Merge tag 'dmaengine-3.12' of git://git.kernel.org/pub/scm/linux/kern…

…el/git/djbw/dmaengine

Pull dmaengine update from Dan Williams:
 "Collection of random updates to the core and some end-driver fixups
  for ioatdma and mv_xor:
   - NUMA aware channel allocation
   - Cleanup dmatest debugfs interface
   - ioat: make raid-support Atom only
   - mv_xor: big endian

  Aside from the top three commits these have all had some soak time in
  -next.  The top commit fixes a recent build breakage.

  It has been a long while since my last pull request, hopefully it does
  not show.  Thanks to Vinod for keeping an eye on drivers/dma/ this
  past year"

* tag 'dmaengine-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/dmaengine:
  dmaengine: dma_sync_wait and dma_find_channel undefined
  MAINTAINERS: update email for Dan Williams
  dma: mv_xor: Fix incorrect error path
  ioatdma: silence GCC warnings
  dmaengine: make dma_channel_rebalance() NUMA aware
  dmaengine: make dma_submit_error() return an error code
  ioatdma: disable RAID on non-Atom platforms and reenable unaligned copies
  mv_xor: support big endian systems using descriptor swap feature
  mv_xor: use {readl, writel}_relaxed instead of __raw_{readl, writel}
  dmatest: print message on debug level in case of no error
  dmatest: remove IS_ERR_OR_NULL checks of debugfs calls
  dmatest: make module parameters writable

Documentation/dmatest.txt

@@ -16,15 +16,16 @@ be built as module or inside kernel. Let's consider those cases.
 	Part 2 - When dmatest is built as a module...
 
 After mounting debugfs and loading the module, the /sys/kernel/debug/dmatest
-folder with nodes will be created. They are the same as module parameters with
-addition of the 'run' node that controls run and stop phases of the test.
+folder with nodes will be created. There are two important files located. First
+is the 'run' node that controls run and stop phases of the test, and the second
+one, 'results', is used to get the test case results.
 
 Note that in this case test will not run on load automatically.
 
 Example of usage:
-	% echo dma0chan0 > /sys/kernel/debug/dmatest/channel
-	% echo 2000 > /sys/kernel/debug/dmatest/timeout
-	% echo 1 > /sys/kernel/debug/dmatest/iterations
+	% echo dma0chan0 > /sys/module/dmatest/parameters/channel
+	% echo 2000 > /sys/module/dmatest/parameters/timeout
+	% echo 1 > /sys/module/dmatest/parameters/iterations
 	% echo 1 > /sys/kernel/debug/dmatest/run
 
 Hint: available channel list could be extracted by running the following
@@ -55,8 +56,8 @@ for the first performed test. After user gets a control, the test could be
 re-run with the same or different parameters. For the details see the above
 section "Part 2 - When dmatest is built as a module..."
 
-In both cases the module parameters are used as initial values for the test case.
-You always could check them at run-time by running
+In both cases the module parameters are used as the actual values for the test
+case. You always could check them at run-time by running
 	% grep -H . /sys/module/dmatest/parameters/*
 
 	Part 4 - Gathering the test results

MAINTAINERS

@@ -933,24 +933,24 @@ F:	arch/arm/mach-pxa/colibri-pxa270-income.c
 
 ARM/INTEL IOP32X ARM ARCHITECTURE
 M:	Lennert Buytenhek <kernel@wantstofly.org>
-M:	Dan Williams <djbw@fb.com>
+M:	Dan Williams <dan.j.williams@intel.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 
 ARM/INTEL IOP33X ARM ARCHITECTURE
-M:	Dan Williams <djbw@fb.com>
+M:	Dan Williams <dan.j.williams@intel.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 
 ARM/INTEL IOP13XX ARM ARCHITECTURE
 M:	Lennert Buytenhek <kernel@wantstofly.org>
-M:	Dan Williams <djbw@fb.com>
+M:	Dan Williams <dan.j.williams@intel.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 
 ARM/INTEL IQ81342EX MACHINE SUPPORT
 M:	Lennert Buytenhek <kernel@wantstofly.org>
-M:	Dan Williams <djbw@fb.com>
+M:	Dan Williams <dan.j.williams@intel.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 
@@ -975,7 +975,7 @@ F:	drivers/pcmcia/pxa2xx_stargate2.c
 
 ARM/INTEL XSC3 (MANZANO) ARM CORE
 M:	Lennert Buytenhek <kernel@wantstofly.org>
-M:	Dan Williams <djbw@fb.com>
+M:	Dan Williams <dan.j.williams@intel.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 
@@ -1386,7 +1386,7 @@ F:	drivers/platform/x86/asus*.c
 F:	drivers/platform/x86/eeepc*.c
 
