diff options
| -rw-r--r-- | common/bouncebuf.c | 75 | ||||
| -rw-r--r-- | drivers/mmc/mxsmmc.c | 30 | ||||
| -rw-r--r-- | include/bouncebuf.h | 33 |
3 files changed, 72 insertions, 66 deletions
diff --git a/common/bouncebuf.c b/common/bouncebuf.c index 4f827f8..1df12cd 100644 --- a/common/bouncebuf.c +++ b/common/bouncebuf.c @@ -27,21 +27,19 @@ #include <errno.h> #include <bouncebuf.h> -static int addr_aligned(void *data, size_t len) +static int addr_aligned(struct bounce_buffer *state) { const ulong align_mask = ARCH_DMA_MINALIGN - 1; /* Check if start is aligned */ - if ((ulong)data & align_mask) { - debug("Unaligned start address %p\n", data); + if ((ulong)state->user_buffer & align_mask) { + debug("Unaligned buffer address %p\n", state->user_buffer); return 0; } - data += len; - - /* Check if end is aligned */ - if ((ulong)data & align_mask) { - debug("Unaligned end address %p\n", data); + /* Check if length is aligned */ + if (state->len != state->len_aligned) { + debug("Unaligned buffer length %d\n", state->len); return 0; } @@ -49,44 +47,53 @@ static int addr_aligned(void *data, size_t len) return 1; } -int bounce_buffer_start(void **data, size_t len, void **backup, uint8_t flags) +int bounce_buffer_start(struct bounce_buffer *state, void *data, + size_t len, unsigned int flags) { - void *tmp; - size_t alen; - - if (addr_aligned(*data, len)) { - *backup = NULL; - return 0; + state->user_buffer = data; + state->bounce_buffer = data; + state->len = len; + state->len_aligned = roundup(len, ARCH_DMA_MINALIGN); + state->flags = flags; + + if (!addr_aligned(state)) { + state->bounce_buffer = memalign(ARCH_DMA_MINALIGN, + state->len_aligned); + if (!state->bounce_buffer) + return -ENOMEM; + + if (state->flags & GEN_BB_READ) + memcpy(state->bounce_buffer, state->user_buffer, + state->len); } - alen = roundup(len, ARCH_DMA_MINALIGN); - tmp = memalign(ARCH_DMA_MINALIGN, alen); - - if (!tmp) - return -ENOMEM; - - if (flags & GEN_BB_READ) - memcpy(tmp, *data, len); - - *backup = *data; - *data = tmp; + /* + * Flush data to RAM so DMA reads can pick it up, + * and any CPU writebacks don't race with DMA writes + */ + flush_dcache_range((unsigned long)state->bounce_buffer, + (unsigned long)(state->bounce_buffer) + + state->len_aligned); return 0; } -int bounce_buffer_stop(void **data, size_t len, void **backup, uint8_t flags) +int bounce_buffer_stop(struct bounce_buffer *state) { - void *tmp = *data; + if (state->flags & GEN_BB_WRITE) { + /* Invalidate cache so that CPU can see any newly DMA'd data */ + invalidate_dcache_range((unsigned long)state->bounce_buffer, + (unsigned long)(state->bounce_buffer) + + state->len_aligned); + } - /* The buffer was already aligned, since "backup" is NULL. */ - if (!*backup) + if (state->bounce_buffer == state->user_buffer) return 0; - if (flags & GEN_BB_WRITE) - memcpy(*backup, *data, len); + if (state->flags & GEN_BB_WRITE) + memcpy(state->user_buffer, state->bounce_buffer, state->len); - *data = *backup; - free(tmp); + free(state->bounce_buffer); return 0; } diff --git a/drivers/mmc/mxsmmc.c b/drivers/mmc/mxsmmc.c index 109acbf..024df59 100644 --- a/drivers/mmc/mxsmmc.c +++ b/drivers/mmc/mxsmmc.c @@ -96,11 +96,11 @@ static int mxsmmc_send_cmd_pio(struct mxsmmc_priv *priv, struct mmc_data *data) static int mxsmmc_send_cmd_dma(struct mxsmmc_priv *priv, struct mmc_data *data) { uint32_t data_count = data->blocksize * data->blocks; - uint32_t cache_data_count = roundup(data_count, ARCH_DMA_MINALIGN); int dmach; struct mxs_dma_desc *desc = priv->desc; - void *addr, *backup; - uint8_t