[PATCH v7 00/25] dmaengine: dw-edma: Add RP/EP local DMA controllers support

[PATCH v7 00/25] dmaengine: dw-edma: Add RP/EP local DMA controllers support

[Serge Semin]

This is a final patchset in the series created in the framework of
my Baikal-T1 PCIe/eDMA-related work:

[1: Done v5] PCI: dwc: Various fixes and cleanups
Link: https://lore.kernel.org/linux-pci/20220624143428.8334-1-Sergey.Semin@baikalelectronics.ru/
Merged: kernel 6.0-rc1
[2: Done v4] PCI: dwc: Add hw version and dma-ranges support
Link: https://lore.kernel.org/linux-pci/20220624143947.8991-1-Sergey.Semin@baikalelectronics.ru/
Merged: kernel 6.0-rc1
[3: Done v7] PCI: dwc: Add generic resources and Baikal-T1 support
Link: https://lore.kernel.org/linux-pci/20221113191301.5526-1-Sergey.Semin@baikalelectronics.ru/
Merged: kernel 6.2-rc1
[4: In-review v7] dmaengine: dw-edma: Add RP/EP local DMA support
Link: ---you are looking at it---

Note it is very recommended to merge the patchsets in the same order as
they are listed in the set above in order to have them applied smoothly.
Sinc the patchsets 1-3 have already been merged into the mainline kernel
this series can be applied via any DMA-engine or PCI repos.

Here is a short summary regarding this patchset. The series starts with
fixes patches. We discovered that the dw-edma-pcie.c driver incorrectly
initializes the LL/DT base addresses for the platforms with not matching
CPU and PCIe memory spaces. It is fixed by using the pci_bus_address()
method to get a correct base address. After that you can find a series of
the interleaved xfers fixes. It turned out the interleaved transfers
implementation didn't work quite correctly from the very beginning for
instance missing src/dst addresses initialization, etc. In the framework
of the next two patches we suggest to add a new platform-specific
callback - pci_address() and use it to convert the CPU address to the PCIe
space address. It is at least required for the DW eDMA remote End-point
setup on the platforms with not-matching CPU/PCIe address spaces. In case
of the DW eDMA local RP/EP setup the conversion will be done automatically
by the outbound iATU (if no DMA-bypass flag is specified for the
corresponding iATU window). Then we introduce a set of the patches to make
the DebugFS part of the code supporting the multi-eDMA controllers
platforms. It starts with several cleanup patches and is closed joining
the Read/Write channels into a single DMA-device as they originally should
have been. After that you can find the patches with adding the non-atomic
io-64 methods usage, dropping DT-region descriptors allocation, replacing
chip IDs with the device name. In addition to that in order to have the
eDMA embedded into the DW PCIe RP/EP supported we need to bypass the
dma-ranges-based memory ranges mapping since in case of the root port DT
node it's applicable for the peripheral PCIe devices only. Finally at the
series closure we introduce a generic DW eDMA controller support being
available in the DW PCIe Root Port/Endpoint driver.

Link: https://lore.kernel.org/linux-pci/20220324014836.19149-1-Sergey.Semin@baikalelectronics.ru/
Changelog v2:
- Drop the patches:
  [PATCH 1/25] dmaengine: dw-edma: Drop dma_slave_config.direction field usage
  [PATCH 2/25] dmaengine: dw-edma: Fix eDMA Rd/Wr-channels and DMA-direction semantics
  since they are going to be merged in in the framework of the
  Frank's patchset.
- Add a new patch: "dmaengine: dw-edma: Release requested IRQs on
  failure."
- Drop __iomem qualifier from the struct dw_edma_debugfs_entry instance
  definition in the dw_edma_debugfs_u32_get() method. (@Manivannan)
- Add a new patch: "dmaengine: dw-edma: Rename DebugFS dentry variables to
  'dent'." (@Manivannan)
- Slightly extend the eDMA name array size. (@Manivannan)
- Change the specific DMA mapping comment a bit to being
  clearer. (@Manivannan)
- Add a new patch: "PCI: dwc: Add generic iATU/eDMA CSRs space detection
  method."
- Don't fail eDMA detection procedure if the DW eDMA driver couldn't probe
  device. That happens if the driver is disabled. (@Manivannan)
- Add "dma" registers resource mapping procedure. (@Manivannan)
- Move the eDMA CSRs space detection into the dw_pcie_map_detect() method.
- Remove eDMA on the dw_pcie_ep_init() internal errors. (@Manivannan)
- Remove eDMA in the dw_pcie_ep_exit() method.
- Move the dw_pcie_edma_detect() method execution to the tail of the
  dw_pcie_ep_init() function.

Link: https://lore.kernel.org/linux-pci/20220503225104.12108-1-Sergey.Semin@baikalelectronics.ru/
Changelog v3:
- Conditionally set dchan->dev->device.dma_coherent field since it can
  be missing on some platforms. (@Manivannan)
- Drop the patch: "PCI: dwc: Add generic iATU/eDMA CSRs space detection
  method". A similar modification has been done in another patchset.
- Add more comprehensive and less regression prune eDMA block detection
  procedure.
- Drop the patch: "dma-direct: take dma-ranges/offsets into account in
  resource mapping". It will be separately reviewed.
- Remove Manivannan tb tag from the modified patches.
- Rebase onto the kernel v5.18.

Link: https://lore.kernel.org/linux-pci/20220610091459.17612-1-Sergey.Semin@baikalelectronics.ru
Changelog v4:
- Rabase onto the laters Frank Li series:
Link: https://lore.kernel.org/all/20220524152159.2370739-1-Frank.Li@nxp.com/
- Add Vinod' Ab-tag.
- Rebase onto the kernel v5.19-rcX.

Link: https://lore.kernel.org/linux-pci/20220728142841.12305-1-Sergey.Semin@baikalelectronics.ru
Changelog v5:
- Just resend.
- Rebase onto the kernel v6.0-rc2.

Link: https://lore.kernel.org/linux-pci/20220822185332.26149-1-Sergey.Semin@baikalelectronics.ru
Changelog v6:
- Fix some patchlog and in-line comments misspells. (@Bjorn)
- Directly call *_dma_configure() method on the DW eDMA channel child
  device used for the DMA buffers mapping. (@Robin)
- Explicitly set the DMA-mask of the child device in the channel
  allocation proecedure. (@Robin)
- Rebase onto the kernel v6.1-rc3.

