Merge tag 'driver-core-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Just a few patches this time around for the 4.6-rc1 merge window.
Largest is a new firmware driver, but there are some other updates to
the driver core in here as well, the shortlog has the details.
All have been in linux-next for a while with no reported issues"
* tag 'driver-core-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
Revert "driver-core: platform: probe of-devices only using list of compatibles"
firmware: qemu config needs I/O ports
firmware: qemu_fw_cfg.c: fix typo FW_CFG_DATA_OFF
driver-core: platform: probe of-devices only using list of compatibles
driver-core: platform: fix typo in documentation for multi-driver helper
component: remove impossible condition
drivers: dma-coherent: simplify dma_init_coherent_memory return value
devicetree: update documentation for fw_cfg ARM bindings
firmware: create directory hierarchy for sysfs fw_cfg entries
firmware: introduce sysfs driver for QEMU's fw_cfg device
kobject: export kset_find_obj() for module use
driver core: bus: use to_subsys_private and to_device_private_bus
driver core: bus: use list_for_each_entry*
debugfs: Add stub function for debugfs_create_automount().
kernfs: make kernfs_walk_ns() use kernfs_pr_cont_buf[]
diff --git a/Documentation/ABI/testing/sysfs-firmware-qemu_fw_cfg b/Documentation/ABI/testing/sysfs-firmware-qemu_fw_cfg
new file mode 100644
index 0000000..011dda4
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-firmware-qemu_fw_cfg
@@ -0,0 +1,100 @@
+What: /sys/firmware/qemu_fw_cfg/
+Date: August 2015
+Contact: Gabriel Somlo <somlo@cmu.edu>
+Description:
+ Several different architectures supported by QEMU (x86, arm,
+ sun4*, ppc/mac) are provisioned with a firmware configuration
+ (fw_cfg) device, originally intended as a way for the host to
+ provide configuration data to the guest firmware. Starting
+ with QEMU v2.4, arbitrary fw_cfg file entries may be specified
+ by the user on the command line, which makes fw_cfg additionally
+ useful as an out-of-band, asynchronous mechanism for providing
+ configuration data to the guest userspace.
+
+ The authoritative guest-side hardware interface documentation
+ to the fw_cfg device can be found in "docs/specs/fw_cfg.txt"
+ in the QEMU source tree.
+
+ === SysFS fw_cfg Interface ===
+
+ The fw_cfg sysfs interface described in this document is only
+ intended to display discoverable blobs (i.e., those registered
+ with the file directory), as there is no way to determine the
+ presence or size of "legacy" blobs (with selector keys between
+ 0x0002 and 0x0018) programmatically.
+
+ All fw_cfg information is shown under:
+
+ /sys/firmware/qemu_fw_cfg/
+
+ The only legacy blob displayed is the fw_cfg device revision:
+
+ /sys/firmware/qemu_fw_cfg/rev
+
+ --- Discoverable fw_cfg blobs by selector key ---
+
+ All discoverable blobs listed in the fw_cfg file directory are
+ displayed as entries named after their unique selector key
+ value, e.g.:
+
+ /sys/firmware/qemu_fw_cfg/by_key/32
+ /sys/firmware/qemu_fw_cfg/by_key/33
+ /sys/firmware/qemu_fw_cfg/by_key/34
+ ...
+
+ Each such fw_cfg sysfs entry has the following values exported
+ as attributes:
+
+ name : The 56-byte nul-terminated ASCII string used as the
+ blob's 'file name' in the fw_cfg directory.
+ size : The length of the blob, as given in the fw_cfg
+ directory.
+ key : The value of the blob's selector key as given in the
+ fw_cfg directory. This value is the same as used in
+ the parent directory name.
+ raw : The raw bytes of the blob, obtained by selecting the
+ entry via the control register, and reading a number
+ of bytes equal to the blob size from the data
+ register.
