request_firmware() hotplug interface, third round and a halve

request_firmware() hotplug interface, third round and a halve

[Manuel Estrada Sainz]

[-- Attachment #1: Type: text/plain, Size: 2314 bytes --]

 Hi,

 There is some new stuff:
 -----------------------

 - 'struct device *device' is used instead of 'char *device'. So we now
   have the device symlink :)

 - request_firmware_nowait is implemented, please comment on it.
 
 - It doesn't abuse the stack any more, or at least not that much :)
 
 - There is a timeout, changeable from userspace. Feedback on a
   reasonable default value appreciated.
 
 - Extended 'loading' semantics:
 	echo 1 > loading:
		start a new load, and flush any data from a previous
		partial load.
	echo 0 > loading:
		finish load.
	echo -1 > loading:
		cancel load and give an error to the driver.
		
 - adapted to new sysfs interface.
 
 - it is now a patch against current bk-cvs gateway.
 
 - There is a *working* sample on how to use the firmware class without
   using request_firmware(). It is not clean, but it works, if it is
   found to be interesting it should be further polished.

 Some random notes:
 -----------------

 - request_firmware_cancel is not needed, request_firmware_nowait will
   lock the client module into memory until after triggering the
   callback.
   The only other problem that I can think of is the device getting
   unplugged while waiting for firmware, so the driver callback should
   first make sure that the device is still there.

 - firmware-class.diff adds both samples to the kernel tree, that
   doesn't mean that I want them there, it is just for easier testing.

 Patches:
 -------

 - firmware-class.diff:
 	firmware_class code and the two samples.

 - sysfs-bin-flexible-size.diff:
 	Make dynamically sized files possible.
	And return the right value on successful write.

 - sysfs-bin-lost-dget.diff:
 	I was having trouble when calling request_firmware() from a
	work queue, and after a little investigations it seams that this
	dget got lost along the way. Adding it back fixed the issue.
	Or am I causing a dentry leak now?

PS: If you guys consider this abusive CC:ing, please complain.
-- 
--- Manuel Estrada Sainz <ranty@debian.org>
                         <ranty@bigfoot.com>
			 <ranty@users.sourceforge.net>
------------------------ <manuel.estrada@hispalinux.es> -------------------
Let us have the serenity to accept the things we cannot change, courage to
change the things we can, and wisdom to know the difference.

[-- Attachment #2: firmware-class.diff --]
[-- Type: text/plain, Size: 22011 bytes --]

