linux/drivers/net/ipa/ipa_mem.c

// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
 * Copyright (C) 2019-2024 Linaro Ltd.
 */

#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/iommu.h>
#include <linux/platform_device.h>
#include <linux/types.h>

#include <linux/soc/qcom/smem.h>

#include "gsi_trans.h"
#include "ipa.h"
#include "ipa_cmd.h"
#include "ipa_data.h"
#include "ipa_mem.h"
#include "ipa_reg.h"
#include "ipa_table.h"

/* "Canary" value placed between memory regions to detect overflow */
#define IPA_MEM_CANARY_VAL …

/* SMEM host id representing the modem. */
#define QCOM_SMEM_HOST_MODEM …

const struct ipa_mem *ipa_mem_find(struct ipa *ipa, enum ipa_mem_id mem_id)
{ … }

/* Add an immediate command to a transaction that zeroes a memory region */
static void
ipa_mem_zero_region_add(struct gsi_trans *trans, enum ipa_mem_id mem_id)
{ … }

/**
 * ipa_mem_setup() - Set up IPA AP and modem shared memory areas
 * @ipa:	IPA pointer
 *
 * Set up the shared memory regions in IPA local memory.  This involves
 * zero-filling memory regions, and in the case of header memory, telling
 * the IPA where it's located.
 *
 * This function performs the initial setup of this memory.  If the modem
 * crashes, its regions are re-zeroed in ipa_mem_zero_modem().
 *
 * The AP informs the modem where its portions of memory are located
 * in a QMI exchange that occurs at modem startup.
 *
 * There is no need for a matching ipa_mem_teardown() function.
 *
 * Return:	0 if successful, or a negative error code
 */
int ipa_mem_setup(struct ipa *ipa)
{ … }

/* Is the given memory region ID is valid for the current IPA version? */
static bool ipa_mem_id_valid(struct ipa *ipa, enum ipa_mem_id mem_id)
{ … }

/* Must the given memory region be present in the configuration? */
static bool ipa_mem_id_required(struct ipa *ipa, enum ipa_mem_id mem_id)
{ … }

static bool ipa_mem_valid_one(struct ipa *ipa, const struct ipa_mem *mem)
{ … }

/* Verify each defined memory region is valid. */
static bool ipa_mem_valid(struct ipa *ipa, const struct ipa_mem_data *mem_data)
{ … }

/* Do all memory regions fit within the IPA local memory? */
static bool ipa_mem_size_valid(struct ipa *ipa)
{ … }

/**
 * ipa_mem_config() - Configure IPA shared memory
 * @ipa:	IPA pointer
 *
 * Return:	0 if successful, or a negative error code
 */
int ipa_mem_config(struct ipa *ipa)
{ … }

/* Inverse of ipa_mem_config() */
void ipa_mem_deconfig(struct ipa *ipa)
{ … }

/**
 * ipa_mem_zero_modem() - Zero IPA-local memory regions owned by the modem
 * @ipa:	IPA pointer
 *
 * Zero regions of IPA-local memory used by the modem.  These are configured
 * (and initially zeroed) by ipa_mem_setup(), but if the modem crashes and
 * restarts via SSR we need to re-initialize them.  A QMI message tells the
 * modem where to find regions of IPA local memory it needs to know about
 * (these included).
 */
int ipa_mem_zero_modem(struct ipa *ipa)
{ … }

/**
 * ipa_imem_init() - Initialize IMEM memory used by the IPA
 * @ipa:	IPA pointer
 * @addr:	Physical address of the IPA region in IMEM
 * @size:	Size (bytes) of the IPA region in IMEM
 *
 * IMEM is a block of shared memory separate from system DRAM, and
 * a portion of this memory is available for the IPA to use.  The
 * modem accesses this memory directly, but the IPA accesses it
 * via the IOMMU, using the AP's credentials.
 *
 * If this region exists (size > 0) we map it for read/write access
 * through the IOMMU using the IPA device.
 *
 * Note: @addr and @size are not guaranteed to be page-aligned.
 */
static int ipa_imem_init(struct ipa *ipa, unsigned long addr, size_t size)
{ … }

static void ipa_imem_exit(struct ipa *ipa)
{ … }

/**
 * ipa_smem_init() - Initialize SMEM memory used by the IPA
 * @ipa:	IPA pointer
 * @item:	Item ID of SMEM memory
 * @size:	Size (bytes) of SMEM memory region
 *
 * SMEM is a managed block of shared DRAM, from which numbered "items"
 * can be allocated.  One item is designated for use by the IPA.
 *
 * The modem accesses SMEM memory directly, but the IPA accesses it
 * via the IOMMU, using the AP's credentials.
 *
 * If size provided is non-zero, we allocate it and map it for
 * access through the IOMMU.
 *
 * Note: @size and the item address are is not guaranteed to be page-aligned.
 */
static int ipa_smem_init(struct ipa *ipa, u32 item, size_t size)
{ … }

static void ipa_smem_exit(struct ipa *ipa)
{ … }

/* Perform memory region-related initialization */
int ipa_mem_init(struct ipa *ipa, struct platform_device *pdev,
		 const struct ipa_mem_data *mem_data)
{ … }

/* Inverse of ipa_mem_init() */
void ipa_mem_exit(struct ipa *ipa)
{ … }