+
+ --- Listing fw_cfg blobs by file name ---
+
+ While the fw_cfg device does not impose any specific naming
+ convention on the blobs registered in the file directory,
+ QEMU developers have traditionally used path name semantics
+ to give each blob a descriptive name. For example:
+
+ "bootorder"
+ "genroms/kvmvapic.bin"
+ "etc/e820"
+ "etc/boot-fail-wait"
+ "etc/system-states"
+ "etc/table-loader"
+ "etc/acpi/rsdp"
+ "etc/acpi/tables"
+ "etc/smbios/smbios-tables"
+ "etc/smbios/smbios-anchor"
+ ...
+
+ In addition to the listing by unique selector key described
+ above, the fw_cfg sysfs driver also attempts to build a tree
+ of directories matching the path name components of fw_cfg
+ blob names, ending in symlinks to the by_key entry for each
+ "basename", as illustrated below (assume current directory is
+ /sys/firmware):
+
+ qemu_fw_cfg/by_name/bootorder -> ../by_key/38
+ qemu_fw_cfg/by_name/etc/e820 -> ../../by_key/35
+ qemu_fw_cfg/by_name/etc/acpi/rsdp -> ../../../by_key/41
+ ...
+
+ Construction of the directory tree and symlinks is done on a
+ "best-effort" basis, as there is no guarantee that components
+ of fw_cfg blob names are always "well behaved". I.e., there is
+ the possibility that a symlink (basename) will conflict with
+ a dirname component of another fw_cfg blob, in which case the
+ creation of the offending /sys/firmware/qemu_fw_cfg/by_name
+ entry will be skipped.
+
+ The authoritative list of entries will continue to be found
+ under the /sys/firmware/qemu_fw_cfg/by_key directory.
diff --git a/Documentation/devicetree/bindings/arm/fw-cfg.txt b/Documentation/devicetree/bindings/arm/fw-cfg.txt
index 953fb64..fd54e1d 100644
--- a/Documentation/devicetree/bindings/arm/fw-cfg.txt
+++ b/Documentation/devicetree/bindings/arm/fw-cfg.txt
@@ -11,43 +11,9 @@
registers; their location is communicated to the guest's UEFI firmware in the
DTB that QEMU places at the bottom of the guest's DRAM.
-The guest writes a selector value (a key) to the selector register, and then
-can read the corresponding data (produced by QEMU) via the data register. If
-the selected entry is writable, the guest can rewrite it through the data
-register.
+The authoritative guest-side hardware interface documentation to the fw_cfg
+device can be found in "docs/specs/fw_cfg.txt" in the QEMU source tree.
-The selector register takes keys in big endian byte order.
-
-The data register allows accesses with 8, 16, 32 and 64-bit width (only at
-offset 0 of the register). Accesses larger than a byte are interpreted as
-arrays, bundled together only for better performance. The bytes constituting
-such a word, in increasing address order, correspond to the bytes that would
-have been transferred by byte-wide accesses in chronological order.
-
-The interface allows guest firmware to download various parameters and blobs
-that affect how the firmware works and what tables it installs for the guest
-OS. For example, boot order of devices, ACPI tables, SMBIOS tables, kernel and
-initrd images for direct kernel booting, virtual machine UUID, SMP information,
-virtual NUMA topology, and so on.
-
-The authoritative registry of the valid selector values and their meanings is
-the QEMU source code; the structure of the data blobs corresponding to the
-individual key values is also defined in the QEMU source code.
-
-The presence of the registers can be verified by selecting the "signature" blob
-with key 0x0000, and reading four bytes from the data register. The returned
-signature is "QEMU".
-
-The outermost protocol (involving the write / read sequences of the control and
-data registers) is expected to be versioned, and/or described by feature bits.
-The interface revision / feature bitmap can be retrieved with key 0x0001. The
-blob to be read from the data register has size 4, and it is to be interpreted
-as a uint32_t value in little endian byte order. The current value
-(corresponding to the above outer protocol) is zero.
