[src/trunk]: src/sys/arch/arm/acpi Create bus_dma tags for each device node b...

[jmcneill <jmcneill%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/aa11b571f952
branches:  trunk
changeset: 466700:aa11b571f952
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Tue Dec 31 13:54:22 2019 +0000

description:
Create bus_dma tags for each device node based on _CCA and _DMA properties
found by walking up the device node tree. These tags encode range
restrictions, address translations, and whether or not the device is
cache coherent.

diffstat:

 sys/arch/arm/acpi/acpi_machdep.c |  150 ++++++++++++++++++++++++--------------
 1 files changed, 93 insertions(+), 57 deletions(-)

diffs (189 lines):

diff -r 5e718511693e -r aa11b571f952 sys/arch/arm/acpi/acpi_machdep.c
--- a/sys/arch/arm/acpi/acpi_machdep.c  Tue Dec 31 13:39:15 2019 +0000
+++ b/sys/arch/arm/acpi/acpi_machdep.c  Tue Dec 31 13:54:22 2019 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: acpi_machdep.c,v 1.16 2019/12/31 11:42:46 jmcneill Exp $ */
+/* $NetBSD: acpi_machdep.c,v 1.17 2019/12/31 13:54:22 jmcneill Exp $ */
 
 /*-
  * Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -32,13 +32,14 @@
 #include "pci.h"
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: acpi_machdep.c,v 1.16 2019/12/31 11:42:46 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: acpi_machdep.c,v 1.17 2019/12/31 13:54:22 jmcneill Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/bus.h>
 #include <sys/cpu.h>
 #include <sys/device.h>
+#include <sys/kmem.h>
 
 #include <uvm/uvm_extern.h>
 
@@ -372,44 +373,6 @@
        NULL
 };
 
-static bus_dma_tag_t
-arm_acpi_dma_tag_subregion(struct acpi_softc *sc, bus_dma_tag_t dmat,
-    ACPI_HANDLE handle)
-{
-       struct acpi_resources res;
-       struct acpi_mem *mem;
-       bus_dma_tag_t newtag;
-       ACPI_STATUS rv;
-       int error;
-
-       rv = acpi_resource_parse(sc->sc_dev, handle, "_DMA", &res,
-           &acpi_resource_parse_ops_quiet);
-       if (ACPI_FAILURE(rv))
-               return dmat;    /* no translation required */
-
-       mem = acpi_res_mem(&res, 0);
-       if (mem == NULL)
-               goto done;
-
-       aprint_debug_dev(sc->sc_dev, "_DMA range %#lx-%#lx\n",
-           mem->ar_base, mem->ar_base + mem->ar_length - 1);
-
-       error = bus_dmatag_subregion(dmat,
-           mem->ar_base, mem->ar_base + mem->ar_length - 1,
-           &newtag, BUS_DMA_WAITOK);
-       if (error != 0) {
-               aprint_error_dev(sc->sc_dev,
-                   "_DMA subregion failed: %d\n", error);
-               goto done;
-       }
-       dmat = newtag;
-
-done:
-       acpi_resource_cleanup(&res);
-
-       return dmat;
-}
-
 static ACPI_HANDLE
 arm_acpi_dma_module(struct acpi_softc *sc, struct acpi_devnode *ad)
 {
@@ -432,28 +395,101 @@
        return NULL;
 }
 
