[src/trunk]: src/sys/arch/arm/acpi If a device node is a child of a module de...

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

details:   https://anonhg.NetBSD.org/src/rev/20f2b9537058
branches:  trunk
changeset: 466681:20f2b9537058
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Mon Dec 30 19:50:29 2019 +0000

description:
If a device node is a child of a module device, and the module device declares DMA range restrictions, use them.

diffstat:

 sys/arch/arm/acpi/acpi_machdep.c |  64 +++++++++++++++++++++++++++++++++++++--
 1 files changed, 60 insertions(+), 4 deletions(-)

diffs (95 lines):

diff -r 2546edcfdc88 -r 20f2b9537058 sys/arch/arm/acpi/acpi_machdep.c
--- a/sys/arch/arm/acpi/acpi_machdep.c  Mon Dec 30 19:49:38 2019 +0000
+++ b/sys/arch/arm/acpi/acpi_machdep.c  Mon Dec 30 19:50:29 2019 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: acpi_machdep.c,v 1.14 2019/12/29 23:47:56 jmcneill Exp $ */
+/* $NetBSD: acpi_machdep.c,v 1.15 2019/12/30 19:50:29 jmcneill Exp $ */
 
 /*-
  * Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -32,7 +32,7 @@
 #include "pci.h"
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: acpi_machdep.c,v 1.14 2019/12/29 23:47:56 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: acpi_machdep.c,v 1.15 2019/12/30 19:50:29 jmcneill Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -367,18 +367,74 @@
                config_found_ia(sc->sc_dev, "acpisdtbus", hdrp, NULL);
 }
 
+static const char * const module_hid[] = {
+       "ACPI0004",     /* Module device */
+       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;
+}
+
 bus_dma_tag_t
 arm_acpi_dma_tag(struct acpi_softc *sc, struct acpi_devnode *ad)
 {
        ACPI_INTEGER cca;
+       bus_dma_tag_t dmat;
 
        if (ACPI_FAILURE(acpi_eval_integer(ad->ad_handle, "_CCA", &cca)))
                cca = 1;
 
        if (cca)
-               return &acpi_coherent_dma_tag;
+               dmat = &acpi_coherent_dma_tag;
        else
-               return &arm_generic_dma_tag;
+               dmat = &arm_generic_dma_tag;
+
+       /*
+        * If the parent device is a bus, it may define valid DMA ranges
+        * and translations for child nodes.
+        */
+       if (ad->ad_parent != NULL &&
+           acpi_match_hid(ad->ad_parent->ad_devinfo, module_hid)) {
+               dmat = arm_acpi_dma_tag_subregion(sc, dmat,
+                   ad->ad_parent->ad_handle);
+       }
+
+       return dmat;
 }
 __strong_alias(acpi_get_dma_tag,arm_acpi_dma_tag);
 __strong_alias(acpi_get_dma64_tag,arm_acpi_dma_tag);