14cf841e3STony Luck // SPDX-License-Identifier: GPL-2.0
24cf841e3STony Luck /*
34cf841e3STony Luck * Address translation interface via ACPI DSM.
44cf841e3STony Luck * Copyright (C) 2018 Intel Corporation
54cf841e3STony Luck *
64cf841e3STony Luck * Specification for this interface is available at:
74cf841e3STony Luck *
84cf841e3STony Luck * https://cdrdv2.intel.com/v1/dl/getContent/603354
94cf841e3STony Luck */
104cf841e3STony Luck
114cf841e3STony Luck #include <linux/acpi.h>
124cf841e3STony Luck #include <linux/adxl.h>
134cf841e3STony Luck
144cf841e3STony Luck #define ADXL_REVISION 0x1
154cf841e3STony Luck #define ADXL_IDX_GET_ADDR_PARAMS 0x1
164cf841e3STony Luck #define ADXL_IDX_FORWARD_TRANSLATE 0x2
174cf841e3STony Luck #define ACPI_ADXL_PATH "\\_SB.ADXL"
184cf841e3STony Luck
194cf841e3STony Luck /*
204cf841e3STony Luck * The specification doesn't provide a limit on how many
214cf841e3STony Luck * components are in a memory address. But since we allocate
224cf841e3STony Luck * memory based on the number the BIOS tells us, we should
234cf841e3STony Luck * defend against insane values.
244cf841e3STony Luck */
254cf841e3STony Luck #define ADXL_MAX_COMPONENTS 500
264cf841e3STony Luck
274cf841e3STony Luck #undef pr_fmt
284cf841e3STony Luck #define pr_fmt(fmt) "ADXL: " fmt
294cf841e3STony Luck
304cf841e3STony Luck static acpi_handle handle;
314cf841e3STony Luck static union acpi_object *params;
324cf841e3STony Luck static const guid_t adxl_guid =
334cf841e3STony Luck GUID_INIT(0xAA3C050A, 0x7EA4, 0x4C1F,
344cf841e3STony Luck 0xAF, 0xDA, 0x12, 0x67, 0xDF, 0xD3, 0xD4, 0x8D);
354cf841e3STony Luck
364cf841e3STony Luck static int adxl_count;
374cf841e3STony Luck static char **adxl_component_names;
384cf841e3STony Luck
adxl_dsm(int cmd,union acpi_object argv[])394cf841e3STony Luck static union acpi_object *adxl_dsm(int cmd, union acpi_object argv[])
404cf841e3STony Luck {
414cf841e3STony Luck union acpi_object *obj, *o;
424cf841e3STony Luck
434cf841e3STony Luck obj = acpi_evaluate_dsm_typed(handle, &adxl_guid, ADXL_REVISION,
444cf841e3STony Luck cmd, argv, ACPI_TYPE_PACKAGE);
454cf841e3STony Luck if (!obj) {
464cf841e3STony Luck pr_info("DSM call failed for cmd=%d\n", cmd);
474cf841e3STony Luck return NULL;
484cf841e3STony Luck }
494cf841e3STony Luck
504cf841e3STony Luck if (obj->package.count != 2) {
514cf841e3STony Luck pr_info("Bad pkg count %d\n", obj->package.count);
524cf841e3STony Luck goto err;
534cf841e3STony Luck }
544cf841e3STony Luck
554cf841e3STony Luck o = obj->package.elements;
564cf841e3STony Luck if (o->type != ACPI_TYPE_INTEGER) {
574cf841e3STony Luck pr_info("Bad 1st element type %d\n", o->type);
584cf841e3STony Luck goto err;
594cf841e3STony Luck }
604cf841e3STony Luck if (o->integer.value) {
614cf841e3STony Luck pr_info("Bad ret val %llu\n", o->integer.value);
624cf841e3STony Luck goto err;
634cf841e3STony Luck }
644cf841e3STony Luck
654cf841e3STony Luck o = obj->package.elements + 1;
664cf841e3STony Luck if (o->type != ACPI_TYPE_PACKAGE) {
674cf841e3STony Luck pr_info("Bad 2nd element type %d\n", o->type);
684cf841e3STony Luck goto err;
694cf841e3STony Luck }
704cf841e3STony Luck return obj;
714cf841e3STony Luck
724cf841e3STony Luck err:
734cf841e3STony Luck ACPI_FREE(obj);
744cf841e3STony Luck return NULL;
754cf841e3STony Luck }
764cf841e3STony Luck
774cf841e3STony Luck /**
784cf841e3STony Luck * adxl_get_component_names - get list of memory component names
794cf841e3STony Luck * Returns NULL terminated list of string names
804cf841e3STony Luck *
814cf841e3STony Luck * Give the caller a pointer to the list of memory component names
824cf841e3STony Luck * e.g. { "SystemAddress", "ProcessorSocketId", "ChannelId", ... NULL }
834cf841e3STony Luck * Caller should count how many strings in order to allocate a buffer
844cf841e3STony Luck * for the return from adxl_decode().
854cf841e3STony Luck */
adxl_get_component_names(void)864cf841e3STony Luck const char * const *adxl_get_component_names(void)
874cf841e3STony Luck {
884cf841e3STony Luck return (const char * const *)adxl_component_names;
894cf841e3STony Luck }
904cf841e3STony Luck EXPORT_SYMBOL_GPL(adxl_get_component_names);
914cf841e3STony Luck
924cf841e3STony Luck /**
934cf841e3STony Luck * adxl_decode - ask BIOS to decode a system address to memory address
944cf841e3STony Luck * @addr: the address to decode
954cf841e3STony Luck * @component_values: pointer to array of values for each component
964cf841e3STony Luck * Returns 0 on success, negative error code otherwise
974cf841e3STony Luck *
984cf841e3STony Luck * The index of each value returned in the array matches the index of
994cf841e3STony Luck * each component name returned by adxl_get_component_names().