+static void
+arm_acpi_dma_init_ranges(struct acpi_softc *sc, struct acpi_devnode *ad,
+    struct arm32_bus_dma_tag *dmat, uint32_t flags)
+{
+       struct acpi_resources res;
+       struct acpi_mem *mem;
+       ACPI_HANDLE module;
+       ACPI_STATUS rv;
+       int n;
+
+       module = arm_acpi_dma_module(sc, ad->ad_parent);
+       if (module == NULL) {
+default_tag:
+               /* No translation required */
+               dmat->_nranges = 1;
+               dmat->_ranges = kmem_zalloc(sizeof(*dmat->_ranges), KM_SLEEP);
+               dmat->_ranges[0].dr_sysbase = 0;
+               dmat->_ranges[0].dr_busbase = 0;
+               dmat->_ranges[0].dr_len = UINTPTR_MAX;
+               dmat->_ranges[0].dr_flags = flags;
+               return;
+       }
+
+       rv = acpi_resource_parse(sc->sc_dev, module, "_DMA", &res,
+           &acpi_resource_parse_ops_quiet);
+       if (ACPI_FAILURE(rv)) {
+               aprint_error_dev(sc->sc_dev,
+                   "failed to parse _DMA on %s: %s\n",
+                   acpi_name(module), AcpiFormatException(rv));
+               goto default_tag;
+       }
+       if (res.ar_nmem == 0) {
+               acpi_resource_cleanup(&res);
+               goto default_tag;
+       }
+
+       dmat->_nranges = res.ar_nmem;
+       dmat->_ranges = kmem_zalloc(sizeof(*dmat->_ranges) * res.ar_nmem,
+           KM_SLEEP);
+
+       for (n = 0; n < res.ar_nmem; n++) {
+               mem = acpi_res_mem(&res, n);
+               dmat->_ranges[n].dr_busbase = mem->ar_base;
+               dmat->_ranges[n].dr_sysbase = mem->ar_base;
+               if (mem->ar_decode == ACPI_POS_DECODE)
+                       dmat->_ranges[n].dr_sysbase += mem->ar_offset;
+               else
+                       dmat->_ranges[n].dr_sysbase -= mem->ar_offset;
+               dmat->_ranges[n].dr_len = mem->ar_length;
+               dmat->_ranges[n].dr_flags = flags;
+
+               aprint_debug_dev(sc->sc_dev,
+                   "%s: DMA sysbase %#lx busbase %#lx len %#lx%s\n",
+                   acpi_name(ad->ad_handle),
+                   dmat->_ranges[n].dr_sysbase,
+                   dmat->_ranges[n].dr_busbase,
+                   dmat->_ranges[n].dr_len,
+                   flags ? " (coherent)" : "");
+       }
+
+       acpi_resource_cleanup(&res);
+}
+
+static uint32_t
+arm_acpi_dma_flags(struct acpi_softc *sc, struct acpi_devnode *ad)
+{
+       ACPI_INTEGER cca = 1;   /* default cache coherent */
+       ACPI_STATUS rv;
+
+       for (; ad != NULL; ad = ad->ad_parent) {
+               if (ad->ad_devinfo->Type != ACPI_TYPE_DEVICE)
+                       continue;
+
+               rv = acpi_eval_integer(ad->ad_handle, "_CCA", &cca);
+               if (ACPI_SUCCESS(rv))
+                       break;
+       }
+
+       return cca ? _BUS_DMAMAP_COHERENT : 0;
+}
+
+
 bus_dma_tag_t
 arm_acpi_dma_tag(struct acpi_softc *sc, struct acpi_devnode *ad)
 {
-       ACPI_HANDLE module;
-       ACPI_INTEGER cca;
-       bus_dma_tag_t dmat;
-
-       if (ACPI_FAILURE(acpi_eval_integer(ad->ad_handle, "_CCA", &cca)))
-               cca = 1;
+       struct arm32_bus_dma_tag *dmat;
 
-       if (cca)
-               dmat = &acpi_coherent_dma_tag;
-       else
-               dmat = &arm_generic_dma_tag;
+       if (ad->ad_dmat != NULL)
+               return ad->ad_dmat;
+               
+       dmat = kmem_alloc(sizeof(*dmat), KM_SLEEP);
+       *dmat = arm_generic_dma_tag;
 
-       /*
-        * If a parent device is a bus, it may define valid DMA ranges
-        * and translations for child nodes.
-        */
-       module = arm_acpi_dma_module(sc, ad);
-       if (module != NULL)
-               dmat = arm_acpi_dma_tag_subregion(sc, dmat, module);
+       const uint32_t flags = arm_acpi_dma_flags(sc, ad);
+       arm_acpi_dma_init_ranges(sc, ad, dmat, flags);
 
        return dmat;
 }