Ping.

-----Original Message-----
From: Robin Gong 
Sent: 2018年3月23日 0:18
To: dan.j.willi...@intel.com; vinod.k...@intel.com
Cc: dmaeng...@vger.kernel.org; linux-arm-ker...@lists.infradead.org; 
linux-kernel@vger.kernel.org; dl-linux-imx <linux-...@nxp.com>
Subject: [PATCH v1] dma: imx-sdma: add virt-dma support

The legacy sdma driver has below limitations or drawbacks:
  1. Hardcode the max BDs number as "PAGE_SIZE / sizeof(*)", and alloc
     one page size for one channel regardless of only few BDs needed
     most time. But in few cases, the max PAGE_SIZE maybe not enough.
  2. One SDMA channel can't stop immediatley once channel disabled which
     means SDMA interrupt may come in after this channel terminated.There
     are some patches for this corner case such as commit "2746e2c389f9",
     but not cover non-cyclic.

The common virt-dma overcomes the above limitations. It can alloc bd 
dynamically and free bd once this tx transfer done. No memory wasted or maximum 
limititation here, only depends on how many memory can be requested from 
kernel. For No.2, such issue can be workaround by checking if there is 
available descript("sdmac->desc") now once the unwanted interrupt coming. At 
last the common virt-dma is easier for sdma driver maintain.

Signed-off-by: Robin Gong <yibin.g...@nxp.com>
---
 drivers/dma/Kconfig    |   1 +
 drivers/dma/imx-sdma.c | 395 +++++++++++++++++++++++++++++++------------------
 2 files changed, 253 insertions(+), 143 deletions(-)

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index 27df3e2..c4ce43c 
100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -247,6 +247,7 @@ config IMX_SDMA
        tristate "i.MX SDMA support"
        depends on ARCH_MXC
        select DMA_ENGINE
+       select DMA_VIRTUAL_CHANNELS
        help
          Support the i.MX SDMA engine. This engine is integrated into
          Freescale i.MX25/31/35/51/53/6 chips.
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index 
ccd03c3..df79e73 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -48,6 +48,7 @@
 #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
 
 #include "dmaengine.h"
+#include "virt-dma.h"
 
 /* SDMA registers */
 #define SDMA_H_C0PTR           0x000
@@ -291,10 +292,19 @@ struct sdma_context_data {
        u32  scratch7;
 } __attribute__ ((packed));
 
-#define NUM_BD (int)(PAGE_SIZE / sizeof(struct sdma_buffer_descriptor))
-
 struct sdma_engine;
 
+struct sdma_desc {
+       struct virt_dma_desc    vd;
+       struct list_head        node;
+       unsigned int            num_bd;
+       dma_addr_t              bd_phys;
+       unsigned int            buf_tail;
+       unsigned int            buf_ptail;
+       struct sdma_channel     *sdmac;
+       struct sdma_buffer_descriptor *bd;
+};
+
 /**
  * struct sdma_channel - housekeeping for a SDMA channel
  *
@@ -310,19 +320,17 @@ struct sdma_engine;
  * @num_bd             max NUM_BD. number of descriptors currently handling
  */
 struct sdma_channel {
+       struct virt_dma_chan            vc;
+       struct list_head                pending;
        struct sdma_engine              *sdma;
+       struct sdma_desc                *desc;
        unsigned int                    channel;
        enum dma_transfer_direction             direction;
        enum sdma_peripheral_type       peripheral_type;
        unsigned int                    event_id0;
        unsigned int                    event_id1;
        enum dma_slave_buswidth         word_size;
-       unsigned int                    buf_tail;
-       unsigned int                    buf_ptail;
-       unsigned int                    num_bd;
        unsigned int                    period_len;
-       struct sdma_buffer_descriptor   *bd;
-       dma_addr_t                      bd_phys;
        unsigned int                    pc_from_device, pc_to_device;
        unsigned int                    device_to_device;
        unsigned long                   flags;
@@ -330,15 +338,12 @@ struct sdma_channel {
        unsigned long                   event_mask[2];
        unsigned long                   watermark_level;
        u32                             shp_addr, per_addr;
-       struct dma_chan                 chan;
-       spinlock_t                      lock;
-       struct dma_async_tx_descriptor  desc;
        enum dma_status                 status;
        unsigned int                    chn_count;
        unsigned int                    chn_real_count;
-       struct tasklet_struct           tasklet;
        struct imx_dma_data             data;
        bool                            enabled;
+       u32                             bd_size_sum;
 };
 
