swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: 4b972a01a7da614b4796475f933094751a295a2f authored by Linus Torvalds on 22 June 2019, 23:01:36 UTC
Linux 5.2-rc6
Linux 5.2-rc6
Tip revision: 4b972a0
cmd-db.c
/* 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;
}
static struct cmd_db_header *cmd_db_header;
static inline const void *rsc_to_entry_header(const struct rsc_hdr *hdr)
{
u16 offset = le16_to_cpu(hdr->header_offset);
return cmd_db_header->data + offset;
}
static inline void *
rsc_offset(const struct rsc_hdr *hdr, const 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;
}
/**
* 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;
}
EXPORT_SYMBOL(cmd_db_ready);
static int cmd_db_get_header(const char *id, const struct entry_header **eh,
const struct rsc_hdr **rh)
{
const struct rsc_hdr *rsc_hdr;
const struct entry_header *ent;
int ret, i, j;
u8 query[8];
ret = cmd_db_ready();
if (ret)
return ret;
/* 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) {
if (eh)
*eh = ent;
if (rh)
*rh = rsc_hdr;
return 0;
}
}
}
return -ENODEV;
}
/**
* 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;
const struct entry_header *ent;
ret = cmd_db_get_header(id, &ent, NULL);
return ret < 0 ? 0 : le32_to_cpu(ent->addr);
}
EXPORT_SYMBOL(cmd_db_read_addr);
/**
* cmd_db_read_aux_data() - Query command db for aux data.
*
* @id: Resource to retrieve AUX Data on
* @len: size of data buffer returned
*
* Return: pointer to data on success, error pointer otherwise
*/
const void *cmd_db_read_aux_data(const char *id, size_t *len)
{
int ret;
const struct entry_header *ent;
const struct rsc_hdr *rsc_hdr;
ret = cmd_db_get_header(id, &ent, &rsc_hdr);
if (ret)
return ERR_PTR(ret);
if (len)
*len = le16_to_cpu(ent->len);
return rsc_offset(rsc_hdr, ent);
}
EXPORT_SYMBOL(cmd_db_read_aux_data);
/**
* 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;
const struct entry_header *ent;
u32 addr;
ret = cmd_db_get_header(id, &ent, NULL);
if (ret < 0)
return CMD_DB_HW_INVALID;
addr = le32_to_cpu(ent->addr);
return (addr >> SLAVE_ID_SHIFT) & SLAVE_ID_MASK;
}
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 (!cmd_db_header) {
ret = -ENOMEM;
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;
}
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);
}
arch_initcall(cmd_db_device_init);