/*
* Copyright (c) 2015, Sony Mobile Communications AB.
* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/hwspinlock.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/soc/qcom/smem.h>
/*
* The Qualcomm shared memory system is a allocate only heap structure that
* consists of one of more memory areas that can be accessed by the processors
* in the SoC.
*
* All systems contains a global heap, accessible by all processors in the SoC,
* with a table of contents data structure (@smem_header) at the beginning of
* the main shared memory block.
*
* The global header contains meta data for allocations as well as a fixed list
* of 512 entries (@smem_global_entry) that can be initialized to reference
* parts of the shared memory space.
*
*
* In addition to this global heap a set of "private" heaps can be set up at
* boot time with access restrictions so that only certain processor pairs can
* access the data.
*
* These partitions are referenced from an optional partition table
* (@smem_ptable), that is found 4kB from the end of the main smem region. The
* partition table entries (@smem_ptable_entry) lists the involved processors
* (or hosts) and their location in the main shared memory region.
*
* Each partition starts with a header (@smem_partition_header) that identifies
* the partition and holds properties for the two internal memory regions. The
* two regions are cached and non-cached memory respectively. Each region
* contain a link list of allocation headers (@smem_private_entry) followed by
* their data.
*
* Items in the non-cached region are allocated from the start of the partition
* while items in the cached region are allocated from the end. The free area
* is hence the region between the cached and non-cached offsets.
*
*
* To synchronize allocations in the shared memory heaps a remote spinlock must
* be held - currently lock number 3 of the sfpb or tcsr is used for this on all
* platforms.
*
*/
/*
* Item 3 of the global heap contains an array of versions for the various
* software components in the SoC. We verify that the boot loader version is
* what the expected version (SMEM_EXPECTED_VERSION) as a sanity check.
*/
#define SMEM_ITEM_VERSION 3
#define SMEM_MASTER_SBL_VERSION_INDEX 7
#define SMEM_EXPECTED_VERSION 11
/*
* The first 8 items are only to be allocated by the boot loader while
* initializing the heap.
*/
#define SMEM_ITEM_LAST_FIXED 8
/* Highest accepted item number, for both global and private heaps */
#define SMEM_ITEM_COUNT 512
/* Processor/host identifier for the application processor */
#define SMEM_HOST_APPS 0
/* Max number of processors/hosts in a system */
#define SMEM_HOST_COUNT 9
/**
* struct smem_proc_comm - proc_comm communication struct (legacy)
* @command: current command to be executed
* @status: status of the currently requested command
* @params: parameters to the command
*/
struct smem_proc_comm {
__le32 command;
__le32 status;
__le32 params[2];
};
/**
* struct smem_global_entry - entry to reference smem items on the heap
* @allocated: boolean to indicate if this entry is used
* @offset: offset to the allocated space
* @size: size of the allocated space, 8 byte aligned
* @aux_base: base address for the memory region used by this unit, or 0 for
* the default region. bits 0,1 are reserved
*/
struct smem_global_entry {
__le32 allocated;
__le32 offset;
__le32 size;
__le32 aux_base; /* bits 1:0 reserved */
};
#define AUX_BASE_MASK 0xfffffffc
/**
* struct smem_header - header found in beginning of primary smem region
* @proc_comm: proc_comm communication interface (legacy)
* @version: array of versions for the various subsystems
* @initialized: boolean to indicate that smem is initialized
* @free_offset: index of the first unallocated byte in smem
* @available: number of bytes available for allocation
* @reserved: reserved field, must be 0
* toc: array of references to items
*/
struct smem_header {
struct smem_proc_comm proc_comm[4];
__le32 version[32];
__le32 initialized;
__le32 free_offset;
__le32 available;
__le32 reserved;
struct smem_global_entry toc[SMEM_ITEM_COUNT];
};
/**
* struct smem_ptable_entry - one entry in the @smem_ptable list
* @offset: offset, within the main shared memory region, of the partition
* @size: size of the partition
* @flags: flags for the partition (currently unused)
* @host0: first processor/host with access to this partition
* @host1: second processor/host with access to this partition
* @reserved: reserved entries for later use
*/
struct smem_ptable_entry {
__le32 offset;
__le32 size;
__le32 flags;
__le16 host0;
__le16 host1;
__le32 reserved[8];
};
/**
* struct smem_ptable - partition table for the private partitions
