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); 102