diff --exclude=CVS -urN linux-2.5.orig/drivers/base/Makefile linux-2.5.mine/drivers/base/Makefile
--- linux-2.5.orig/drivers/base/Makefile	2003-05-17 20:44:03.000000000 +0200
+++ linux-2.5.mine/drivers/base/Makefile	2003-05-17 23:17:21.000000000 +0200
@@ -3,4 +3,6 @@
 obj-y			:= core.o sys.o interface.o power.o bus.o \
 			   driver.o class.o platform.o \
 			   cpu.o firmware.o init.o
+obj-m			:= firmware_class.o firmware_sample_driver.o \
+			   firmware_sample_firmware_class.o
 obj-$(CONFIG_NUMA)	+= node.o  memblk.o
diff --exclude=CVS -urN linux-2.5.orig/drivers/base/firmware_class.c linux-2.5.mine/drivers/base/firmware_class.c
--- linux-2.5.orig/drivers/base/firmware_class.c	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.5.mine/drivers/base/firmware_class.c	2003-05-17 22:44:27.000000000 +0200
@@ -0,0 +1,425 @@
+/*
+ * firmware_class.c - Multi purpose firmware loading support
+ *
+ * Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org>
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <asm/hardirq.h>
+
+#include "linux/firmware.h"
+
+MODULE_AUTHOR("Manuel Estrada Sainz <ranty@debian.org>");
+MODULE_DESCRIPTION("Multi purpose firmware loading support");
+MODULE_LICENSE("GPL");
+
+static int loading_timeout = 10; /* In seconds */
+
+static inline struct class_device *to_class_dev(struct kobject *obj)
+{
+	return container_of(obj,struct class_device,kobj);
+}
+static inline
+struct class_device_attribute *to_class_dev_attr(struct attribute *_attr)
+{
+	return container_of(_attr,struct class_device_attribute,attr);
+}
+
+int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr);
+int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr);
+
+struct firmware_priv {
+	char fw_id[FIRMWARE_NAME_MAX];
+	struct completion completion;
+	struct bin_attribute attr_data;
+	struct firmware *fw;
+	s32 loading:2;
+	u32 abort:1;
+	int alloc_size;
+	struct timer_list timeout;
+};
+
+static ssize_t firmware_timeout_show(struct class *class, char *buf)
+{
+	return sprintf(buf, "%d\n", loading_timeout);
+}
+static ssize_t firmware_timeout_store(struct class *class,
+				      const char *buf, size_t count)
+{
+	loading_timeout = simple_strtol(buf, NULL, 10);
+	return count;
+}
+CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store);
+
+int firmware_class_hotplug(struct class_device *dev, char **envp,
+			   int num_envp, char *buffer, int buffer_size);
+
+struct class firmware_class = {
+        .name           = "firmware",
+	.hotplug        = firmware_class_hotplug,
+};
+
+
+int firmware_class_hotplug(struct class_device *class_dev, char **envp,
+			   int num_envp, char *buffer, int buffer_size)
+{
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+	int i=0;
+	char *scratch=buffer;
+
+	if (buffer_size < (FIRMWARE_NAME_MAX+10))
+		return -ENOMEM;
+
+	envp [i++] = scratch;
+	scratch += sprintf(scratch, "FIRMWARE=%s", fw_priv->fw_id) + 1;
+	return 0;
+}
+
+static ssize_t firmware_loading_show(struct class_device *class_dev, char *buf)
+{
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+	return sprintf(buf, "%d\n", fw_priv->loading);
+}
+static ssize_t firmware_loading_store(struct class_device *class_dev,
+				      const char *buf, size_t count)
+{
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+	int prev_loading = fw_priv->loading;
+
+	fw_priv->loading = simple_strtol(buf, NULL, 10);
+	
+	switch(fw_priv->loading){
+	case -1:
+		fw_priv->abort = 1;
+		wmb();
+		complete(&fw_priv->completion);
+		break;
+	case 1:
+		kfree(fw_priv->fw->data);
+		fw_priv->fw->data=NULL;
+		fw_priv->fw->size=0;
+		fw_priv->alloc_size=0;
+		break;
+	case 0:
+		if(prev_loading==1)
+			complete(&fw_priv->completion);
+		break;
+	}
+
+	return count;
+}
+CLASS_DEVICE_ATTR(loading, 0644,
+		  firmware_loading_show, firmware_loading_store);
+
+static ssize_t firmware_data_read(struct kobject *kobj,
+				  char *buffer, loff_t offset, size_t count)
+{
+	struct class_device *class_dev = to_class_dev(kobj);
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+	struct firmware *fw = fw_priv->fw;
+
+	printk("%s: count:%d offset:%lld\n", __FUNCTION__, count, offset);
+
+	if (offset > fw->size)
+		return 0;
+	if (offset + count > fw->size)
+		count = fw->size - offset;
+
+	memcpy(buffer, fw->data, fw->size);
+	return count;
+}
+static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
+{
+	u8 *new_data;
+
+	if (min_size <= fw_priv->alloc_size)
+		return 0;
+
+	new_data = kmalloc(fw_priv->alloc_size+PAGE_SIZE, GFP_KERNEL);
+	if(!new_data){
+		printk(KERN_ERR "%s: unable to alloc buffer\n",
+		       __FUNCTION__);
+		/* Make sure that we don't keep incomplete data */
+		fw_priv->abort = 1;
+		return -ENOMEM;
+	}
+	fw_priv->alloc_size += PAGE_SIZE;
+	if(fw_priv->fw->data){
+		memcpy(new_data, fw_priv->fw->data, fw_priv->fw->size);
+		kfree(fw_priv->fw->data);
+	}
+	fw_priv->fw->data=new_data;
+	BUG_ON(min_size > fw_priv->alloc_size);
+	return 0;
+}
+static ssize_t firmware_data_write(struct kobject *kobj,
+				   char *buffer, loff_t offset, size_t count)
+{
+	struct class_device *class_dev = to_class_dev(kobj);
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+	struct firmware *fw = fw_priv->fw;
+	int retval;
+
+	printk("%s: count:%d offset:%lld\n", __FUNCTION__, count, offset);
+	retval = fw_realloc_buffer(fw_priv, offset+count);
+	if(retval){
+		printk("%s: retval:%d\n", __FUNCTION__, retval);
+		return retval;
+	}