 ASYNCHRONOUS TRANSFERS/TRANSFORMS (IOAT) API
-M:	Dan Williams <djbw@fb.com>
+M:	Dan Williams <dan.j.williams@intel.com>
 W:	http://sourceforge.net/projects/xscaleiop
 S:	Maintained
 F:	Documentation/crypto/async-tx-api.txt
@@ -2691,7 +2691,7 @@ T:	git git://git.linaro.org/people/sumitsemwal/linux-dma-buf.git
 
 DMA GENERIC OFFLOAD ENGINE SUBSYSTEM
 M:	Vinod Koul <vinod.koul@intel.com>
-M:	Dan Williams <djbw@fb.com>
+M:	Dan Williams <dan.j.williams@intel.com>
 S:	Supported
 F:	drivers/dma/
 F:	include/linux/dma*
@@ -4323,7 +4323,7 @@ F:	arch/x86/kernel/microcode_core.c
 F:	arch/x86/kernel/microcode_intel.c
 
 INTEL I/OAT DMA DRIVER
-M:	Dan Williams <djbw@fb.com>
+M:	Dan Williams <dan.j.williams@intel.com>
 S:	Maintained
 F:	drivers/dma/ioat*
 
@@ -4336,7 +4336,7 @@ F:	drivers/iommu/intel-iommu.c
 F:	include/linux/intel-iommu.h
 
 INTEL IOP-ADMA DMA DRIVER
-M:	Dan Williams <djbw@fb.com>
+M:	Dan Williams <dan.j.williams@intel.com>
 S:	Odd fixes
 F:	drivers/dma/iop-adma.c
 

drivers/dma/dmaengine.c

@@ -382,20 +382,30 @@ void dma_issue_pending_all(void)
 EXPORT_SYMBOL(dma_issue_pending_all);
 
 /**
- * nth_chan - returns the nth channel of the given capability
+ * dma_chan_is_local - returns true if the channel is in the same numa-node as the cpu
+ */
+static bool dma_chan_is_local(struct dma_chan *chan, int cpu)
+{
+	int node = dev_to_node(chan->device->dev);
+	return node == -1 || cpumask_test_cpu(cpu, cpumask_of_node(node));
+}
+
+/**
+ * min_chan - returns the channel with min count and in the same numa-node as the cpu
  * @cap: capability to match
- * @n: nth channel desired
+ * @cpu: cpu index which the channel should be close to
  *
- * Defaults to returning the channel with the desired capability and the
- * lowest reference count when 'n' cannot be satisfied.  Must be called
- * under dma_list_mutex.
+ * If some channels are close to the given cpu, the one with the lowest
+ * reference count is returned. Otherwise, cpu is ignored and only the
+ * reference count is taken into account.
+ * Must be called under dma_list_mutex.
  */
-static struct dma_chan *nth_chan(enum dma_transaction_type cap, int n)
+static struct dma_chan *min_chan(enum dma_transaction_type cap, int cpu)
 {
 	struct dma_device *device;
 	struct dma_chan *chan;
-	struct dma_chan *ret = NULL;
 	struct dma_chan *min = NULL;
+	struct dma_chan *localmin = NULL;
 
 	list_for_each_entry(device, &dma_device_list, global_node) {
 		if (!dma_has_cap(cap, device->cap_mask) ||
@@ -404,27 +414,22 @@ static struct dma_chan *nth_chan(enum dma_transaction_type cap, int n)
 		list_for_each_entry(chan, &device->channels, device_node) {
 			if (!chan->client_count)
 				continue;
-			if (!min)
-				min = chan;
-			else if (chan->table_count < min->table_count)
+			if (!min || chan->table_count < min->table_count)
 				min = chan;
 
-			if (n-- == 0) {
-				ret = chan;
-				break; /* done */
-			}
+			if (dma_chan_is_local(chan, cpu))
+				if (!localmin ||
+				    chan->table_count < localmin->table_count)
+					localmin = chan;
 		}
-		if (ret)
-			break; /* done */
 	}
 
-	if (!ret)
-		ret = min;
+	chan = localmin ? localmin : min;
 
-	if (ret)
-		ret->table_count++;
+	if (chan)
+		chan->table_count++;
 
-	return ret;
+	return chan;
 }
 
 /**
@@ -441,7 +446,6 @@ static void dma_channel_rebalance(void)
 	struct dma_device *device;
 	int cpu;
 	int cap;
-	int n;
 
 	/* undo the last distribution */
 	for_each_dma_cap_mask(cap, dma_cap_mask_all)
@@ -460,14 +464,9 @@ static void dma_channel_rebalance(void)
 		return;
 
 	/* redistribute available channels */
-	n = 0;
 	for_each_dma_cap_mask(cap, dma_cap_mask_all)
 		for_each_online_cpu(cpu) {
-			if (num_possible_cpus() > 1)
-				chan = nth_chan(cap, n++);
-			else
-				chan = nth_chan(cap, -1);
-
+			chan = min_chan(cap, cpu);
 			per_cpu_ptr(channel_table[cap], cpu)->chan = chan;
 		}
 }