drivers/ras/amd/atl/prm.c

   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 }