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intel_mid_dma: Add sg list support to DMA driver
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For a very high speed DMA various periphral devices need
scatter-gather list support. The DMA hardware support link list items.
This list can be circular also (adding new flag DMA_PREP_CIRCULAR_LIST)
Right now this flag is in driver header and should be moved to
dmaengine header file eventually

Signed-off-by: Ramesh Babu K V <ramesh.b.k.v@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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Ramesh Babu K V authored and Dan Williams committed Oct 7, 2010
1 parent 03b96dc commit 576e3c3
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Showing 3 changed files with 250 additions and 50 deletions.
267 changes: 221 additions & 46 deletions drivers/dma/intel_mid_dma.c
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Original file line number Diff line number Diff line change
Expand Up @@ -258,16 +258,17 @@ static void midc_dostart(struct intel_mid_dma_chan *midc,
/*write registers and en*/
iowrite32(first->sar, midc->ch_regs + SAR);
iowrite32(first->dar, midc->ch_regs + DAR);
iowrite32(first->lli_phys, midc->ch_regs + LLP);
iowrite32(first->cfg_hi, midc->ch_regs + CFG_HIGH);
iowrite32(first->cfg_lo, midc->ch_regs + CFG_LOW);
iowrite32(first->ctl_lo, midc->ch_regs + CTL_LOW);
iowrite32(first->ctl_hi, midc->ch_regs + CTL_HIGH);
pr_debug("MDMA:TX SAR %x,DAR %x,CFGL %x,CFGH %x,CTLH %x, CTLL %x\n",
(int)first->sar, (int)first->dar, first->cfg_hi,
first->cfg_lo, first->ctl_hi, first->ctl_lo);
first->status = DMA_IN_PROGRESS;

iowrite32(ENABLE_CHANNEL(midc->ch_id), mid->dma_base + DMA_CHAN_EN);
first->status = DMA_IN_PROGRESS;
}

/**
Expand All @@ -284,20 +285,36 @@ static void midc_descriptor_complete(struct intel_mid_dma_chan *midc,
{
struct dma_async_tx_descriptor *txd = &desc->txd;
dma_async_tx_callback callback_txd = NULL;
struct intel_mid_dma_lli *llitem;
void *param_txd = NULL;

midc->completed = txd->cookie;
callback_txd = txd->callback;
param_txd = txd->callback_param;

list_move(&desc->desc_node, &midc->free_list);
midc->busy = false;
if (desc->lli != NULL) {
/*clear the DONE bit of completed LLI in memory*/
llitem = desc->lli + desc->current_lli;
llitem->ctl_hi &= CLEAR_DONE;
if (desc->current_lli < desc->lli_length-1)
(desc->current_lli)++;
else
desc->current_lli = 0;
}
spin_unlock_bh(&midc->lock);
if (callback_txd) {
pr_debug("MDMA: TXD callback set ... calling\n");
callback_txd(param_txd);
spin_lock_bh(&midc->lock);
return;
}
if (midc->raw_tfr) {
desc->status = DMA_SUCCESS;
if (desc->lli != NULL) {
pci_pool_free(desc->lli_pool, desc->lli,
desc->lli_phys);
pci_pool_destroy(desc->lli_pool);
}
list_move(&desc->desc_node, &midc->free_list);
midc->busy = false;
}
spin_lock_bh(&midc->lock);

Expand All @@ -318,14 +335,89 @@ static void midc_scan_descriptors(struct middma_device *mid,

/*tx is complete*/
list_for_each_entry_safe(desc, _desc, &midc->active_list, desc_node) {
if (desc->status == DMA_IN_PROGRESS) {
desc->status = DMA_SUCCESS;
if (desc->status == DMA_IN_PROGRESS)
midc_descriptor_complete(midc, desc);
}
}
return;
}
}
/**
* midc_lli_fill_sg - Helper function to convert
* SG list to Linked List Items.
*@midc: Channel
*@desc: DMA descriptor
*@sglist: Pointer to SG list
*@sglen: SG list length
*@flags: DMA transaction flags
*
* Walk through the SG list and convert the SG list into Linked
* List Items (LLI).
*/
static int midc_lli_fill_sg(struct intel_mid_dma_chan *midc,
struct intel_mid_dma_desc *desc,
struct scatterlist *sglist,
unsigned int sglen,
unsigned int flags)
{
struct intel_mid_dma_slave *mids;
struct scatterlist *sg;
dma_addr_t lli_next, sg_phy_addr;
struct intel_mid_dma_lli *lli_bloc_desc;
union intel_mid_dma_ctl_lo ctl_lo;
union intel_mid_dma_ctl_hi ctl_hi;
int i;

