[PATCH v8 03/12] mmci: implement pre_req() and post_req()

Per Forlin
2011-06-28T08:11:48Z

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-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
drivers/mmc/host/mmci.c | 147 ++++++++++++++++++++++++++++++++++++++++++----
drivers/mmc/host/mmci.h | 8 +++
2 files changed, 142 insertions(+), 13 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index b4a7e4f..6ed6770 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -211,6 +211,9 @@ 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);
@@ -320,7 +323,8 @@ 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.
@@ -338,7 +342,8 @@ 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 = {
@@ -349,13 +354,20 @@ 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;
@@ -370,7 +382,7 @@ 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;
@@ -384,14 +396,38 @@ 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;

@@ -406,14 +442,90 @@ 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)
{
}
@@ -434,6 +546,10 @@ 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)
@@ -852,6 +968,9 @@ 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);

@@ -966,6 +1085,8 @@ 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 ec9a7bc6..e21d850 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -150,6 +150,12 @@ 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;
@@ -187,6 +193,8 @@ 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
--
1.7.4.1