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SubjectRe: [PATCH] dmaengine: fsl-edma: dma map slave device address
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Hi Angelo,

On 18.01.2019 23:50, Angelo Dureghello wrote:
> Hi Laurentiu,
>
> On Fri, Jan 18, 2019 at 12:06:23PM +0200, Laurentiu Tudor wrote:
>> This mapping needs to be created in order for slave dma transfers
>> to work on systems with SMMU. The implementation mostly mimics the
>> one in pl330 dma driver, authored by Robin Murphy.
>>
>> Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
>> Suggested-by: Robin Murphy <robin.murphy@arm.com>
>> ---
>> Original approach was to add the missing mappings in the i2c client driver,
>> see here for discussion: https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatchwork.ozlabs.org%2Fpatch%2F1026013%2F&amp;data=02%7C01%7Claurentiu.tudor%40nxp.com%7C7861dfe95dfb4fceeb8208d67d907488%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C1%7C636834456718898365&amp;sdata=XM5shQdcIRgFLtCmuRuFtViR6ttPDWI%2BNHXoPi68Xs8%3D&amp;reserved=0
>>
>> drivers/dma/fsl-edma-common.c | 66 ++++++++++++++++++++++++++++++++---
>> drivers/dma/fsl-edma-common.h | 4 +++
>> drivers/dma/fsl-edma.c | 1 +
>> drivers/dma/mcf-edma.c | 1 +
>> 4 files changed, 68 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c
>> index 8876c4c1bb2c..0e95ee24b6d4 100644
>> --- a/drivers/dma/fsl-edma-common.c
>> +++ b/drivers/dma/fsl-edma-common.c
>> @@ -6,6 +6,7 @@
>> #include <linux/dmapool.h>
>> #include <linux/module.h>
>> #include <linux/slab.h>
>> +#include <linux/dma-mapping.h>
>>
>> #include "fsl-edma-common.h"
>>
>> @@ -173,12 +174,62 @@ int fsl_edma_resume(struct dma_chan *chan)
>> }
>> EXPORT_SYMBOL_GPL(fsl_edma_resume);
>>
>> +static void fsl_edma_unprep_slave_dma(struct fsl_edma_chan *fsl_chan)
>> +{
>> + if (fsl_chan->dma_dir != DMA_NONE)
>> + dma_unmap_resource(fsl_chan->vchan.chan.device->dev,
>> + fsl_chan->dma_dev_addr,
>> + fsl_chan->dma_dev_size,
>> + fsl_chan->dma_dir, 0);
>> + fsl_chan->dma_dir = DMA_NONE;
>> +}
>> +
>> +static bool fsl_edma_prep_slave_dma(struct fsl_edma_chan *fsl_chan,
>> + enum dma_transfer_direction dir)
>> +{
>> + struct device *dev = fsl_chan->vchan.chan.device->dev;
>> + enum dma_data_direction dma_dir;
>> + phys_addr_t addr = 0;
>> + u32 size = 0;
>> +
>> + switch (dir) {
>> + case DMA_MEM_TO_DEV:
>> + dma_dir = DMA_FROM_DEVICE;
>> + addr = fsl_chan->cfg.dst_addr;
>> + size = fsl_chan->cfg.dst_maxburst;
>> + break;
>> + case DMA_DEV_TO_MEM:
>> + dma_dir = DMA_TO_DEVICE;
>> + addr = fsl_chan->cfg.src_addr;
>> + size = fsl_chan->cfg.src_maxburst;
>> + break;
>> + default:
>> + dma_dir = DMA_NONE;
>> + break;
>> + }
>> +
>> + /* Already mapped for this config? */
>> + if (fsl_chan->dma_dir == dma_dir)
>> + return true;
>> +
>> + fsl_edma_unprep_slave_dma(fsl_chan);
>> +
>> + fsl_chan->dma_dev_addr = dma_map_resource(dev, addr, size, dma_dir, 0);
>> + if (dma_mapping_error(dev, fsl_chan->dma_dev_addr))
>> + return false;
>> + fsl_chan->dma_dev_size = size;
>> + fsl_chan->dma_dir = dma_dir;
>> +
>> + return true;
>> +}
>> +
>> int fsl_edma_slave_config(struct dma_chan *chan,
>> struct dma_slave_config *cfg)
>> {
>> struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
>>
>> memcpy(&fsl_chan->cfg, cfg, sizeof(*cfg));
>> + fsl_edma_unprep_slave_dma(fsl_chan);
>>
>> return 0;
>> }
>> @@ -378,6 +429,9 @@ struct dma_async_tx_descriptor *fsl_edma_prep_dma_cyclic(
>> if (!is_slave_direction(direction))
>> return NULL;
>>
>> + if (!fsl_edma_prep_slave_dma(fsl_chan, direction))
>> + return NULL;
>> +
>> sg_len = buf_len / period_len;
