arch/ia64/kernel/acpi-ext.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * (c) Copyright 2003, 2006 Hewlett-Packard Development Company, L.P.
   4  *      Alex Williamson <alex.williamson@hp.com>
   5  *      Bjorn Helgaas <bjorn.helgaas@hp.com>
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/types.h>
  10 #include <linux/slab.h>
  11 #include <linux/acpi.h>
  12
  13 #include <asm/acpi-ext.h>
  14
  15 /*
  16  * Device CSRs that do not appear in PCI config space should be described
  17  * via ACPI.  This would normally be done with Address Space Descriptors
  18  * marked as "consumer-only," but old versions of Windows and Linux ignore
  19  * the producer/consumer flag, so HP invented a vendor-defined resource to
  20  * describe the location and size of CSR space.
  21  */
  22
  23 struct acpi_vendor_uuid hp_ccsr_uuid = {
  24         .subtype = 2,
  25         .data = { 0xf9, 0xad, 0xe9, 0x69, 0x4f, 0x92, 0x5f, 0xab, 0xf6, 0x4a,
  26             0x24, 0xd2, 0x01, 0x37, 0x0e, 0xad },
  27 };
  28
  29 static acpi_status hp_ccsr_locate(acpi_handle obj, u64 *base, u64 *length)
  30 {
  31         acpi_status status;
  32         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  33         struct acpi_resource *resource;
  34         struct acpi_resource_vendor_typed *vendor;
  35
  36         status = acpi_get_vendor_resource(obj, METHOD_NAME__CRS, &hp_ccsr_uuid,
  37                 &buffer);
  38
  39         resource = buffer.pointer;
  40         vendor = &resource->data.vendor_typed;
  41
  42         if (ACPI_FAILURE(status) || vendor->byte_length < 16) {
  43                 status = AE_NOT_FOUND;
  44                 goto exit;
  45         }
  46
  47         memcpy(base, vendor->byte_data, sizeof(*base));
  48         memcpy(length, vendor->byte_data + 8, sizeof(*length));
  49
  50   exit:
  51         kfree(buffer.pointer);
  52         return status;
  53 }
  54
  55 struct csr_space {
  56         u64     base;
  57         u64     length;
  58 };
  59
  60 static acpi_status find_csr_space(struct acpi_resource *resource, void *data)
  61 {
  62         struct csr_space *space = data;
  63         struct acpi_resource_address64 addr;
  64         acpi_status status;
  65
  66         status = acpi_resource_to_address64(resource, &addr);
  67         if (ACPI_SUCCESS(status) &&
  68             addr.resource_type == ACPI_MEMORY_RANGE &&
  69             addr.address.address_length &&
  70             addr.producer_consumer == ACPI_CONSUMER) {
  71                 space->base = addr.address.minimum;
  72                 space->length = addr.address.address_length;
  73                 return AE_CTRL_TERMINATE;
  74         }
  75         return AE_OK;           /* keep looking */
  76 }
  77
  78 static acpi_status hp_crs_locate(acpi_handle obj, u64 *base, u64 *length)
  79 {
  80         struct csr_space space = { 0, 0 };
  81
  82         acpi_walk_resources(obj, METHOD_NAME__CRS, find_csr_space, &space);
  83         if (!space.length)
  84                 return AE_NOT_FOUND;
  85
  86         *base = space.base;
  87         *length = space.length;
  88         return AE_OK;
  89 }
  90
  91 acpi_status hp_acpi_csr_space(acpi_handle obj, u64 *csr_base, u64 *csr_length)
  92 {
  93         acpi_status status;
  94
  95         status = hp_ccsr_locate(obj, csr_base, csr_length);
  96         if (ACPI_SUCCESS(status))
  97                 return status;
  98
  99         return hp_crs_locate(obj, csr_base, csr_length);
 100 }
 101 EXPORT_SYMBOL(hp_acpi_csr_space);