-
-The guest kernel is not expected to use these registers (although it is
-certainly allowed to); the device tree bindings are documented here because
-this is where device tree bindings reside in general.
Required properties:
diff --git a/Documentation/driver-model/platform.txt b/Documentation/driver-model/platform.txt
index e456696..9d9e47d 100644
--- a/Documentation/driver-model/platform.txt
+++ b/Documentation/driver-model/platform.txt
@@ -75,7 +75,7 @@
point will be unregistered in reverse order. Note that there is a convenience
macro that passes THIS_MODULE as owner parameter:
- #define platform_register_driver(drivers, count)
+ #define platform_register_drivers(drivers, count)
Device Enumeration
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 5005924..6470eb8 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -149,8 +149,7 @@
static void bus_release(struct kobject *kobj)
{
- struct subsys_private *priv =
- container_of(kobj, typeof(*priv), subsys.kobj);
+ struct subsys_private *priv = to_subsys_private(kobj);
struct bus_type *bus = priv->bus;
kfree(priv);
@@ -1019,13 +1018,11 @@
int (*compare)(const struct device *a,
const struct device *b))
{
- struct list_head *pos;
struct klist_node *n;
struct device_private *dev_prv;
struct device *b;
- list_for_each(pos, list) {
- n = container_of(pos, struct klist_node, n_node);
+ list_for_each_entry(n, list, n_node) {
dev_prv = to_device_private_bus(n);
b = dev_prv->device;
if (compare(a, b) <= 0) {
@@ -1042,8 +1039,7 @@
const struct device *b))
{
LIST_HEAD(sorted_devices);
- struct list_head *pos, *tmp;
- struct klist_node *n;
+ struct klist_node *n, *tmp;
struct device_private *dev_prv;
struct device *dev;
struct klist *device_klist;
@@ -1051,8 +1047,7 @@
device_klist = bus_get_device_klist(bus);
spin_lock(&device_klist->k_lock);
- list_for_each_safe(pos, tmp, &device_klist->k_list) {
- n = container_of(pos, struct klist_node, n_node);
+ list_for_each_entry_safe(n, tmp, &device_klist->k_list, n_node) {
dev_prv = to_device_private_bus(n);
dev = dev_prv->device;
device_insertion_sort_klist(dev, &sorted_devices, compare);
@@ -1107,7 +1102,7 @@
knode = klist_next(&iter->ki);
if (!knode)
return NULL;
- dev = container_of(knode, struct device_private, knode_bus)->device;
+ dev = to_device_private_bus(knode)->device;
if (!iter->type || iter->type == dev->type)
return dev;
}
diff --git a/drivers/base/component.c b/drivers/base/component.c
index 04a1582..89b032f 100644
--- a/drivers/base/component.c
+++ b/drivers/base/component.c
@@ -267,7 +267,7 @@
}
if (match->num == match->alloc) {
- size_t new_size = match ? match->alloc + 16 : 15;
+ size_t new_size = match->alloc + 16;
int ret;
ret = component_match_realloc(master, match, new_size);
diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c
index 55b8398..87b8083 100644
--- a/drivers/base/dma-coherent.c
+++ b/drivers/base/dma-coherent.c
@@ -17,9 +17,9 @@
spinlock_t spinlock;
};
-static int dma_init_coherent_memory(phys_addr_t phys_addr, dma_addr_t device_addr,
- size_t size, int flags,
- struct dma_coherent_mem **mem)
+static bool dma_init_coherent_memory(
+ phys_addr_t phys_addr, dma_addr_t device_addr, size_t size, int flags,
+ struct dma_coherent_mem **mem)
{
struct dma_coherent_mem *dma_mem = NULL;
void __iomem *mem_base = NULL;
@@ -50,17 +50,13 @@
spin_lock_init(&dma_mem->spinlock);
*mem = dma_mem;
-
- if (flags & DMA_MEMORY_MAP)
