diff options
author | Ingo Molnar <mingo@kernel.org> | 2012-04-13 09:57:10 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2012-04-13 09:57:10 +0200 |
commit | a385ec4f11bdcf81af094c03e2444ee9b7fad2e5 (patch) | |
tree | a2c186cb828e3713c2ec48a4d7191166fb798b3d /drivers/dma/dmaengine.h | |
parent | 659c36fcda403013a01b85da07cf2d9711e6d6c7 (diff) | |
parent | 0034102808e0dbbf3a2394b82b1bb40b5778de9e (diff) |
Merge tag 'v3.4-rc2' into perf/core
Merge Linux 3.4-rc2: we were on v3.3, update the base.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/dma/dmaengine.h')
-rw-r--r-- | drivers/dma/dmaengine.h | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h new file mode 100644 index 00000000000..17f983a4e9b --- /dev/null +++ b/drivers/dma/dmaengine.h @@ -0,0 +1,89 @@ +/* + * The contents of this file are private to DMA engine drivers, and is not + * part of the API to be used by DMA engine users. + */ +#ifndef DMAENGINE_H +#define DMAENGINE_H + +#include <linux/bug.h> +#include <linux/dmaengine.h> + +/** + * dma_cookie_init - initialize the cookies for a DMA channel + * @chan: dma channel to initialize + */ +static inline void dma_cookie_init(struct dma_chan *chan) +{ + chan->cookie = DMA_MIN_COOKIE; + chan->completed_cookie = DMA_MIN_COOKIE; +} + +/** + * dma_cookie_assign - assign a DMA engine cookie to the descriptor + * @tx: descriptor needing cookie + * + * Assign a unique non-zero per-channel cookie to the descriptor. + * Note: caller is expected to hold a lock to prevent concurrency. + */ +static inline dma_cookie_t dma_cookie_assign(struct dma_async_tx_descriptor *tx) +{ + struct dma_chan *chan = tx->chan; + dma_cookie_t cookie; + + cookie = chan->cookie + 1; + if (cookie < DMA_MIN_COOKIE) + cookie = DMA_MIN_COOKIE; + tx->cookie = chan->cookie = cookie; + + return cookie; +} + +/** + * dma_cookie_complete - complete a descriptor + * @tx: descriptor to complete + * + * Mark this descriptor complete by updating the channels completed + * cookie marker. Zero the descriptors cookie to prevent accidental + * repeated completions. + * + * Note: caller is expected to hold a lock to prevent concurrency. + */ +static inline void dma_cookie_complete(struct dma_async_tx_descriptor *tx) +{ + BUG_ON(tx->cookie < DMA_MIN_COOKIE); + tx->chan->completed_cookie = tx->cookie; + tx->cookie = 0; +} + +/** + * dma_cookie_status - report cookie status + * @chan: dma channel + * @cookie: cookie we are interested in + * @state: dma_tx_state structure to return last/used cookies + * + * Report the status of the cookie, filling in the state structure if + * non-NULL. No locking is required. + */ +static inline enum dma_status dma_cookie_status(struct dma_chan *chan, + dma_cookie_t cookie, struct dma_tx_state *state) +{ + dma_cookie_t used, complete; + + used = chan->cookie; + complete = chan->completed_cookie; + barrier(); + if (state) { + state->last = complete; + state->used = used; + state->residue = 0; + } + return dma_async_is_complete(cookie, complete, used); +} + +static inline void dma_set_residue(struct dma_tx_state *state, u32 residue) +{ + if (state) + state->residue = residue; +} + +#endif |