
+ *     table pointer, subspace ID, and 'arg' as arguments. Returns the
+ *     number of subspaces found.
+ */
+static uint8_t
+pcc_subspace_foreach(ACPI_TABLE_PCCT *pcct, pcc_subspace_callback func,
+    void *arg)
+{
+       ACPI_SUBTABLE_HEADER *header;
+       char *ptr, *end;
+       uint8_t count;
+
+       end = (char *)pcct + pcct->Header.Length;
+       ptr = (char *)pcct + sizeof(*pcct);
+       count = 0;
+
+       while (ptr < end && count < 255) {
+               header = (ACPI_SUBTABLE_HEADER *)ptr;
+               if (header->Length == 0 || ptr + header->Length > end) {
+                       break;
+               }
+               if (func != NULL) {
+                       func(header, count, arg);
+               }
+               ++count;
+               ptr += header->Length;
+       }
+
+       return count;
+}
+
+/*
+ * pcc_subspace_attach --
+ *
+ *     Allocate resources for a PCC subspace.
+ */
+static void
+pcc_subspace_attach(ACPI_SUBTABLE_HEADER *header, uint8_t id, void *arg)
+{
+       struct pcc_softc * const sc = arg;
+       struct pcc_subspace * const ss = &sc->sc_ss[id];
+       ACPI_PCCT_SUBSPACE *generic = (ACPI_PCCT_SUBSPACE *)header;
+
+       ss->ss_id = id;
+       ss->ss_type = header->Type;
+       ss->ss_data = AcpiOsMapMemory(generic->BaseAddress, generic->Length);
+       if (ss->ss_data == NULL) {
+               panic("%s: couldn't map subspace 0x%02x at 0x%016" PRIx64,
+                   device_xname(sc->sc_dev), id, generic->BaseAddress);
+       }
+       ss->ss_len = generic->Length;
+       ss->ss_doorbell_reg.reg_addr = generic->DoorbellRegister;
+       ss->ss_doorbell_reg.reg_preserve = generic->PreserveMask;
+       ss->ss_doorbell_reg.reg_set = generic->WriteMask;
+       mutex_init(&ss->ss_lock, MUTEX_DEFAULT, IPL_NONE);
+}
+
+/*
+ * pcc_wait_command --
+ *
+ *     Wait for command complete to be set on a PCC subspace, with timeout.
+ */
+static ACPI_STATUS
+pcc_wait_command(struct pcc_subspace *ss, bool first)
+{
+       volatile ACPI_PCCT_SHARED_MEMORY *shmem;
+       int retry;
+
+       switch (ss->ss_type) {
+       case ACPI_PCCT_TYPE_GENERIC_SUBSPACE:
+               /*
+                * OSPM does not have to wait for command complete before
+                * sending the first command.
+                */
+               if (first) {
+                       return AE_OK;
+               }
+               /* FALLTHROUGH */
+
+       case ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE:
+       case ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2:
+               /*
+                * Wait for the command complete bit to be set in the status
+                * register.
+                */
+               shmem = ss->ss_data;
+               retry = imax(1000, ss->ss_turnaround + ss->ss_latency * 100);
+               while (retry > 0) {
+                       PCC_MEMORY_BARRIER();
+                       if ((shmem->Status & PCC_STATUS_COMMAND_COMPLETE) != 0)
+                               return AE_OK;
+                       delay(10);
+                       retry -= 10;
+               }
+               return AE_TIME;
+
+       default:
+               return AE_NOT_IMPLEMENTED;
+       }
+}
+
+/*
+ * pcc_doorbell --
+ *
+ *     Ring the door bell by writing to the doorbell register.
+ */
+static ACPI_STATUS
+pcc_doorbell(struct pcc_register *reg)
+{
+       ACPI_STATUS rv;
+       UINT64 val;
+
+       rv = AcpiRead(&val, &reg->reg_addr);
+       if (ACPI_FAILURE(rv)) {
+               return rv;
+       }
+       val &= reg->reg_preserve;
+       val |= reg->reg_set;
+       return AcpiWrite(val, &reg->reg_addr);
+}
+
+/*
+ * pcc_send_command --
+ *
+ *     Write a command into PCC subspace and ring the doorbell.
+ */
+static ACPI_STATUS
+pcc_send_command(struct pcc_subspace *ss, ACPI_GENERIC_ADDRESS *reg,
+    uint32_t command, int flags, ACPI_INTEGER val)
+{
+       volatile ACPI_PCCT_SHARED_MEMORY *shmem = ss->ss_data;
+       uint8_t *data = __UNVOLATILE(shmem + 1);
+       UINT64 tmp, mask;
+
+       KASSERT(ss->ss_type == ACPI_PCCT_TYPE_GENERIC_SUBSPACE ||
+               ss->ss_type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE ||
+               ss->ss_type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2);
+
+       shmem->Signature = PCC_SIGNATURE(ss->ss_id);
+       shmem->Command = command & 0xff;
+       if ((flags & PCC_WRITE) != 0) {
+               mask = __BITS(reg->BitOffset + reg->BitWidth - 1,
+                             reg->BitOffset);
+               ACPI_MOVE_64_TO_64(&tmp, data + reg->Address);
+               tmp &= mask;
+               tmp |= __SHIFTIN(val, mask);
+               ACPI_MOVE_64_TO_64(data + reg->Address, &tmp);
+       }
+       PCC_MEMORY_BARRIER();
+       shmem->Status &= ~(PCC_STATUS_COMMAND_COMPLETE |
+                          PCC_STATUS_COMMAND_ERROR);
+       PCC_DMA_BARRIER();
+
+       return pcc_doorbell(&ss->ss_doorbell_reg);
+}
+
+/*
+ * pcc_receive_response --
+ *
+ *     Process a command response in PCC subspace.
+ */



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