* @magic: magic number, must be SMEM_PTABLE_MAGIC
* @version: version of the partition table
* @num_entries: number of partitions in the table
* @reserved: for now reserved entries
* @entry: list of @smem_ptable_entry for the @num_entries partitions
*/
struct smem_ptable {
u8 magic[4];
__le32 version;
__le32 num_entries;
__le32 reserved[5];
struct smem_ptable_entry entry[];
};
static const u8 SMEM_PTABLE_MAGIC[] = { 0x24, 0x54, 0x4f, 0x43 }; /* "$TOC" */
/**
* struct smem_partition_header - header of the partitions
* @magic: magic number, must be SMEM_PART_MAGIC
* @host0: first processor/host with access to this partition
* @host1: second processor/host with access to this partition
* @size: size of the partition
* @offset_free_uncached: offset to the first free byte of uncached memory in
* this partition
* @offset_free_cached: offset to the first free byte of cached memory in this
* partition
* @reserved: for now reserved entries
*/
struct smem_partition_header {
u8 magic[4];
__le16 host0;
__le16 host1;
__le32 size;
__le32 offset_free_uncached;
__le32 offset_free_cached;
__le32 reserved[3];
};
static const u8 SMEM_PART_MAGIC[] = { 0x24, 0x50, 0x52, 0x54 };
/**
* struct smem_private_entry - header of each item in the private partition
* @canary: magic number, must be SMEM_PRIVATE_CANARY
* @item: identifying number of the smem item
* @size: size of the data, including padding bytes
* @padding_data: number of bytes of padding of data
* @padding_hdr: number of bytes of padding between the header and the data
* @reserved: for now reserved entry
*/
struct smem_private_entry {
u16 canary; /* bytes are the same so no swapping needed */
__le16 item;
__le32 size; /* includes padding bytes */
__le16 padding_data;
__le16 padding_hdr;
__le32 reserved;
};
#define SMEM_PRIVATE_CANARY 0xa5a5
/**
* struct smem_region - representation of a chunk of memory used for smem
* @aux_base: identifier of aux_mem base
* @virt_base: virtual base address of memory with this aux_mem identifier
* @size: size of the memory region
*/
struct smem_region {
u32 aux_base;
void __iomem *virt_base;
size_t size;
};
/**
* struct qcom_smem - device data for the smem device
* @dev: device pointer
* @hwlock: reference to a hwspinlock
* @partitions: list of pointers to partitions affecting the current
* processor/host
* @num_regions: number of @regions
* @regions: list of the memory regions defining the shared memory
*/
struct qcom_smem {
struct device *dev;
struct hwspinlock *hwlock;
struct smem_partition_header *partitions[SMEM_HOST_COUNT];
unsigned num_regions;
struct smem_region regions[0];
};
static struct smem_private_entry *
phdr_to_last_private_entry(struct smem_partition_header *phdr)
{
void *p = phdr;
return p + le32_to_cpu(phdr->offset_free_uncached);
}
static void *phdr_to_first_cached_entry(struct smem_partition_header *phdr)
{
void *p = phdr;
return p + le32_to_cpu(phdr->offset_free_cached);
}
static struct smem_private_entry *
phdr_to_first_private_entry(struct smem_partition_header *phdr)
{
void *p = phdr;
return p + sizeof(*phdr);
}
static struct smem_private_entry *
private_entry_next(struct smem_private_entry *e)
{
void *p = e;
return p + sizeof(*e) + le16_to_cpu(e->padding_hdr) +
le32_to_cpu(e->size);
}
static void *entry_to_item(struct smem_private_entry *e)
{
void *p = e;
return p + sizeof(*e) + le16_to_cpu(e->padding_hdr);
}
/* Pointer to the one and only smem handle */
static struct qcom_smem *__smem;
/* Timeout (ms) for the trylock of remote spinlocks */
#define HWSPINLOCK_TIMEOUT 1000
static int qcom_smem_alloc_private(struct qcom_smem *smem,
unsigned host,
unsigned item,
size_t size)
{
struct smem_partition_header *phdr;
struct smem_private_entry *hdr, *end;
size_t alloc_size;
void *cached;
phdr = smem->partitions[host];
hdr = phdr_to_first_private_entry(phdr);
end = phdr_to_last_private_entry(phdr);
cached = phdr_to_first_cached_entry(phdr);
while (hdr < end) {
if (hdr->canary != SMEM_PRIVATE_CANARY) {
dev_err(smem->dev,
"Found invalid canary in host %d partition\n",
host);
return -EINVAL;
}
if (le16_to_cpu(hdr->item) == item)
return -EEXIST;
hdr = private_entry_next(hdr);
}
/* Check that we don't grow into the cached region */
alloc_size = sizeof(*hdr) + ALIGN(size, 8);
if ((void *)hdr + alloc_size >= cached) {
dev_err(smem->dev, "Out of memory\n");
return -ENOSPC;
}
hdr->canary = SMEM_PRIVATE_CANARY;
hdr->item = cpu_to_le16(item);
hdr->size = cpu_to_le32(ALIGN(size, 8));
hdr->padding_data = cpu_to_le16(le32_to_cpu(hdr->size) - size);
hdr->padding_hdr = 0;
/*
* Ensure the header is written before we advance the free offset, so
* that remote processors that does not take the remote spinlock still
* gets a consistent view of the linked list.
