Merge branch 'dma-debug/2.6.31' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into core/iommu
This commit is contained in:
Ingo Molnar
Коммит
62a6f465f6
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|
@ -704,12 +704,24 @@ this directory the following files can currently be found:
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The current number of free dma_debug_entries
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in the allocator.
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dma-api/driver-filter
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You can write a name of a driver into this file
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to limit the debug output to requests from that
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particular driver. Write an empty string to
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that file to disable the filter and see
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all errors again.
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If you have this code compiled into your kernel it will be enabled by default.
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If you want to boot without the bookkeeping anyway you can provide
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'dma_debug=off' as a boot parameter. This will disable DMA-API debugging.
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Notice that you can not enable it again at runtime. You have to reboot to do
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so.
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If you want to see debug messages only for a special device driver you can
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specify the dma_debug_driver=<drivername> parameter. This will enable the
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driver filter at boot time. The debug code will only print errors for that
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driver afterwards. This filter can be disabled or changed later using debugfs.
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When the code disables itself at runtime this is most likely because it ran
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out of dma_debug_entries. These entries are preallocated at boot. The number
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of preallocated entries is defined per architecture. If it is too low for you
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|
|
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@ -641,6 +641,13 @@ and is between 256 and 4096 characters. It is defined in the file
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DMA-API debugging code disables itself because the
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architectural default is too low.
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dma_debug_driver=<driver_name>
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With this option the DMA-API debugging driver
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filter feature can be enabled at boot time. Just
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pass the driver to filter for as the parameter.
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The filter can be disabled or changed to another
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driver later using sysfs.
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dscc4.setup= [NET]
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dtc3181e= [HW,SCSI]
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|
|
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291
lib/dma-debug.c
291
lib/dma-debug.c
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@ -23,9 +23,11 @@
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#include <linux/dma-debug.h>
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#include <linux/spinlock.h>
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#include <linux/debugfs.h>
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#include <linux/uaccess.h>
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#include <linux/device.h>
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#include <linux/types.h>
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#include <linux/sched.h>
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#include <linux/ctype.h>
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#include <linux/list.h>
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#include <linux/slab.h>
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@ -98,6 +100,16 @@ static struct dentry *show_all_errors_dent __read_mostly;
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static struct dentry *show_num_errors_dent __read_mostly;
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static struct dentry *num_free_entries_dent __read_mostly;
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static struct dentry *min_free_entries_dent __read_mostly;
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static struct dentry *filter_dent __read_mostly;
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/* per-driver filter related state */
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#define NAME_MAX_LEN 64
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static char current_driver_name[NAME_MAX_LEN] __read_mostly;
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static struct device_driver *current_driver __read_mostly;
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static DEFINE_RWLOCK(driver_name_lock);
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static const char *type2name[4] = { "single", "page",
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"scather-gather", "coherent" };
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@ -105,6 +117,11 @@ static const char *type2name[4] = { "single", "page",
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static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
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"DMA_FROM_DEVICE", "DMA_NONE" };
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/* little merge helper - remove it after the merge window */
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#ifndef BUS_NOTIFY_UNBOUND_DRIVER
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#define BUS_NOTIFY_UNBOUND_DRIVER 0x0005
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#endif
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/*
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* The access to some variables in this macro is racy. We can't use atomic_t
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* here because all these variables are exported to debugfs. Some of them even
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@ -128,9 +145,48 @@ static inline void dump_entry_trace(struct dma_debug_entry *entry)
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#endif
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}
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static bool driver_filter(struct device *dev)
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{
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/* driver filter off */
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if (likely(!current_driver_name[0]))
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return true;
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/* driver filter on and initialized */
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if (current_driver && dev->driver == current_driver)
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return true;
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/* driver filter on but not yet initialized */
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if (!current_driver && current_driver_name[0]) {
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struct device_driver *drv = get_driver(dev->driver);
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unsigned long flags;
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bool ret = false;
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if (!drv)
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return false;
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/* lock to protect against change of current_driver_name */
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read_lock_irqsave(&driver_name_lock, flags);
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if (drv->name &&
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strncmp(current_driver_name, drv->name,
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NAME_MAX_LEN-1) == 0) {
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current_driver = drv;
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ret = true;
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}
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read_unlock_irqrestore(&driver_name_lock, flags);
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put_driver(drv);
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return ret;
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}
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return false;
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}
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#define err_printk(dev, entry, format, arg...) do { \
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error_count += 1; \
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if (show_all_errors || show_num_errors > 0) { \
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if (driver_filter(dev) && \
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(show_all_errors || show_num_errors > 0)) { \
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WARN(1, "%s %s: " format, \
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dev_driver_string(dev), \
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dev_name(dev) , ## arg); \
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@ -442,6 +498,97 @@ out_err:
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return -ENOMEM;
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}
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static ssize_t filter_read(struct file *file, char __user *user_buf,
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size_t count, loff_t *ppos)
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{
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unsigned long flags;
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char buf[NAME_MAX_LEN + 1];
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int len;
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if (!current_driver_name[0])
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return 0;
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/*
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* We can't copy to userspace directly because current_driver_name can
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* only be read under the driver_name_lock with irqs disabled. So
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* create a temporary copy first.