Link: https://lore.kernel.org/linux-pci/20221107210438.1515-1-Sergey.Semin@baikalelectronics.ru/
Changelog v7:
- Activate the mapping auto-detection procedure for IP-cores older than
  5.40a. The viewport-based access has been removed since that
  version. (@Yoshihiro)
- Drop the patch
  [PATCH v6 22/24] dmaengine: dw-edma: Bypass dma-ranges mapping for the local setup
  since the problem has been fixed in the commit f1ad5338a4d5 ("of: Fix
  "dma-ranges" handling for bus controllers"). (@Robin)
- Add a new patch:
  [PATCH v7 23/25] PCI: dwc: Restore DMA-mask after MSI-data allocation
  (@Robin)
- Add a new patch:
  [PATCH v7 24/25] PCI: bt1: Set 64-bit DMA-mask
  (@Robin)

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-By: Vinod Koul <vkoul@kernel.org>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>
Cc: "Krzysztof Wilczyński" <kw@linux.com>
Cc: caihuoqing <caihuoqing@baidu.com>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: linux-pci@vger.kernel.org
Cc: dmaengine@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Serge Semin (25):
  dmaengine: Fix dma_slave_config.dst_addr description
  dmaengine: dw-edma: Release requested IRQs on failure
  dmaengine: dw-edma: Convert ll/dt phys-address to PCIe bus/DMA address
  dmaengine: dw-edma: Fix missing src/dst address of the interleaved
    xfers
  dmaengine: dw-edma: Don't permit non-inc interleaved xfers
  dmaengine: dw-edma: Fix invalid interleaved xfers semantics
  dmaengine: dw-edma: Add CPU to PCIe bus address translation
  dmaengine: dw-edma: Add PCIe bus address getter to the remote EP
    glue-driver
  dmaengine: dw-edma: Drop chancnt initialization
  dmaengine: dw-edma: Fix DebugFS reg entry type
  dmaengine: dw-edma: Stop checking debugfs_create_*() return value
  dmaengine: dw-edma: Add dw_edma prefix to the DebugFS nodes descriptor
  dmaengine: dw-edma: Convert DebugFS descs to being kz-allocated
  dmaengine: dw-edma: Rename DebugFS dentry variables to 'dent'
  dmaengine: dw-edma: Simplify the DebugFS context CSRs init procedure
  dmaengine: dw-edma: Move eDMA data pointer to DebugFS node descriptor
  dmaengine: dw-edma: Join Write/Read channels into a single device
  dmaengine: dw-edma: Use DMA-engine device DebugFS subdirectory
  dmaengine: dw-edma: Use non-atomic io-64 methods
  dmaengine: dw-edma: Drop DT-region allocation
  dmaengine: dw-edma: Replace chip ID number with device name
  dmaengine: dw-edma: Skip cleanup procedure if no private data found
  PCI: dwc: Restore DMA-mask after MSI-data allocation
  PCI: bt1: Set 64-bit DMA-mask
  PCI: dwc: Add DW eDMA engine support

 drivers/dma/dw-edma/dw-edma-core.c            | 196 ++++-----
 drivers/dma/dw-edma/dw-edma-core.h            |  10 +-
 drivers/dma/dw-edma/dw-edma-pcie.c            |  24 +-
 drivers/dma/dw-edma/dw-edma-v0-core.c         |  60 +--
 drivers/dma/dw-edma/dw-edma-v0-core.h         |   1 -
 drivers/dma/dw-edma/dw-edma-v0-debugfs.c      | 372 ++++++++----------
 drivers/dma/dw-edma/dw-edma-v0-debugfs.h      |   5 -
 drivers/pci/controller/dwc/pcie-bt1.c         |   4 +
 .../pci/controller/dwc/pcie-designware-ep.c   |  12 +-
 .../pci/controller/dwc/pcie-designware-host.c |  26 +-
 drivers/pci/controller/dwc/pcie-designware.c  | 195 +++++++++
 drivers/pci/controller/dwc/pcie-designware.h  |  21 +
 include/linux/dma/edma.h                      |  18 +-
 include/linux/dmaengine.h                     |   2 +-
 14 files changed, 589 insertions(+), 357 deletions(-)

-- 
2.38.1

[PATCH v7 01/25] dmaengine: Fix dma_slave_config.dst_addr description

[Serge Semin]

Most likely due to a copy-paste mistake the dst_addr member of the
dma_slave_config structure has been marked as ignored if the !source!
address belong to the memory. That is relevant to the src_addr field of
the structure while the dst_addr field as containing a destination device
address is supposed to be ignored if the destination is the CPU memory.
Let's fix the field description accordingly.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 include/linux/dmaengine.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index c923f4e60f24..0c020682d894 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -394,7 +394,7 @@ enum dma_slave_buswidth {
  * should be read (RX), if the source is memory this argument is
  * ignored.
  * @dst_addr: this is the physical address where DMA slave data
- * should be written (TX), if the source is memory this argument
+ * should be written (TX), if the destination is memory this argument
  * is ignored.
  * @src_addr_width: this is the width in bytes of the source (RX)
  * register where DMA data shall be read. If the source
-- 
2.38.1

[PATCH v7 02/25] dmaengine: dw-edma: Release requested IRQs on failure

[Serge Semin]

From very beginning of the DW eDMA driver live in the kernel the method
dw_edma_irq_request() hasn't been designed quite correct. In case if the
request_irq() method fails to initialize the IRQ handler at some point the
previously requested IRQs will be left initialized. It's prune to errors
up to the system crash. Let's fix that by releasing the previously
requested IRQs in the cleanup-on-error path of the dw_edma_irq_request()
function.

