/* * 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 #include #include #include #include #include #include #include /* * 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_wc(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) { if (hwlock_id != -EPROBE_DEFER) 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 "); MODULE_DESCRIPTION("Qualcomm Shared Memory Manager"); MODULE_LICENSE("GPL v2");