+	printk("%s: retval:%d\n", __FUNCTION__, retval);
+
+	memcpy(fw->data+offset, buffer, count);
+
+	fw->size = max_t(size_t, offset+count, fw->size);
+
+	return count;
+}
+static struct bin_attribute firmware_attr_data_tmpl = {
+	.attr = {.name = "data", .mode = 0644},
+	.size = 0,
+	.read = firmware_data_read,
+	.write = firmware_data_write,
+};
+static void firmware_class_timeout(u_long data)
+{
+	struct firmware_priv *fw_priv = (struct firmware_priv *)data;
+	fw_priv->abort=1;
+	wmb();
+	complete(&fw_priv->completion);	
+}
+static inline void fw_setup_class_device_id(struct class_device *class_dev,
+				       struct device *dev)
+{
+#warning we should watch out for name collisions
+	strncpy(class_dev->class_id, dev->bus_id, BUS_ID_SIZE);
+	class_dev->class_id[BUS_ID_SIZE-1] = '\0';
+}
+static int fw_setup_class_device(struct class_device *class_dev,
+				 const char *fw_name,
+				 struct device *device)
+{
+	int retval = 0;
+	struct firmware_priv *fw_priv = kmalloc(sizeof(struct firmware_priv),
+						GFP_KERNEL);
+
+	if(!fw_priv){
+		retval = -ENOMEM;
+		goto out;
+	}
+	memset(fw_priv, 0, sizeof(*fw_priv));
+	memset(class_dev, 0, sizeof(*class_dev));
+
+	init_completion(&fw_priv->completion);
+	memcpy(&fw_priv->attr_data, &firmware_attr_data_tmpl,
+	       sizeof(firmware_attr_data_tmpl));
+
+	strncpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
+	fw_priv->fw_id[FIRMWARE_NAME_MAX-1] = '\0';
+
+	fw_setup_class_device_id(class_dev, device);
+	class_dev->dev = device;
+
+	fw_priv->timeout.function = firmware_class_timeout;
+	fw_priv->timeout.data = (u_long)fw_priv;
+	init_timer(&fw_priv->timeout);
+
+	class_dev->class = &firmware_class,
+	class_set_devdata(class_dev, fw_priv);
+	retval = class_device_register(class_dev);
+	if (retval){
+		printk(KERN_ERR "%s: class_device_register failed\n",
+		       __FUNCTION__);
+		goto error_free_fw_priv;
+	}
+
+	retval = sysfs_create_bin_file(&class_dev->kobj,
+				       &fw_priv->attr_data);
+	if (retval){
+		printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
+		       __FUNCTION__);
+		goto error_unreg_class_dev;
+	}
+
+	retval = class_device_create_file(class_dev,
+					  &class_device_attr_loading);
+	if (retval){
+		printk(KERN_ERR "%s: class_device_create_file failed\n",
+		       __FUNCTION__);
+		goto error_remove_data;
+	}
+
+	fw_priv->fw=kmalloc(sizeof(struct firmware), GFP_KERNEL);
+	if(!fw_priv->fw){
+		printk(KERN_ERR "%s: kmalloc(struct firmware) failed\n",
+		       __FUNCTION__);
+		retval = -ENOMEM;
+		goto error_remove_loading;
+	}
+	memset(fw_priv->fw, 0, sizeof(*fw_priv->fw));
+
+	goto out;
+	
+error_remove_loading:
+	class_device_remove_file(class_dev, &class_device_attr_loading);
+error_remove_data:
+	sysfs_remove_bin_file(&class_dev->kobj, &fw_priv->attr_data);
+error_unreg_class_dev:
+	class_device_unregister(class_dev);
+error_free_fw_priv:
+	kfree(fw_priv);
+out:
+	return retval;
+}
+static void fw_remove_class_device(struct class_device *class_dev)
+{
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+
+	class_device_remove_file(class_dev, &class_device_attr_loading);
+	sysfs_remove_bin_file(&class_dev->kobj, &fw_priv->attr_data);
+	class_device_unregister(class_dev);
+}
+
+int request_firmware (const struct firmware **firmware, const char *name,
+		      struct device *device)
+{
+	struct class_device *class_dev = kmalloc(sizeof(struct class_device),
+						 GFP_KERNEL);
+	struct firmware_priv *fw_priv;
+	int retval;
+
+	if(!class_dev)
+		return -ENOMEM;
+
+	if(!firmware){
+		retval = -EINVAL;
+		goto out;
+	}
+	*firmware=NULL;
+
+	retval = fw_setup_class_device(class_dev, name, device);
+	if(retval)
+		goto out;
+
+	fw_priv = class_get_devdata(class_dev);
+
+	fw_priv->timeout.expires = jiffies + loading_timeout*HZ;
+	add_timer(&fw_priv->timeout);
+
+	wait_for_completion(&fw_priv->completion);
+
+	del_timer(&fw_priv->timeout);
+	fw_remove_class_device(class_dev);
+
+	if(fw_priv->fw->size && !fw_priv->abort){
+		*firmware = fw_priv->fw;
+	} else {
+		retval = -ENOENT;
+		kfree(fw_priv->fw->data);
+		kfree(fw_priv->fw);
+	}
+	kfree(fw_priv);
+out:
+	kfree(class_dev);
+	return retval;
+}
+void release_firmware (const struct firmware *fw)
+{
+	if(fw){
+		kfree(fw->data);
+		kfree(fw);
+	}
+}
+
+void register_firmware (const char *name, const u8 *data, size_t size)
+{
+	/* This is meaningless without firmware caching, so until we
+	 * decide if firmware caching is reasonable just leave it as a
+	 * noop */
+}
+
+/* Async support */
+struct firmware_work {
+	struct work_struct work;
+	struct module *module;
+	const char *name;
+	struct device *device;
+	void *context;
+	void (*cont)(const struct firmware *fw, void *context);
+};
+
+static void request_firmware_work_func(void *arg)
+{
+	struct firmware_work *fw_work = arg;
+	const struct firmware *fw;
+	if(!arg)
+		return;
+	request_firmware(&fw, fw_work->name, fw_work->device);
+	fw_work->cont(fw, fw_work->context);
+	release_firmware(fw);
+	module_put(fw_work->module);
+	kfree(fw_work);
+}
+
+int request_firmware_nowait (
+	struct module *module,
+	const char *name, struct device *device, void *context,
+	void (*cont)(const struct firmware *fw, void *context))
+{
+	struct firmware_work *fw_work = kmalloc(sizeof(struct firmware_work),
+						GFP_ATOMIC);
+	if(!fw_work)
+		return -ENOMEM;
+	if(!try_module_get(module)){
+		kfree(fw_work);
+		return -EFAULT;
+	}
+
+	*fw_work = (struct firmware_work){
