alloc_percpu: Use __get_cpu_ptr in drivers/dma Impact: slight efficiency improvement on some archs. Let's use __get_cpu_ptr and get_cpu_ptr now, rather than per_cpu_ptr(..., smp_processor_id()). Signed-off-by: Rusty Russell Cc: Maciej Sosnowski Cc: Dan Williams --- drivers/dma/dmaengine.c | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-) diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -326,17 +326,10 @@ arch_initcall(dma_channel_table_init); */ struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type) { - struct dma_chan *chan; - int cpu; - WARN_ONCE(dmaengine_ref_count == 0, "client called %s without a reference", __func__); - cpu = get_cpu(); - chan = per_cpu_ptr(channel_table[tx_type], cpu)->chan; - put_cpu(); - - return chan; + return __raw_get_cpu_ptr(channel_table[tx_type])->chan; } EXPORT_SYMBOL(dma_find_channel); @@ -772,6 +765,7 @@ dma_async_memcpy_buf_to_buf(struct dma_c struct dma_async_tx_descriptor *tx; dma_addr_t dma_dest, dma_src; dma_cookie_t cookie; + struct dma_chan_percpu *local; int cpu; dma_src = dma_map_single(dev->dev, src, len, DMA_TO_DEVICE); @@ -788,10 +782,10 @@ dma_async_memcpy_buf_to_buf(struct dma_c tx->callback = NULL; cookie = tx->tx_submit(tx); - cpu = get_cpu(); - per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; - per_cpu_ptr(chan->local, cpu)->memcpy_count++; - put_cpu(); + local = get_cpu_ptr(chan->local); + local->bytes_transferred += len; + local->memcpy_count++; + put_cpu_ptr(chan->local); return cookie; } @@ -818,6 +812,7 @@ dma_async_memcpy_buf_to_pg(struct dma_ch struct dma_async_tx_descriptor *tx; dma_addr_t dma_dest, dma_src; dma_cookie_t cookie; + struct dma_chan_percpu *local; int cpu; dma_src = dma_map_single(dev->dev, kdata, len, DMA_TO_DEVICE); @@ -834,10 +829,10 @@ dma_async_memcpy_buf_to_pg(struct dma_ch tx->callback = NULL; cookie = tx->tx_submit(tx); - cpu = get_cpu(); - per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; - per_cpu_ptr(chan->local, cpu)->memcpy_count++; - put_cpu(); + local = get_cpu_ptr(chan->local); + local->bytes_transferred += len; + local->memcpy_count++; + put_cpu_ptr(chan->local); return cookie; } @@ -866,6 +861,7 @@ dma_async_memcpy_pg_to_pg(struct dma_cha struct dma_async_tx_descriptor *tx; dma_addr_t dma_dest, dma_src; dma_cookie_t cookie; + struct dma_chan_percpu *local; int cpu; dma_src = dma_map_page(dev->dev, src_pg, src_off, len, DMA_TO_DEVICE); @@ -883,10 +879,10 @@ dma_async_memcpy_pg_to_pg(struct dma_cha tx->callback = NULL; cookie = tx->tx_submit(tx); - cpu = get_cpu(); - per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; - per_cpu_ptr(chan->local, cpu)->memcpy_count++; - put_cpu(); + local = get_cpu_ptr(chan->local); + local->bytes_transferred += len; + local->memcpy_count++; + put_cpu_ptr(chan->local); return cookie; }