Fixes: e63d79d1ffcd ("dmaengine: Add Synopsys eDMA IP core driver")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>

---

Changelog v2:
- This is a new patch added in v2 iteration of the series.
---
 drivers/dma/dw-edma/dw-edma-core.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index c54b24ff5206..a8c1bd9c7ae9 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -893,10 +893,8 @@ static int dw_edma_irq_request(struct dw_edma *dw,
 						dw_edma_interrupt_read,
 					  IRQF_SHARED, dw->name,
 					  &dw->irq[i]);
-			if (err) {
-				dw->nr_irqs = i;
-				return err;
-			}
+			if (err)
+				goto err_irq_free;
 
 			if (irq_get_msi_desc(irq))
 				get_cached_msi_msg(irq, &dw->irq[i].msi);
@@ -905,6 +903,14 @@ static int dw_edma_irq_request(struct dw_edma *dw,
 		dw->nr_irqs = i;
 	}
 
+	return 0;
+
+err_irq_free:
+	for  (i--; i >= 0; i--) {
+		irq = chip->ops->irq_vector(dev, i);
+		free_irq(irq, &dw->irq[i]);
+	}
+
 	return err;
 }
 
-- 
2.38.1

[PATCH v7 03/25] dmaengine: dw-edma: Convert ll/dt phys-address to PCIe bus/DMA address

[Serge Semin]

In accordance with the dw_edma_region.paddr field semantics it is supposed
to be initialized with a memory base address visible by the DW eDMA
controller. If the DMA engine is embedded into the DW PCIe Host/EP
controller, then the address should belong to the Local CPU/Application
memory. If eDMA is remotely accessible across the PCIe bus via the PCIe
memory IOs, then the address needs to be a part of the PCIe bus memory
space. The later case hasn't been well covered in the corresponding
glue-driver. Since in general the PCIe memory space doesn't have to match
the CPU memory space and the pci_dev.resource[] arrays contain the
resources defined in the CPU memory space, a proper conversion needs to be
performed, otherwise either the driver won't properly work or much worse
the memory corruption will happen. The conversion can be done by means of
the pci_bus_address() method. Let's use it to retrieve the LL, DT and CSRs
PCIe memory ranges.

Note in addition to that we need to extend the dw_edma_region.paddr field
size. The field normally contains a memory range base address to be set in
the DW eDMA Linked-List pointer register or as a base address of the
Linked-List data buffer. In accordance with [1] the LL range is supposed
to be created in the Local CPU/Application memory, but depending on the DW
eDMA utilization the memory can be created as a part of the PCIe bus
address space (as in the case of the DW PCIe EP prototype kit). Thus in
the former case the dw_edma_region.paddr field should have the dma_addr_t
type, while in the later one - pci_bus_addr_t. Seeing the corresponding
CSRs are always 64-bits wide let's convert the dw_edma_region.paddr field
type to be u64 and let the client code logic to make sure it has a valid
address visible by the DW eDMA controller. For instance the DW eDMA PCIe
glue-driver initializes the field with the addresses from the PCIe bus
memory space.

[1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port,
    v.5.40a, March 2019, p.1103

Fixes: 41aaff2a2ac0 ("dmaengine: Add Synopsys eDMA IP PCIe glue-logic")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-pcie.c | 8 ++++----
 include/linux/dma/edma.h           | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c b/drivers/dma/dw-edma/dw-edma-pcie.c
index d6b5e2463884..04c95cba1244 100644
--- a/drivers/dma/dw-edma/dw-edma-pcie.c
+++ b/drivers/dma/dw-edma/dw-edma-pcie.c
@@ -231,7 +231,7 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
 			return -ENOMEM;
 
 		ll_region->vaddr += ll_block->off;
-		ll_region->paddr = pdev->resource[ll_block->bar].start;
+		ll_region->paddr = pci_bus_address(pdev, ll_block->bar);
 		ll_region->paddr += ll_block->off;
 		ll_region->sz = ll_block->sz;
 
@@ -240,7 +240,7 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
 			return -ENOMEM;
 
 		dt_region->vaddr += dt_block->off;
-		dt_region->paddr = pdev->resource[dt_block->bar].start;
+		dt_region->paddr = pci_bus_address(pdev, dt_block->bar);
 		dt_region->paddr += dt_block->off;
 		dt_region->sz = dt_block->sz;
 	}
@@ -256,7 +256,7 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
 			return -ENOMEM;
 
 		ll_region->vaddr += ll_block->off;
-		ll_region->paddr = pdev->resource[ll_block->bar].start;
+		ll_region->paddr = pci_bus_address(pdev, ll_block->bar);
 		ll_region->paddr += ll_block->off;
 		ll_region->sz = ll_block->sz;
 
@@ -265,7 +265,7 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
 			return -ENOMEM;
 
 		dt_region->vaddr += dt_block->off;
-		dt_region->paddr = pdev->resource[dt_block->bar].start;
+		dt_region->paddr = pci_bus_address(pdev, dt_block->bar);
 		dt_region->paddr += dt_block->off;
 		dt_region->sz = dt_block->sz;
 	}
diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
index 7d8062e9c544..a864978ddd27 100644
--- a/include/linux/dma/edma.h
+++ b/include/linux/dma/edma.h
@@ -18,7 +18,7 @@
 struct dw_edma;
 
 struct dw_edma_region {
-	phys_addr_t	paddr;
+	u64		paddr;
 	void __iomem	*vaddr;
 	size_t		sz;
 };
-- 
2.38.1

[PATCH v7 04/25] dmaengine: dw-edma: Fix missing src/dst address of the interleaved xfers

[Serge Semin]

The interleaved DMA transfers support was added in the commit 85e7518f42c8
("dmaengine: dw-edma: Add device_prep_interleave_dma() support"). It
seems like the support was broken from the very beginning. Depending on
the selected channel either source or destination address are left
uninitialized which was obviously wrong. I don't really know how come the
original modification was working for the commit author. Anyway let's fix
it by initializing the destination address of the eDMA burst descriptors
for the DEV_TO_MEM interleaved operations and by initializing the source
address of the eDMA burst descriptors for the MEM_TO_DEV interleaved
operations.

Fixes: 85e7518f42c8 ("dmaengine: dw-edma: Add device_prep_interleave_dma() support")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index a8c1bd9c7ae9..778d91d9fc1b 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -455,6 +455,8 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 				 * and destination addresses are increased
 				 * by the same portion (data length)
 				 */
+			} else if (xfer->type == EDMA_XFER_INTERLEAVED) {
+				burst->dar = dst_addr;
 			}
 		} else {
 			burst->dar = dst_addr;
@@ -470,6 +472,8 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 				 * and destination addresses are increased
 				 * by the same portion (data length)
 				 */
+			}  else if (xfer->type == EDMA_XFER_INTERLEAVED) {
+				burst->sar = src_addr;
 			}
 		}
 
-- 
2.38.1

[PATCH v7 05/25] dmaengine: dw-edma: Don't permit non-inc interleaved xfers

[Serge Semin]

DW eDMA controller always increments both source and destination
addresses. Permitting DMA interleaved transfers with no src_inc/dst_inc
flags set may lead to unexpected behaviour for the device users. Let's fix
that by terminating the interleaved transfers if at least one of the
dma_interleaved_template.{src_inc,dst_inc} flag is initialized with false
value. Note in addition to that we need to increase the source and
destination addresses accordingly after each iteration.