*/
wmb();
le32_add_cpu(&phdr->offset_free_uncached, alloc_size);
return 0;
}
static int qcom_smem_alloc_global(struct qcom_smem *smem,
unsigned item,
size_t size)
{
struct smem_header *header;
struct smem_global_entry *entry;
if (WARN_ON(item >= SMEM_ITEM_COUNT))
return -EINVAL;
header = smem->regions[0].virt_base;
entry = &header->toc[item];
if (entry->allocated)
return -EEXIST;
size = ALIGN(size, 8);
if (WARN_ON(size > le32_to_cpu(header->available)))
return -ENOMEM;
entry->offset = header->free_offset;
entry->size = cpu_to_le32(size);
/*
* Ensure the header is consistent before we mark the item allocated,
* so that remote processors will get a consistent view of the item
* even though they do not take the spinlock on read.
*/
wmb();
entry->allocated = cpu_to_le32(1);
le32_add_cpu(&header->free_offset, size);
le32_add_cpu(&header->available, -size);
return 0;
}
/**
* qcom_smem_alloc() - allocate space for a smem item
* @host: remote processor id, or -1
* @item: smem item handle
* @size: number of bytes to be allocated
*
* Allocate space for a given smem item of size @size, given that the item is
* not yet allocated.
*/
int qcom_smem_alloc(unsigned host, unsigned item, size_t size)
{
unsigned long flags;
int ret;
if (!__smem)
return -EPROBE_DEFER;
if (item < SMEM_ITEM_LAST_FIXED) {
dev_err(__smem->dev,
"Rejecting allocation of static entry %d\n", item);
return -EINVAL;
}
ret = hwspin_lock_timeout_irqsave(__smem->hwlock,
HWSPINLOCK_TIMEOUT,
&flags);
if (ret)
return ret;
if (host < SMEM_HOST_COUNT && __smem->partitions[host])
ret = qcom_smem_alloc_private(__smem, host, item, size);
else
ret = qcom_smem_alloc_global(__smem, item, size);
hwspin_unlock_irqrestore(__smem->hwlock, &flags);
return ret;
}
EXPORT_SYMBOL(qcom_smem_alloc);
static void *qcom_smem_get_global(struct qcom_smem *smem,
unsigned item,
size_t *size)
{
struct smem_header *header;
struct smem_region *area;
struct smem_global_entry *entry;
u32 aux_base;
unsigned i;
if (WARN_ON(item >= SMEM_ITEM_COUNT))
return ERR_PTR(-EINVAL);
header = smem->regions[0].virt_base;
entry = &header->toc[item];
if (!entry->allocated)
return ERR_PTR(-ENXIO);
aux_base = le32_to_cpu(entry->aux_base) & AUX_BASE_MASK;
for (i = 0; i < smem->num_regions; i++) {
area = &smem->regions[i];
if (area->aux_base == aux_base || !aux_base) {
if (size != NULL)
*size = le32_to_cpu(entry->size);
return area->virt_base + le32_to_cpu(entry->offset);
}
}
return ERR_PTR(-ENOENT);
}
static void *qcom_smem_get_private(struct qcom_smem *smem,
unsigned host,
unsigned item,
size_t *size)
{
struct smem_partition_header *phdr;
struct smem_private_entry *e, *end;
phdr = smem->partitions[host];
e = phdr_to_first_private_entry(phdr);
end = phdr_to_last_private_entry(phdr);
while (e < end) {
if (e->canary != SMEM_PRIVATE_CANARY) {
dev_err(smem->dev,
"Found invalid canary in host %d partition\n",
host);
return ERR_PTR(-EINVAL);
}
if (le16_to_cpu(e->item) == item) {
if (size != NULL)
*size = le32_to_cpu(e->size) -
le16_to_cpu(e->padding_data);
return entry_to_item(e);
}
e = private_entry_next(e);
}
return ERR_PTR(-ENOENT);
}
/**
* qcom_smem_get() - resolve ptr of size of a smem item
* @host: the remote processor, or -1
* @item: smem item handle
* @size: pointer to be filled out with size of the item
*
* Looks up smem item and returns pointer to it. Size of smem
* item is returned in @size.
