Merge branch 'iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (61 commits)
  amd-iommu: remove unnecessary "AMD IOMMU: " prefix
  amd-iommu: detach device explicitly before attaching it to a new domain
  amd-iommu: remove BUS_NOTIFY_BOUND_DRIVER handling
  dma-debug: simplify logic in driver_filter()
  dma-debug: disable/enable irqs only once in device_dma_allocations
  dma-debug: use pr_* instead of printk(KERN_* ...)
  dma-debug: code style fixes
  dma-debug: comment style fixes
  dma-debug: change hash_bucket_find from first-fit to best-fit
  x86: enable GART-IOMMU only after setting up protection methods
  amd_iommu: fix lock imbalance
  dma-debug: add documentation for the driver filter
  dma-debug: add dma_debug_driver kernel command line
  dma-debug: add debugfs file for driver filter
  dma-debug: add variables and checks for driver filter
  dma-debug: fix debug_dma_sync_sg_for_cpu and debug_dma_sync_sg_for_device
  dma-debug: use sg_dma_len accessor
  dma-debug: use sg_dma_address accessor instead of using dma_address directly
  amd-iommu: don't free dma adresses below 512MB with CONFIG_IOMMU_STRESS
  amd-iommu: don't preallocate page tables with CONFIG_IOMMU_STRESS
  ...

1 files changed, 12 insertions, 0 deletions

diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index d9aa43d78bcc..25fb8bcf32a2 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -704,12 +704,24 @@ this directory the following files can currently be found:
                                 The current number of free dma_debug_entries
                                 in the allocator.
 
+        dma-api/driver-filter
+                                You can write a name of a driver into this file
+                                to limit the debug output to requests from that
+                                particular driver. Write an empty string to
+                                that file to disable the filter and see
+                                all errors again.
+
 If you have this code compiled into your kernel it will be enabled by default.
 If you want to boot without the bookkeeping anyway you can provide
 'dma_debug=off' as a boot parameter. This will disable DMA-API debugging.
 Notice that you can not enable it again at runtime. You have to reboot to do
 so.
 
+If you want to see debug messages only for a special device driver you can
+specify the dma_debug_driver=<drivername> parameter. This will enable the
+driver filter at boot time. The debug code will only print errors for that
+driver afterwards. This filter can be disabled or changed later using debugfs.
+
 When the code disables itself at runtime this is most likely because it ran
 out of dma_debug_entries. These entries are preallocated at boot. The number
 of preallocated entries is defined per architecture. If it is too low for you