diff options
Diffstat (limited to 'kernel/drivers/soc/qcom/smem.c')
| -rw-r--r-- | kernel/drivers/soc/qcom/smem.c | 795 |
1 files changed, 795 insertions, 0 deletions
diff --git a/kernel/drivers/soc/qcom/smem.c b/kernel/drivers/soc/qcom/smem.c new file mode 100644 index 000000000..19019aa09 --- /dev/null +++ b/kernel/drivers/soc/qcom/smem.c @@ -0,0 +1,795 @@ +/* + * 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"); |