flags; + void *addr; + unsigned int flags; + struct bounce_buffer bbstate; memset(desc, 0, sizeof(struct mxs_dma_desc)); desc->address = (dma_addr_t)desc; @@ -115,19 +115,9 @@ static int mxsmmc_send_cmd_dma(struct mxsmmc_priv *priv, struct mmc_data *data) flags = GEN_BB_READ; } - bounce_buffer_start(&addr, data_count, &backup, flags); + bounce_buffer_start(&bbstate, addr, data_count, flags); - priv->desc->cmd.address = (dma_addr_t)addr; - - if (data->flags & MMC_DATA_WRITE) { - /* Flush data to DRAM so DMA can pick them up */ - flush_dcache_range((uint32_t)addr, - (uint32_t)(addr) + cache_data_count); - } - - /* Invalidate the area, so no writeback into the RAM races with DMA */ - invalidate_dcache_range((uint32_t)priv->desc->cmd.address, - (uint32_t)(priv->desc->cmd.address + cache_data_count)); + priv->desc->cmd.address = (dma_addr_t)bbstate.bounce_buffer; priv->desc->cmd.data |= MXS_DMA_DESC_IRQ | MXS_DMA_DESC_DEC_SEM | (data_count << MXS_DMA_DESC_BYTES_OFFSET); @@ -135,17 +125,11 @@ static int mxsmmc_send_cmd_dma(struct mxsmmc_priv *priv, struct mmc_data *data) dmach = MXS_DMA_CHANNEL_AHB_APBH_SSP0 + priv->id; mxs_dma_desc_append(dmach, priv->desc); if (mxs_dma_go(dmach)) { - bounce_buffer_stop(&addr, data_count, &backup, flags); + bounce_buffer_stop(&bbstate); return COMM_ERR; } - /* The data arrived into DRAM, invalidate cache over them */ - if (data->flags & MMC_DATA_READ) { - invalidate_dcache_range((uint32_t)addr, - (uint32_t)(addr) + cache_data_count); - } - - bounce_buffer_stop(&addr, data_count, &backup, flags); + bounce_buffer_stop(&bbstate); return 0; } diff --git a/include/bouncebuf.h b/include/bouncebuf.h index aa2278c..707b588 100644 --- a/include/bouncebuf.h +++ b/include/bouncebuf.h @@ -25,6 +25,8 @@ #ifndef __INCLUDE_BOUNCEBUF_H__ #define __INCLUDE_BOUNCEBUF_H__ +#include <linux/types.h> + /* * GEN_BB_READ -- Data are read from the buffer eg. by DMA hardware. * The source buffer is copied into the bounce buffer (if unaligned, otherwise @@ -51,23 +53,36 @@ */ #define GEN_BB_RW (GEN_BB_READ | GEN_BB_WRITE) +struct bounce_buffer { + /* Copy of data parameter passed to start() */ + void *user_buffer; + /* + * DMA-aligned buffer. This field is always set to the value that + * should be used for DMA; either equal to .user_buffer, or to a + * freshly allocated aligned buffer. + */ + void *bounce_buffer; + /* Copy of len parameter passed to start() */ + size_t len; + /* DMA-aligned buffer length */ + size_t len_aligned; + /* Copy of flags parameter passed to start() */ + unsigned int flags; +}; + /** * bounce_buffer_start() -- Start the bounce buffer session + * state: stores state passed between bounce_buffer_{start,stop} * data: pointer to buffer to be aligned * len: length of the buffer - * backup: pointer to backup buffer (the original value is stored here if - * needed * flags: flags describing the transaction, see above. */ -int bounce_buffer_start(void **data, size_t len, void **backup, uint8_t flags); +int bounce_buffer_start(struct bounce_buffer *state, void *data, + size_t len, unsigned int flags); /** * bounce_buffer_stop() -- Finish the bounce buffer session - * data: pointer to buffer that was aligned - * len: length of the buffer - * backup: pointer to backup buffer (the original value is stored here if - * needed - * flags: flags describing the transaction, see above. + * state: stores state passed between bounce_buffer_{start,stop} */ -int bounce_buffer_stop(void **data, size_t len, void **backup, uint8_t flags); +int bounce_buffer_stop(struct bounce_buffer *state); #endif |