| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Gabriel Somlo | 2769 | 75.04% | 4 | 22.22% |
| Marc-André Lureau | 896 | 24.28% | 9 | 50.00% |
| Michael S. Tsirkin | 17 | 0.46% | 1 | 5.56% |
| Dan Carpenter | 3 | 0.08% | 1 | 5.56% |
| Arnd Bergmann | 3 | 0.08% | 1 | 5.56% |
| Valentin Rothberg | 1 | 0.03% | 1 | 5.56% |
| Vasyl Gomonovych | 1 | 0.03% | 1 | 5.56% |
| Total | 3690 | 18 |
/* * 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 attribute *a, char *buf) { return sprintf(buf, "%u\n", fw_cfg_rev); } static const struct { struct attribute attr; ssize_t (*show)(struct kobject *k, struct attribute *a, char *buf); } 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) goto err_register; /* 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); err_register: 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);
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