- return DMA_MEMORY_MAP;
-
- return DMA_MEMORY_IO;
+ return true;
out:
kfree(dma_mem);
if (mem_base)
iounmap(mem_base);
- return 0;
+ return false;
}
static void dma_release_coherent_memory(struct dma_coherent_mem *mem)
@@ -88,15 +84,13 @@
dma_addr_t device_addr, size_t size, int flags)
{
struct dma_coherent_mem *mem;
- int ret;
- ret = dma_init_coherent_memory(phys_addr, device_addr, size, flags,
- &mem);
- if (ret == 0)
+ if (!dma_init_coherent_memory(phys_addr, device_addr, size, flags,
+ &mem))
return 0;
if (dma_assign_coherent_memory(dev, mem) == 0)
- return ret;
+ return flags & DMA_MEMORY_MAP ? DMA_MEMORY_MAP : DMA_MEMORY_IO;
dma_release_coherent_memory(mem);
return 0;
@@ -281,9 +275,9 @@
struct dma_coherent_mem *mem = rmem->priv;
if (!mem &&
- dma_init_coherent_memory(rmem->base, rmem->base, rmem->size,
- DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE,
- &mem) != DMA_MEMORY_MAP) {
+ !dma_init_coherent_memory(rmem->base, rmem->base, rmem->size,
+ DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE,
+ &mem)) {
pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n",
&rmem->base, (unsigned long)rmem->size / SZ_1M);
return -ENODEV;
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 49a3a11..6664f11 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -161,6 +161,26 @@
This option enables support for communicating with the firmware on the
Raspberry Pi.
+config FW_CFG_SYSFS
+ tristate "QEMU fw_cfg device support in sysfs"
+ depends on SYSFS && (ARM || ARM64 || PPC_PMAC || SPARC || X86)
+ depends on HAS_IOPORT_MAP
+ default n
+ help
+ Say Y or M here to enable the exporting of the QEMU firmware
+ configuration (fw_cfg) file entries via sysfs. Entries are
+ found under /sys/firmware/fw_cfg when this option is enabled
+ and loaded.
+
+config FW_CFG_SYSFS_CMDLINE
+ bool "QEMU fw_cfg device parameter parsing"
+ depends on FW_CFG_SYSFS
+ help
+ Allow the qemu_fw_cfg device to be initialized via the kernel
+ command line or using a module parameter.
+ WARNING: Using incorrect parameters (base address in particular)
+ may crash your system.
+
config QCOM_SCM
bool
depends on ARM || ARM64
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 48dd417..474bada 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -14,6 +14,7 @@
obj-$(CONFIG_ISCSI_IBFT) += iscsi_ibft.o
obj-$(CONFIG_FIRMWARE_MEMMAP) += memmap.o
obj-$(CONFIG_RASPBERRYPI_FIRMWARE) += raspberrypi.o
+obj-$(CONFIG_FW_CFG_SYSFS) += qemu_fw_cfg.o
obj-$(CONFIG_QCOM_SCM) += qcom_scm.o
obj-$(CONFIG_QCOM_SCM_64) += qcom_scm-64.o
obj-$(CONFIG_QCOM_SCM_32) += qcom_scm-32.o
diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c
new file mode 100644
index 0000000..fedbff5
--- /dev/null
+++ b/drivers/firmware/qemu_fw_cfg.c
@@ -0,0 +1,751 @@
+/*
+ * 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:
+ *
+ * [fw_cfg.]ioport=<size>@<base>[:<ctrl_off>:<data_off>]
+ * or
+ * [fw_cfg.]mmio=<size>@<base>[:<ctrl_off>:<data_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
+ *
+ * e.g.:
+ * fw_cfg.ioport=2@0x510:0:1 (the default on x86)
+ * or
+ * fw_cfg.mmio=0xA@0x9020000:8:0 (the default on arm)
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/acpi.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+
+MODULE_AUTHOR("Gabriel L. Somlo <somlo@cmu.edu>");
+MODULE_DESCRIPTION("QEMU fw_cfg sysfs support");
+MODULE_LICENSE("GPL");
+
+/* selector key values for "well-known" fw_cfg entries */