 #define IMX_DMA_SG_LOOP                BIT(0)
@@ -398,6 +403,9 @@ struct sdma_engine {
        u32                             spba_start_addr;
        u32                             spba_end_addr;
        unsigned int                    irq;
+       /* channel0 bd */
+       dma_addr_t                      bd0_phys;
+       struct sdma_buffer_descriptor   *bd0;
 };
 
 static struct sdma_driver_data sdma_imx31 = { @@ -553,6 +561,8 @@ 
MODULE_DEVICE_TABLE(of, sdma_dt_ids);
 #define SDMA_H_CONFIG_ACR      BIT(4)  /* indicates if AHB freq /core freq = 2 
or 1 */
 #define SDMA_H_CONFIG_CSM      (3)       /* indicates which context switch 
mode is selected*/
 
+static void sdma_start_desc(struct sdma_channel *sdmac);
+
 static inline u32 chnenbl_ofs(struct sdma_engine *sdma, unsigned int event)  {
        u32 chnenbl0 = sdma->drvdata->chnenbl0; @@ -597,14 +607,7 @@ static int 
sdma_config_ownership(struct sdma_channel *sdmac,
 
 static void sdma_enable_channel(struct sdma_engine *sdma, int channel)  {
-       unsigned long flags;
-       struct sdma_channel *sdmac = &sdma->channel[channel];
-
        writel(BIT(channel), sdma->regs + SDMA_H_START);
-
-       spin_lock_irqsave(&sdmac->lock, flags);
-       sdmac->enabled = true;
-       spin_unlock_irqrestore(&sdmac->lock, flags);
 }
 
 /*
@@ -632,7 +635,7 @@ static int sdma_run_channel0(struct sdma_engine *sdma)  
static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size,
                u32 address)
 {
-       struct sdma_buffer_descriptor *bd0 = sdma->channel[0].bd;
+       struct sdma_buffer_descriptor *bd0 = sdma->bd0;
        void *buf_virt;
        dma_addr_t buf_phys;
        int ret;
@@ -691,23 +694,16 @@ static void sdma_event_disable(struct sdma_channel 
*sdmac, unsigned int event)  static void sdma_update_channel_loop(struct 
sdma_channel *sdmac)  {
        struct sdma_buffer_descriptor *bd;
+       struct sdma_desc *desc = sdmac->desc;
        int error = 0;
        enum dma_status old_status = sdmac->status;
-       unsigned long flags;
-
-       spin_lock_irqsave(&sdmac->lock, flags);
-       if (!sdmac->enabled) {
-               spin_unlock_irqrestore(&sdmac->lock, flags);
-               return;
-       }
-       spin_unlock_irqrestore(&sdmac->lock, flags);
 
        /*
         * loop mode. Iterate over descriptors, re-setup them and
         * call callback function.
         */
-       while (1) {
-               bd = &sdmac->bd[sdmac->buf_tail];
+       while (desc) {
+               bd = &desc->bd[desc->buf_tail];
 
                if (bd->mode.status & BD_DONE)
                        break;
@@ -726,8 +722,8 @@ static void sdma_update_channel_loop(struct sdma_channel 
*sdmac)
                sdmac->chn_real_count = bd->mode.count;
                bd->mode.status |= BD_DONE;
                bd->mode.count = sdmac->period_len;
-               sdmac->buf_ptail = sdmac->buf_tail;
-               sdmac->buf_tail = (sdmac->buf_tail + 1) % sdmac->num_bd;
+               desc->buf_ptail = desc->buf_tail;
+               desc->buf_tail = (desc->buf_tail + 1) % desc->num_bd;
 
