diff options
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/mv_xor.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c index b165e0b31a48..a0e118725ae3 100644 --- a/drivers/dma/mv_xor.c +++ b/drivers/dma/mv_xor.c @@ -26,6 +26,7 @@ #include <linux/of.h> #include <linux/of_irq.h> #include <linux/irqdomain.h> +#include <linux/cpumask.h> #include <linux/platform_data/dma-mv_xor.h> #include "dmaengine.h" @@ -1127,12 +1128,15 @@ static const struct of_device_id mv_xor_dt_ids[] = { }; MODULE_DEVICE_TABLE(of, mv_xor_dt_ids); +static unsigned int mv_xor_engine_count; + static int mv_xor_probe(struct platform_device *pdev) { const struct mbus_dram_target_info *dram; struct mv_xor_device *xordev; struct mv_xor_platform_data *pdata = dev_get_platdata(&pdev->dev); struct resource *res; + unsigned int max_engines, max_channels; int i, ret; int op_in_desc; @@ -1176,6 +1180,21 @@ static int mv_xor_probe(struct platform_device *pdev) if (!IS_ERR(xordev->clk)) clk_prepare_enable(xordev->clk); + /* + * We don't want to have more than one channel per CPU in + * order for async_tx to perform well. So we limit the number + * of engines and channels so that we take into account this + * constraint. Note that we also want to use channels from + * separate engines when possible. + */ + max_engines = num_present_cpus(); + max_channels = min_t(unsigned int, + MV_XOR_MAX_CHANNELS, + DIV_ROUND_UP(num_present_cpus(), 2)); + + if (mv_xor_engine_count >= max_engines) + return 0; + if (pdev->dev.of_node) { struct device_node *np; int i = 0; @@ -1189,6 +1208,9 @@ static int mv_xor_probe(struct platform_device *pdev) int irq; op_in_desc = (int)of_id->data; + if (i >= max_channels) + continue; + dma_cap_zero(cap_mask); dma_cap_set(DMA_MEMCPY, cap_mask); dma_cap_set(DMA_XOR, cap_mask); @@ -1212,7 +1234,7 @@ static int mv_xor_probe(struct platform_device *pdev) i++; } } else if (pdata && pdata->channels) { - for (i = 0; i < MV_XOR_MAX_CHANNELS; i++) { + for (i = 0; i < max_channels; i++) { struct mv_xor_channel_data *cd; struct mv_xor_chan *chan; int irq; |