+#define FW_CFG_SIGNATURE 0x00
+#define FW_CFG_ID 0x01
+#define FW_CFG_FILE_DIR 0x19
+
+/* size in bytes of fw_cfg signature */
+#define FW_CFG_SIG_SIZE 4
+
+/* fw_cfg "file name" is up to 56 characters (including terminating nul) */
+#define FW_CFG_MAX_FILE_PATH 56
+
+/* fw_cfg file directory entry type */
+struct fw_cfg_file {
+ u32 size;
+ u16 select;
+ u16 reserved;
+ char name[FW_CFG_MAX_FILE_PATH];
+};
+
+/* 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;
+
+/* 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 inline u16 fw_cfg_sel_endianness(u16 key)
+{
+ return fw_cfg_is_mmio ? cpu_to_be16(key) : cpu_to_le16(key);
+}
+
+/* read chunk of given fw_cfg blob (caller responsible for sanity-check) */
+static inline void fw_cfg_read_blob(u16 key,
+ void *buf, loff_t pos, size_t count)
+{
+ mutex_lock(&fw_cfg_dev_lock);
+ iowrite16(fw_cfg_sel_endianness(key), fw_cfg_reg_ctrl);
+ while (pos-- > 0)
+ ioread8(fw_cfg_reg_data);
+ ioread8_rep(fw_cfg_reg_data, buf, count);
+ mutex_unlock(&fw_cfg_dev_lock);
+}
+
+/* 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
+# 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
+# else
+# warning "QEMU FW_CFG may not be available on this architecture!"
+# define FW_CFG_CTRL_OFF 0x00
+# define FW_CFG_DATA_OFF 0x01
+# 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;
+
+ /* 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");
+ 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;
+ }
+
+ /* verify fw_cfg device signature */
+ fw_cfg_read_blob(FW_CFG_SIGNATURE, sig, 0, FW_CFG_SIG_SIZE);
+ if (memcmp(sig, "QEMU", FW_CFG_SIG_SIZE) != 0) {
+ fw_cfg_io_cleanup();
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+/* fw_cfg revision attribute, in /sys/firmware/qemu_fw_cfg top-level dir. */
+static u32 fw_cfg_rev;
+
+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;
+ struct fw_cfg_file f;
+ struct list_head list;
+};
+
+/* 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->f.size);
+}
+
+static ssize_t fw_cfg_sysfs_show_key(struct fw_cfg_sysfs_entry *e, char *buf)
+{
+ return sprintf(buf, "%u\n", e->f.select);
+}
+
+static ssize_t fw_cfg_sysfs_show_name(struct fw_cfg_sysfs_entry *e, char *buf)
+{
+ return sprintf(buf, "%s\n", e->f.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->f.size)
+ return -EINVAL;
+
+ if (count > entry->f.size - pos)
+ count = entry->f.size - pos;
+
+ fw_cfg_read_blob(entry->f.select, buf, pos, count);
+ return 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;
+
+ /* allocate new entry */
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return -ENOMEM;
+
+ /* set file entry information */
+ memcpy(&entry->f, f, sizeof(struct fw_cfg_file));
+
+ /* 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->f.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->f.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;
+ u32 count, i;
+ struct fw_cfg_file *dir;
+ size_t dir_size;
+
+ fw_cfg_read_blob(FW_CFG_FILE_DIR, &count, 0, sizeof(count));
+ count = be32_to_cpu(count);
+ dir_size = count * sizeof(struct fw_cfg_file);
+
+ dir = kmalloc(dir_size, GFP_KERNEL);
+ if (!dir)
+ return -ENOMEM;
+
+ fw_cfg_read_blob(FW_CFG_FILE_DIR, dir, sizeof(count), dir_size);
+
+ for (i = 0; i < count; i++) {
+ dir[i].size = be32_to_cpu(dir[i].size);
+ dir[i].select = be16_to_cpu(dir[i].select);
+ ret = fw_cfg_register_file(&dir[i]);
+ if (ret)