                /*
                 * The callback is called from the interrupt context in order 
@@ -735,15 +731,16 @@ static void sdma_update_channel_loop(struct sdma_channel 
*sdmac)
                 * SDMA transaction status by the time the client tasklet is
                 * executed.
                 */
-
-               dmaengine_desc_get_callback_invoke(&sdmac->desc, NULL);
+               spin_unlock(&sdmac->vc.lock);
+               dmaengine_desc_get_callback_invoke(&desc->vd.tx, NULL);
+               spin_lock(&sdmac->vc.lock);
 
                if (error)
                        sdmac->status = old_status;
        }
 }
 
-static void mxc_sdma_handle_channel_normal(unsigned long data)
+static void mxc_sdma_handle_channel_normal(struct sdma_channel *data)
 {
        struct sdma_channel *sdmac = (struct sdma_channel *) data;
        struct sdma_buffer_descriptor *bd;
@@ -754,8 +751,8 @@ static void mxc_sdma_handle_channel_normal(unsigned long 
data)
         * non loop mode. Iterate over all descriptors, collect
         * errors and call callback function
         */
-       for (i = 0; i < sdmac->num_bd; i++) {
-               bd = &sdmac->bd[i];
+       for (i = 0; i < sdmac->desc->num_bd; i++) {
+               bd = &sdmac->desc->bd[i];
 
                 if (bd->mode.status & (BD_DONE | BD_RROR))
                        error = -EIO;
@@ -766,10 +763,6 @@ static void mxc_sdma_handle_channel_normal(unsigned long 
data)
                sdmac->status = DMA_ERROR;
        else
                sdmac->status = DMA_COMPLETE;
-
-       dma_cookie_complete(&sdmac->desc);
-
-       dmaengine_desc_get_callback_invoke(&sdmac->desc, NULL);
 }
 
 static irqreturn_t sdma_int_handler(int irq, void *dev_id) @@ -785,13 +778,24 
@@ static irqreturn_t sdma_int_handler(int irq, void *dev_id)
        while (stat) {
                int channel = fls(stat) - 1;
                struct sdma_channel *sdmac = &sdma->channel[channel];
-
-               if (sdmac->flags & IMX_DMA_SG_LOOP)
-                       sdma_update_channel_loop(sdmac);
-               else
-                       tasklet_schedule(&sdmac->tasklet);
+               struct sdma_desc *desc;
+
+               spin_lock(&sdmac->vc.lock);
+               desc = sdmac->desc;
+               if (desc) {
+                       if (sdmac->flags & IMX_DMA_SG_LOOP) {
+                               sdma_update_channel_loop(sdmac);
+                       } else {
+                               mxc_sdma_handle_channel_normal(sdmac);
+                               vchan_cookie_complete(&desc->vd);
+                               if (!list_empty(&sdmac->pending))
+                                       list_del(&desc->node);
+                                sdma_start_desc(sdmac);
+                       }
+               }
 
                __clear_bit(channel, &stat);
+               spin_unlock(&sdmac->vc.lock);
        }
 
        return IRQ_HANDLED;
@@ -897,7 +901,7 @@ static int sdma_load_context(struct sdma_channel *sdmac)
        int channel = sdmac->channel;
        int load_address;
        struct sdma_context_data *context = sdma->context;
-       struct sdma_buffer_descriptor *bd0 = sdma->channel[0].bd;
+       struct sdma_buffer_descriptor *bd0 = sdma->bd0;
        int ret;
        unsigned long flags;
 