+		.module = module,
+		.name = name,
+		.device = device,
+		.context = context,
+		.cont = cont,
+	};
+	INIT_WORK(&fw_work->work, request_firmware_work_func, fw_work);
+
+	schedule_work(&fw_work->work);
+	return 0;
+}
+
+
+
+static int __init firmware_class_init(void)
+{
+	int error;
+        error = class_register(&firmware_class);
+        if (error) {
+		printk(KERN_ERR "%s: class_register failed\n",
+		       __FUNCTION__);
+	}
+	error = class_create_file(&firmware_class, &class_attr_timeout);
+	if (error){
+		printk(KERN_ERR "%s: class_create_file failed\n",
+		       __FUNCTION__);
+		class_unregister(&firmware_class);
+	}
+        return error;
+
+}
+static void __exit firmware_class_exit(void)
+{
+	class_remove_file(&firmware_class, &class_attr_timeout);
+	class_unregister(&firmware_class);
+}
+module_init(firmware_class_init);
+module_exit(firmware_class_exit);
+
+EXPORT_SYMBOL(release_firmware);
+EXPORT_SYMBOL(request_firmware);
+EXPORT_SYMBOL(request_firmware_nowait);
+EXPORT_SYMBOL(register_firmware);
+EXPORT_SYMBOL(firmware_class);
diff --exclude=CVS -urN linux-2.5.orig/drivers/base/firmware_sample_driver.c linux-2.5.mine/drivers/base/firmware_sample_driver.c
--- linux-2.5.orig/drivers/base/firmware_sample_driver.c	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.5.mine/drivers/base/firmware_sample_driver.c	2003-05-17 23:20:45.000000000 +0200
@@ -0,0 +1,115 @@
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/device.h>
+
+#include "linux/firmware.h"
+
+#define WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
+#ifdef WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
+char __init inkernel_firmware[] = "let's say that this is firmware\n";
+#endif
+
+static struct device ghost_device = {
+	.name      = "Ghost Device",
+	.bus_id    = "ghost0",
+};
+
+
+static void sample_firmware_load(char *firmware, int size)
+{
+	u8 buf[size+1];
+	memcpy(buf, firmware, size);
+	buf[size] = '\0';
+	printk("firmware_sample_driver: firmware: %s\n", buf);
+}
+
+static void sample_probe_default(void)
+{
+	/* uses the default method to get the firmware */
+        const struct firmware *fw_entry;
+	printk("firmware_sample_driver: a ghost device got inserted :)\n");
+
+        if(request_firmware(&fw_entry, "sample_driver_fw", &ghost_device)!=0)
+	{
+		printk(KERN_ERR
+		       "firmware_sample_driver: Firmware not available\n");
+		return;
+	}
+	
+	sample_firmware_load(fw_entry->data, fw_entry->size);
+
+	release_firmware(fw_entry);
+
+	/* finish setting up the device */
+}
+static void sample_probe_specific(void)
+{
+	/* Uses some specific hotplug support to get the firmware from
+	 * userspace  directly into the hardware, or via some sysfs file */
+
+	/* NOTE: This currently doesn't work */
+
+	printk("firmware_sample_driver: a ghost device got inserted :)\n");
+
+        if(request_firmware(NULL, "sample_driver_fw", &ghost_device)!=0)
+	{
+		printk(KERN_ERR
+		       "firmware_sample_driver: Firmware load failed\n");
+		return;
+	}
+	
+	/* request_firmware blocks until userspace finished, so at
+	 * this point the firmware should be already in the device */
+
+	/* finish setting up the device */
+}
+static void sample_probe_async_cont(const struct firmware *fw, void *context)
+{
+	if(!fw){
+		printk(KERN_ERR
+		       "firmware_sample_driver: firmware load failed\n");
+		return;
+	}
+
+	printk("firmware_sample_driver: device pointer \"%s\"\n",
+	       (char *)context);
+	sample_firmware_load(fw->data, fw->size);
+}
+static void sample_probe_async(void)
+{
+	/* Let's say that I can't sleep */
+	int error;
+	error = request_firmware_nowait (THIS_MODULE,
+					 "sample_driver_fw", &ghost_device,
+					 "my device pointer",
+					 sample_probe_async_cont);
+	if(error){
+		printk(KERN_ERR 
+		       "firmware_sample_driver:"
+		       " request_firmware_nowait failed\n");
+	}
+}
+
+static int sample_init(void)
+{
+#ifdef WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
+	register_firmware("sample_driver_fw", inkernel_firmware,
+			  sizeof(inkernel_firmware));
+#endif
+	device_initialize(&ghost_device);
+	/* since there is no real hardware insertion I just call the
+	 * sample probe functions here */
+	sample_probe_specific();
+	sample_probe_default();
+	sample_probe_async();
+	return 0;
+}
+static void __exit sample_exit(void)
+{
+}
+
+module_init (sample_init);
+module_exit (sample_exit);
+
+MODULE_LICENSE("GPL");
diff --exclude=CVS -urN linux-2.5.orig/drivers/base/firmware_sample_firmware_class.c linux-2.5.mine/drivers/base/firmware_sample_firmware_class.c
--- linux-2.5.orig/drivers/base/firmware_sample_firmware_class.c	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.5.mine/drivers/base/firmware_sample_firmware_class.c	2003-05-17 23:19:44.000000000 +0200
@@ -0,0 +1,200 @@
+/*
+ * firmware_class.c - Multi purpose firmware loading support
+ *
+ * Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org>
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <asm/hardirq.h>
+
+#include "linux/firmware.h"
+
+MODULE_AUTHOR("Manuel Estrada Sainz <ranty@debian.org>");
+MODULE_DESCRIPTION("Hackish sample for using firmware class directly");
+MODULE_LICENSE("GPL");
+
+static inline struct class_device *to_class_dev(struct kobject *obj)
+{
+	return container_of(obj,struct class_device,kobj);
+}
+static inline
+struct class_device_attribute *to_class_dev_attr(struct attribute *_attr)
+{