Fixes: 85e7518f42c8 ("dmaengine: dw-edma: Add device_prep_interleave_dma() support")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-core.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 778d91d9fc1b..35588e14f79a 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -385,6 +385,8 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 			return NULL;
 		if (xfer->xfer.il->numf > 0 && xfer->xfer.il->frame_size > 0)
 			return NULL;
+		if (!xfer->xfer.il->src_inc || !xfer->xfer.il->dst_inc)
+			return NULL;
 	} else {
 		return NULL;
 	}
@@ -484,15 +486,13 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 			struct dma_interleaved_template *il = xfer->xfer.il;
 			struct data_chunk *dc = &il->sgl[i];
 
-			if (il->src_sgl) {
-				src_addr += burst->sz;
+			src_addr += burst->sz;
+			if (il->src_sgl)
 				src_addr += dmaengine_get_src_icg(il, dc);
-			}
 
-			if (il->dst_sgl) {
-				dst_addr += burst->sz;
+			dst_addr += burst->sz;
+			if (il->dst_sgl)
 				dst_addr += dmaengine_get_dst_icg(il, dc);
-			}
 		}
 	}
 
-- 
2.38.1

[PATCH v7 06/25] dmaengine: dw-edma: Fix invalid interleaved xfers semantics

[Serge Semin]

The interleaved DMA transfer support added in commit 85e7518f42c8
("dmaengine: dw-edma: Add device_prep_interleave_dma() support") seems
contradicting to what the DMA-engine defines. The next conditional
statements:
	if (!xfer->xfer.il->numf)
		return NULL;
	if (xfer->xfer.il->numf > 0 && xfer->xfer.il->frame_size > 0)
		return NULL;
basically mean that numf can't be zero and frame_size must always be zero,
otherwise the transfer won't be executed. But further the transfer
execution method takes the frames size from the
dma_interleaved_template.sgl[] array for each frame. That array in
accordance with [1] is supposed to be of
dma_interleaved_template.frame_size size, which as we discovered before
the code expects to be zero. So judging by the dw_edma_device_transfer()
implementation the method implies the dma_interleaved_template.sgl[] array
being of dma_interleaved_template.numf size, which is wrong. Since the
dw_edma_device_transfer() method doesn't permit
dma_interleaved_template.frame_size being non-zero then actual multi-chunk
interleaved transfer turns to be unsupported even though the code implies
having it supported.

Let's fix that by adding a fully functioning support of the interleaved
DMA transfers. First of all dma_interleaved_template.frame_size is
supposed to be greater or equal to one thus having at least simple linear
chunked frames. Secondly we can create a walk-through all over the chunks
and frames just by initializing the number of the eDMA burst transactios
as a multiple of dma_interleaved_template.numf and
dma_interleaved_template.frame_size and getting the frame_size-modulo of
the iteration step as an index of the dma_interleaved_template.sgl[]
array. The rest of the dw_edma_device_transfer() method code can be left
unchanged.

[1] include/linux/dmaengine.h: doc struct dma_interleaved_template

Fixes: 85e7518f42c8 ("dmaengine: dw-edma: Add device_prep_interleave_dma() support")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-core.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 35588e14f79a..d5c4192141ef 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -332,6 +332,7 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 	struct dw_edma_chunk *chunk;
 	struct dw_edma_burst *burst;
 	struct dw_edma_desc *desc;
+	size_t fsz = 0;
 	u32 cnt = 0;
 	int i;
 
@@ -381,9 +382,7 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 		if (xfer->xfer.sg.len < 1)
 			return NULL;
 	} else if (xfer->type == EDMA_XFER_INTERLEAVED) {
-		if (!xfer->xfer.il->numf)
-			return NULL;
-		if (xfer->xfer.il->numf > 0 && xfer->xfer.il->frame_size > 0)
+		if (!xfer->xfer.il->numf || xfer->xfer.il->frame_size < 1)
 			return NULL;
 		if (!xfer->xfer.il->src_inc || !xfer->xfer.il->dst_inc)
 			return NULL;
@@ -413,10 +412,8 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 		cnt = xfer->xfer.sg.len;
 		sg = xfer->xfer.sg.sgl;
 	} else if (xfer->type == EDMA_XFER_INTERLEAVED) {
-		if (xfer->xfer.il->numf > 0)
-			cnt = xfer->xfer.il->numf;
-		else
-			cnt = xfer->xfer.il->frame_size;
+		cnt = xfer->xfer.il->numf * xfer->xfer.il->frame_size;
+		fsz = xfer->xfer.il->frame_size;
 	}
 
 	for (i = 0; i < cnt; i++) {
@@ -438,7 +435,7 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 		else if (xfer->type == EDMA_XFER_SCATTER_GATHER)
 			burst->sz = sg_dma_len(sg);
 		else if (xfer->type == EDMA_XFER_INTERLEAVED)
-			burst->sz = xfer->xfer.il->sgl[i].size;
+			burst->sz = xfer->xfer.il->sgl[i % fsz].size;
 
 		chunk->ll_region.sz += burst->sz;
 		desc->alloc_sz += burst->sz;
@@ -481,10 +478,9 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 
 		if (xfer->type == EDMA_XFER_SCATTER_GATHER) {
 			sg = sg_next(sg);
-		} else if (xfer->type == EDMA_XFER_INTERLEAVED &&
-			   xfer->xfer.il->frame_size > 0) {
+		} else if (xfer->type == EDMA_XFER_INTERLEAVED) {
 			struct dma_interleaved_template *il = xfer->xfer.il;
-			struct data_chunk *dc = &il->sgl[i];
+			struct data_chunk *dc = &il->sgl[i % fsz];
 
 			src_addr += burst->sz;
 			if (il->src_sgl)
-- 
2.38.1

[PATCH v7 07/25] dmaengine: dw-edma: Add CPU to PCIe bus address translation

[Serge Semin]

Starting from commit 9575632052ba ("dmaengine: make slave address
physical") the source and destination addresses of the DMA-slave device
have been converted to being defined in CPU address space. It's DMA-device
driver responsibility to properly convert them to the reachable DMA bus
spaces. In case of the DW eDMA device, the source or destination
peripheral (slave) devices reside PCIe bus space. Thus we need to perform
the PCIe Host/EP windows-based (i.e. ranges DT-property) addresses
translation otherwise the eDMA transactions won't work as expected (or can
be even harmful) in case if the CPU and PCIe address spaces don't match.