@@ -946,7 +950,7 @@ static int sdma_load_context(struct sdma_channel *sdmac)
 
 static struct sdma_channel *to_sdma_chan(struct dma_chan *chan)  {
-       return container_of(chan, struct sdma_channel, chan);
+       return container_of(chan, struct sdma_channel, vc.chan);
 }
 
 static int sdma_disable_channel(struct dma_chan *chan) @@ -954,15 +958,10 @@ 
static int sdma_disable_channel(struct dma_chan *chan)
        struct sdma_channel *sdmac = to_sdma_chan(chan);
        struct sdma_engine *sdma = sdmac->sdma;
        int channel = sdmac->channel;
-       unsigned long flags;
 
        writel_relaxed(BIT(channel), sdma->regs + SDMA_H_STATSTOP);
        sdmac->status = DMA_ERROR;
 
-       spin_lock_irqsave(&sdmac->lock, flags);
-       sdmac->enabled = false;
-       spin_unlock_irqrestore(&sdmac->lock, flags);
-
        return 0;
 }
 
@@ -1097,42 +1096,101 @@ static int sdma_set_channel_priority(struct 
sdma_channel *sdmac,
        return 0;
 }
 
-static int sdma_request_channel(struct sdma_channel *sdmac)
+static int sdma_alloc_bd(struct sdma_desc *desc)
 {
-       struct sdma_engine *sdma = sdmac->sdma;
-       int channel = sdmac->channel;
-       int ret = -EBUSY;
+       u32 bd_size = desc->num_bd * sizeof(struct sdma_buffer_descriptor);
+       int ret = 0;
+       unsigned long flags;
 
-       sdmac->bd = dma_zalloc_coherent(NULL, PAGE_SIZE, &sdmac->bd_phys,
+       desc->bd = dma_zalloc_coherent(NULL, bd_size, &desc->bd_phys,
                                        GFP_KERNEL);
-       if (!sdmac->bd) {
+       if (!desc->bd) {
                ret = -ENOMEM;
                goto out;
        }
 
-       sdma->channel_control[channel].base_bd_ptr = sdmac->bd_phys;
-       sdma->channel_control[channel].current_bd_ptr = sdmac->bd_phys;
+       spin_lock_irqsave(&desc->sdmac->vc.lock, flags);
+       desc->sdmac->bd_size_sum += bd_size;
+       spin_unlock_irqrestore(&desc->sdmac->vc.lock, flags);
 
-       sdma_set_channel_priority(sdmac, MXC_SDMA_DEFAULT_PRIORITY);
-       return 0;
 out:
-
        return ret;
 }
 
-static dma_cookie_t sdma_tx_submit(struct dma_async_tx_descriptor *tx)
+static void sdma_free_bd(struct sdma_desc *desc)
 {
+       u32 bd_size = desc->num_bd * sizeof(struct sdma_buffer_descriptor);
        unsigned long flags;
-       struct sdma_channel *sdmac = to_sdma_chan(tx->chan);
-       dma_cookie_t cookie;
 
-       spin_lock_irqsave(&sdmac->lock, flags);
+       if (desc->bd) {
+               dma_free_coherent(NULL, bd_size, desc->bd, desc->bd_phys);
+
+               spin_lock_irqsave(&desc->sdmac->vc.lock, flags);
+               desc->sdmac->bd_size_sum -= bd_size;
+               spin_unlock_irqrestore(&desc->sdmac->vc.lock, flags);
+       }
+}
+
+static int sdma_request_channel0(struct sdma_engine *sdma) {
+       int ret = 0;
+
+       sdma->bd0 = dma_zalloc_coherent(NULL, PAGE_SIZE, &sdma->bd0_phys,
+                                       GFP_KERNEL);
+       if (!sdma->bd0) {
+               ret = -ENOMEM;
+               goto out;
+       }
 
-       cookie = dma_cookie_assign(tx);
+       sdma->channel_control[0].base_bd_ptr = sdma->bd0_phys;
+       sdma->channel_control[0].current_bd_ptr = sdma->bd0_phys;
 
-       spin_unlock_irqrestore(&sdmac->lock, flags);
+       sdma_set_channel_priority(&sdma->channel[0], 
+MXC_SDMA_DEFAULT_PRIORITY);
+out:
 
