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Release 4.18 drivers/soc/qcom/cmd-db.c

Directory: drivers/soc/qcom
/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (c) 2016-2018, The Linux Foundation. All rights reserved. */

#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>
#include <linux/types.h>

#include <soc/qcom/cmd-db.h>


#define NUM_PRIORITY		2

#define MAX_SLV_ID		8

#define SLAVE_ID_MASK		0x7

#define SLAVE_ID_SHIFT		16

/**
 * struct entry_header: header for each entry in cmddb
 *
 * @id: resource's identifier
 * @priority: unused
 * @addr: the address of the resource
 * @len: length of the data
 * @offset: offset from :@data_offset, start of the data
 */

struct entry_header {
	
u8 id[8];
	
__le32 priority[NUM_PRIORITY];
	
__le32 addr;
	
__le16 len;
	
__le16 offset;
};

/**
 * struct rsc_hdr: resource header information
 *
 * @slv_id: id for the resource
 * @header_offset: entry's header at offset from the end of the cmd_db_header
 * @data_offset: entry's data at offset from the end of the cmd_db_header
 * @cnt: number of entries for HW type
 * @version: MSB is major, LSB is minor
 * @reserved: reserved for future use.
 */

struct rsc_hdr {
	
__le16 slv_id;
	
__le16 header_offset;
	
__le16 data_offset;
	
__le16 cnt;
	
__le16 version;
	
__le16 reserved[3];
};

/**
 * struct cmd_db_header: The DB header information
 *
 * @version: The cmd db version
 * @magic: constant expected in the database
 * @header: array of resources
 * @checksum: checksum for the header. Unused.
 * @reserved: reserved memory
 * @data: driver specific data
 */

struct cmd_db_header {
	
__le32 version;
	
u8 magic[4];
	
struct rsc_hdr header[MAX_SLV_ID];
	
__le32 checksum;
	
__le32 reserved;
	
u8 data[];
};

/**
 * DOC: Description of the Command DB database.
 *
 * At the start of the command DB memory is the cmd_db_header structure.
 * The cmd_db_header holds the version, checksum, magic key as well as an
 * array for header for each slave (depicted by the rsc_header). Each h/w
 * based accelerator is a 'slave' (shared resource) and has slave id indicating
 * the type of accelerator. The rsc_header is the header for such individual
 * slaves of a given type. The entries for each of these slaves begin at the
 * rsc_hdr.header_offset. In addition each slave could have auxiliary data
 * that may be needed by the driver. The data for the slave starts at the
 * entry_header.offset to the location pointed to by the rsc_hdr.data_offset.
 *
 * Drivers have a stringified key to a slave/resource. They can query the slave
 * information and get the slave id and the auxiliary data and the length of the
 * data. Using this information, they can format the request to be sent to the
 * h/w accelerator and request a resource state.
 */


static const u8 CMD_DB_MAGIC[] = { 0xdb, 0x30, 0x03, 0x0c };


static bool cmd_db_magic_matches(const struct cmd_db_header *header) { const u8 *magic = header->magic; return memcmp(magic, CMD_DB_MAGIC, ARRAY_SIZE(CMD_DB_MAGIC)) == 0; }

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static struct cmd_db_header *cmd_db_header;
static inline void *rsc_to_entry_header(struct rsc_hdr *hdr) { u16 offset = le16_to_cpu(hdr->header_offset); return cmd_db_header->data + offset; }

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static inline void * rsc_offset(struct rsc_hdr *hdr, struct entry_header *ent) { u16 offset = le16_to_cpu(hdr->data_offset); u16 loffset = le16_to_cpu(ent->offset); return cmd_db_header->data + offset + loffset; }

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/** * cmd_db_ready - Indicates if command DB is available * * Return: 0 on success, errno otherwise */
int cmd_db_ready(void) { if (cmd_db_header == NULL) return -EPROBE_DEFER; else if (!cmd_db_magic_matches(cmd_db_header)) return -EINVAL; return 0; }

