From: Pierre Ossman Date: Sun, 20 Jul 2008 22:32:11 +0000 (+0200) Subject: sdhci: highmem capable PIO routines X-Git-Tag: v2.6.27-rc1~851^2 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7659150c60839a2bd31f74e866374abb9be17e43;p=linux-2.6 sdhci: highmem capable PIO routines Improve the PIO handling so that it can service highmem pages. Signed-off-by: Pierre Ossman --- diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 8b1f412144..c3a5db72dd 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -173,119 +173,95 @@ static void sdhci_led_control(struct led_classdev *led, * * \*****************************************************************************/ -static inline char* sdhci_sg_to_buffer(struct sdhci_host* host) -{ - return sg_virt(host->cur_sg); -} - -static inline int sdhci_next_sg(struct sdhci_host* host) -{ - /* - * Skip to next SG entry. - */ - host->cur_sg++; - host->num_sg--; - - /* - * Any entries left? - */ - if (host->num_sg > 0) { - host->offset = 0; - host->remain = host->cur_sg->length; - } - - return host->num_sg; -} - static void sdhci_read_block_pio(struct sdhci_host *host) { - int blksize, chunk_remain; - u32 data; - char *buffer; - int size; + unsigned long flags; + size_t blksize, len, chunk; + u32 scratch; + u8 *buf; DBG("PIO reading\n"); blksize = host->data->blksz; - chunk_remain = 0; - data = 0; + chunk = 0; - buffer = sdhci_sg_to_buffer(host) + host->offset; + local_irq_save(flags); while (blksize) { - if (chunk_remain == 0) { - data = readl(host->ioaddr + SDHCI_BUFFER); - chunk_remain = min(blksize, 4); - } + if (!sg_miter_next(&host->sg_miter)) + BUG(); - size = min(host->remain, chunk_remain); + len = min(host->sg_miter.length, blksize); - chunk_remain -= size; - blksize -= size; - host->offset += size; - host->remain -= size; + blksize -= len; + host->sg_miter.consumed = len; - while (size) { - *buffer = data & 0xFF; - buffer++; - data >>= 8; - size--; - } + buf = host->sg_miter.addr; - if (host->remain == 0) { - if (sdhci_next_sg(host) == 0) { - BUG_ON(blksize != 0); - return; + while (len) { + if (chunk == 0) { + scratch = readl(host->ioaddr + SDHCI_BUFFER); + chunk = 4; } - buffer = sdhci_sg_to_buffer(host); + + *buf = scratch & 0xFF; + + buf++; + scratch >>= 8; + chunk--; + len--; } } + + sg_miter_stop(&host->sg_miter); + + local_irq_restore(flags); } static void sdhci_write_block_pio(struct sdhci_host *host) { - int blksize, chunk_remain; - u32 data; - char *buffer; - int bytes, size; + unsigned long flags; + size_t blksize, len, chunk; + u32 scratch; + u8 *buf; DBG("PIO writing\n"); blksize = host->data->blksz; - chunk_remain = 4; - data = 0; + chunk = 0; + scratch = 0; - bytes = 0; - buffer = sdhci_sg_to_buffer(host) + host->offset; + local_irq_save(flags); while (blksize) { - size = min(host->remain, chunk_remain); - - chunk_remain -= size; - blksize -= size; - host->offset += size; - host->remain -= size; - - while (size) { - data >>= 8; - data |= (u32)*buffer << 24; - buffer++; - size--; - } + if (!sg_miter_next(&host->sg_miter)) + BUG(); - if (chunk_remain == 0) { - writel(data, host->ioaddr + SDHCI_BUFFER); - chunk_remain = min(blksize, 4); - } + len = min(host->sg_miter.length, blksize); + + blksize -= len; + host->sg_miter.consumed = len; + + buf = host->sg_miter.addr; - if (host->remain == 0) { - if (sdhci_next_sg(host) == 0) { - BUG_ON(blksize != 0); - return; + while (len) { + scratch |= (u32)*buf << (chunk * 8); + + buf++; + chunk++; + len--; + + if ((chunk == 4) || ((len == 0) && (blksize == 0))) { + writel(scratch, host->ioaddr + SDHCI_BUFFER); + chunk = 0; + scratch = 0; } - buffer = sdhci_sg_to_buffer(host); } } + + sg_miter_stop(&host->sg_miter); + + local_irq_restore(flags); } static void sdhci_transfer_pio(struct sdhci_host *host) @@ -294,7 +270,7 @@ static void sdhci_transfer_pio(struct sdhci_host *host) BUG_ON(!host->data); - if (host->num_sg == 0) + if (host->blocks == 0) return; if (host->data->flags & MMC_DATA_READ) @@ -308,7 +284,8 @@ static void sdhci_transfer_pio(struct sdhci_host *host) else sdhci_write_block_pio(host); - if (host->num_sg == 0) + host->blocks--; + if (host->blocks == 0) break; } @@ -713,11 +690,9 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data) } if (!(host->flags & SDHCI_REQ_USE_DMA)) { - host->cur_sg = data->sg; - host->num_sg = data->sg_len; - - host->offset = 0; - host->remain = host->cur_sg->length; + sg_miter_start(&host->sg_miter, + data->sg, data->sg_len, SG_MITER_ATOMIC); + host->blocks = data->blocks; } /* We do not handle DMA boundaries, so set it to max (512 KiB) */ @@ -1583,9 +1558,15 @@ int sdhci_add_host(struct sdhci_host *host) } } - /* XXX: Hack to get MMC layer to avoid highmem */ - if (!(host->flags & SDHCI_USE_DMA)) - mmc_dev(host->mmc)->dma_mask = NULL; + /* + * If we use DMA, then it's up to the caller to set the DMA + * mask, but PIO does not need the hw shim so we set a new + * mask here in that case. + */ + if (!(host->flags & SDHCI_USE_DMA)) { + host->dma_mask = DMA_BIT_MASK(64); + mmc_dev(host->mmc)->dma_mask = &host->dma_mask; + } host->max_clk = (caps & SDHCI_CLOCK_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT; diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index 5bb3552817..a06bf8b893 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -212,6 +212,7 @@ struct sdhci_host { /* Internal data */ struct mmc_host *mmc; /* MMC structure */ + u64 dma_mask; /* custom DMA mask */ #ifdef CONFIG_LEDS_CLASS struct led_classdev led; /* LED control */ @@ -238,10 +239,8 @@ struct sdhci_host { struct mmc_data *data; /* Current data request */ unsigned int data_early:1; /* Data finished before cmd */ - struct scatterlist *cur_sg; /* We're working on this */ - int num_sg; /* Entries left */ - int offset; /* Offset into current sg */ - int remain; /* Bytes left in current */ + struct sg_mapping_iter sg_miter; /* SG state for PIO */ + unsigned int blocks; /* remaining PIO blocks */ int sg_count; /* Mapped sg entries */