-       return cookie;
+       return ret;
+}
+
+static struct sdma_desc *to_sdma_desc(struct dma_async_tx_descriptor 
+*t) {
+       return container_of(t, struct sdma_desc, vd.tx); }
+
+static void sdma_desc_free(struct virt_dma_desc *vd) {
+       struct sdma_desc *desc = container_of(vd, struct sdma_desc, vd);
+
+       if (desc) {
+               sdma_free_bd(desc);
+               kfree(desc);
+       }
+}
+
+static int sdma_terminate_all(struct dma_chan *chan) {
+       struct sdma_channel *sdmac = to_sdma_chan(chan);
+       unsigned long flags;
+       LIST_HEAD(head);
+
+       spin_lock_irqsave(&sdmac->vc.lock, flags);
+       vchan_get_all_descriptors(&sdmac->vc, &head);
+       while (!list_empty(&sdmac->pending)) {
+               struct sdma_desc *desc = list_first_entry(&sdmac->pending,
+                       struct sdma_desc, node);
+
+                list_del(&desc->node);
+                spin_unlock_irqrestore(&sdmac->vc.lock, flags);
+                sdmac->vc.desc_free(&desc->vd);
+                spin_lock_irqsave(&sdmac->vc.lock, flags);
+       }
+
+       if (sdmac->desc)
+               sdmac->desc = NULL;
+       spin_unlock_irqrestore(&sdmac->vc.lock, flags);
+       vchan_dma_desc_free_list(&sdmac->vc, &head);
+       sdma_disable_channel_with_delay(chan);
+
+       return 0;
 }
 
 static int sdma_alloc_chan_resources(struct dma_chan *chan) @@ -1168,18 
+1226,11 @@ static int sdma_alloc_chan_resources(struct dma_chan *chan)
        if (ret)
                goto disable_clk_ipg;
 
-       ret = sdma_request_channel(sdmac);
-       if (ret)
-               goto disable_clk_ahb;
-
        ret = sdma_set_channel_priority(sdmac, prio);
        if (ret)
                goto disable_clk_ahb;
 
-       dma_async_tx_descriptor_init(&sdmac->desc, chan);
-       sdmac->desc.tx_submit = sdma_tx_submit;
-       /* txd.flags will be overwritten in prep funcs */
-       sdmac->desc.flags = DMA_CTRL_ACK;
+       sdmac->bd_size_sum = 0;
 
        return 0;
 
@@ -1195,7 +1246,7 @@ static void sdma_free_chan_resources(struct dma_chan 
*chan)
        struct sdma_channel *sdmac = to_sdma_chan(chan);
        struct sdma_engine *sdma = sdmac->sdma;
 
-       sdma_disable_channel(chan);
+       sdma_terminate_all(chan);
 
        if (sdmac->event_id0)
                sdma_event_disable(sdmac, sdmac->event_id0); @@ -1207,12 
+1258,43 @@ static void sdma_free_chan_resources(struct dma_chan *chan)
 
        sdma_set_channel_priority(sdmac, 0);
 
-       dma_free_coherent(NULL, PAGE_SIZE, sdmac->bd, sdmac->bd_phys);
-
        clk_disable(sdma->clk_ipg);
        clk_disable(sdma->clk_ahb);
 }
 
+static struct sdma_desc *sdma_transfer_init(struct sdma_channel *sdmac,
+                               enum dma_transfer_direction direction, u32 bds) 
{
+       struct sdma_desc *desc;
+
+       desc = kzalloc((sizeof(*desc)), GFP_KERNEL);
+       if (!desc)
+               goto err_out;
+
+       sdmac->status = DMA_IN_PROGRESS;
+       sdmac->direction = direction;
+       sdmac->flags = 0;
+       sdmac->chn_count = 0;
+       sdmac->chn_real_count = 0;
+
+       desc->sdmac = sdmac;
+       desc->num_bd = bds;
+       INIT_LIST_HEAD(&desc->node);
+
+       if (sdma_alloc_bd(desc))
+               goto err_desc_out;
+
+       if (sdma_load_context(sdmac))
+               goto err_desc_out;
+
+       return desc;
+
+err_desc_out:
+       kfree(desc);
+err_out:
+       return NULL;
+}
+
 static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
                struct dma_chan *chan, struct scatterlist *sgl,
                unsigned int sg_len, enum dma_transfer_direction direction, @@ 
-1223,35 +1305,24 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
        int ret, i, count;
        int channel = sdmac->channel;
        struct scatterlist *sg;
+       struct sdma_desc *desc;
 