+	return container_of(_attr,struct class_device_attribute,attr);
+}
+
+int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr);
+int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr);
+
+struct firmware_priv {
+	char fw_id[FIRMWARE_NAME_MAX];
+	s32 loading:2;
+	u32 abort:1;
+};
+
+extern struct class firmware_class;
+
+static ssize_t firmware_loading_show(struct class_device *class_dev, char *buf)
+{
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+	return sprintf(buf, "%d\n", fw_priv->loading);
+}
+static ssize_t firmware_loading_store(struct class_device *class_dev,
+				      const char *buf, size_t count)
+{
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+	int prev_loading = fw_priv->loading;
+
+	fw_priv->loading = simple_strtol(buf, NULL, 10);
+	
+	switch(fw_priv->loading){
+	case -1:
+		/* abort load an panic */
+		break;
+	case 1:
+		/* setup load */
+		break;
+	case 0:
+		if(prev_loading==1){
+			/* finish load and get the device back to working
+			 * state */
+		}
+		break;
+	}
+
+	return count;
+}
+CLASS_DEVICE_ATTR(loading, 0644,
+		  firmware_loading_show, firmware_loading_store);
+
+static ssize_t firmware_data_read(struct kobject *kobj,
+				  char *buffer, loff_t offset, size_t count)
+{
+	struct class_device *class_dev = to_class_dev(kobj);
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+
+	/* read from the devices firmware memory */
+
+	return count;
+}
+static ssize_t firmware_data_write(struct kobject *kobj,
+				   char *buffer, loff_t offset, size_t count)
+{
+	struct class_device *class_dev = to_class_dev(kobj);
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+
+	/* write to the devices firmware memory */
+
+	return count;
+}
+static struct bin_attribute firmware_attr_data = {
+	.attr = {.name = "data", .mode = 0644},
+	.size = 0,
+	.read = firmware_data_read,
+	.write = firmware_data_write,
+};
+static int fw_setup_class_device(struct class_device *class_dev,
+				 const char *fw_name,
+				 struct device *device)
+{
+	int retval = 0;
+	struct firmware_priv *fw_priv = kmalloc(sizeof(struct firmware_priv),
+						GFP_KERNEL);
+
+	if(!fw_priv){
+		retval = -ENOMEM;
+		goto out;
+	}
+	memset(fw_priv, 0, sizeof(*fw_priv));
+	memset(class_dev, 0, sizeof(*class_dev));
+
+	strncpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
+	fw_priv->fw_id[FIRMWARE_NAME_MAX-1] = '\0';
+
+	strncpy(class_dev->class_id, device->bus_id, BUS_ID_SIZE);
+	class_dev->class_id[BUS_ID_SIZE-1] = '\0';
+	class_dev->dev = device;
+
+	class_dev->class = &firmware_class,
+	class_set_devdata(class_dev, fw_priv);
+	retval = class_device_register(class_dev);
+	if (retval){
+		printk(KERN_ERR "%s: class_device_register failed\n",
+		       __FUNCTION__);
+		goto error_free_fw_priv;
+	}
+
+	retval = sysfs_create_bin_file(&class_dev->kobj, &firmware_attr_data);
+	if (retval){
+		printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
+		       __FUNCTION__);
+		goto error_unreg_class_dev;
+	}
+
+	retval = class_device_create_file(class_dev,
+					  &class_device_attr_loading);
+	if (retval){
+		printk(KERN_ERR "%s: class_device_create_file failed\n",
+		       __FUNCTION__);
+		goto error_remove_data;
+	}
+
+	goto out;
+	
+error_remove_data:
+	sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data);
+error_unreg_class_dev:
+	class_device_unregister(class_dev);
+error_free_fw_priv:
+	kfree(fw_priv);
+out:
+	return retval;
+}
+static void fw_remove_class_device(struct class_device *class_dev)
+{
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+
+	class_device_remove_file(class_dev, &class_device_attr_loading);
+	sysfs_remove_bin_file(&class_dev->kobj, &firmware_attr_data);
+	class_device_unregister(class_dev);
+}
+
+static struct class_device *class_dev;
+
+static struct device my_device = {
+	.name      = "Sample Device",
+	.bus_id    = "my_dev0",
+};
+
+static int __init firmware_sample_init(void)
+{
+	int error;
+
+	device_initialize(&my_device);
+	class_dev = kmalloc(sizeof(struct class_device), GFP_KERNEL);
+	if(!class_dev)
+		return -ENOMEM;
+
+	error = fw_setup_class_device(class_dev, "my_firmware_image",
+				      &my_device);
+	if(error){
+		kfree(class_dev);
+		return error;
+	}
+        return 0;
+
+}
+static void __exit firmware_sample_exit(void)
+{
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+	fw_remove_class_device(class_dev);
+	kfree(fw_priv);
+	kfree(class_dev);
+}
+module_init(firmware_sample_init);
+module_exit(firmware_sample_exit);
+
diff --exclude=CVS -urN linux-2.5.orig/include/linux/firmware.h linux-2.5.mine/include/linux/firmware.h
--- linux-2.5.orig/include/linux/firmware.h	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.5.mine/include/linux/firmware.h	2003-05-17 22:16:36.000000000 +0200
@@ -0,0 +1,20 @@
+#ifndef _LINUX_FIRMWARE_H
+#define _LINUX_FIRMWARE_H
+#include <linux/module.h>
+#include <linux/types.h>
+#define FIRMWARE_NAME_MAX 30 
+struct firmware {
+	size_t size;
+	u8 *data;
+};
+int request_firmware (const struct firmware **fw, const char *name,
+		      struct device *device);
+int request_firmware_nowait (
+	struct module *module,
+	const char *name, struct device *device, void *context,
+	void (*cont)(const struct firmware *fw, void *context));
+/* Maybe 'device' should be 'struct device *' */
+
+void release_firmware (const struct firmware *fw);
+void register_firmware (const char *name, const u8 *data, size_t size);
+#endif