pr_debug("MDMA: Entered midc_lli_fill_sg\n");
mids = midc->chan.private;

lli_bloc_desc = desc->lli;
lli_next = desc->lli_phys;

ctl_lo.ctl_lo = desc->ctl_lo;
ctl_hi.ctl_hi = desc->ctl_hi;
for_each_sg(sglist, sg, sglen, i) {
/*Populate CTL_LOW and LLI values*/
if (i != sglen - 1) {
lli_next = lli_next +
sizeof(struct intel_mid_dma_lli);
} else {
/*Check for circular list, otherwise terminate LLI to ZERO*/
if (flags & DMA_PREP_CIRCULAR_LIST) {
pr_debug("MDMA: LLI is configured in circular mode\n");
lli_next = desc->lli_phys;
} else {
lli_next = 0;
ctl_lo.ctlx.llp_dst_en = 0;
ctl_lo.ctlx.llp_src_en = 0;
}
}
/*Populate CTL_HI values*/
ctl_hi.ctlx.block_ts = get_block_ts(sg->length,
desc->width,
midc->dma->block_size);
/*Populate SAR and DAR values*/
sg_phy_addr = sg_phys(sg);
if (desc->dirn == DMA_TO_DEVICE) {
lli_bloc_desc->sar = sg_phy_addr;
lli_bloc_desc->dar = mids->per_addr;
} else if (desc->dirn == DMA_FROM_DEVICE) {
lli_bloc_desc->sar = mids->per_addr;
lli_bloc_desc->dar = sg_phy_addr;
}
/*Copy values into block descriptor in system memroy*/
lli_bloc_desc->llp = lli_next;
lli_bloc_desc->ctl_lo = ctl_lo.ctl_lo;
lli_bloc_desc->ctl_hi = ctl_hi.ctl_hi;

lli_bloc_desc++;
}
/*Copy very first LLI values to descriptor*/
desc->ctl_lo = desc->lli->ctl_lo;
desc->ctl_hi = desc->lli->ctl_hi;
desc->sar = desc->lli->sar;
desc->dar = desc->lli->dar;

return 0;
}
/*****************************************************************************
DMA engine callback Functions*/
/**
Expand All @@ -350,12 +442,12 @@ static dma_cookie_t intel_mid_dma_tx_submit(struct dma_async_tx_descriptor *tx)
desc->txd.cookie = cookie;


if (list_empty(&midc->active_list)) {
midc_dostart(midc, desc);
if (list_empty(&midc->active_list))
list_add_tail(&desc->desc_node, &midc->active_list);
} else {
else
list_add_tail(&desc->desc_node, &midc->queue);
}

midc_dostart(midc, desc);
spin_unlock_bh(&midc->lock);

return cookie;
Expand Down Expand Up @@ -429,7 +521,7 @@ static int intel_mid_dma_device_control(struct dma_chan *chan,
struct intel_mid_dma_chan *midc = to_intel_mid_dma_chan(chan);
struct middma_device *mid = to_middma_device(chan->device);
struct intel_mid_dma_desc *desc, *_desc;
LIST_HEAD(list);
union intel_mid_dma_cfg_lo cfg_lo;

if (cmd != DMA_TERMINATE_ALL)
return -ENXIO;
Expand All @@ -439,39 +531,29 @@ static int intel_mid_dma_device_control(struct dma_chan *chan,
spin_unlock_bh(&midc->lock);
return 0;
}
list_splice_init(&midc->free_list, &list);
midc->descs_allocated = 0;
midc->slave = NULL;