Note 1. Even though the DMA interleaved template has both source and
destination addresses declared of dma_addr_t type only CPU memory range is
supposed to be mapped in a way so to be seen by the DMA device since it's
a subject of the DMA getting towards the system side. The device part must
not be mapped since slave device resides in the PCIe bus space, which
isn't affected by IOMMUs or iATU translations. DW PCIe eDMA generates
corresponding MWr/MRd TLPs on its own.

Note 2. This functionality is mainly required for the remote eDMA setup
since the CPU address must be manually translated into the PCIe bus space
before being written to LLI.{SAR,DAR}. If eDMA is embedded into the
locally accessible DW PCIe RP/EP software-based translation isn't required
since it will be done by hardware by means of the Outbound iATU as long as
the DMA_BYPASS flag is cleared. If the later flag is set or there is no
Outbound iATU entry found to which the SAR or DAR falls in (for Read and
Write channel respectfully), there won't be any translation performed but
DMA will proceed with the corresponding source/destination address as is.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-core.c | 18 +++++++++++++++++-
 include/linux/dma/edma.h           | 15 +++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index d5c4192141ef..6c9f95a8e397 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -39,6 +39,17 @@ struct dw_edma_desc *vd2dw_edma_desc(struct virt_dma_desc *vd)
 	return container_of(vd, struct dw_edma_desc, vd);
 }
 
+static inline
+u64 dw_edma_get_pci_address(struct dw_edma_chan *chan, phys_addr_t cpu_addr)
+{
+	struct dw_edma_chip *chip = chan->dw->chip;
+
+	if (chip->ops->pci_address)
+		return chip->ops->pci_address(chip->dev, cpu_addr);
+
+	return cpu_addr;
+}
+
 static struct dw_edma_burst *dw_edma_alloc_burst(struct dw_edma_chunk *chunk)
 {
 	struct dw_edma_burst *burst;
@@ -327,11 +338,11 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 {
 	struct dw_edma_chan *chan = dchan2dw_edma_chan(xfer->dchan);
 	enum dma_transfer_direction dir = xfer->direction;
-	phys_addr_t src_addr, dst_addr;
 	struct scatterlist *sg = NULL;
 	struct dw_edma_chunk *chunk;
 	struct dw_edma_burst *burst;
 	struct dw_edma_desc *desc;
+	u64 src_addr, dst_addr;
 	size_t fsz = 0;
 	u32 cnt = 0;
 	int i;
@@ -406,6 +417,11 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 		dst_addr = chan->config.dst_addr;
 	}
 
+	if (dir == DMA_DEV_TO_MEM)
+		src_addr = dw_edma_get_pci_address(chan, (phys_addr_t)src_addr);
+	else
+		dst_addr = dw_edma_get_pci_address(chan, (phys_addr_t)dst_addr);
+
 	if (xfer->type == EDMA_XFER_CYCLIC) {
 		cnt = xfer->xfer.cyclic.cnt;
 	} else if (xfer->type == EDMA_XFER_SCATTER_GATHER) {
diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
index a864978ddd27..380a0a3e251f 100644
--- a/include/linux/dma/edma.h
+++ b/include/linux/dma/edma.h
@@ -23,8 +23,23 @@ struct dw_edma_region {
 	size_t		sz;
 };
 
+/**
+ * struct dw_edma_core_ops - platform-specific eDMA methods
+ * @irq_vector:		Get IRQ number of the passed eDMA channel. Note the
+ *                      method accepts the channel id in the end-to-end
+ *                      numbering with the eDMA write channels being placed
+ *                      first in the row.
+ * @pci_address:	Get PCIe bus address corresponding to the passed CPU
+ *			address. Note there is no need in specifying this
+ *			function if the address translation is performed by
+ *			the DW PCIe RP/EP controller with the DW eDMA device in
+ *			subject and DMA_BYPASS isn't set for all the outbound
+ *			iATU windows. That will be done by the controller
+ *			automatically.
+ */
 struct dw_edma_core_ops {
 	int (*irq_vector)(struct device *dev, unsigned int nr);
+	u64 (*pci_address)(struct device *dev, phys_addr_t cpu_addr);
 };
 
 enum dw_edma_map_format {
-- 
2.38.1

[PATCH v7 08/25] dmaengine: dw-edma: Add PCIe bus address getter to the remote EP glue-driver

[Serge Semin]

In general the Synopsys PCIe EndPoint IP prototype kit can be attached to
a PCIe bus with any PCIe Host controller including to the one with
distinctive from CPU address space. Due to that we need to make sure that
the source and destination addresses of the DMA-slave devices are properly
converted to the PCIe bus address space, otherwise the DMA transaction
will not only work as expected, but may cause the memory corruption with
subsequent system crash. Let's do that by introducing a new
dw_edma_pcie_address() method defined in the dw-edma-pcie.c, which will
perform the denoted translation by using the pcibios_resource_to_bus()
method.