[-- Attachment #3: sysfs-bin-flexible-size.diff --]
[-- Type: text/plain, Size: 1313 bytes --]

diff --exclude=CVS -urN linux-2.5.orig/fs/sysfs/bin.c linux-2.5.mine/fs/sysfs/bin.c
--- linux-2.5.orig/fs/sysfs/bin.c	2003-05-17 20:44:03.000000000 +0200
+++ linux-2.5.mine/fs/sysfs/bin.c	2003-05-17 14:53:01.000000000 +0200
@@ -30,10 +30,15 @@
 	loff_t offs = *off;
 	int ret;
 
-	if (offs > size)
-		return 0;
-	if (offs + count > size)
-		count = size - offs;
+	if (count > PAGE_SIZE)
+		count = PAGE_SIZE;
+
+	if(size){
+		if (offs > size)
+			return 0;
+		if (offs + count > size)
+			count = size - offs;
+	}
 
 	ret = fill_read(dentry, buffer, offs, count);
 	if (ret < 0) 
@@ -69,10 +74,14 @@
 	loff_t offs = *off;
 	int ret;
 
-	if (offs > size)
-		return 0;
-	if (offs + count > size)
-		count = size - offs;
+	if (count > PAGE_SIZE)
+		count = PAGE_SIZE;
+	if (size) {
+		if (offs > size)
+			return 0;
+		if (offs + count > size)
+			count = size - offs;
+	}
 
 	ret = -EFAULT;
 	if (copy_from_user(buffer + offs, userbuf, count))
@@ -81,7 +90,7 @@
 	count = flush_write(dentry, buffer, offs, count);
 	if (count > 0)
 		*off = offs + count;
-	ret = 0;
+	ret = count;
  Done:
 	return ret;
 }
@@ -102,7 +111,7 @@
 		goto Done;
 
 	error = -ENOMEM;
-	file->private_data = kmalloc(attr->size, GFP_KERNEL);
+	file->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!file->private_data)
 		goto Done;
 

[-- Attachment #4: sysfs-bin-lost-dget.diff --]
[-- Type: text/plain, Size: 476 bytes --]

diff --exclude=CVS -urN linux-2.5.orig/fs/sysfs/inode.c linux-2.5.mine/fs/sysfs/inode.c
--- linux-2.5.orig/fs/sysfs/inode.c	2003-05-17 20:44:03.000000000 +0200
+++ linux-2.5.mine/fs/sysfs/inode.c	2003-05-17 20:30:34.000000000 +0200
@@ -60,9 +60,10 @@
  Proceed:
 	if (init)
 		error = init(inode);
-	if (!error)
+	if (!error){
 		d_instantiate(dentry, inode);
-	else
+		dget(dentry); /* Extra count - pin the dentry in core */
+	} else
 		iput(inode);
  Done:
 	return error;

Re: request_firmware() hotplug interface, third round and a halve

[Alexey Mahotkin]

Two comments on firmware_class_hotplug(), maybe both are irrelevant.

+int firmware_class_hotplug(struct class_device *class_dev, char **envp,
+			   int num_envp, char *buffer, int buffer_size)
+{
+	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
+	int i=0;
+	char *scratch=buffer;
+
+	if (buffer_size < (FIRMWARE_NAME_MAX+10))
+		return -ENOMEM;
+
+	envp [i++] = scratch;
+	scratch += sprintf(scratch, "FIRMWARE=%s", fw_priv->fw_id) + 1;
+	return 0;
+}
+

First, I do not understand how the environment is handled here.  You're
just setting first element of provided environment to "FIRMWARE=%s",
possibly overwriting the existing value.  Then why are you incrementing
`i'?  Why are you using `i' at all?  Why are you incrementing `scratch'?

Ah, it seems like you should be using num_envp somehow, and you're not.

Also, environment pointer list must be terminated with a NULL pointer. Is
it not done or is that handled somewhere else?  The machine I have 2.5.69
sources is not reachable now so I cannot check it.  Sorry if I am wrong.

--alexm

Re: request_firmware() hotplug interface, third round and a halve

[Manuel Estrada Sainz]

On Sun, May 18, 2003 at 08:14:06PM +0400, Alexey Mahotkin wrote:
> 
> Two comments on firmware_class_hotplug(), maybe both are irrelevant.
> 
> +int firmware_class_hotplug(struct class_device *class_dev, char **envp,
> +			   int num_envp, char *buffer, int buffer_size)
> +{
> +	struct firmware_priv *fw_priv = class_get_devdata(class_dev);
> +	int i=0;
> +	char *scratch=buffer;
> +
> +	if (buffer_size < (FIRMWARE_NAME_MAX+10))
> +		return -ENOMEM;
> +
> +	envp [i++] = scratch;
> +	scratch += sprintf(scratch, "FIRMWARE=%s", fw_priv->fw_id) + 1;
> +	return 0;
> +}
> +
> 
> First, I do not understand how the environment is handled here. 

 You can take a look at lib/kobject.c:kset_hotplug()

> You're just setting first element of provided environment to
> "FIRMWARE=%s", possibly overwriting the existing value.

 envp points to the first empty slot of the environment being
 constructed, so no, I am not overwriting anything.

> Then why are you incrementing `i'?  Why are you using `i' at all?  Why
> are you incrementing `scratch'?

 The code is ready to add a new environment variable if needed. If we
 really don't need more variables, it could be simplified, but I don't
 think it is so important.
 
> Ah, it seems like you should be using num_envp somehow, and you're not.
 
 OK, I just added:
	if (num_envp < 1)
		return -ENOMEM;

> Also, environment pointer list must be terminated with a NULL pointer. Is
> it not done or is that handled somewhere else?

 The envp array we get is reset to zero, so anything we don't explicitly
 set is already NULL.

> The machine I have 2.5.69 sources is not reachable now so I cannot
> check it.  Sorry if I am wrong.