*/
void *qcom_smem_get(unsigned host, unsigned item, size_t *size)
{
unsigned long flags;
int ret;
void *ptr = ERR_PTR(-EPROBE_DEFER);
if (!__smem)
return ptr;
ret = hwspin_lock_timeout_irqsave(__smem->hwlock,
HWSPINLOCK_TIMEOUT,
&flags);
if (ret)
return ERR_PTR(ret);
if (host < SMEM_HOST_COUNT && __smem->partitions[host])
ptr = qcom_smem_get_private(__smem, host, item, size);
else
ptr = qcom_smem_get_global(__smem, item, size);
hwspin_unlock_irqrestore(__smem->hwlock, &flags);
return ptr;
}
EXPORT_SYMBOL(qcom_smem_get);
/**
* qcom_smem_get_free_space() - retrieve amount of free space in a partition
* @host: the remote processor identifying a partition, or -1
*
* To be used by smem clients as a quick way to determine if any new
* allocations has been made.
*/
int qcom_smem_get_free_space(unsigned host)
{
struct smem_partition_header *phdr;
struct smem_header *header;
unsigned ret;
if (!__smem)
return -EPROBE_DEFER;
if (host < SMEM_HOST_COUNT && __smem->partitions[host]) {
phdr = __smem->partitions[host];
ret = le32_to_cpu(phdr->offset_free_cached) -
le32_to_cpu(phdr->offset_free_uncached);
} else {
header = __smem->regions[0].virt_base;
ret = le32_to_cpu(header->available);
}
return ret;
}
EXPORT_SYMBOL(qcom_smem_get_free_space);
static int qcom_smem_get_sbl_version(struct qcom_smem *smem)
{
__le32 *versions;
size_t size;
versions = qcom_smem_get_global(smem, SMEM_ITEM_VERSION, &size);
if (IS_ERR(versions)) {
dev_err(smem->dev, "Unable to read the version item\n");
return -ENOENT;
}
if (size < sizeof(unsigned) * SMEM_MASTER_SBL_VERSION_INDEX) {
dev_err(smem->dev, "Version item is too small\n");
return -EINVAL;
}
return le32_to_cpu(versions[SMEM_MASTER_SBL_VERSION_INDEX]);
}
static int qcom_smem_enumerate_partitions(struct qcom_smem *smem,
unsigned local_host)
{
struct smem_partition_header *header;
struct smem_ptable_entry *entry;
struct smem_ptable *ptable;
unsigned remote_host;
u32 version, host0, host1;
int i;
ptable = smem->regions[0].virt_base + smem->regions[0].size - SZ_4K;
if (memcmp(ptable->magic, SMEM_PTABLE_MAGIC, sizeof(ptable->magic)))
return 0;
version = le32_to_cpu(ptable->version);
if (version != 1) {
dev_err(smem->dev,
"Unsupported partition header version %d\n", version);
return -EINVAL;
}
for (i = 0; i < le32_to_cpu(ptable->num_entries); i++) {
entry = &ptable->entry[i];
host0 = le16_to_cpu(entry->host0);
host1 = le16_to_cpu(entry->host1);
if (host0 != local_host && host1 != local_host)
continue;
if (!le32_to_cpu(entry->offset))
continue;
if (!le32_to_cpu(entry->size))
continue;
if (host0 == local_host)
remote_host = host1;
else
remote_host = host0;
if (remote_host >= SMEM_HOST_COUNT) {
dev_err(smem->dev,
"Invalid remote host %d\n",
remote_host);
return -EINVAL;
}
if (smem->partitions[remote_host]) {
dev_err(smem->dev,
"Already found a partition for host %d\n",
remote_host);
return -EINVAL;
}
header = smem->regions[0].virt_base + le32_to_cpu(entry->offset);
host0 = le16_to_cpu(header->host0);
host1 = le16_to_cpu(header->host1);
if (memcmp(header->magic, SMEM_PART_MAGIC,
sizeof(header->magic))) {
dev_err(smem->dev,
"Partition %d has invalid magic\n", i);
return -EINVAL;
}
if (host0 != local_host && host1 != local_host) {
dev_err(smem->dev,
"Partition %d hosts are invalid\n", i);
return -EINVAL;
}