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*/
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read_lock_irqsave(&driver_name_lock, flags);
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len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name);
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read_unlock_irqrestore(&driver_name_lock, flags);
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return simple_read_from_buffer(user_buf, count, ppos, buf, len);
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}
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static ssize_t filter_write(struct file *file, const char __user *userbuf,
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size_t count, loff_t *ppos)
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{
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unsigned long flags;
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char buf[NAME_MAX_LEN];
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size_t len = NAME_MAX_LEN - 1;
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int i;
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/*
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* We can't copy from userspace directly. Access to
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* current_driver_name is protected with a write_lock with irqs
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* disabled. Since copy_from_user can fault and may sleep we
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* need to copy to temporary buffer first
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*/
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len = min(count, len);
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if (copy_from_user(buf, userbuf, len))
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return -EFAULT;
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buf[len] = 0;
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write_lock_irqsave(&driver_name_lock, flags);
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/* Now handle the string we got from userspace very carefully.
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* The rules are:
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* - only use the first token we got
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* - token delimiter is everything looking like a space
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* character (' ', '\n', '\t' ...)
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*
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*/
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if (!isalnum(buf[0])) {
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/*
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If the first character userspace gave us is not
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* alphanumerical then assume the filter should be
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* switched off.
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*/
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if (current_driver_name[0])
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printk(KERN_INFO "DMA-API: switching off dma-debug "
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"driver filter\n");
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current_driver_name[0] = 0;
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current_driver = NULL;
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goto out_unlock;
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}
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|
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/*
|
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* Now parse out the first token and use it as the name for the
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* driver to filter for.
|
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*/
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for (i = 0; i < NAME_MAX_LEN; ++i) {
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current_driver_name[i] = buf[i];
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if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
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break;
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}
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current_driver_name[i] = 0;
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current_driver = NULL;
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printk(KERN_INFO "DMA-API: enable driver filter for driver [%s]\n",
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current_driver_name);
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out_unlock:
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write_unlock_irqrestore(&driver_name_lock, flags);
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return count;
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}
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const struct file_operations filter_fops = {
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.read = filter_read,
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.write = filter_write,
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};
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static int dma_debug_fs_init(void)
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{
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dma_debug_dent = debugfs_create_dir("dma-api", NULL);
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@ -485,6 +632,11 @@ static int dma_debug_fs_init(void)
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if (!min_free_entries_dent)
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goto out_err;
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filter_dent = debugfs_create_file("driver_filter", 0644,
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dma_debug_dent, NULL, &filter_fops);
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if (!filter_dent)
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goto out_err;
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return 0;
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out_err:
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@ -493,9 +645,60 @@ out_err:
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return -ENOMEM;
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}
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static int device_dma_allocations(struct device *dev)
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{
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struct dma_debug_entry *entry;
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unsigned long flags;
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int count = 0, i;
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|
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for (i = 0; i < HASH_SIZE; ++i) {
|
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spin_lock_irqsave(&dma_entry_hash[i].lock, flags);
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list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
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if (entry->dev == dev)
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count += 1;
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}
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spin_unlock_irqrestore(&dma_entry_hash[i].lock, flags);