-       if (sdmac->status == DMA_IN_PROGRESS)
+       if (!chan)
                return NULL;
-       sdmac->status = DMA_IN_PROGRESS;
-
-       sdmac->flags = 0;
 
-       sdmac->buf_tail = 0;
-       sdmac->buf_ptail = 0;
-       sdmac->chn_real_count = 0;
+       desc = sdma_transfer_init(sdmac, direction, sg_len);
+       if (!desc)
+               goto err_out;
 
        dev_dbg(sdma->dev, "setting up %d entries for channel %d.\n",
                        sg_len, channel);
 
-       sdmac->direction = direction;
        ret = sdma_load_context(sdmac);
        if (ret)
                goto err_out;
 
-       if (sg_len > NUM_BD) {
-               dev_err(sdma->dev, "SDMA channel %d: maximum number of sg 
exceeded: %d > %d\n",
-                               channel, sg_len, NUM_BD);
-               ret = -EINVAL;
-               goto err_out;
-       }
-
-       sdmac->chn_count = 0;
        for_each_sg(sgl, sg, sg_len, i) {
-               struct sdma_buffer_descriptor *bd = &sdmac->bd[i];
+               struct sdma_buffer_descriptor *bd = &desc->bd[i];
                int param;
 
                bd->buffer_addr = sg->dma_address;
@@ -1262,7 +1333,7 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
                        dev_err(sdma->dev, "SDMA channel %d: maximum bytes for 
sg entry exceeded: %d > %d\n",
                                        channel, count, 0xffff);
                        ret = -EINVAL;
-                       goto err_out;
+                       goto err_bd_out;
                }
 
                bd->mode.count = count;
@@ -1307,10 +1378,11 @@ static struct dma_async_tx_descriptor 
*sdma_prep_slave_sg(
                bd->mode.status = param;
        }
 
-       sdmac->num_bd = sg_len;
-       sdma->channel_control[channel].current_bd_ptr = sdmac->bd_phys;
+       return vchan_tx_prep(&sdmac->vc, &desc->vd, flags);
 
-       return &sdmac->desc;
+err_bd_out:
+       sdma_free_bd(desc);
+       kfree(desc);
 err_out:
        sdmac->status = DMA_ERROR;
        return NULL;
@@ -1326,39 +1398,32 @@ static struct dma_async_tx_descriptor 
*sdma_prep_dma_cyclic(
        int num_periods = buf_len / period_len;
        int channel = sdmac->channel;
        int ret, i = 0, buf = 0;
+       struct sdma_desc *desc;
 
        dev_dbg(sdma->dev, "%s channel: %d\n", __func__, channel);
 
-       if (sdmac->status == DMA_IN_PROGRESS)
-               return NULL;
-
-       sdmac->status = DMA_IN_PROGRESS;
+       /* Now allocate and setup the descriptor. */
+       desc = sdma_transfer_init(sdmac, direction, num_periods);
+       if (!desc)
+               goto err_out;
 
-       sdmac->buf_tail = 0;
-       sdmac->buf_ptail = 0;
-       sdmac->chn_real_count = 0;
+       desc->buf_tail = 0;
+       desc->buf_ptail = 0;
        sdmac->period_len = period_len;
-
        sdmac->flags |= IMX_DMA_SG_LOOP;
-       sdmac->direction = direction;
+
        ret = sdma_load_context(sdmac);
        if (ret)
                goto err_out;
 
