mmc: mmci: implement pre_req() and post_req()

pre_req() runs dma_map_sg() and prepares the dma descriptor for the next
mmc data transfer. post_req() runs dma_unmap_sg.  If not calling pre_req()
before mmci_request(), mmci_request() will prepare the cache and dma just
like it did it before.  It is optional to use pre_req() and post_req()
for mmci.

Signed-off-by: Per Forlin <per.forlin@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index fe14072..fef7140 100644 (file)
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -226,6 +226,9 @@ static void __devinit mmci_dma_setup(struct mmci_host *host)
                return;
        }
 
+       /* initialize pre request cookie */
+       host->next_data.cookie = 1;
+
        /* Try to acquire a generic DMA engine slave channel */
        dma_cap_zero(mask);
        dma_cap_set(DMA_SLAVE, mask);
@@ -335,7 +338,8 @@ static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
                dir = DMA_FROM_DEVICE;
        }
 
-       dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
+       if (!data->host_cookie)
+               dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
 
        /*
         * Use of DMA with scatter-gather is impossible.
@@ -353,7 +357,8 @@ static void mmci_dma_data_error(struct mmci_host *host)
        dmaengine_terminate_all(host->dma_current);
 }
 
-static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
+static int mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
+                             struct mmci_host_next *next)
 {
        struct variant_data *variant = host->variant;
        struct dma_slave_config conf = {
@@ -364,13 +369,20 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
                .src_maxburst = variant->fifohalfsize >> 2, /* # of words */
                .dst_maxburst = variant->fifohalfsize >> 2, /* # of words */
        };
-       struct mmc_data *data = host->data;
        struct dma_chan *chan;
        struct dma_device *device;
        struct dma_async_tx_descriptor *desc;
        int nr_sg;
 
-       host->dma_current = NULL;
+       /* Check if next job is already prepared */
+       if (data->host_cookie && !next &&
+           host->dma_current && host->dma_desc_current)
+               return 0;
+
+       if (!next) {
+               host->dma_current = NULL;
+               host->dma_desc_current = NULL;
+       }
 
        if (data->flags & MMC_DATA_READ) {
                conf.direction = DMA_FROM_DEVICE;
@@ -385,7 +397,7 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
                return -EINVAL;
 
        /* If less than or equal to the fifo size, don't bother with DMA */
-       if (host->size <= variant->fifosize)
+       if (data->blksz * data->blocks <= variant->fifosize)
                return -EINVAL;
 
        device = chan->device;
@@ -399,14 +411,38 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
        if (!desc)
                goto unmap_exit;
 
-       /* Okay, go for it. */
-       host->dma_current = chan;
+       if (next) {
+               next->dma_chan = chan;
+               next->dma_desc = desc;
+       } else {
+               host->dma_current = chan;
+               host->dma_desc_current = desc;
+       }
+
+       return 0;
 
+ unmap_exit:
+       if (!next)
+               dmaengine_terminate_all(chan);
+       dma_unmap_sg(device->dev, data->sg, data->sg_len, conf.direction);
+       return -ENOMEM;
+}
+
+static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
+{
+       int ret;
+       struct mmc_data *data = host->data;
+
+       ret = mmci_dma_prep_data(host, host->data, NULL);
+       if (ret)
+               return ret;
+
+       /* Okay, go for it. */
        dev_vdbg(mmc_dev(host->mmc),
                 "Submit MMCI DMA job, sglen %d blksz %04x blks %04x flags %08x\n",
                 data->sg_len, data->blksz, data->blocks, data->flags);
-       dmaengine_submit(desc);
-       dma_async_issue_pending(chan);
+       dmaengine_submit(host->dma_desc_current);
+       dma_async_issue_pending(host->dma_current);
 
        datactrl |= MCI_DPSM_DMAENABLE;
 
@@ -421,14 +457,90 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
        writel(readl(host->base + MMCIMASK0) | MCI_DATAENDMASK,
               host->base + MMCIMASK0);
        return 0;
+}
 