>> fsl_desc = fsl_edma_alloc_desc(fsl_chan, sg_len);
>> if (!fsl_desc)
>> @@ -409,11 +463,11 @@ struct dma_async_tx_descriptor *fsl_edma_prep_dma_cyclic(
>>
>> if (direction == DMA_MEM_TO_DEV) {
>> src_addr = dma_buf_next;
>> - dst_addr = fsl_chan->cfg.dst_addr;
>> + dst_addr = fsl_chan->dma_dev_addr;
>> soff = fsl_chan->cfg.dst_addr_width;
>> doff = 0;
>> } else {
>> - src_addr = fsl_chan->cfg.src_addr;
>> + src_addr = fsl_chan->dma_dev_addr;
>> dst_addr = dma_buf_next;
>> soff = 0;
>> doff = fsl_chan->cfg.src_addr_width;
>> @@ -444,6 +498,9 @@ struct dma_async_tx_descriptor *fsl_edma_prep_slave_sg(
>> if (!is_slave_direction(direction))
>> return NULL;
>>
>> + if (!fsl_edma_prep_slave_dma(fsl_chan, direction))
>> + return NULL;
>> +
>> fsl_desc = fsl_edma_alloc_desc(fsl_chan, sg_len);
>> if (!fsl_desc)
>> return NULL;
>> @@ -468,11 +525,11 @@ struct dma_async_tx_descriptor *fsl_edma_prep_slave_sg(
>>
>> if (direction == DMA_MEM_TO_DEV) {
>> src_addr = sg_dma_address(sg);
>> - dst_addr = fsl_chan->cfg.dst_addr;
>> + dst_addr = fsl_chan->dma_dev_addr;
>> soff = fsl_chan->cfg.dst_addr_width;
>> doff = 0;
>> } else {
>> - src_addr = fsl_chan->cfg.src_addr;
>> + src_addr = fsl_chan->dma_dev_addr;
>> dst_addr = sg_dma_address(sg);
>> soff = 0;
>> doff = fsl_chan->cfg.src_addr_width;
>> @@ -555,6 +612,7 @@ void fsl_edma_free_chan_resources(struct dma_chan *chan)
>> fsl_edma_chan_mux(fsl_chan, 0, false);
>> fsl_chan->edesc = NULL;
>> vchan_get_all_descriptors(&fsl_chan->vchan, &head);
>> + fsl_edma_unprep_slave_dma(fsl_chan);
>> spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
>>
>> vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
>> diff --git a/drivers/dma/fsl-edma-common.h b/drivers/dma/fsl-edma-common.h
>> index 8917e8865959..b435d8e1e3a1 100644
>> --- a/drivers/dma/fsl-edma-common.h
>> +++ b/drivers/dma/fsl-edma-common.h
>> @@ -6,6 +6,7 @@
>> #ifndef _FSL_EDMA_COMMON_H_
>> #define _FSL_EDMA_COMMON_H_
>>
>> +#include <linux/dma-direction.h>
>> #include "virt-dma.h"
>>
>> #define EDMA_CR_EDBG BIT(1)
>> @@ -120,6 +121,9 @@ struct fsl_edma_chan {
>> struct dma_slave_config cfg;
>> u32 attr;
>> struct dma_pool *tcd_pool;
>> + dma_addr_t dma_dev_addr;
>> + u32 dma_dev_size;
>> + enum dma_data_direction dma_dir;
>> };
>>
>> struct fsl_edma_desc {
>> diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c
>> index 34d70112fcc9..75e8a7ba3a22 100644
>> --- a/drivers/dma/fsl-edma.c
>> +++ b/drivers/dma/fsl-edma.c
>> @@ -254,6 +254,7 @@ static int fsl_edma_probe(struct platform_device *pdev)
>> fsl_chan->pm_state = RUNNING;
>> fsl_chan->slave_id = 0;
>> fsl_chan->idle = true;
>> + fsl_chan->dma_dir = DMA_NONE;
>> fsl_chan->vchan.desc_free = fsl_edma_free_desc;
>> vchan_init(&fsl_chan->vchan, &fsl_edma->dma_dev);
>>
>> diff --git a/drivers/dma/mcf-edma.c b/drivers/dma/mcf-edma.c
>> index 5de1b07eddff..7de54b2fafdb 100644
>> --- a/drivers/dma/mcf-edma.c
>> +++ b/drivers/dma/mcf-edma.c
>> @@ -214,6 +214,7 @@ static int mcf_edma_probe(struct platform_device *pdev)
>> mcf_chan->edma = mcf_edma;
>> mcf_chan->slave_id = i;
>> mcf_chan->idle = true;
>> + mcf_chan->dma_dir = DMA_NONE;
>> mcf_chan->vchan.desc_free = fsl_edma_free_desc;
>> vchan_init(&mcf_chan->vchan, &mcf_edma->dma_dev);
>> iowrite32(0x0, &regs->tcd[i].csr);
>> --
>> 2.17.1
>>
>
> I tested this patch on:
>
> - Vybrid VF50N (Toradex Colibri VF50)
> - ColdFire mcf54415 (Sysam stmark2 board)
>
> and dma still works properly.
>
> Tested-by: Angelo Dureghello <angelo@sysam.it>
>

Thanks a lot for testing!

---
Best Regards, Laurentiu
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