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@xxxxxxx> > Suggested-by: Robin Murphy <robin.murphy@xxxxxxx> > --- > Original approach was to add the missing mappings in the i2c client driver, > see here for discussion: https://patchwork.ozlabs.org/patch/1026013/ > > 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, ®s->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@xxxxxxxx>
