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authorLinus Torvalds <torvalds@linux-foundation.org>2013-09-09 18:07:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-09-09 18:07:15 -0700
commit26b0332e30c7f93e780aaa054bd84e3437f84354 (patch)
treee9cf240b67bf7eebae9fabbdba4e6a0fdfd359d7 /drivers/dma/dmaengine.c
parent640414171818c6293c23e74a28d1c69b2a1a7fe5 (diff)
parent4a43f394a08214eaf92cdd8ce3eae75e555323d8 (diff)
downloadop-kernel-dev-26b0332e30c7f93e780aaa054bd84e3437f84354.zip
op-kernel-dev-26b0332e30c7f93e780aaa054bd84e3437f84354.tar.gz
Merge tag 'dmaengine-3.12' of git://git.kernel.org/pub/scm/linux/kernel/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
Diffstat (limited to 'drivers/dma/dmaengine.c')
-rw-r--r--drivers/dma/dmaengine.c55
1 files changed, 27 insertions, 28 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 99af4db..eee16b0 100644
--- a/drivers/dma/dmaengine.c
+++ b/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;
}
}
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