-unmap_exit:
-       dmaengine_terminate_all(chan);
-       dma_unmap_sg(device->dev, data->sg, data->sg_len, conf.direction);
-       return -ENOMEM;
+static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
+{
+       struct mmci_host_next *next = &host->next_data;
+
+       if (data->host_cookie && data->host_cookie != next->cookie) {
+               printk(KERN_WARNING "[%s] invalid cookie: data->host_cookie %d"
+                      " host->next_data.cookie %d\n",
+                      __func__, data->host_cookie, host->next_data.cookie);
+               data->host_cookie = 0;
+       }
+
+       if (!data->host_cookie)
+               return;
+
+       host->dma_desc_current = next->dma_desc;
+       host->dma_current = next->dma_chan;
+
+       next->dma_desc = NULL;
+       next->dma_chan = NULL;
 }
+
+static void mmci_pre_request(struct mmc_host *mmc, struct mmc_request *mrq,
+                            bool is_first_req)
+{
+       struct mmci_host *host = mmc_priv(mmc);
+       struct mmc_data *data = mrq->data;
+       struct mmci_host_next *nd = &host->next_data;
+
+       if (!data)
+               return;
+
+       if (data->host_cookie) {
+               data->host_cookie = 0;
+               return;
+       }
+
+       /* if config for dma */
+       if (((data->flags & MMC_DATA_WRITE) && host->dma_tx_channel) ||
+           ((data->flags & MMC_DATA_READ) && host->dma_rx_channel)) {
+               if (mmci_dma_prep_data(host, data, nd))
+                       data->host_cookie = 0;
+               else
+                       data->host_cookie = ++nd->cookie < 0 ? 1 : nd->cookie;
+       }
+}
+
+static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
+                             int err)
+{
+       struct mmci_host *host = mmc_priv(mmc);
+       struct mmc_data *data = mrq->data;
+       struct dma_chan *chan;
+       enum dma_data_direction dir;
+
+       if (!data)
+               return;
+
+       if (data->flags & MMC_DATA_READ) {
+               dir = DMA_FROM_DEVICE;
+               chan = host->dma_rx_channel;
+       } else {
+               dir = DMA_TO_DEVICE;
+               chan = host->dma_tx_channel;
+       }
+
+
+       /* if config for dma */
+       if (chan) {
+               if (err)
+                       dmaengine_terminate_all(chan);
+               if (err || data->host_cookie)
+                       dma_unmap_sg(mmc_dev(host->mmc), data->sg,
+                                    data->sg_len, dir);
+               mrq->data->host_cookie = 0;
+       }
+}
+
 #else
 /* Blank functions if the DMA engine is not available */
+static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
+{
+}
 static inline void mmci_dma_setup(struct mmci_host *host)
 {
 }
@@ -449,6 +561,10 @@ static inline int mmci_dma_start_data(struct mmci_host *host, unsigned int datac
 {
        return -ENOSYS;
 }
+
+#define mmci_pre_request NULL
+#define mmci_post_request NULL
+
 #endif
 
 static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
@@ -872,6 +988,9 @@ static void mmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 
        host->mrq = mrq;
 
+       if (mrq->data)
+               mmci_get_next_data(host, mrq->data);
+
        if (mrq->data && mrq->data->flags & MMC_DATA_READ)
                mmci_start_data(host, mrq->data);
 
@@ -986,6 +1105,8 @@ static irqreturn_t mmci_cd_irq(int irq, void *dev_id)
 
 static const struct mmc_host_ops mmci_ops = {
        .request        = mmci_request,
+       .pre_req        = mmci_pre_request,
+       .post_req       = mmci_post_request,
        .set_ios        = mmci_set_ios,
        .get_ro         = mmci_get_ro,
        .get_cd         = mmci_get_cd,

diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index 2164e8c..79e4143 100644 (file)
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -166,6 +166,12 @@ struct clk;
 struct variant_data;
 struct dma_chan;
 
+struct mmci_host_next {
+       struct dma_async_tx_descriptor  *dma_desc;
+       struct dma_chan                 *dma_chan;
+       s32                             cookie;
+};
+
 struct mmci_host {
        phys_addr_t             phybase;
        void __iomem            *base;
@@ -203,6 +209,8 @@ struct mmci_host {
        struct dma_chan         *dma_current;
        struct dma_chan         *dma_rx_channel;
        struct dma_chan         *dma_tx_channel;
+       struct dma_async_tx_descriptor  *dma_desc_current;
+       struct mmci_host_next   next_data;
 
 #define dma_inprogress(host)   ((host)->dma_current)
 #else