 The num_envp issue was real, and anyway, I appreciate a little
 feedback, it seams like people don't hack the kernel on Sunday :-P

 Thanks

 	Manuel

-- 
--- Manuel Estrada Sainz <ranty@debian.org>
                         <ranty@bigfoot.com>
			 <ranty@users.sourceforge.net>
------------------------ <manuel.estrada@hispalinux.es> -------------------
Let us have the serenity to accept the things we cannot change, courage to
change the things we can, and wisdom to know the difference.

Re: request_firmware() hotplug interface, third round and a halve

[Greg KH]

Oops, forgot to respond to this, sorry...

On Sun, May 18, 2003 at 12:19:22AM +0200, Manuel Estrada Sainz wrote:
>  Hi,
> 
>  There is some new stuff:
>  -----------------------
> 
>  - 'struct device *device' is used instead of 'char *device'. So we now
>    have the device symlink :)

Nice.

>  - request_firmware_nowait is implemented, please comment on it.

Looks sane.

>  - It doesn't abuse the stack any more, or at least not that much :)

Thanks.

>  - There is a timeout, changeable from userspace. Feedback on a
>    reasonable default value appreciated.

Is this really needed?  Especially as you now have:

>  - Extended 'loading' semantics:
>  	echo 1 > loading:
> 		start a new load, and flush any data from a previous
> 		partial load.
> 	echo 0 > loading:
> 		finish load.
> 	echo -1 > loading:
> 		cancel load and give an error to the driver.

Looks good.

I'd recommend sending the sysfs patches to Pat Mochel.  He's the one to
take those.

Some minor comments about the code:

> diff --exclude=CVS -urN linux-2.5.orig/drivers/base/Makefile linux-2.5.mine/drivers/base/Makefile
> --- linux-2.5.orig/drivers/base/Makefile	2003-05-17 20:44:03.000000000 +0200
> +++ linux-2.5.mine/drivers/base/Makefile	2003-05-17 23:17:21.000000000 +0200
> @@ -3,4 +3,6 @@
>  obj-y			:= core.o sys.o interface.o power.o bus.o \
>  			   driver.o class.o platform.o \
>  			   cpu.o firmware.o init.o
> +obj-m			:= firmware_class.o firmware_sample_driver.o \
> +			   firmware_sample_firmware_class.o

Why make the firmware_class.o always a module?  Shouldn't it only be
included in the core, if a driver that uses it is selected?

> +static inline struct class_device *to_class_dev(struct kobject *obj)
> +{
> +	return container_of(obj,struct class_device,kobj);
> +}
> +static inline
> +struct class_device_attribute *to_class_dev_attr(struct attribute *_attr)
> +{
> +	return container_of(_attr,struct class_device_attribute,attr);
> +}

Move these two to drivers/base/base.h as they shouldn't be defined in
two different files.

> +int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr);
> +int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr);

If you need these, add them to include/linux/sysfs.h.

> +struct firmware_priv {
> +	char fw_id[FIRMWARE_NAME_MAX];
> +	struct completion completion;
> +	struct bin_attribute attr_data;
> +	struct firmware *fw;
> +	s32 loading:2;
> +	u32 abort:1;

Why s32 and u32?  Why not just ints for both of them?

> +struct class firmware_class = {
> +        .name           = "firmware",
> +	.hotplug        = firmware_class_hotplug,
> +};

Oops, forgot tabs there...

> +	switch(fw_priv->loading){

Please add a space before the '{'.

> +	case 0:
> +		if(prev_loading==1)

And a space after the if.  You do this in lots of places.

Other than those very minor things, this looks quite good.

thanks,

greg k-h

Re: request_firmware() hotplug interface, third round and a halve

[David Gibson]

On Wed, May 21, 2003 at 12:23:18AM -0700, Greg Kroah-Hartman wrote:
> > +struct firmware_priv {
> > +	char fw_id[FIRMWARE_NAME_MAX];
> > +	struct completion completion;
> > +	struct bin_attribute attr_data;
> > +	struct firmware *fw;
> > +	s32 loading:2;
> > +	u32 abort:1;
> 
> Why s32 and u32?  Why not just ints for both of them?

And for that matter, I don't think there's any point using bitfields,
61 bits is not worth it.

-- 
David Gibson			| For every complex problem there is a
david@gibson.dropbear.id.au	| solution which is simple, neat and
				| wrong.
http://www.ozlabs.org/people/dgibson

Re: request_firmware() hotplug interface, third round and a halve

[Manuel Estrada Sainz]

On Wed, May 21, 2003 at 12:23:18AM -0700, Greg KH wrote:
> Oops, forgot to respond to this, sorry...
> 
> On Sun, May 18, 2003 at 12:19:22AM +0200, Manuel Estrada Sainz wrote:
[snip]
> >  - There is a timeout, changeable from userspace. Feedback on a
> >    reasonable default value appreciated.
> 
> Is this really needed?  Especially as you now have:

 There is currently no way to know if hotplug couldn't be called at all
 or if it failed because it didn't have firmware load support.

 If that happens, we would be waiting for ever. And I'd rather make that
 a countable number of seconds :)

 I'll make '0' mean no timeout at all.

> >  - Extended 'loading' semantics:
> >  	echo 1 > loading:
> > 		start a new load, and flush any data from a previous
> > 		partial load.
> > 	echo 0 > loading:
> > 		finish load.
> > 	echo -1 > loading:
> > 		cancel load and give an error to the driver.
> 
> Looks good.
> 
> I'd recommend sending the sysfs patches to Pat Mochel.  He's the one to
> take those.

 Done.
 
