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Simple PCIe FMC carrier SPEC
Commit a32476d7 authored by Federico Vaga's avatar Federico Vaga
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sw:drv: use coherent memory for DMA to simplify code 

NOTE: for the time being we are able to do perform maximumx 0x3FFF
Bytes in a single transfer due to HDL limitations
Signed-off-by: Federico Vaga's avatarFederico Vaga <federico.vaga@cern.ch>
parent fa9a17be
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Showing with 36 additions and 66 deletions
software/kernel/spec-core-fpga.c
View file @ a32476d7
......@@ -128,6 +128,9 @@ static const struct file_operations spec_fpga_dbg_bld_ops = {
struct spec_fpga_dbg_dma {
struct spec_fpga *spec_fpga;
struct dma_chan *dchan;
size_t datalen;
void *data;
dma_addr_t datadma;
struct dmaengine_result dma_res;
struct completion compl;
};
......@@ -167,39 +170,11 @@ static int spec_fpga_dbg_dma_transfer(struct spec_fpga_dbg_dma *dbgdma,
enum dma_transfer_direction dir,
void *data, size_t count, loff_t offset)
{
size_t max_segment_size;
unsigned int nr_pages = (count / PAGE_SIZE) + 1;
struct page **pages;
struct sg_table sgt;
int i;
int err;
int sg_len;
struct dma_slave_config sconfig;
struct dma_async_tx_descriptor *tx;
dma_cookie_t cookie;
pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
if (!pages)
return -ENOMEM;
for (i = 0; i < nr_pages; ++i)
pages[i] = virt_to_page(data + PAGE_SIZE * i);
max_segment_size = dma_get_max_seg_size(dbgdma->dchan->device->dev);
max_segment_size &= PAGE_MASK; /* to make alloc_table happy */
err = __sg_alloc_table_from_pages(&sgt, pages, nr_pages,
offset_in_page(data), count,
max_segment_size, GFP_KERNEL);
if (err)
goto err_alloc;
sg_len = dma_map_sg(dbgdma->spec_fpga->dev.parent,
sgt.sgl, sgt.nents, dir);
if (sg_len < 0) {
err = sg_len;
goto err_map;
}
memset(&sconfig, 0, sizeof(sconfig));
sconfig.direction = dir;
sconfig.src_addr = offset;
......@@ -207,8 +182,9 @@ static int spec_fpga_dbg_dma_transfer(struct spec_fpga_dbg_dma *dbgdma,
if (err)
goto err_cfg;
tx = dmaengine_prep_slave_sg(dbgdma->dchan, sgt.sgl, sg_len,
DMA_DEV_TO_MEM, 0);
tx = dmaengine_prep_slave_single(dbgdma->dchan,
dbgdma->datadma, count,
DMA_DEV_TO_MEM, 0);
if (!tx) {
err = -EINVAL;
goto err_prep;
......@@ -245,44 +221,33 @@ static int spec_fpga_dbg_dma_transfer(struct spec_fpga_dbg_dma *dbgdma,
err_sub:
err_prep:
err_cfg:
dma_unmap_sg(dbgdma->spec_fpga->dev.parent,
sgt.sgl, sgt.nents, dir);
err_map:
sg_free_table(&sgt);
err_alloc:
kfree(pages);
return err;
}
static ssize_t spec_fpga_dbg_dma_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct spec_fpga_dbg_dma *dbgdma = file->private_data;
int err;
void *data;
if (count == 0)
return 0;
count = min(KMALLOC_MAX_SIZE / 2, count);
data = kmalloc(count, GFP_KERNEL);
if (!data)
return -ENOMEM;
count = min(dbgdma->datalen, count);
err = spec_fpga_dbg_dma_transfer(file->private_data, DMA_DEV_TO_MEM,
data, count, *ppos);
dbgdma->data, count, *ppos);
if (err)
goto err_trans;
err = copy_to_user(data, buf, count);
err = copy_to_user(dbgdma->data, buf, count);
if (err)
goto err_cpy;
kfree(data);
*ppos += count;
return count;
err_cpy:
err_trans:
kfree(data);
return err;
}
......@@ -290,33 +255,26 @@ static ssize_t spec_fpga_dbg_dma_write(struct file *file,
const char __user *buf, size_t count,
loff_t *ppos)
{
struct spec_fpga_dbg_dma *dbgdma = file->private_data;
int err;
void *data;
if (count == 0)
return 0;
count = max(KMALLOC_MAX_SIZE / 2, count);
data = kmalloc(count, GFP_KERNEL);
if (!data)
return -ENOMEM;
err = copy_from_user(data, buf, count);
count = min(dbgdma->datalen, count);
err = copy_from_user(dbgdma->data, buf, count);
if (err)
goto err_cpy;
err = spec_fpga_dbg_dma_transfer(file->private_data, DMA_MEM_TO_DEV,
data, count, *ppos);
err = spec_fpga_dbg_dma_transfer(dbgdma, DMA_MEM_TO_DEV,
dbgdma->data, count, *ppos);
if (err)
goto err_trans;
kfree(data);
*ppos += count;
return count;
err_trans:
err_cpy:
kfree(data);
return err;
}
......@@ -332,15 +290,24 @@ static int spec_fpga_dbg_dma_open(struct inode *inode, struct file *file)
dma_cap_mask_t dma_mask;
int err;
dbgdma = kzalloc(sizeof(*dbgdma), GFP_KERNEL);
if (!dbgdma)
return -ENOMEM;
if (!spec_fpga->dma_pdev) {
dev_warn(&spec_fpga->dev,
"Not able to find DMA engine: platform_device missing\n");
err = -ENODEV;
goto err_nodma;
return -ENODEV;
}
dbgdma = kzalloc(sizeof(*dbgdma), GFP_KERNEL);
if (!dbgdma)
return -ENOMEM;
init_completion(&dbgdma->compl);
dbgdma->spec_fpga = spec_fpga;
dbgdma->datalen = 0x3FFF;
dbgdma->data = dma_alloc_coherent(dbgdma->spec_fpga->dev.parent,
dbgdma->datalen, &dbgdma->datadma,
GFP_KERNEL);
if (!dbgdma->data) {
err = -ENOMEM;
goto err_dma_alloc;
}
dma_cap_zero(dma_mask);
......@@ -354,14 +321,15 @@ static int spec_fpga_dbg_dma_open(struct inode *inode, struct file *file)
err = -EBUSY;
goto err_req;
}
init_completion(&dbgdma->compl);
dbgdma->spec_fpga = spec_fpga;
file->private_data = dbgdma;
return 0;
err_req:
dma_free_coherent(dbgdma->spec_fpga->dev.parent,
dbgdma->datalen, dbgdma->data, dbgdma->datadma);
err_dma_alloc:
kfree(dbgdma);
err_nodma:
return err;
}
......@@ -374,6 +342,8 @@ static int spec_fpga_dbg_dma_release(struct inode *inode, struct file *file)
{
struct spec_fpga_dbg_dma *dbgdma = file->private_data;
dma_free_coherent(dbgdma->spec_fpga->dev.parent,
dbgdma->datalen, dbgdma->data, dbgdma->datadma);
dma_release_channel(dbgdma->dchan);
kfree(dbgdma);
......
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