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}
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return count;
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}
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static int dma_debug_device_change(struct notifier_block *nb,
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unsigned long action, void *data)
|
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{
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struct device *dev = data;
|
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int count;
|
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|
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|
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switch (action) {
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case BUS_NOTIFY_UNBOUND_DRIVER:
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count = device_dma_allocations(dev);
|
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if (count == 0)
|
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break;
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err_printk(dev, NULL, "DMA-API: device driver has pending "
|
||||
"DMA allocations while released from device "
|
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"[count=%d]\n", count);
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break;
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default:
|
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break;
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}
|
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|
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return 0;
|
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}
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|
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void dma_debug_add_bus(struct bus_type *bus)
|
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{
|
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/* FIXME: register notifier */
|
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struct notifier_block *nb;
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|
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nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
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if (nb == NULL) {
|
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printk(KERN_ERR "dma_debug_add_bus: out of memory\n");
|
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return;
|
||||
}
|
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|
||||
nb->notifier_call = dma_debug_device_change;
|
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|
||||
bus_register_notifier(bus, nb);
|
||||
}
|
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|
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/*
|
||||
|
|
@ -818,15 +1021,15 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
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entry->type = dma_debug_sg;
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entry->dev = dev;
|
||||
entry->paddr = sg_phys(s);
|
||||
entry->size = s->length;
|
||||
entry->dev_addr = s->dma_address;
|
||||
entry->size = sg_dma_len(s);
|
||||
entry->dev_addr = sg_dma_address(s);
|
||||
entry->direction = direction;
|
||||
entry->sg_call_ents = nents;
|
||||
entry->sg_mapped_ents = mapped_ents;
|
||||
|
||||
if (!PageHighMem(sg_page(s))) {
|
||||
check_for_stack(dev, sg_virt(s));
|
||||
check_for_illegal_area(dev, sg_virt(s), s->length);
|
||||
check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
|
||||
}
|
||||
|
||||
add_dma_entry(entry);
|
||||
|
|
@ -834,13 +1037,32 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
|
|||
}
|
||||
EXPORT_SYMBOL(debug_dma_map_sg);
|
||||
|
||||
static int get_nr_mapped_entries(struct device *dev, struct scatterlist *s)
|
||||
{
|
||||
struct dma_debug_entry *entry;
|
||||
struct hash_bucket *bucket;
|
||||
unsigned long flags;
|
||||
int mapped_ents = 0;
|
||||
struct dma_debug_entry ref;
|
||||
|
||||
ref.dev = dev;
|
||||
ref.dev_addr = sg_dma_address(s);
|
||||
ref.size = sg_dma_len(s),
|
||||
|
||||
bucket = get_hash_bucket(&ref, &flags);
|
||||
entry = hash_bucket_find(bucket, &ref);
|
||||
if (entry)
|
||||
mapped_ents = entry->sg_mapped_ents;
|
||||
put_hash_bucket(bucket, &flags);
|
||||
|
||||
return mapped_ents;
|
||||
}
|
||||
|
||||
void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
|
||||
int nelems, int dir)
|
||||
{
|
||||
struct dma_debug_entry *entry;
|
||||
struct scatterlist *s;
|
||||
int mapped_ents = 0, i;
|
||||
unsigned long flags;
|
||||
|
||||
if (unlikely(global_disable))
|
||||
return;
|
||||
|
|
@ -851,8 +1073,8 @@ void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
|
|||
.type = dma_debug_sg,
|
||||
.dev = dev,
|
||||
.paddr = sg_phys(s),
|
||||
.dev_addr = s->dma_address,
|
||||
.size = s->length,
|
||||
.dev_addr = sg_dma_address(s),
|
||||
.size = sg_dma_len(s),
|
||||
.direction = dir,
|
||||
.sg_call_ents = 0,
|
||||
};
|
||||
|
|
@ -860,14 +1082,9 @@ void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
|
|||
if (mapped_ents && i >= mapped_ents)
|
||||
break;
|
||||
|
||||
if (mapped_ents == 0) {
|
||||
struct hash_bucket *bucket;
|
||||
if (!i) {
|
||||
ref.sg_call_ents = nelems;
|
||||
bucket = get_hash_bucket(&ref, &flags);
|
||||
entry = hash_bucket_find(bucket, &ref);
|
||||
if (entry)
|
||||
mapped_ents = entry->sg_mapped_ents;
|
||||
put_hash_bucket(bucket, &flags);
|
||||
mapped_ents = get_nr_mapped_entries(dev, s);
|
||||
}
|
||||
|
||||
check_unmap(&ref);
|
||||
|
|
@ -969,14 +1186,20 @@ void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
|
|||
int nelems, int direction)
|
||||
{
|
||||
struct scatterlist *s;
|
||||
int i;
|
||||
int mapped_ents = 0, i;
|
||||
|
||||
if (unlikely(global_disable))
|
||||
return;
|
||||
|
||||
for_each_sg(sg, s, nelems, i) {
|
||||
check_sync(dev, s->dma_address, s->dma_length, 0,
|
||||
direction, true);
|
||||
if (!i)
|
||||
mapped_ents = get_nr_mapped_entries(dev, s);
|
||||
|
||||
if (i >= mapped_ents)
|
||||
break;
|
||||
|
||||
check_sync(dev, sg_dma_address(s), sg_dma_len(s), 0,
|
||||
direction, true);
|
||||
}
|
||||
}
|
||||
EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
|
||||
|
|
@ -985,15 +1208,39 @@ void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
|
|||
int nelems, int direction)
|
||||
{
|
||||
struct scatterlist *s;
|
||||
int i;
|
||||
int mapped_ents = 0, i;
|
||||
|
||||
if (unlikely(global_disable))
|
||||
return;
|
||||
|
||||
for_each_sg(sg, s, nelems, i) {
|
||||
check_sync(dev, s->dma_address, s->dma_length, 0,
|
||||
direction, false);
|
||||
if (!i)
|
||||
mapped_ents = get_nr_mapped_entries(dev, s);
|
||||
|
||||
if (i >= mapped_ents)
|
||||
break;
|
||||
|
||||
check_sync(dev, sg_dma_address(s), sg_dma_len(s), 0,
|
||||
direction, false);
|
||||
}
|
||||
}
|
||||
EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
|
||||
|
||||
static int __init dma_debug_driver_setup(char *str)
|
||||
{
|
||||
int i;
|
||||
|
||||
for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
|
||||
current_driver_name[i] = *str;
|
||||
if (*str == 0)
|
||||
break;
|
||||
}
|
||||
|
||||
if (current_driver_name[0])
|
||||
printk(KERN_INFO "DMA-API: enable driver filter for "
|
||||
"driver [%s]\n", current_driver_name);
|
||||
|
||||
|
||||
return 1;
|
||||
}
|
||||
__setup("dma_debug_driver=", dma_debug_driver_setup);
|
||||
|
|
|
|||
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