> Some minor comments about the code:
> 
> > diff --exclude=CVS -urN linux-2.5.orig/drivers/base/Makefile linux-2.5.mine/drivers/base/Makefile
> > --- linux-2.5.orig/drivers/base/Makefile	2003-05-17 20:44:03.000000000 +0200
> > +++ linux-2.5.mine/drivers/base/Makefile	2003-05-17 23:17:21.000000000 +0200
> > @@ -3,4 +3,6 @@
> >  obj-y			:= core.o sys.o interface.o power.o bus.o \
> >  			   driver.o class.o platform.o \
> >  			   cpu.o firmware.o init.o
> > +obj-m			:= firmware_class.o firmware_sample_driver.o \
> > +			   firmware_sample_firmware_class.o
> 
> Why make the firmware_class.o always a module?  Shouldn't it only be
> included in the core, if a driver that uses it is selected?

 That was the quickest way to get modules to play with :-)

 I am not sure on how to implement "if a driver that uses it is
 selected" and not sure on where to add the Kconfig entries to make it
 available to out-of-kernel modules.

 If the approach in the attached patches is still not right, please
 complain.
 
 Maybe kbuild could allow forcing one option from another, a companion
 for 'depends', lets call it 'hard_depends'

	 depends FOO
		If FOO is not there the entry won't even be shown in the
		menu.
	 hard_depends FOO 
		FOO gets set to satisfy the dependency.

 When trying to deselect an item that is hard_depended upon, the system
 could complain and tell you which options should be deselected or even
 offer to do it automatically.

 This would also simplify the selection of crc32 and
 compression/decompression code. And allow removal of all those comments
 like "Video4Linux support is needed for USB Multimedia device support".

> > +static inline struct class_device *to_class_dev(struct kobject *obj)
> > +{
> > +	return container_of(obj,struct class_device,kobj);
> > +}
> > +static inline
> > +struct class_device_attribute *to_class_dev_attr(struct attribute *_attr)
> > +{
> > +	return container_of(_attr,struct class_device_attribute,attr);
> > +}
> 
> Move these two to drivers/base/base.h as they shouldn't be defined in
> two different files.

 OK, I also removed equivalent macros from class.c
 
> > +int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr);
> > +int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr);
> 
> If you need these, add them to include/linux/sysfs.h.
> 
> > +struct firmware_priv {
> > +	char fw_id[FIRMWARE_NAME_MAX];
> > +	struct completion completion;
> > +	struct bin_attribute attr_data;
> > +	struct firmware *fw;
> > +	s32 loading:2;
> > +	u32 abort:1;
> 
> Why s32 and u32?  Why not just ints for both of them?

 Since they are bit fields, I wanted to have more control over them and a
 single bit bit-field should be unsigned, but I guess that David is
 right, it is not worth it. Both are full int's now.
 
> > +struct class firmware_class = {
> > +        .name           = "firmware",
> > +	.hotplug        = firmware_class_hotplug,
> > +};
> 
> Oops, forgot tabs there...
> 
> > +	switch(fw_priv->loading){
> 
> Please add a space before the '{'.
> 
> > +	case 0:
> > +		if(prev_loading==1)
> 
> And a space after the if.  You do this in lots of places.

 Fixed, and just in case, I put it through Lindent which BTW is a little
 evil :-) so I hand removed the evilness I could not take.

> Other than those very minor things, this looks quite good.

 Great.

 Patches:
	firmware-class.diff:
		The code itself against bk-cvs.

	class-casts.diff:
		to_class_dev/to_class_dev_attr changes against bk-cvs.

	sysfs-bin-header.diff
	sysfs-bin-lost-dget.diff
	sysfs-bin-flexible-size.diff:
		Just for completeness, since the above will not work
		without them, but I already send them to Pat Mochel in a
		separate mail.

 	incremental.diff:
		Incremental patch for easier reading, although there are
		lots of formating changes.

 Thanks

 	Manuel
-- 
--- Manuel Estrada Sainz <ranty@debian.org>
                         <ranty@bigfoot.com>
			 <ranty@users.sourceforge.net>
------------------------ <manuel.estrada@hispalinux.es> -------------------
Let us have the serenity to accept the things we cannot change, courage to
change the things we can, and wisdom to know the difference.

Re: request_firmware() hotplug interface, third round and a halve

[Manuel Estrada Sainz]

On Wed, May 21, 2003 at 05:44:56PM +1000, David Gibson wrote:
> On Wed, May 21, 2003 at 12:23:18AM -0700, Greg Kroah-Hartman wrote:
> > > +struct firmware_priv {
> > > +	char fw_id[FIRMWARE_NAME_MAX];
> > > +	struct completion completion;
> > > +	struct bin_attribute attr_data;
> > > +	struct firmware *fw;
> > > +	s32 loading:2;
> > > +	u32 abort:1;
> > 
> > Why s32 and u32?  Why not just ints for both of them?
> 
> And for that matter, I don't think there's any point using bitfields,
> 61 bits is not worth it.

 Done, I just sent updated patches.

 Thanks

 	Manuel

-- 
--- Manuel Estrada Sainz <ranty@debian.org>
                         <ranty@bigfoot.com>
			 <ranty@users.sourceforge.net>
------------------------ <manuel.estrada@hispalinux.es> -------------------
Let us have the serenity to accept the things we cannot change, courage to
change the things we can, and wisdom to know the difference.

Re: request_firmware() hotplug interface, third round and a halve

[Greg KH]

On Wed, May 21, 2003 at 08:34:35PM +0200, Manuel Estrada Sainz wrote:
> 
>  If the approach in the attached patches is still not right, please
>  complain.

-ENOPATCHES  :)