/*Suspend and disable the channel*/
cfg_lo.cfg_lo = ioread32(midc->ch_regs + CFG_LOW);
cfg_lo.cfgx.ch_susp = 1;
iowrite32(cfg_lo.cfg_lo, midc->ch_regs + CFG_LOW);
iowrite32(DISABLE_CHANNEL(midc->ch_id), mid->dma_base + DMA_CHAN_EN);
midc->busy = false;
/* Disable interrupts */
disable_dma_interrupt(midc);
midc->descs_allocated = 0;
midc->slave = NULL;

spin_unlock_bh(&midc->lock);
list_for_each_entry_safe(desc, _desc, &list, desc_node) {
pr_debug("MDMA: freeing descriptor %p\n", desc);
pci_pool_free(mid->dma_pool, desc, desc->txd.phys);
list_for_each_entry_safe(desc, _desc, &midc->active_list, desc_node) {
if (desc->lli != NULL) {
pci_pool_free(desc->lli_pool, desc->lli,
desc->lli_phys);
pci_pool_destroy(desc->lli_pool);
}
list_move(&desc->desc_node, &midc->free_list);
}
return 0;
}

/**
* intel_mid_dma_prep_slave_sg - Prep slave sg txn
* @chan: chan for DMA transfer
* @sgl: scatter gather list
* @sg_len: length of sg txn
* @direction: DMA transfer dirtn
* @flags: DMA flags
*
* Do DMA sg txn: NOT supported now
*/
static struct dma_async_tx_descriptor *intel_mid_dma_prep_slave_sg(
struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_data_direction direction,
unsigned long flags)
{
/*not supported now*/
return NULL;
}

/**
* intel_mid_dma_prep_memcpy - Prep memcpy txn
Expand Down Expand Up @@ -553,6 +635,7 @@ static struct dma_async_tx_descriptor *intel_mid_dma_prep_memcpy(

/*calculate CTL_HI*/
ctl_hi.ctlx.reser = 0;
ctl_hi.ctlx.done = 0;
width = mids->src_width;

ctl_hi.ctlx.block_ts = get_block_ts(len, width, midc->dma->block_size);
Expand Down Expand Up @@ -599,13 +682,95 @@ static struct dma_async_tx_descriptor *intel_mid_dma_prep_memcpy(
desc->ctl_hi = ctl_hi.ctl_hi;
desc->width = width;
desc->dirn = mids->dirn;
desc->lli_phys = 0;
desc->lli = NULL;
desc->lli_pool = NULL;
return &desc->txd;

err_desc_get:
pr_err("ERR_MDMA: Failed to get desc\n");
midc_desc_put(midc, desc);
return NULL;
}
/**
* intel_mid_dma_prep_slave_sg - Prep slave sg txn
* @chan: chan for DMA transfer
* @sgl: scatter gather list
* @sg_len: length of sg txn
* @direction: DMA transfer dirtn
* @flags: DMA flags
*
* Prepares LLI based periphral transfer
*/
static struct dma_async_tx_descriptor *intel_mid_dma_prep_slave_sg(
struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_data_direction direction,
unsigned long flags)
{
struct intel_mid_dma_chan *midc = NULL;
struct intel_mid_dma_slave *mids = NULL;
struct intel_mid_dma_desc *desc = NULL;
struct dma_async_tx_descriptor *txd = NULL;
union intel_mid_dma_ctl_lo ctl_lo;

pr_debug("MDMA: Prep for slave SG\n");

if (!sg_len) {
pr_err("MDMA: Invalid SG length\n");
return NULL;
}
midc = to_intel_mid_dma_chan(chan);
BUG_ON(!midc);

mids = chan->private;
BUG_ON(!mids);

if (!midc->dma->pimr_mask) {
pr_debug("MDMA: SG list is not supported by this controller\n");
return NULL;
}

pr_debug("MDMA: SG Length = %d, direction = %d, Flags = %#lx\n",
sg_len, direction, flags);

