linux/drivers/ras/amd/atl/access.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * AMD Address Translation Library
 *
 * access.c : DF Indirect Access functions
 *
 * Copyright (c) 2023, Advanced Micro Devices, Inc.
 * All Rights Reserved.
 *
 * Author: Yazen Ghannam <[email protected]>
 */

#include "internal.h"

/* Protect the PCI config register pairs used for DF indirect access. */
static DEFINE_MUTEX(df_indirect_mutex);

/*
 * Data Fabric Indirect Access uses FICAA/FICAD.
 *
 * Fabric Indirect Configuration Access Address (FICAA): constructed based
 * on the device's Instance Id and the PCI function and register offset of
 * the desired register.
 *
 * Fabric Indirect Configuration Access Data (FICAD): there are FICAD
 * low and high registers but so far only the low register is needed.
 *
 * Use Instance Id 0xFF to indicate a broadcast read.
 */
#define DF_BROADCAST …

#define DF_FICAA_INST_EN …
#define DF_FICAA_REG_NUM …
#define DF_FICAA_FUNC_NUM …
#define DF_FICAA_INST_ID …

#define DF_FICAA_REG_NUM_LEGACY …

static u16 get_accessible_node(u16 node)
{ … }

static int __df_indirect_read(u16 node, u8 func, u16 reg, u8 instance_id, u32 *lo)
{ … }

int df_indirect_read_instance(u16 node, u8 func, u16 reg, u8 instance_id, u32 *lo)
{ … }

int df_indirect_read_broadcast(u16 node, u8 func, u16 reg, u32 *lo)
{ … }