Fixes: 41aaff2a2ac0 ("dmaengine: Add Synopsys eDMA IP PCIe glue-logic")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>

---

Note this patch depends on the patch "dmaengine: dw-edma: Add CPU to PCIe
bus address translation" from this series.
---
 drivers/dma/dw-edma/dw-edma-pcie.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c b/drivers/dma/dw-edma/dw-edma-pcie.c
index 04c95cba1244..f530bacfd716 100644
--- a/drivers/dma/dw-edma/dw-edma-pcie.c
+++ b/drivers/dma/dw-edma/dw-edma-pcie.c
@@ -95,8 +95,23 @@ static int dw_edma_pcie_irq_vector(struct device *dev, unsigned int nr)
 	return pci_irq_vector(to_pci_dev(dev), nr);
 }
 
+static u64 dw_edma_pcie_address(struct device *dev, phys_addr_t cpu_addr)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pci_bus_region region;
+	struct resource res = {
+		.flags = IORESOURCE_MEM,
+		.start = cpu_addr,
+		.end = cpu_addr,
+	};
+
+	pcibios_resource_to_bus(pdev->bus, &region, &res);
+	return region.start;
+}
+
 static const struct dw_edma_core_ops dw_edma_pcie_core_ops = {
 	.irq_vector = dw_edma_pcie_irq_vector,
+	.pci_address = dw_edma_pcie_address,
 };
 
 static void dw_edma_pcie_get_vsec_dma_data(struct pci_dev *pdev,
-- 
2.38.1

[PATCH v7 09/25] dmaengine: dw-edma: Drop chancnt initialization

[Serge Semin]

DMA device drivers aren't supposed to initialize the dma_device.chancnt
field. It will be done by the DMA-engine core in accordance with number of
added virtual DMA-channels. Pre-initializing it with some value causes
having a wrong number of channels printed in the device summary.

Fixes: e63d79d1ffcd ("dmaengine: Add Synopsys eDMA IP core driver")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-core.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 6c9f95a8e397..ecd3e8f7ac5d 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -817,7 +817,6 @@ static int dw_edma_channel_setup(struct dw_edma *dw, bool write,
 	dma->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
 	dma->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
 	dma->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
-	dma->chancnt = cnt;
 
 	/* Set DMA channel callbacks */
 	dma->dev = chip->dev;
-- 
2.38.1

[PATCH v7 10/25] dmaengine: dw-edma: Fix DebugFS reg entry type

[Serge Semin]

debugfs_entries structure declared in the dw-edma-v0-debugfs.c module
contains the DebugFS node' register address. The address is declared as
dma_addr_t type, but first it's assigned with virtual CPU IOMEM address
and then it's cast back to the virtual address. Even though the castes
sandwich will unlikely cause any problem since normally DMA address is at
least of the same size as the CPU virtual address, it's at the very least
redundant if not to say logically incorrect. Let's fix it by just stop
casting the pointer back and worth and just preserve the address as a
pointer to void with __iomem qualifier.

Fixes: 305aebeff879 ("dmaengine: Add Synopsys eDMA IP version 0 debugfs support")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-v0-debugfs.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
index 5226c9014703..8e61810dea4b 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
+++ b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
@@ -14,7 +14,7 @@
 #include "dw-edma-core.h"
 
 #define REGS_ADDR(name) \
-	((void __force *)&regs->name)
+	((void __iomem *)&regs->name)
 #define REGISTER(name) \
 	{ #name, REGS_ADDR(name) }
 
@@ -48,12 +48,13 @@ static struct {
 
 struct debugfs_entries {
 	const char				*name;
-	dma_addr_t				*reg;
+	void __iomem				*reg;
 };
 
 static int dw_edma_debugfs_u32_get(void *data, u64 *val)
 {
-	void __iomem *reg = (void __force __iomem *)data;
+	void __iomem *reg = data;
+
 	if (dw->chip->mf == EDMA_MF_EDMA_LEGACY &&
 	    reg >= (void __iomem *)&regs->type.legacy.ch) {
 		void __iomem *ptr = &regs->type.legacy.ch;
-- 
2.38.1

[PATCH v7 11/25] dmaengine: dw-edma: Stop checking debugfs_create_*() return value

[Serge Semin]

First of all they never return NULL. So checking their return value for
being not NULL just pointless. Secondly the DebugFS subsystem is designed
in a way to be used as simple as possible. So if one of the
debugfs_create_*() method in a hierarchy fails, the following methods will
just silently return the passed erroneous parental dentry. Finally the
code is supposed to be working no matter whether anything DebugFS-related
fails. So in order to make code simpler and DebugFS-independent let's drop
the debugfs_create_*() methods return value checking in the same way as
the most of the kernel drivers do.

Note in order to preserve some memory space we suggest to skip the DebugFS
nodes initialization if the file system in unavailable.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-v0-debugfs.c | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
index 8e61810dea4b..6e7f3ef60ca7 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
+++ b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
@@ -100,9 +100,8 @@ static void dw_edma_debugfs_create_x32(const struct debugfs_entries entries[],
 	int i;
 
 	for (i = 0; i < nr_entries; i++) {
-		if (!debugfs_create_file_unsafe(entries[i].name, 0444, dir,
-						entries[i].reg,	&fops_x32))
-			break;
+		debugfs_create_file_unsafe(entries[i].name, 0444, dir,
+					   entries[i].reg, &fops_x32);
 	}
 }
 
@@ -168,8 +167,6 @@ static void dw_edma_debugfs_regs_wr(struct dentry *dir)
 	char name[16];
 
 	regs_dir = debugfs_create_dir(WRITE_STR, dir);
-	if (!regs_dir)
-		return;
 
 	nr_entries = ARRAY_SIZE(debugfs_regs);
 	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, regs_dir);
@@ -184,8 +181,6 @@ static void dw_edma_debugfs_regs_wr(struct dentry *dir)
 		snprintf(name, sizeof(name), "%s:%d", CHANNEL_STR, i);
 
 		ch_dir = debugfs_create_dir(name, regs_dir);
-		if (!ch_dir)
-			return;
 
 		dw_edma_debugfs_regs_ch(&regs->type.unroll.ch[i].wr, ch_dir);
 
@@ -237,8 +232,6 @@ static void dw_edma_debugfs_regs_rd(struct dentry *dir)
 	char name[16];
 
 	regs_dir = debugfs_create_dir(READ_STR, dir);
-	if (!regs_dir)
-		return;
 
 	nr_entries = ARRAY_SIZE(debugfs_regs);
 	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, regs_dir);
@@ -253,8 +246,6 @@ static void dw_edma_debugfs_regs_rd(struct dentry *dir)
 		snprintf(name, sizeof(name), "%s:%d", CHANNEL_STR, i);
 
 		ch_dir = debugfs_create_dir(name, regs_dir);
-		if (!ch_dir)
-			return;
 
 		dw_edma_debugfs_regs_ch(&regs->type.unroll.ch[i].rd, ch_dir);
 