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EXPORT_SYMBOL(cmd_db_ready);
static int cmd_db_get_header(const char *id, struct entry_header *eh, struct rsc_hdr *rh) { struct rsc_hdr *rsc_hdr; struct entry_header *ent; int ret, i, j; u8 query[8]; ret = cmd_db_ready(); if (ret) return ret; if (!eh || !rh) return -EINVAL; /* Pad out query string to same length as in DB */ strncpy(query, id, sizeof(query)); for (i = 0; i < MAX_SLV_ID; i++) { rsc_hdr = &cmd_db_header->header[i]; if (!rsc_hdr->slv_id) break; ent = rsc_to_entry_header(rsc_hdr); for (j = 0; j < le16_to_cpu(rsc_hdr->cnt); j++, ent++) { if (memcmp(ent->id, query, sizeof(ent->id)) == 0) break; } if (j < le16_to_cpu(rsc_hdr->cnt)) { memcpy(eh, ent, sizeof(*ent)); memcpy(rh, rsc_hdr, sizeof(*rh)); return 0; } } return -ENODEV; }

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/** * cmd_db_read_addr() - Query command db for resource id address. * * @id: resource id to query for address * * Return: resource address on success, 0 on error * * This is used to retrieve resource address based on resource * id. */
u32 cmd_db_read_addr(const char *id) { int ret; struct entry_header ent; struct rsc_hdr rsc_hdr; ret = cmd_db_get_header(id, &ent, &rsc_hdr); return ret < 0 ? 0 : le32_to_cpu(ent.addr); }

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EXPORT_SYMBOL(cmd_db_read_addr); /** * cmd_db_read_aux_data() - Query command db for aux data. * * @id: Resource to retrieve AUX Data on. * @data: Data buffer to copy returned aux data to. Returns size on NULL * @len: Caller provides size of data buffer passed in. * * Return: size of data on success, errno otherwise */
int cmd_db_read_aux_data(const char *id, u8 *data, size_t len) { int ret; struct entry_header ent; struct rsc_hdr rsc_hdr; u16 ent_len; if (!data) return -EINVAL; ret = cmd_db_get_header(id, &ent, &rsc_hdr); if (ret) return ret; ent_len = le16_to_cpu(ent.len); if (len < ent_len) return -EINVAL; len = min_t(u16, ent_len, len); memcpy(data, rsc_offset(&rsc_hdr, &ent), len); return len; }

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EXPORT_SYMBOL(cmd_db_read_aux_data); /** * cmd_db_read_aux_data_len - Get the length of the auxiliary data stored in DB. * * @id: Resource to retrieve AUX Data. * * Return: size on success, 0 on error */
size_t cmd_db_read_aux_data_len(const char *id) { int ret; struct entry_header ent; struct rsc_hdr rsc_hdr; ret = cmd_db_get_header(id, &ent, &rsc_hdr); return ret < 0 ? 0 : le16_to_cpu(ent.len); }

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EXPORT_SYMBOL(cmd_db_read_aux_data_len); /** * cmd_db_read_slave_id - Get the slave ID for a given resource address * * @id: Resource id to query the DB for version * * Return: cmd_db_hw_type enum on success, CMD_DB_HW_INVALID on error */
enum cmd_db_hw_type cmd_db_read_slave_id(const char *id) { int ret; struct entry_header ent; struct rsc_hdr rsc_hdr; u32 addr; ret = cmd_db_get_header(id, &ent, &rsc_hdr); if (ret < 0) return CMD_DB_HW_INVALID; addr = le32_to_cpu(ent.addr); return (addr >> SLAVE_ID_SHIFT) & SLAVE_ID_MASK; }

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EXPORT_SYMBOL(cmd_db_read_slave_id);
static int cmd_db_dev_probe(struct platform_device *pdev) { struct reserved_mem *rmem; int ret = 0; rmem = of_reserved_mem_lookup(pdev->dev.of_node); if (!rmem) { dev_err(&pdev->dev, "failed to acquire memory region\n"); return -EINVAL; } cmd_db_header = memremap(rmem->base, rmem->size, MEMREMAP_WB); if (IS_ERR_OR_NULL(cmd_db_header)) { ret = PTR_ERR(cmd_db_header); cmd_db_header = NULL; return ret; } if (!cmd_db_magic_matches(cmd_db_header)) { dev_err(&pdev->dev, "Invalid Command DB Magic\n"); return -EINVAL; } return 0; }

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static const struct of_device_id cmd_db_match_table[] = { { .compatible = "qcom,cmd-db" }, { }, }; static struct platform_driver cmd_db_dev_driver = { .probe = cmd_db_dev_probe, .driver = { .name = "cmd-db", .of_match_table = cmd_db_match_table, }, };
static int __init cmd_db_device_init(void) { return platform_driver_register(&cmd_db_dev_driver); }

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arch_initcall(cmd_db_device_init);

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Directory: drivers/soc/qcom
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