1004cf841e3STony Luck * Components that are not defined for this address translation (e.g.
1014cf841e3STony Luck * mirror channel number for a non-mirrored address) are set to ~0ull.
1024cf841e3STony Luck */
adxl_decode(u64 addr,u64 component_values[])1034cf841e3STony Luck int adxl_decode(u64 addr, u64 component_values[])
1044cf841e3STony Luck {
1054cf841e3STony Luck union acpi_object argv4[2], *results, *r;
1064cf841e3STony Luck int i, cnt;
1074cf841e3STony Luck
1084cf841e3STony Luck if (!adxl_component_names)
1094cf841e3STony Luck return -EOPNOTSUPP;
1104cf841e3STony Luck
1114cf841e3STony Luck argv4[0].type = ACPI_TYPE_PACKAGE;
1124cf841e3STony Luck argv4[0].package.count = 1;
1134cf841e3STony Luck argv4[0].package.elements = &argv4[1];
1144cf841e3STony Luck argv4[1].integer.type = ACPI_TYPE_INTEGER;
1154cf841e3STony Luck argv4[1].integer.value = addr;
1164cf841e3STony Luck
1174cf841e3STony Luck results = adxl_dsm(ADXL_IDX_FORWARD_TRANSLATE, argv4);
1184cf841e3STony Luck if (!results)
1194cf841e3STony Luck return -EINVAL;
1204cf841e3STony Luck
1214cf841e3STony Luck r = results->package.elements + 1;
1224cf841e3STony Luck cnt = r->package.count;
1234cf841e3STony Luck if (cnt != adxl_count) {
1244cf841e3STony Luck ACPI_FREE(results);
1254cf841e3STony Luck return -EINVAL;
1264cf841e3STony Luck }
1274cf841e3STony Luck r = r->package.elements;
1284cf841e3STony Luck
1294cf841e3STony Luck for (i = 0; i < cnt; i++)
1304cf841e3STony Luck component_values[i] = r[i].integer.value;
1314cf841e3STony Luck
1324cf841e3STony Luck ACPI_FREE(results);
1334cf841e3STony Luck
1344cf841e3STony Luck return 0;
1354cf841e3STony Luck }
1364cf841e3STony Luck EXPORT_SYMBOL_GPL(adxl_decode);
1374cf841e3STony Luck
adxl_init(void)1384cf841e3STony Luck static int __init adxl_init(void)
1394cf841e3STony Luck {
1404cf841e3STony Luck char *path = ACPI_ADXL_PATH;
1414cf841e3STony Luck union acpi_object *p;
1424cf841e3STony Luck acpi_status status;
1434cf841e3STony Luck int i;
1444cf841e3STony Luck
1454cf841e3STony Luck status = acpi_get_handle(NULL, path, &handle);
1464cf841e3STony Luck if (ACPI_FAILURE(status)) {
1474cf841e3STony Luck pr_debug("No ACPI handle for path %s\n", path);
1484cf841e3STony Luck return -ENODEV;
1494cf841e3STony Luck }
1504cf841e3STony Luck
1514cf841e3STony Luck if (!acpi_has_method(handle, "_DSM")) {
1524cf841e3STony Luck pr_info("No DSM method\n");
1534cf841e3STony Luck return -ENODEV;
1544cf841e3STony Luck }
1554cf841e3STony Luck
1564cf841e3STony Luck if (!acpi_check_dsm(handle, &adxl_guid, ADXL_REVISION,
1574cf841e3STony Luck ADXL_IDX_GET_ADDR_PARAMS |
1584cf841e3STony Luck ADXL_IDX_FORWARD_TRANSLATE)) {
1594cf841e3STony Luck pr_info("DSM method does not support forward translate\n");
1604cf841e3STony Luck return -ENODEV;
1614cf841e3STony Luck }
1624cf841e3STony Luck
1634cf841e3STony Luck params = adxl_dsm(ADXL_IDX_GET_ADDR_PARAMS, NULL);
1644cf841e3STony Luck if (!params) {
1654cf841e3STony Luck pr_info("Failed to get component names\n");
1664cf841e3STony Luck return -ENODEV;
1674cf841e3STony Luck }
1684cf841e3STony Luck
1694cf841e3STony Luck p = params->package.elements + 1;
1704cf841e3STony Luck adxl_count = p->package.count;
1714cf841e3STony Luck if (adxl_count > ADXL_MAX_COMPONENTS) {
1724cf841e3STony Luck pr_info("Insane number of address component names %d\n", adxl_count);
1734cf841e3STony Luck ACPI_FREE(params);
1744cf841e3STony Luck return -ENODEV;
1754cf841e3STony Luck }
1764cf841e3STony Luck p = p->package.elements;
1774cf841e3STony Luck
1784cf841e3STony Luck /*
1794cf841e3STony Luck * Allocate one extra for NULL termination.
1804cf841e3STony Luck */
1814cf841e3STony Luck adxl_component_names = kcalloc(adxl_count + 1, sizeof(char *), GFP_KERNEL);
1824cf841e3STony Luck if (!adxl_component_names) {
1834cf841e3STony Luck ACPI_FREE(params);
1844cf841e3STony Luck return -ENOMEM;
1854cf841e3STony Luck }
1864cf841e3STony Luck
1874cf841e3STony Luck for (i = 0; i < adxl_count; i++)
1884cf841e3STony Luck adxl_component_names[i] = p[i].string.pointer;
1894cf841e3STony Luck
1904cf841e3STony Luck return 0;
1914cf841e3STony Luck }
1924cf841e3STony Luck subsys_initcall(adxl_init);
193