xref: /linux/drivers/ras/amd/atl/prm.c (revision 46f2dd5ce5723a2c07051d332f8f1c4c4ce548f3)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * AMD Address Translation Library
4  *
5  * prm.c : Plumbing code for ACPI Platform Runtime Mechanism (PRM)
6  *
7  * Information on AMD PRM modules and handlers including the GUIDs and buffer
8  * structures used here are defined in the AMD ACPI Porting Guide in the
9  * chapter "Platform Runtime Mechanism Table (PRMT)"
10  *
11  * Copyright (c) 2024, Advanced Micro Devices, Inc.
12  * All Rights Reserved.
13  *
14  * Author: John Allen <john.allen@amd.com>
15  */
16 
17 #include "internal.h"
18 
19 #include <linux/prmt.h>
20 
21 /*
22  * PRM parameter buffer - normalized to system physical address, as described
23  * in the "PRM Parameter Buffer" section of the AMD ACPI Porting Guide.
24  */
25 struct norm_to_sys_param_buf {
26 	u64 norm_addr;
27 	u8 socket;
28 	u64 bank_id;
29 	void *out_buf;
30 } __packed;
31 
32 static const guid_t norm_to_sys_guid = GUID_INIT(0xE7180659, 0xA65D, 0x451D,
33 						 0x92, 0xCD, 0x2B, 0x56, 0xF1,
34 						 0x2B, 0xEB, 0xA6);
35 
36 unsigned long prm_umc_norm_to_sys_addr(u8 socket_id, u64 bank_id, unsigned long addr)
37 {
38 	struct norm_to_sys_param_buf p_buf;
39 	unsigned long ret_addr;
40 	int ret;
41 
42 	p_buf.norm_addr = addr;
43 	p_buf.socket    = socket_id;
44 	p_buf.bank_id   = bank_id;
45 	p_buf.out_buf   = &ret_addr;
46 
47 	ret = acpi_call_prm_handler(norm_to_sys_guid, &p_buf);
48 	if (!ret)
49 		return ret_addr;
50 
51 	if (ret == -ENODEV)
52 		pr_debug("PRM module/handler not available\n");
53 	else
54 		pr_notice_once("PRM address translation failed\n");
55 
56 	return ret;
57 }
58