@@ -273,8 +264,6 @@ static void dw_edma_debugfs_regs(void)
 	int nr_entries;
 
 	regs_dir = debugfs_create_dir(REGISTERS_STR, dw->debugfs);
-	if (!regs_dir)
-		return;
 
 	nr_entries = ARRAY_SIZE(debugfs_regs);
 	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, regs_dir);
@@ -285,6 +274,9 @@ static void dw_edma_debugfs_regs(void)
 
 void dw_edma_v0_debugfs_on(struct dw_edma *_dw)
 {
+	if (!debugfs_initialized())
+		return;
+
 	dw = _dw;
 	if (!dw)
 		return;
@@ -294,8 +286,6 @@ void dw_edma_v0_debugfs_on(struct dw_edma *_dw)
 		return;
 
 	dw->debugfs = debugfs_create_dir(dw->name, NULL);
-	if (!dw->debugfs)
-		return;
 
 	debugfs_create_u32("mf", 0444, dw->debugfs, &dw->chip->mf);
 	debugfs_create_u16("wr_ch_cnt", 0444, dw->debugfs, &dw->wr_ch_cnt);
-- 
2.38.1

[PATCH v7 12/25] dmaengine: dw-edma: Add dw_edma prefix to the DebugFS nodes descriptor

[Serge Semin]

The rest of the locally defined and used methods and structures have
dw_edma prefix in their names. It's right in accordance with the kernel
coding style to follow the locally defined rule of naming. Let's add that
prefix to the debugfs_entries structure too especially seeing it's name
may be confusing as if that structure belongs to the global DebugFS space.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-v0-debugfs.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
index 6e7f3ef60ca7..2121ffc33cf3 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
+++ b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
@@ -46,7 +46,7 @@ static struct {
 	void					__iomem *end;
 } lim[2][EDMA_V0_MAX_NR_CH];
 
-struct debugfs_entries {
+struct dw_edma_debugfs_entry {
 	const char				*name;
 	void __iomem				*reg;
 };
@@ -94,7 +94,7 @@ static int dw_edma_debugfs_u32_get(void *data, u64 *val)
 }
 DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, dw_edma_debugfs_u32_get, NULL, "0x%08llx\n");
 
-static void dw_edma_debugfs_create_x32(const struct debugfs_entries entries[],
+static void dw_edma_debugfs_create_x32(const struct dw_edma_debugfs_entry entries[],
 				       int nr_entries, struct dentry *dir)
 {
 	int i;
@@ -108,8 +108,7 @@ static void dw_edma_debugfs_create_x32(const struct debugfs_entries entries[],
 static void dw_edma_debugfs_regs_ch(struct dw_edma_v0_ch_regs __iomem *regs,
 				    struct dentry *dir)
 {
-	int nr_entries;
-	const struct debugfs_entries debugfs_regs[] = {
+	const struct dw_edma_debugfs_entry debugfs_regs[] = {
 		REGISTER(ch_control1),
 		REGISTER(ch_control2),
 		REGISTER(transfer_size),
@@ -120,6 +119,7 @@ static void dw_edma_debugfs_regs_ch(struct dw_edma_v0_ch_regs __iomem *regs,
 		REGISTER(llp.lsb),
 		REGISTER(llp.msb),
 	};
+	int nr_entries;
 
 	nr_entries = ARRAY_SIZE(debugfs_regs);
 	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, dir);
@@ -127,7 +127,7 @@ static void dw_edma_debugfs_regs_ch(struct dw_edma_v0_ch_regs __iomem *regs,
 
 static void dw_edma_debugfs_regs_wr(struct dentry *dir)
 {
-	const struct debugfs_entries debugfs_regs[] = {
+	const struct dw_edma_debugfs_entry debugfs_regs[] = {
 		/* eDMA global registers */
 		WR_REGISTER(engine_en),
 		WR_REGISTER(doorbell),
@@ -148,7 +148,7 @@ static void dw_edma_debugfs_regs_wr(struct dentry *dir)
 		WR_REGISTER(ch67_imwr_data),
 		WR_REGISTER(linked_list_err_en),
 	};
-	const struct debugfs_entries debugfs_unroll_regs[] = {
+	const struct dw_edma_debugfs_entry debugfs_unroll_regs[] = {
 		/* eDMA channel context grouping */
 		WR_REGISTER_UNROLL(engine_chgroup),
 		WR_REGISTER_UNROLL(engine_hshake_cnt.lsb),
@@ -191,7 +191,7 @@ static void dw_edma_debugfs_regs_wr(struct dentry *dir)
 
 static void dw_edma_debugfs_regs_rd(struct dentry *dir)
 {
-	const struct debugfs_entries debugfs_regs[] = {
+	const struct dw_edma_debugfs_entry debugfs_regs[] = {
 		/* eDMA global registers */
 		RD_REGISTER(engine_en),
 		RD_REGISTER(doorbell),
@@ -213,7 +213,7 @@ static void dw_edma_debugfs_regs_rd(struct dentry *dir)
 		RD_REGISTER(ch45_imwr_data),
 		RD_REGISTER(ch67_imwr_data),
 	};
-	const struct debugfs_entries debugfs_unroll_regs[] = {
+	const struct dw_edma_debugfs_entry debugfs_unroll_regs[] = {
 		/* eDMA channel context grouping */
 		RD_REGISTER_UNROLL(engine_chgroup),
 		RD_REGISTER_UNROLL(engine_hshake_cnt.lsb),
@@ -256,7 +256,7 @@ static void dw_edma_debugfs_regs_rd(struct dentry *dir)
 
 static void dw_edma_debugfs_regs(void)
 {
-	const struct debugfs_entries debugfs_regs[] = {
+	const struct dw_edma_debugfs_entry debugfs_regs[] = {
 		REGISTER(ctrl_data_arb_prior),
 		REGISTER(ctrl),
 	};
-- 
2.38.1

[PATCH v7 13/25] dmaengine: dw-edma: Convert DebugFS descs to being kz-allocated

[Serge Semin]

Currently all the DW eDMA DebugFS nodes descriptors are allocated on
stack, while the DW eDMA driver private data and CSR limits are statically
preserved. Such design won't work for the multi-eDMA platforms. As a
preparation to adding the multi-eDMA system setups support we need to have
each DebugFS node separately allocated and described. Afterwards we'll put
an addition info there like Read/Write channel flag, channel ID, DW eDMA
private data reference.