if (host0 != remote_host && host1 != remote_host) {
dev_err(smem->dev,
"Partition %d hosts are invalid\n", i);
return -EINVAL;
}
if (header->size != entry->size) {
dev_err(smem->dev,
"Partition %d has invalid size\n", i);
return -EINVAL;
}
if (le32_to_cpu(header->offset_free_uncached) > le32_to_cpu(header->size)) {
dev_err(smem->dev,
"Partition %d has invalid free pointer\n", i);
return -EINVAL;
}
smem->partitions[remote_host] = header;
}
return 0;
}
static int qcom_smem_map_memory(struct qcom_smem *smem, struct device *dev,
const char *name, int i)
{
struct device_node *np;
struct resource r;
int ret;
np = of_parse_phandle(dev->of_node, name, 0);
if (!np) {
dev_err(dev, "No %s specified\n", name);
return -EINVAL;
}
ret = of_address_to_resource(np, 0, &r);
of_node_put(np);
if (ret)
return ret;
smem->regions[i].aux_base = (u32)r.start;
smem->regions[i].size = resource_size(&r);
smem->regions[i].virt_base = devm_ioremap_nocache(dev, r.start,
resource_size(&r));
if (!smem->regions[i].virt_base)
return -ENOMEM;
return 0;
}
static int qcom_smem_probe(struct platform_device *pdev)
{
struct smem_header *header;
struct qcom_smem *smem;
size_t array_size;
int num_regions;
int hwlock_id;
u32 version;
int ret;
num_regions = 1;
if (of_find_property(pdev->dev.of_node, "qcom,rpm-msg-ram", NULL))
num_regions++;
array_size = num_regions * sizeof(struct smem_region);
smem = devm_kzalloc(&pdev->dev, sizeof(*smem) + array_size, GFP_KERNEL);
if (!smem)
return -ENOMEM;
smem->dev = &pdev->dev;
smem->num_regions = num_regions;
ret = qcom_smem_map_memory(smem, &pdev->dev, "memory-region", 0);
if (ret)
return ret;
if (num_regions > 1 && (ret = qcom_smem_map_memory(smem, &pdev->dev,
"qcom,rpm-msg-ram", 1)))
return ret;
header = smem->regions[0].virt_base;
if (le32_to_cpu(header->initialized) != 1 ||
le32_to_cpu(header->reserved)) {
dev_err(&pdev->dev, "SMEM is not initialized by SBL\n");
return -EINVAL;
}
version = qcom_smem_get_sbl_version(smem);
if (version >> 16 != SMEM_EXPECTED_VERSION) {
dev_err(&pdev->dev, "Unsupported SMEM version 0x%x\n", version);
return -EINVAL;
}
ret = qcom_smem_enumerate_partitions(smem, SMEM_HOST_APPS);
if (ret < 0)
return ret;
hwlock_id = of_hwspin_lock_get_id(pdev->dev.of_node, 0);
if (hwlock_id < 0) {
dev_err(&pdev->dev, "failed to retrieve hwlock\n");
return hwlock_id;
}
smem->hwlock = hwspin_lock_request_specific(hwlock_id);
if (!smem->hwlock)
return -ENXIO;
__smem = smem;
return 0;
}
static int qcom_smem_remove(struct platform_device *pdev)
{
hwspin_lock_free(__smem->hwlock);
__smem = NULL;
return 0;
}
static const struct of_device_id qcom_smem_of_match[] = {
{ .compatible = "qcom,smem" },
{}
};
MODULE_DEVICE_TABLE(of, qcom_smem_of_match);
static struct platform_driver qcom_smem_driver = {
.probe = qcom_smem_probe,
.remove = qcom_smem_remove,
.driver = {
.name = "qcom-smem",
.of_match_table = qcom_smem_of_match,
.suppress_bind_attrs = true,
},
};
static int __init qcom_smem_init(void)
{
return platform_driver_register(&qcom_smem_driver);
}
arch_initcall(qcom_smem_init);
static void __exit qcom_smem_exit(void)
{
platform_driver_unregister(&qcom_smem_driver);
}
module_exit(qcom_smem_exit)
MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
MODULE_DESCRIPTION("Qualcomm Shared Memory Manager");
MODULE_LICENSE("GPL v2");