-       if (num_periods > NUM_BD) {
-               dev_err(sdma->dev, "SDMA channel %d: maximum number of sg 
exceeded: %d > %d\n",
-                               channel, num_periods, NUM_BD);
-               goto err_out;
-       }
-
        if (period_len > 0xffff) {
                dev_err(sdma->dev, "SDMA channel %d: maximum period size 
exceeded: %zu > %d\n",
                                channel, period_len, 0xffff);
-               goto err_out;
+               goto err_bd_out;
        }
 
        while (buf < buf_len) {
-               struct sdma_buffer_descriptor *bd = &sdmac->bd[i];
+               struct sdma_buffer_descriptor *bd = &desc->bd[i];
                int param;
 
                bd->buffer_addr = dma_addr;
@@ -1366,7 +1431,7 @@ static struct dma_async_tx_descriptor 
*sdma_prep_dma_cyclic(
                bd->mode.count = period_len;
 
                if (sdmac->word_size > DMA_SLAVE_BUSWIDTH_4_BYTES)
-                       goto err_out;
+                       goto err_bd_out;
                if (sdmac->word_size == DMA_SLAVE_BUSWIDTH_4_BYTES)
                        bd->mode.command = 0;
                else
@@ -1389,10 +1454,10 @@ static struct dma_async_tx_descriptor 
*sdma_prep_dma_cyclic(
                i++;
        }
 
-       sdmac->num_bd = num_periods;
-       sdma->channel_control[channel].current_bd_ptr = sdmac->bd_phys;
-
-       return &sdmac->desc;
+       return vchan_tx_prep(&sdmac->vc, &desc->vd, flags);
+err_bd_out:
+       sdma_free_bd(desc);
+       kfree(desc);
 err_out:
        sdmac->status = DMA_ERROR;
        return NULL;
@@ -1432,26 +1497,74 @@ static enum dma_status sdma_tx_status(struct dma_chan 
*chan,  {
        struct sdma_channel *sdmac = to_sdma_chan(chan);
        u32 residue;
+       struct virt_dma_desc *vd;
+       struct sdma_desc *desc;
+       enum dma_status ret;
+       unsigned long flags;
 
-       if (sdmac->flags & IMX_DMA_SG_LOOP)
-               residue = (sdmac->num_bd - sdmac->buf_ptail) *
+       ret = dma_cookie_status(chan, cookie, txstate);
+       if (ret == DMA_COMPLETE && txstate) {
+               residue = sdmac->chn_count - sdmac->chn_real_count;
+               return ret;
+       }
+
+       spin_lock_irqsave(&sdmac->vc.lock, flags);
+       vd = vchan_find_desc(&sdmac->vc, cookie);
+       desc = to_sdma_desc(&vd->tx);
+       if (vd) {
+               if (sdmac->flags & IMX_DMA_SG_LOOP)
+                       residue = (desc->num_bd - desc->buf_ptail) *
                           sdmac->period_len - sdmac->chn_real_count;
-       else
+               else
+                       residue = sdmac->chn_count - sdmac->chn_real_count;
+       } else if (sdmac->desc && sdmac->desc->vd.tx.cookie == cookie) {
                residue = sdmac->chn_count - sdmac->chn_real_count;
+       } else {
+               residue = 0;
+       }
+       ret = sdmac->status;
+       spin_unlock_irqrestore(&sdmac->vc.lock, flags);
 
        dma_set_tx_state(txstate, chan->completed_cookie, chan->cookie,
                         residue);
 
-       return sdmac->status;
+       return ret;
+}
+
+static void sdma_start_desc(struct sdma_channel *sdmac) {
+       struct virt_dma_desc *vd = vchan_next_desc(&sdmac->vc);
+       struct sdma_desc *desc;
+       struct sdma_engine *sdma = sdmac->sdma;
+       int channel = sdmac->channel;
+
+       if (!vd) {
+               sdmac->desc = NULL;
+               return;
+       }
+       sdmac->desc = desc = to_sdma_desc(&vd->tx);
+       /*
+        * Do not delete the node in desc_issued list in cyclic mode, otherwise
+        * the desc alloced will never be freed in vchan_dma_desc_free_list
+        */
+       if (!(sdmac->flags & IMX_DMA_SG_LOOP)) {
+               list_add_tail(&sdmac->desc->node, &sdmac->pending);
+               list_del(&vd->node);
+       }
+       sdma->channel_control[channel].base_bd_ptr = desc->bd_phys;
+       sdma->channel_control[channel].current_bd_ptr = desc->bd_phys;
+       sdma_enable_channel(sdma, sdmac->channel);
 }
 
