PNPACPI: add support for HP vendor-specific CCSR descriptors

The HP CCSR descriptor describes MMIO address space that should appear
as a MEM resource.  This patch adds support for parsing these descriptors
in the _CRS data.

The visible effect of this is that these MEM resources will appear
in /sys/devices/pnp0/.../resources, which means that "lspnp -v" will
report it, user applications can use this to locate device CSR space,
and kernel drivers can use the normal PNP resource accessors to
locate them.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

1 files changed, 60 insertions, 0 deletions

diff --git a/drivers/pnp/pnpacpi/rsparser.c b/drivers/pnp/pnpacpi/rsparser.c
index c2f59f4d20bc..d7e9f2152df0 100644
--- a/drivers/pnp/pnpacpi/rsparser.c
+++ b/drivers/pnp/pnpacpi/rsparser.c
@@ -3,6 +3,8 @@
  *
  * Copyright (c) 2004 Matthieu Castet <castet.matthieu@free.fr>
  * Copyright (c) 2004 Li Shaohua <shaohua.li@intel.com>
+ * Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
+ *      Bjorn Helgaas <bjorn.helgaas@hp.com>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -187,6 +189,61 @@ static void pnpacpi_parse_allocated_ioresource(struct pnp_dev *dev, u64 start,
         pnp_add_io_resource(dev, start, end, flags);
 }
 
+/*
+ * Device CSRs that do not appear in PCI config space should be described
+ * via ACPI.  This would normally be done with Address Space Descriptors
+ * marked as "consumer-only," but old versions of Windows and Linux ignore
+ * the producer/consumer flag, so HP invented a vendor-defined resource to
+ * describe the location and size of CSR space.
+ */
+static struct acpi_vendor_uuid hp_ccsr_uuid = {
+        .subtype = 2,
+        .data = { 0xf9, 0xad, 0xe9, 0x69, 0x4f, 0x92, 0x5f, 0xab, 0xf6, 0x4a,
+            0x24, 0xd2, 0x01, 0x37, 0x0e, 0xad },
+};
+
+static int vendor_resource_matches(struct pnp_dev *dev,
+                                   struct acpi_resource_vendor_typed *vendor,
+                                   struct acpi_vendor_uuid *match,
+                                   int expected_len)
+{
+        int uuid_len = sizeof(vendor->uuid);
+        u8 uuid_subtype = vendor->uuid_subtype;
+        u8 *uuid = vendor->uuid;
+        int actual_len;
+
+        /* byte_length includes uuid_subtype and uuid */
+        actual_len = vendor->byte_length - uuid_len - 1;
+
+        if (uuid_subtype == match->subtype &&
+            uuid_len == sizeof(match->data) &&
+            memcmp(uuid, match->data, uuid_len) == 0) {
+                if (expected_len && expected_len != actual_len) {
+                        dev_err(&dev->dev, "wrong vendor descriptor size; "
+                                "expected %d, found %d bytes\n",
+                                expected_len, actual_len);
+                        return 0;
+                }
+
+                return 1;
+        }
+
+        return 0;
+}
+
+static void pnpacpi_parse_allocated_vendor(struct pnp_dev *dev,
+                                    struct acpi_resource_vendor_typed *vendor)
+{
+        if (vendor_resource_matches(dev, vendor, &hp_ccsr_uuid, 16)) {
+                u64 start, length;
+
+                memcpy(&start, vendor->byte_data, sizeof(start));
+                memcpy(&length, vendor->byte_data + 8, sizeof(length));
+
+                pnp_add_mem_resource(dev, start, start + length - 1, 0);
+        }
+}
+
 static void pnpacpi_parse_allocated_memresource(struct pnp_dev *dev,
                                                 u64 start, u64 len,
                                                 int write_protect)
@@ -237,6 +294,7 @@ static acpi_status pnpacpi_allocated_resource(struct acpi_resource *res,
         struct acpi_resource_dma *dma;
         struct acpi_resource_io *io;
         struct acpi_resource_fixed_io *fixed_io;
+        struct acpi_resource_vendor_typed *vendor_typed;
         struct acpi_resource_memory24 *memory24;
         struct acpi_resource_memory32 *memory32;
         struct acpi_resource_fixed_memory32 *fixed_memory32;
@@ -306,6 +364,8 @@ static acpi_status pnpacpi_allocated_resource(struct acpi_resource *res,
                 break;
 
         case ACPI_RESOURCE_TYPE_VENDOR:
+                vendor_typed = &res->data.vendor_typed;
+                pnpacpi_parse_allocated_vendor(dev, vendor_typed);
                 break;
 
         case ACPI_RESOURCE_TYPE_END_TAG: