| /* |
| * drivers/firmware/qemu_fw_cfg.c |
| * |
| * Copyright 2015 Carnegie Mellon University |
| * |
| * Expose entries from QEMU's firmware configuration (fw_cfg) device in |
| * sysfs (read-only, under "/sys/firmware/qemu_fw_cfg/..."). |
| * |
| * The fw_cfg device may be instantiated via either an ACPI node (on x86 |
| * and select subsets of aarch64), a Device Tree node (on arm), or using |
| * a kernel module (or command line) parameter with the following syntax: |
| * |
| * [qemu_fw_cfg.]ioport=<size>@<base>[:<ctrl_off>:<data_off>[:<dma_off>]] |
| * or |
| * [qemu_fw_cfg.]mmio=<size>@<base>[:<ctrl_off>:<data_off>[:<dma_off>]] |
| * |
| * where: |
| * <size> := size of ioport or mmio range |
| * <base> := physical base address of ioport or mmio range |
| * <ctrl_off> := (optional) offset of control register |
| * <data_off> := (optional) offset of data register |
| * <dma_off> := (optional) offset of dma register |
| * |
| * e.g.: |
| * qemu_fw_cfg.ioport=12@0x510:0:1:4 (the default on x86) |
| * or |
| * qemu_fw_cfg.mmio=16@0x9020000:8:0:16 (the default on arm) |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/mod_devicetable.h> |
| #include <linux/platform_device.h> |
| #include <linux/acpi.h> |
| #include <linux/slab.h> |
| #include <linux/io.h> |
| #include <linux/ioport.h> |
| #include <uapi/linux/qemu_fw_cfg.h> |
| #include <linux/delay.h> |
| #include <linux/crash_dump.h> |
| #include <linux/crash_core.h> |
| |
| MODULE_AUTHOR("Gabriel L. Somlo <somlo@cmu.edu>"); |
| MODULE_DESCRIPTION("QEMU fw_cfg sysfs support"); |
| MODULE_LICENSE("GPL"); |
| |
| /* fw_cfg revision attribute, in /sys/firmware/qemu_fw_cfg top-level dir. */ |
| static u32 fw_cfg_rev; |
| |
| /* fw_cfg device i/o register addresses */ |
| static bool fw_cfg_is_mmio; |
| static phys_addr_t fw_cfg_p_base; |
| static resource_size_t fw_cfg_p_size; |
| static void __iomem *fw_cfg_dev_base; |
| static void __iomem *fw_cfg_reg_ctrl; |
| static void __iomem *fw_cfg_reg_data; |
| static void __iomem *fw_cfg_reg_dma; |
| |
| /* atomic access to fw_cfg device (potentially slow i/o, so using mutex) */ |
| static DEFINE_MUTEX(fw_cfg_dev_lock); |
| |
| /* pick appropriate endianness for selector key */ |
| static void fw_cfg_sel_endianness(u16 key) |
| { |
| if (fw_cfg_is_mmio) |
| iowrite16be(key, fw_cfg_reg_ctrl); |
| else |
| iowrite16(key, fw_cfg_reg_ctrl); |
| } |
| |
| #ifdef CONFIG_CRASH_CORE |
| static inline bool fw_cfg_dma_enabled(void) |
| { |
| return (fw_cfg_rev & FW_CFG_VERSION_DMA) && fw_cfg_reg_dma; |
| } |
| |
| /* qemu fw_cfg device is sync today, but spec says it may become async */ |
| static void fw_cfg_wait_for_control(struct fw_cfg_dma_access *d) |
| { |
| for (;;) { |
| u32 ctrl = be32_to_cpu(READ_ONCE(d->control)); |
| |
| /* do not reorder the read to d->control */ |
| rmb(); |
| if ((ctrl & ~FW_CFG_DMA_CTL_ERROR) == 0) |
| return; |
| |
| cpu_relax(); |
| } |
| } |
| |
| static ssize_t fw_cfg_dma_transfer(void *address, u32 length, u32 control) |
| { |
| phys_addr_t dma; |
| struct fw_cfg_dma_access *d = NULL; |
| ssize_t ret = length; |
| |
| d = kmalloc(sizeof(*d), GFP_KERNEL); |
| if (!d) { |
| ret = -ENOMEM; |
| goto end; |
| } |
| |
| /* fw_cfg device does not need IOMMU protection, so use physical addresses */ |
| *d = (struct fw_cfg_dma_access) { |
| .address = cpu_to_be64(address ? virt_to_phys(address) : 0), |
| .length = cpu_to_be32(length), |
| .control = cpu_to_be32(control) |
| }; |
| |
| dma = virt_to_phys(d); |
| |
| iowrite32be((u64)dma >> 32, fw_cfg_reg_dma); |
| /* force memory to sync before notifying device via MMIO */ |
| wmb(); |
| iowrite32be(dma, fw_cfg_reg_dma + 4); |
| |
| fw_cfg_wait_for_control(d); |
| |
| if (be32_to_cpu(READ_ONCE(d->control)) & FW_CFG_DMA_CTL_ERROR) { |
| ret = -EIO; |
| } |
| |
| end: |
| kfree(d); |
| |
| return ret; |
| } |
| #endif |
| |
| /* read chunk of given fw_cfg blob (caller responsible for sanity-check) */ |
| static ssize_t fw_cfg_read_blob(u16 key, |
| void *buf, loff_t pos, size_t count) |
| { |
| u32 glk = -1U; |
| acpi_status status; |
| |
| /* If we have ACPI, ensure mutual exclusion against any potential |
| * device access by the firmware, e.g. via AML methods: |
| */ |
| status = acpi_acquire_global_lock(ACPI_WAIT_FOREVER, &glk); |
| if (ACPI_FAILURE(status) && status != AE_NOT_CONFIGURED) { |
| /* Should never get here */ |
| WARN(1, "fw_cfg_read_blob: Failed to lock ACPI!\n"); |
| memset(buf, 0, count); |
| return -EINVAL; |
| } |
| |
| mutex_lock(&fw_cfg_dev_lock); |
| fw_cfg_sel_endianness(key); |
| while (pos-- > 0) |
| ioread8(fw_cfg_reg_data); |
| ioread8_rep(fw_cfg_reg_data, buf, count); |
| mutex_unlock(&fw_cfg_dev_lock); |
| |
| acpi_release_global_lock(glk); |
| return count; |
| } |
| |
| #ifdef CONFIG_CRASH_CORE |
| /* write chunk of given fw_cfg blob (caller responsible for sanity-check) */ |
| static ssize_t fw_cfg_write_blob(u16 key, |
| void *buf, loff_t pos, size_t count) |
| { |
| u32 glk = -1U; |
| acpi_status status; |
| ssize_t ret = count; |
| |
| /* If we have ACPI, ensure mutual exclusion against any potential |
| * device access by the firmware, e.g. via AML methods: |
| */ |
| status = acpi_acquire_global_lock(ACPI_WAIT_FOREVER, &glk); |
| if (ACPI_FAILURE(status) && status != AE_NOT_CONFIGURED) { |
| /* Should never get here */ |
| WARN(1, "%s: Failed to lock ACPI!\n", __func__); |
| return -EINVAL; |
| } |
| |
| mutex_lock(&fw_cfg_dev_lock); |
| if (pos == 0) { |
| ret = fw_cfg_dma_transfer(buf, count, key << 16 |
| | FW_CFG_DMA_CTL_SELECT |
| | FW_CFG_DMA_CTL_WRITE); |
| } else { |
| fw_cfg_sel_endianness(key); |
| ret = fw_cfg_dma_transfer(NULL, pos, FW_CFG_DMA_CTL_SKIP); |
| if (ret < 0) |
| goto end; |
| ret = fw_cfg_dma_transfer(buf, count, FW_CFG_DMA_CTL_WRITE); |
| } |
| |
| end: |
| mutex_unlock(&fw_cfg_dev_lock); |
| |
| acpi_release_global_lock(glk); |
| |
| return ret; |
| } |
| #endif /* CONFIG_CRASH_CORE */ |
| |
| /* clean up fw_cfg device i/o */ |
| static void fw_cfg_io_cleanup(void) |
| { |
| if (fw_cfg_is_mmio) { |
| iounmap(fw_cfg_dev_base); |
| release_mem_region(fw_cfg_p_base, fw_cfg_p_size); |
| } else { |
| ioport_unmap(fw_cfg_dev_base); |
| release_region(fw_cfg_p_base, fw_cfg_p_size); |
| } |
| } |
| |
| /* arch-specific ctrl & data register offsets are not available in ACPI, DT */ |
| #if !(defined(FW_CFG_CTRL_OFF) && defined(FW_CFG_DATA_OFF)) |
| # if (defined(CONFIG_ARM) || defined(CONFIG_ARM64)) |
| # define FW_CFG_CTRL_OFF 0x08 |
| # define FW_CFG_DATA_OFF 0x00 |
| # define FW_CFG_DMA_OFF 0x10 |
| # elif (defined(CONFIG_PPC_PMAC) || defined(CONFIG_SPARC32)) /* ppc/mac,sun4m */ |
| # define FW_CFG_CTRL_OFF 0x00 |
| # define FW_CFG_DATA_OFF 0x02 |
| # elif (defined(CONFIG_X86) || defined(CONFIG_SPARC64)) /* x86, sun4u */ |
| # define FW_CFG_CTRL_OFF 0x00 |
| # define FW_CFG_DATA_OFF 0x01 |
| # define FW_CFG_DMA_OFF 0x04 |
| # else |
| # error "QEMU FW_CFG not available on this architecture!" |
| # endif |
| #endif |
| |
| /* initialize fw_cfg device i/o from platform data */ |
| static int fw_cfg_do_platform_probe(struct platform_device *pdev) |
| { |
| char sig[FW_CFG_SIG_SIZE]; |
| struct resource *range, *ctrl, *data, *dma; |
| |
| /* acquire i/o range details */ |
| fw_cfg_is_mmio = false; |
| range = platform_get_resource(pdev, IORESOURCE_IO, 0); |
| if (!range) { |
| fw_cfg_is_mmio = true; |
| range = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| if (!range) |
| return -EINVAL; |
| } |
| fw_cfg_p_base = range->start; |
| fw_cfg_p_size = resource_size(range); |
| |
| if (fw_cfg_is_mmio) { |
| if (!request_mem_region(fw_cfg_p_base, |
| fw_cfg_p_size, "fw_cfg_mem")) |
| return -EBUSY; |
| fw_cfg_dev_base = ioremap(fw_cfg_p_base, fw_cfg_p_size); |
| if (!fw_cfg_dev_base) { |
| release_mem_region(fw_cfg_p_base, fw_cfg_p_size); |
| return -EFAULT; |
| } |
| } else { |
| if (!request_region(fw_cfg_p_base, |
| fw_cfg_p_size, "fw_cfg_io")) |
| return -EBUSY; |
| fw_cfg_dev_base = ioport_map(fw_cfg_p_base, fw_cfg_p_size); |
| if (!fw_cfg_dev_base) { |
| release_region(fw_cfg_p_base, fw_cfg_p_size); |
| return -EFAULT; |
| } |
| } |
| |
| /* were custom register offsets provided (e.g. on the command line)? */ |
| ctrl = platform_get_resource_byname(pdev, IORESOURCE_REG, "ctrl"); |
| data = platform_get_resource_byname(pdev, IORESOURCE_REG, "data"); |
| dma = platform_get_resource_byname(pdev, IORESOURCE_REG, "dma"); |
| if (ctrl && data) { |
| fw_cfg_reg_ctrl = fw_cfg_dev_base + ctrl->start; |
| fw_cfg_reg_data = fw_cfg_dev_base + data->start; |
| } else { |
| /* use architecture-specific offsets */ |
| fw_cfg_reg_ctrl = fw_cfg_dev_base + FW_CFG_CTRL_OFF; |
| fw_cfg_reg_data = fw_cfg_dev_base + FW_CFG_DATA_OFF; |
| } |
| |
| if (dma) |
| fw_cfg_reg_dma = fw_cfg_dev_base + dma->start; |
| #ifdef FW_CFG_DMA_OFF |
| else |
| fw_cfg_reg_dma = fw_cfg_dev_base + FW_CFG_DMA_OFF; |
| #endif |
| |
| /* verify fw_cfg device signature */ |
| if (fw_cfg_read_blob(FW_CFG_SIGNATURE, sig, |
| 0, FW_CFG_SIG_SIZE) < 0 || |
| memcmp(sig, "QEMU", FW_CFG_SIG_SIZE) != 0) { |
| fw_cfg_io_cleanup(); |
| return -ENODEV; |
| } |
| |
| return 0; |
| } |
| |
| static ssize_t fw_cfg_showrev(struct kobject *k, struct kobj_attribute *a, |
| char *buf) |
| { |
| return sprintf(buf, "%u\n", fw_cfg_rev); |
| } |
| |
| static const struct kobj_attribute fw_cfg_rev_attr = { |
| .attr = { .name = "rev", .mode = S_IRUSR }, |
| .show = fw_cfg_showrev, |
| }; |
| |
| /* fw_cfg_sysfs_entry type */ |
| struct fw_cfg_sysfs_entry { |
| struct kobject kobj; |
| u32 size; |
| u16 select; |
| char name[FW_CFG_MAX_FILE_PATH]; |
| struct list_head list; |
| }; |
| |
| #ifdef CONFIG_CRASH_CORE |
| static ssize_t fw_cfg_write_vmcoreinfo(const struct fw_cfg_file *f) |
| { |
| static struct fw_cfg_vmcoreinfo *data; |
| ssize_t ret; |
| |
| data = kmalloc(sizeof(struct fw_cfg_vmcoreinfo), GFP_KERNEL); |
| if (!data) |
| return -ENOMEM; |
| |
| *data = (struct fw_cfg_vmcoreinfo) { |
| .guest_format = cpu_to_le16(FW_CFG_VMCOREINFO_FORMAT_ELF), |
| .size = cpu_to_le32(VMCOREINFO_NOTE_SIZE), |
| .paddr = cpu_to_le64(paddr_vmcoreinfo_note()) |
| }; |
| /* spare ourself reading host format support for now since we |
| * don't know what else to format - host may ignore ours |
| */ |
| ret = fw_cfg_write_blob(be16_to_cpu(f->select), data, |
| 0, sizeof(struct fw_cfg_vmcoreinfo)); |
| |
| kfree(data); |
| return ret; |
| } |
| #endif /* CONFIG_CRASH_CORE */ |
| |
| /* get fw_cfg_sysfs_entry from kobject member */ |
| static inline struct fw_cfg_sysfs_entry *to_entry(struct kobject *kobj) |
| { |
| return container_of(kobj, struct fw_cfg_sysfs_entry, kobj); |
| } |
| |
| /* fw_cfg_sysfs_attribute type */ |
| struct fw_cfg_sysfs_attribute { |
| struct attribute attr; |
| ssize_t (*show)(struct fw_cfg_sysfs_entry *entry, char *buf); |
| }; |
| |
| /* get fw_cfg_sysfs_attribute from attribute member */ |
| static inline struct fw_cfg_sysfs_attribute *to_attr(struct attribute *attr) |
| { |
| return container_of(attr, struct fw_cfg_sysfs_attribute, attr); |
| } |
| |
| /* global cache of fw_cfg_sysfs_entry objects */ |
| static LIST_HEAD(fw_cfg_entry_cache); |
| |
| /* kobjects removed lazily by kernel, mutual exclusion needed */ |
| static DEFINE_SPINLOCK(fw_cfg_cache_lock); |
| |
| static inline void fw_cfg_sysfs_cache_enlist(struct fw_cfg_sysfs_entry *entry) |
| { |
| spin_lock(&fw_cfg_cache_lock); |
| list_add_tail(&entry->list, &fw_cfg_entry_cache); |
| spin_unlock(&fw_cfg_cache_lock); |
| } |
| |
| static inline void fw_cfg_sysfs_cache_delist(struct fw_cfg_sysfs_entry *entry) |
| { |
| spin_lock(&fw_cfg_cache_lock); |
| list_del(&entry->list); |
| spin_unlock(&fw_cfg_cache_lock); |
| } |
| |
| static void fw_cfg_sysfs_cache_cleanup(void) |
| { |
| struct fw_cfg_sysfs_entry *entry, *next; |
| |
| list_for_each_entry_safe(entry, next, &fw_cfg_entry_cache, list) { |
| /* will end up invoking fw_cfg_sysfs_cache_delist() |
| * via each object's release() method (i.e. destructor) |
| */ |
| kobject_put(&entry->kobj); |
| } |
| } |
| |
| /* default_attrs: per-entry attributes and show methods */ |
| |
| #define FW_CFG_SYSFS_ATTR(_attr) \ |
| struct fw_cfg_sysfs_attribute fw_cfg_sysfs_attr_##_attr = { \ |
| .attr = { .name = __stringify(_attr), .mode = S_IRUSR }, \ |
| .show = fw_cfg_sysfs_show_##_attr, \ |
| } |
| |
| static ssize_t fw_cfg_sysfs_show_size(struct fw_cfg_sysfs_entry *e, char *buf) |
| { |
| return sprintf(buf, "%u\n", e->size); |
| } |
| |
| static ssize_t fw_cfg_sysfs_show_key(struct fw_cfg_sysfs_entry *e, char *buf) |
| { |
| return sprintf(buf, "%u\n", e->select); |
| } |
| |
| static ssize_t fw_cfg_sysfs_show_name(struct fw_cfg_sysfs_entry *e, char *buf) |
| { |
| return sprintf(buf, "%s\n", e->name); |
| } |
| |
| static FW_CFG_SYSFS_ATTR(size); |
| static FW_CFG_SYSFS_ATTR(key); |
| static FW_CFG_SYSFS_ATTR(name); |
| |
| static struct attribute *fw_cfg_sysfs_entry_attrs[] = { |
| &fw_cfg_sysfs_attr_size.attr, |
| &fw_cfg_sysfs_attr_key.attr, |
| &fw_cfg_sysfs_attr_name.attr, |
| NULL, |
| }; |
| |
| /* sysfs_ops: find fw_cfg_[entry, attribute] and call appropriate show method */ |
| static ssize_t fw_cfg_sysfs_attr_show(struct kobject *kobj, struct attribute *a, |
| char *buf) |
| { |
| struct fw_cfg_sysfs_entry *entry = to_entry(kobj); |
| struct fw_cfg_sysfs_attribute *attr = to_attr(a); |
| |
| return attr->show(entry, buf); |
| } |
| |
| static const struct sysfs_ops fw_cfg_sysfs_attr_ops = { |
| .show = fw_cfg_sysfs_attr_show, |
| }; |
| |
| /* release: destructor, to be called via kobject_put() */ |
| static void fw_cfg_sysfs_release_entry(struct kobject *kobj) |
| { |
| struct fw_cfg_sysfs_entry *entry = to_entry(kobj); |
| |
| fw_cfg_sysfs_cache_delist(entry); |
| kfree(entry); |
| } |
| |
| /* kobj_type: ties together all properties required to register an entry */ |
| static struct kobj_type fw_cfg_sysfs_entry_ktype = { |
| .default_attrs = fw_cfg_sysfs_entry_attrs, |
| .sysfs_ops = &fw_cfg_sysfs_attr_ops, |
| .release = fw_cfg_sysfs_release_entry, |
| }; |
| |
| /* raw-read method and attribute */ |
| static ssize_t fw_cfg_sysfs_read_raw(struct file *filp, struct kobject *kobj, |
| struct bin_attribute *bin_attr, |
| char *buf, loff_t pos, size_t count) |
| { |
| struct fw_cfg_sysfs_entry *entry = to_entry(kobj); |
| |
| if (pos > entry->size) |
| return -EINVAL; |
| |
| if (count > entry->size - pos) |
| count = entry->size - pos; |
| |
| return fw_cfg_read_blob(entry->select, buf, pos, count); |
| } |
| |
| static struct bin_attribute fw_cfg_sysfs_attr_raw = { |
| .attr = { .name = "raw", .mode = S_IRUSR }, |
| .read = fw_cfg_sysfs_read_raw, |
| }; |
| |
| /* |
| * Create a kset subdirectory matching each '/' delimited dirname token |
| * in 'name', starting with sysfs kset/folder 'dir'; At the end, create |
| * a symlink directed at the given 'target'. |
| * NOTE: We do this on a best-effort basis, since 'name' is not guaranteed |
| * to be a well-behaved path name. Whenever a symlink vs. kset directory |
| * name collision occurs, the kernel will issue big scary warnings while |
| * refusing to add the offending link or directory. We follow up with our |
| * own, slightly less scary error messages explaining the situation :) |
| */ |
| static int fw_cfg_build_symlink(struct kset *dir, |
| struct kobject *target, const char *name) |
| { |
| int ret; |
| struct kset *subdir; |
| struct kobject *ko; |
| char *name_copy, *p, *tok; |
| |
| if (!dir || !target || !name || !*name) |
| return -EINVAL; |
| |
| /* clone a copy of name for parsing */ |
| name_copy = p = kstrdup(name, GFP_KERNEL); |
| if (!name_copy) |
| return -ENOMEM; |
| |
| /* create folders for each dirname token, then symlink for basename */ |
| while ((tok = strsep(&p, "/")) && *tok) { |
| |
| /* last (basename) token? If so, add symlink here */ |
| if (!p || !*p) { |
| ret = sysfs_create_link(&dir->kobj, target, tok); |
| break; |
| } |
| |
| /* does the current dir contain an item named after tok ? */ |
| ko = kset_find_obj(dir, tok); |
| if (ko) { |
| /* drop reference added by kset_find_obj */ |
| kobject_put(ko); |
| |
| /* ko MUST be a kset - we're about to use it as one ! */ |
| if (ko->ktype != dir->kobj.ktype) { |
| ret = -EINVAL; |
| break; |
| } |
| |
| /* descend into already existing subdirectory */ |
| dir = to_kset(ko); |
| } else { |
| /* create new subdirectory kset */ |
| subdir = kzalloc(sizeof(struct kset), GFP_KERNEL); |
| if (!subdir) { |
| ret = -ENOMEM; |
| break; |
| } |
| subdir->kobj.kset = dir; |
| subdir->kobj.ktype = dir->kobj.ktype; |
| ret = kobject_set_name(&subdir->kobj, "%s", tok); |
| if (ret) { |
| kfree(subdir); |
| break; |
| } |
| ret = kset_register(subdir); |
| if (ret) { |
| kfree(subdir); |
| break; |
| } |
| |
| /* descend into newly created subdirectory */ |
| dir = subdir; |
| } |
| } |
| |
| /* we're done with cloned copy of name */ |
| kfree(name_copy); |
| return ret; |
| } |
| |
| /* recursively unregister fw_cfg/by_name/ kset directory tree */ |
| static void fw_cfg_kset_unregister_recursive(struct kset *kset) |
| { |
| struct kobject *k, *next; |
| |
| list_for_each_entry_safe(k, next, &kset->list, entry) |
| /* all set members are ksets too, but check just in case... */ |
| if (k->ktype == kset->kobj.ktype) |
| fw_cfg_kset_unregister_recursive(to_kset(k)); |
| |
| /* symlinks are cleanly and automatically removed with the directory */ |
| kset_unregister(kset); |
| } |
| |
| /* kobjects & kset representing top-level, by_key, and by_name folders */ |
| static struct kobject *fw_cfg_top_ko; |
| static struct kobject *fw_cfg_sel_ko; |
| static struct kset *fw_cfg_fname_kset; |
| |
| /* register an individual fw_cfg file */ |
| static int fw_cfg_register_file(const struct fw_cfg_file *f) |
| { |
| int err; |
| struct fw_cfg_sysfs_entry *entry; |
| |
| #ifdef CONFIG_CRASH_CORE |
| if (fw_cfg_dma_enabled() && |
| strcmp(f->name, FW_CFG_VMCOREINFO_FILENAME) == 0 && |
| !is_kdump_kernel()) { |
| if (fw_cfg_write_vmcoreinfo(f) < 0) |
| pr_warn("fw_cfg: failed to write vmcoreinfo"); |
| } |
| #endif |
| |
| /* allocate new entry */ |
| entry = kzalloc(sizeof(*entry), GFP_KERNEL); |
| if (!entry) |
| return -ENOMEM; |
| |
| /* set file entry information */ |
| entry->size = be32_to_cpu(f->size); |
| entry->select = be16_to_cpu(f->select); |
| memcpy(entry->name, f->name, FW_CFG_MAX_FILE_PATH); |
| |
| /* register entry under "/sys/firmware/qemu_fw_cfg/by_key/" */ |
| err = kobject_init_and_add(&entry->kobj, &fw_cfg_sysfs_entry_ktype, |
| fw_cfg_sel_ko, "%d", entry->select); |
| if (err) { |
| kobject_put(&entry->kobj); |
| return err; |
| } |
| |
| /* add raw binary content access */ |
| err = sysfs_create_bin_file(&entry->kobj, &fw_cfg_sysfs_attr_raw); |
| if (err) |
| goto err_add_raw; |
| |
| /* try adding "/sys/firmware/qemu_fw_cfg/by_name/" symlink */ |
| fw_cfg_build_symlink(fw_cfg_fname_kset, &entry->kobj, entry->name); |
| |
| /* success, add entry to global cache */ |
| fw_cfg_sysfs_cache_enlist(entry); |
| return 0; |
| |
| err_add_raw: |
| kobject_del(&entry->kobj); |
| kfree(entry); |
| return err; |
| } |
| |
| /* iterate over all fw_cfg directory entries, registering each one */ |
| static int fw_cfg_register_dir_entries(void) |
| { |
| int ret = 0; |
| __be32 files_count; |
| u32 count, i; |
| struct fw_cfg_file *dir; |
| size_t dir_size; |
| |
| ret = fw_cfg_read_blob(FW_CFG_FILE_DIR, &files_count, |
| 0, sizeof(files_count)); |
| if (ret < 0) |
| return ret; |
| |
| count = be32_to_cpu(files_count); |
| dir_size = count * sizeof(struct fw_cfg_file); |
| |
| dir = kmalloc(dir_size, GFP_KERNEL); |
| if (!dir) |
| return -ENOMEM; |
| |
| ret = fw_cfg_read_blob(FW_CFG_FILE_DIR, dir, |
| sizeof(files_count), dir_size); |
| if (ret < 0) |
| goto end; |
| |
| for (i = 0; i < count; i++) { |
| ret = fw_cfg_register_file(&dir[i]); |
| if (ret) |
| break; |
| } |
| |
| end: |
| kfree(dir); |
| return ret; |
| } |
| |
| /* unregister top-level or by_key folder */ |
| static inline void fw_cfg_kobj_cleanup(struct kobject *kobj) |
| { |
| kobject_del(kobj); |
| kobject_put(kobj); |
| } |
| |
| static int fw_cfg_sysfs_probe(struct platform_device *pdev) |
| { |
| int err; |
| __le32 rev; |
| |
| /* NOTE: If we supported multiple fw_cfg devices, we'd first create |
| * a subdirectory named after e.g. pdev->id, then hang per-device |
| * by_key (and by_name) subdirectories underneath it. However, only |
| * one fw_cfg device exist system-wide, so if one was already found |
| * earlier, we might as well stop here. |
| */ |
| if (fw_cfg_sel_ko) |
| return -EBUSY; |
| |
| /* create by_key and by_name subdirs of /sys/firmware/qemu_fw_cfg/ */ |
| err = -ENOMEM; |
| fw_cfg_sel_ko = kobject_create_and_add("by_key", fw_cfg_top_ko); |
| if (!fw_cfg_sel_ko) |
| goto err_sel; |
| fw_cfg_fname_kset = kset_create_and_add("by_name", NULL, fw_cfg_top_ko); |
| if (!fw_cfg_fname_kset) |
| goto err_name; |
| |
| /* initialize fw_cfg device i/o from platform data */ |
| err = fw_cfg_do_platform_probe(pdev); |
| if (err) |
| goto err_probe; |
| |
| /* get revision number, add matching top-level attribute */ |
| err = fw_cfg_read_blob(FW_CFG_ID, &rev, 0, sizeof(rev)); |
| if (err < 0) |
| goto err_probe; |
| |
| fw_cfg_rev = le32_to_cpu(rev); |
| err = sysfs_create_file(fw_cfg_top_ko, &fw_cfg_rev_attr.attr); |
| if (err) |
| goto err_rev; |
| |
| /* process fw_cfg file directory entry, registering each file */ |
| err = fw_cfg_register_dir_entries(); |
| if (err) |
| goto err_dir; |
| |
| /* success */ |
| pr_debug("fw_cfg: loaded.\n"); |
| return 0; |
| |
| err_dir: |
| fw_cfg_sysfs_cache_cleanup(); |
| sysfs_remove_file(fw_cfg_top_ko, &fw_cfg_rev_attr.attr); |
| err_rev: |
| fw_cfg_io_cleanup(); |
| err_probe: |
| fw_cfg_kset_unregister_recursive(fw_cfg_fname_kset); |
| err_name: |
| fw_cfg_kobj_cleanup(fw_cfg_sel_ko); |
| err_sel: |
| return err; |
| } |
| |
| static int fw_cfg_sysfs_remove(struct platform_device *pdev) |
| { |
| pr_debug("fw_cfg: unloading.\n"); |
| fw_cfg_sysfs_cache_cleanup(); |
| sysfs_remove_file(fw_cfg_top_ko, &fw_cfg_rev_attr.attr); |
| fw_cfg_io_cleanup(); |
| fw_cfg_kset_unregister_recursive(fw_cfg_fname_kset); |
| fw_cfg_kobj_cleanup(fw_cfg_sel_ko); |
| return 0; |
| } |
| |
| static const struct of_device_id fw_cfg_sysfs_mmio_match[] = { |
| { .compatible = "qemu,fw-cfg-mmio", }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, fw_cfg_sysfs_mmio_match); |
| |
| #ifdef CONFIG_ACPI |
| static const struct acpi_device_id fw_cfg_sysfs_acpi_match[] = { |
| { FW_CFG_ACPI_DEVICE_ID, }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(acpi, fw_cfg_sysfs_acpi_match); |
| #endif |
| |
| static struct platform_driver fw_cfg_sysfs_driver = { |
| .probe = fw_cfg_sysfs_probe, |
| .remove = fw_cfg_sysfs_remove, |
| .driver = { |
| .name = "fw_cfg", |
| .of_match_table = fw_cfg_sysfs_mmio_match, |
| .acpi_match_table = ACPI_PTR(fw_cfg_sysfs_acpi_match), |
| }, |
| }; |
| |
| #ifdef CONFIG_FW_CFG_SYSFS_CMDLINE |
| |
| static struct platform_device *fw_cfg_cmdline_dev; |
| |
| /* this probably belongs in e.g. include/linux/types.h, |
| * but right now we are the only ones doing it... |
| */ |
| #ifdef CONFIG_PHYS_ADDR_T_64BIT |
| #define __PHYS_ADDR_PREFIX "ll" |
| #else |
| #define __PHYS_ADDR_PREFIX "" |
| #endif |
| |
| /* use special scanf/printf modifier for phys_addr_t, resource_size_t */ |
| #define PH_ADDR_SCAN_FMT "@%" __PHYS_ADDR_PREFIX "i%n" \ |
| ":%" __PHYS_ADDR_PREFIX "i" \ |
| ":%" __PHYS_ADDR_PREFIX "i%n" \ |
| ":%" __PHYS_ADDR_PREFIX "i%n" |
| |
| #define PH_ADDR_PR_1_FMT "0x%" __PHYS_ADDR_PREFIX "x@" \ |
| "0x%" __PHYS_ADDR_PREFIX "x" |
| |
| #define PH_ADDR_PR_3_FMT PH_ADDR_PR_1_FMT \ |
| ":%" __PHYS_ADDR_PREFIX "u" \ |
| ":%" __PHYS_ADDR_PREFIX "u" |
| |
| #define PH_ADDR_PR_4_FMT PH_ADDR_PR_3_FMT \ |
| ":%" __PHYS_ADDR_PREFIX "u" |
| |
| static int fw_cfg_cmdline_set(const char *arg, const struct kernel_param *kp) |
| { |
| struct resource res[4] = {}; |
| char *str; |
| phys_addr_t base; |
| resource_size_t size, ctrl_off, data_off, dma_off; |
| int processed, consumed = 0; |
| |
| /* only one fw_cfg device can exist system-wide, so if one |
| * was processed on the command line already, we might as |
| * well stop here. |
| */ |
| if (fw_cfg_cmdline_dev) { |
| /* avoid leaking previously registered device */ |
| platform_device_unregister(fw_cfg_cmdline_dev); |
| return -EINVAL; |
| } |
| |
| /* consume "<size>" portion of command line argument */ |
| size = memparse(arg, &str); |
| |
| /* get "@<base>[:<ctrl_off>:<data_off>[:<dma_off>]]" chunks */ |
| processed = sscanf(str, PH_ADDR_SCAN_FMT, |
| &base, &consumed, |
| &ctrl_off, &data_off, &consumed, |
| &dma_off, &consumed); |
| |
| /* sscanf() must process precisely 1, 3 or 4 chunks: |
| * <base> is mandatory, optionally followed by <ctrl_off> |
| * and <data_off>, and <dma_off>; |
| * there must be no extra characters after the last chunk, |
| * so str[consumed] must be '\0'. |
| */ |
| if (str[consumed] || |
| (processed != 1 && processed != 3 && processed != 4)) |
| return -EINVAL; |
| |
| res[0].start = base; |
| res[0].end = base + size - 1; |
| res[0].flags = !strcmp(kp->name, "mmio") ? IORESOURCE_MEM : |
| IORESOURCE_IO; |
| |
| /* insert register offsets, if provided */ |
| if (processed > 1) { |
| res[1].name = "ctrl"; |
| res[1].start = ctrl_off; |
| res[1].flags = IORESOURCE_REG; |
| res[2].name = "data"; |
| res[2].start = data_off; |
| res[2].flags = IORESOURCE_REG; |
| } |
| if (processed > 3) { |
| res[3].name = "dma"; |
| res[3].start = dma_off; |
| res[3].flags = IORESOURCE_REG; |
| } |
| |
| /* "processed" happens to nicely match the number of resources |
| * we need to pass in to this platform device. |
| */ |
| fw_cfg_cmdline_dev = platform_device_register_simple("fw_cfg", |
| PLATFORM_DEVID_NONE, res, processed); |
| |
| return PTR_ERR_OR_ZERO(fw_cfg_cmdline_dev); |
| } |
| |
| static int fw_cfg_cmdline_get(char *buf, const struct kernel_param *kp) |
| { |
| /* stay silent if device was not configured via the command |
| * line, or if the parameter name (ioport/mmio) doesn't match |
| * the device setting |
| */ |
| if (!fw_cfg_cmdline_dev || |
| (!strcmp(kp->name, "mmio") ^ |
| (fw_cfg_cmdline_dev->resource[0].flags == IORESOURCE_MEM))) |
| return 0; |
| |
| switch (fw_cfg_cmdline_dev->num_resources) { |
| case 1: |
| return snprintf(buf, PAGE_SIZE, PH_ADDR_PR_1_FMT, |
| resource_size(&fw_cfg_cmdline_dev->resource[0]), |
| fw_cfg_cmdline_dev->resource[0].start); |
| case 3: |
| return snprintf(buf, PAGE_SIZE, PH_ADDR_PR_3_FMT, |
| resource_size(&fw_cfg_cmdline_dev->resource[0]), |
| fw_cfg_cmdline_dev->resource[0].start, |
| fw_cfg_cmdline_dev->resource[1].start, |
| fw_cfg_cmdline_dev->resource[2].start); |
| case 4: |
| return snprintf(buf, PAGE_SIZE, PH_ADDR_PR_4_FMT, |
| resource_size(&fw_cfg_cmdline_dev->resource[0]), |
| fw_cfg_cmdline_dev->resource[0].start, |
| fw_cfg_cmdline_dev->resource[1].start, |
| fw_cfg_cmdline_dev->resource[2].start, |
| fw_cfg_cmdline_dev->resource[3].start); |
| } |
| |
| /* Should never get here */ |
| WARN(1, "Unexpected number of resources: %d\n", |
| fw_cfg_cmdline_dev->num_resources); |
| return 0; |
| } |
| |
| static const struct kernel_param_ops fw_cfg_cmdline_param_ops = { |
| .set = fw_cfg_cmdline_set, |
| .get = fw_cfg_cmdline_get, |
| }; |
| |
| device_param_cb(ioport, &fw_cfg_cmdline_param_ops, NULL, S_IRUSR); |
| device_param_cb(mmio, &fw_cfg_cmdline_param_ops, NULL, S_IRUSR); |
| |
| #endif /* CONFIG_FW_CFG_SYSFS_CMDLINE */ |
| |
| static int __init fw_cfg_sysfs_init(void) |
| { |
| int ret; |
| |
| /* create /sys/firmware/qemu_fw_cfg/ top level directory */ |
| fw_cfg_top_ko = kobject_create_and_add("qemu_fw_cfg", firmware_kobj); |
| if (!fw_cfg_top_ko) |
| return -ENOMEM; |
| |
| ret = platform_driver_register(&fw_cfg_sysfs_driver); |
| if (ret) |
| fw_cfg_kobj_cleanup(fw_cfg_top_ko); |
| |
| return ret; |
| } |
| |
| static void __exit fw_cfg_sysfs_exit(void) |
| { |
| platform_driver_unregister(&fw_cfg_sysfs_driver); |
| |
| #ifdef CONFIG_FW_CFG_SYSFS_CMDLINE |
| platform_device_unregister(fw_cfg_cmdline_dev); |
| #endif |
| |
| /* clean up /sys/firmware/qemu_fw_cfg/ */ |
| fw_cfg_kobj_cleanup(fw_cfg_top_ko); |
| } |
| |
| module_init(fw_cfg_sysfs_init); |
| module_exit(fw_cfg_sysfs_exit); |