txd = intel_mid_dma_prep_memcpy(chan, 0, 0, sgl->length, flags);
if (NULL == txd) {
pr_err("MDMA: Prep memcpy failed\n");
return NULL;
}
desc = to_intel_mid_dma_desc(txd);
desc->dirn = direction;
ctl_lo.ctl_lo = desc->ctl_lo;
ctl_lo.ctlx.llp_dst_en = 1;
ctl_lo.ctlx.llp_src_en = 1;
desc->ctl_lo = ctl_lo.ctl_lo;
desc->lli_length = sg_len;
desc->current_lli = 0;
/* DMA coherent memory pool for LLI descriptors*/
desc->lli_pool = pci_pool_create("intel_mid_dma_lli_pool",
midc->dma->pdev,
(sizeof(struct intel_mid_dma_lli)*sg_len),
32, 0);
if (NULL == desc->lli_pool) {
pr_err("MID_DMA:LLI pool create failed\n");
return NULL;
}

desc->lli = pci_pool_alloc(desc->lli_pool, GFP_KERNEL, &desc->lli_phys);
if (!desc->lli) {
pr_err("MID_DMA: LLI alloc failed\n");
pci_pool_destroy(desc->lli_pool);
return NULL;
}

midc_lli_fill_sg(midc, desc, sgl, sg_len, flags);
if (flags & DMA_PREP_INTERRUPT) {
iowrite32(UNMASK_INTR_REG(midc->ch_id),
midc->dma_base + MASK_BLOCK);
pr_debug("MDMA:Enabled Block interrupt\n");
}
return &desc->txd;
}

/**
* intel_mid_dma_free_chan_resources - Frees dma resources
Expand Down Expand Up @@ -728,7 +893,7 @@ static void dma_tasklet(unsigned long data)
{
struct middma_device *mid = NULL;
struct intel_mid_dma_chan *midc = NULL;
u32 status;
u32 status, raw_tfr, raw_block;
int i;

mid = (struct middma_device *)data;
Expand All @@ -737,8 +902,9 @@ static void dma_tasklet(unsigned long data)
return;
}
pr_debug("MDMA: in tasklet for device %x\n", mid->pci_id);
status = ioread32(mid->dma_base + RAW_TFR);
pr_debug("MDMA:RAW_TFR %x\n", status);
raw_tfr = ioread32(mid->dma_base + RAW_TFR);
raw_block = ioread32(mid->dma_base + RAW_BLOCK);
status = raw_tfr | raw_block;
status &= mid->intr_mask;
while (status) {
/*txn interrupt*/
Expand All @@ -754,15 +920,23 @@ static void dma_tasklet(unsigned long data)
}
pr_debug("MDMA:Tx complete interrupt %x, Ch No %d Index %d\n",
status, midc->ch_id, i);
midc->raw_tfr = raw_tfr;
midc->raw_block = raw_block;
spin_lock_bh(&midc->lock);
/*clearing this interrupts first*/
iowrite32((1 << midc->ch_id), mid->dma_base + CLEAR_TFR);
iowrite32((1 << midc->ch_id), mid->dma_base + CLEAR_BLOCK);

spin_lock_bh(&midc->lock);
if (raw_block) {
iowrite32((1 << midc->ch_id),
mid->dma_base + CLEAR_BLOCK);
}
midc_scan_descriptors(mid, midc);
pr_debug("MDMA:Scan of desc... complete, unmasking\n");
iowrite32(UNMASK_INTR_REG(midc->ch_id),
mid->dma_base + MASK_TFR);
if (raw_block) {
iowrite32(UNMASK_INTR_REG(midc->ch_id),
mid->dma_base + MASK_BLOCK);
}
spin_unlock_bh(&midc->lock);
}

Expand Down Expand Up @@ -836,7 +1010,8 @@ static irqreturn_t intel_mid_dma_interrupt(int irq, void *data)
tfr_status &= mid->intr_mask;
if (tfr_status) {
/*need to disable intr*/
iowrite32((tfr_status << 8), mid->dma_base + MASK_TFR);
iowrite32((tfr_status << INT_MASK_WE), mid->dma_base + MASK_TFR);
iowrite32((tfr_status << INT_MASK_WE), mid->dma_base + MASK_BLOCK);
pr_debug("MDMA: Calling tasklet %x\n", tfr_status);
call_tasklet = 1;
}
Expand Down
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