+ break;
+ }
+
+ 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;
+
+ /* 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 */
+ fw_cfg_read_blob(FW_CFG_ID, &fw_cfg_rev, 0, sizeof(fw_cfg_rev));
+ fw_cfg_rev = le32_to_cpu(fw_cfg_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();
+ fw_cfg_kset_unregister_recursive(fw_cfg_fname_kset);
+ fw_cfg_kobj_cleanup(fw_cfg_sel_ko);
+ fw_cfg_io_cleanup();
+ 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[] = {
+ { "QEMU0002", },
+ {},
+};
+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"
+
+#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"
+
+static int fw_cfg_cmdline_set(const char *arg, const struct kernel_param *kp)
+{
+ struct resource res[3] = {};
+ char *str;
+ phys_addr_t base;
+ resource_size_t size, ctrl_off, data_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>]" chunks */
+ processed = sscanf(str, PH_ADDR_SCAN_FMT,
+ &base, &consumed,
+ &ctrl_off, &data_off, &consumed);
+
+ /* sscanf() must process precisely 1 or 3 chunks:
+ * <base> is mandatory, optionally followed by <ctrl_off>
+ * and <data_off>;
+ * there must be no extra characters after the last chunk,
+ * so str[consumed] must be '\0'.
+ */
+ if (str[consumed] ||
+ (processed != 1 && processed != 3))
+ 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;
+ }
+
+ /* "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);
+ if (IS_ERR(fw_cfg_cmdline_dev))
+ return PTR_ERR(fw_cfg_cmdline_dev);
+
+ return 0;
+}
+
+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);
+ }
+
+ /* 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)
+{
+ /* 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;
+
+ return platform_driver_register(&fw_cfg_sysfs_driver);
+}
+
+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);
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 996b774..118d033 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -691,15 +691,22 @@
const unsigned char *path,
const void *ns)
{
- static char path_buf[PATH_MAX]; /* protected by kernfs_mutex */
- size_t len = strlcpy(path_buf, path, PATH_MAX);
- char *p = path_buf;
- char *name;
+ size_t len;
+ char *p, *name;
lockdep_assert_held(&kernfs_mutex);
- if (len >= PATH_MAX)
+ /* grab kernfs_rename_lock to piggy back on kernfs_pr_cont_buf */
+ spin_lock_irq(&kernfs_rename_lock);
+
+ len = strlcpy(kernfs_pr_cont_buf, path, sizeof(kernfs_pr_cont_buf));
+
+ if (len >= sizeof(kernfs_pr_cont_buf)) {
+ spin_unlock_irq(&kernfs_rename_lock);
return NULL;
+ }
+
+ p = kernfs_pr_cont_buf;
while ((name = strsep(&p, "/")) && parent) {
if (*name == '\0')
@@ -707,6 +714,8 @@
parent = kernfs_find_ns(parent, name, ns);
}
+ spin_unlock_irq(&kernfs_rename_lock);
+
return parent;
}
diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index 19c066d..981e53a 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -162,6 +162,14 @@
return ERR_PTR(-ENODEV);
}
+static inline struct dentry *debugfs_create_automount(const char *name,
+ struct dentry *parent,
+ struct vfsmount *(*f)(void *),
+ void *data)
+{
+ return ERR_PTR(-ENODEV);
+}
+
static inline void debugfs_remove(struct dentry *dentry)
{ }
diff --git a/lib/kobject.c b/lib/kobject.c
index 7cbccd2..445dcae 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -861,6 +861,7 @@
spin_unlock(&kset->list_lock);
return ret;
}
+EXPORT_SYMBOL_GPL(kset_find_obj);
static void kset_release(struct kobject *kobj)
{