 static void sdma_issue_pending(struct dma_chan *chan)  {
        struct sdma_channel *sdmac = to_sdma_chan(chan);
-       struct sdma_engine *sdma = sdmac->sdma;
+       unsigned long flags;
 
-       if (sdmac->status == DMA_IN_PROGRESS)
-               sdma_enable_channel(sdma, sdmac->channel);
+       spin_lock_irqsave(&sdmac->vc.lock, flags);
+       if (vchan_issue_pending(&sdmac->vc) && !sdmac->desc)
+               sdma_start_desc(sdmac);
+       spin_unlock_irqrestore(&sdmac->vc.lock, flags);
 }
 
 #define SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V1        34
@@ -1657,7 +1770,7 @@ static int sdma_init(struct sdma_engine *sdma)
        for (i = 0; i < MAX_DMA_CHANNELS; i++)
                writel_relaxed(0, sdma->regs + SDMA_CHNPRI_0 + i * 4);
 
-       ret = sdma_request_channel(&sdma->channel[0]);
+       ret = sdma_request_channel0(sdma);
        if (ret)
                goto err_dma_alloc;
 
@@ -1819,22 +1932,17 @@ static int sdma_probe(struct platform_device *pdev)
                struct sdma_channel *sdmac = &sdma->channel[i];
 
                sdmac->sdma = sdma;
-               spin_lock_init(&sdmac->lock);
-
-               sdmac->chan.device = &sdma->dma_device;
-               dma_cookie_init(&sdmac->chan);
                sdmac->channel = i;
-
-               tasklet_init(&sdmac->tasklet, mxc_sdma_handle_channel_normal,
-                            (unsigned long) sdmac);
+               sdmac->status = DMA_IN_PROGRESS;
+               sdmac->vc.desc_free = sdma_desc_free;
+               INIT_LIST_HEAD(&sdmac->pending);
                /*
                 * Add the channel to the DMAC list. Do not add channel 0 though
                 * because we need it internally in the SDMA driver. This also 
means
                 * that channel 0 in dmaengine counting matches sdma channel 1.
                 */
                if (i)
-                       list_add_tail(&sdmac->chan.device_node,
-                                       &sdma->dma_device.channels);
+                       vchan_init(&sdmac->vc, &sdma->dma_device);
        }
 
        ret = sdma_init(sdma);
@@ -1879,7 +1987,7 @@ static int sdma_probe(struct platform_device *pdev)
        sdma->dma_device.device_prep_slave_sg = sdma_prep_slave_sg;
        sdma->dma_device.device_prep_dma_cyclic = sdma_prep_dma_cyclic;
        sdma->dma_device.device_config = sdma_config;
-       sdma->dma_device.device_terminate_all = sdma_disable_channel_with_delay;
+       sdma->dma_device.device_terminate_all = sdma_terminate_all;
        sdma->dma_device.src_addr_widths = SDMA_DMA_BUSWIDTHS;
        sdma->dma_device.dst_addr_widths = SDMA_DMA_BUSWIDTHS;
        sdma->dma_device.directions = SDMA_DMA_DIRECTIONS; @@ -1939,7 +2047,8 
@@ static int sdma_remove(struct platform_device *pdev)
        for (i = 0; i < MAX_DMA_CHANNELS; i++) {
                struct sdma_channel *sdmac = &sdma->channel[i];
 
-               tasklet_kill(&sdmac->tasklet);
+               tasklet_kill(&sdmac->vc.task);
+               sdma_free_chan_resources(&sdmac->vc.chan);
        }
 
        platform_set_drvdata(pdev, NULL);
--
2.7.4

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