Note this conversion is mainly required due to having the legacy DW eDMA
controllers with indirect Read/Write channels context CSRs access. If we
didn't need to have a synchronized access to these registers the DebugFS
code of the driver would have been much simpler.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>

---

Changelog v2:
- Drop __iomem qualifier from the struct dw_edma_debugfs_entry instance
  definition in the dw_edma_debugfs_u32_get() method. (@Manivannan)
---
 drivers/dma/dw-edma/dw-edma-v0-debugfs.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
index 2121ffc33cf3..78f15e4b07ac 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
+++ b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
@@ -53,7 +53,8 @@ struct dw_edma_debugfs_entry {
 
 static int dw_edma_debugfs_u32_get(void *data, u64 *val)
 {
-	void __iomem *reg = data;
+	struct dw_edma_debugfs_entry *entry = data;
+	void __iomem *reg = entry->reg;
 
 	if (dw->chip->mf == EDMA_MF_EDMA_LEGACY &&
 	    reg >= (void __iomem *)&regs->type.legacy.ch) {
@@ -94,14 +95,22 @@ static int dw_edma_debugfs_u32_get(void *data, u64 *val)
 }
 DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, dw_edma_debugfs_u32_get, NULL, "0x%08llx\n");
 
-static void dw_edma_debugfs_create_x32(const struct dw_edma_debugfs_entry entries[],
+static void dw_edma_debugfs_create_x32(const struct dw_edma_debugfs_entry ini[],
 				       int nr_entries, struct dentry *dir)
 {
+	struct dw_edma_debugfs_entry *entries;
 	int i;
 
+	entries = devm_kcalloc(dw->chip->dev, nr_entries, sizeof(*entries),
+			       GFP_KERNEL);
+	if (!entries)
+		return;
+
 	for (i = 0; i < nr_entries; i++) {
+		entries[i] = ini[i];
+
 		debugfs_create_file_unsafe(entries[i].name, 0444, dir,
-					   entries[i].reg, &fops_x32);
+					   &entries[i], &fops_x32);
 	}
 }
 
-- 
2.38.1

[PATCH v7 14/25] dmaengine: dw-edma: Rename DebugFS dentry variables to 'dent'

[Serge Semin]

Since we are about to add the eDMA channels direction support to the
debugfs module it will be confusing to have both the DebugFS directory and
the channels direction short names used in the same code. As a preparation
patch let's convert the DebugFS dentry 'dir' variables to having the
'dent' name so to prevent the confusion.

Suggested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>

---

Changelog v2:
- This is a new patch added in v2. (@Manivannan)
---
 drivers/dma/dw-edma/dw-edma-v0-debugfs.c | 46 ++++++++++++------------
 1 file changed, 23 insertions(+), 23 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
index 78f15e4b07ac..7bb3363b40e4 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
+++ b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
@@ -96,7 +96,7 @@ static int dw_edma_debugfs_u32_get(void *data, u64 *val)
 DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, dw_edma_debugfs_u32_get, NULL, "0x%08llx\n");
 
 static void dw_edma_debugfs_create_x32(const struct dw_edma_debugfs_entry ini[],
-				       int nr_entries, struct dentry *dir)
+				       int nr_entries, struct dentry *dent)
 {
 	struct dw_edma_debugfs_entry *entries;
 	int i;
@@ -109,13 +109,13 @@ static void dw_edma_debugfs_create_x32(const struct dw_edma_debugfs_entry ini[],
 	for (i = 0; i < nr_entries; i++) {
 		entries[i] = ini[i];
 
-		debugfs_create_file_unsafe(entries[i].name, 0444, dir,
+		debugfs_create_file_unsafe(entries[i].name, 0444, dent,
 					   &entries[i], &fops_x32);
 	}
 }
 
 static void dw_edma_debugfs_regs_ch(struct dw_edma_v0_ch_regs __iomem *regs,
-				    struct dentry *dir)
+				    struct dentry *dent)
 {
 	const struct dw_edma_debugfs_entry debugfs_regs[] = {
 		REGISTER(ch_control1),
@@ -131,10 +131,10 @@ static void dw_edma_debugfs_regs_ch(struct dw_edma_v0_ch_regs __iomem *regs,
 	int nr_entries;
 
 	nr_entries = ARRAY_SIZE(debugfs_regs);
-	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, dir);
+	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, dent);
 }
 
-static void dw_edma_debugfs_regs_wr(struct dentry *dir)
+static void dw_edma_debugfs_regs_wr(struct dentry *dent)
 {
 	const struct dw_edma_debugfs_entry debugfs_regs[] = {
 		/* eDMA global registers */
@@ -171,34 +171,34 @@ static void dw_edma_debugfs_regs_wr(struct dentry *dir)
 		WR_REGISTER_UNROLL(ch6_pwr_en),
 		WR_REGISTER_UNROLL(ch7_pwr_en),
 	};
-	struct dentry *regs_dir, *ch_dir;
+	struct dentry *regs_dent, *ch_dent;
 	int nr_entries, i;
 	char name[16];
 
-	regs_dir = debugfs_create_dir(WRITE_STR, dir);
+	regs_dent = debugfs_create_dir(WRITE_STR, dent);
 
 	nr_entries = ARRAY_SIZE(debugfs_regs);
-	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, regs_dir);
+	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, regs_dent);
 
 	if (dw->chip->mf == EDMA_MF_HDMA_COMPAT) {
 		nr_entries = ARRAY_SIZE(debugfs_unroll_regs);
 		dw_edma_debugfs_create_x32(debugfs_unroll_regs, nr_entries,
-					   regs_dir);
+					   regs_dent);
 	}
 
 	for (i = 0; i < dw->wr_ch_cnt; i++) {
 		snprintf(name, sizeof(name), "%s:%d", CHANNEL_STR, i);
 
-		ch_dir = debugfs_create_dir(name, regs_dir);
+		ch_dent = debugfs_create_dir(name, regs_dent);
 
-		dw_edma_debugfs_regs_ch(&regs->type.unroll.ch[i].wr, ch_dir);
+		dw_edma_debugfs_regs_ch(&regs->type.unroll.ch[i].wr, ch_dent);
 
 		lim[0][i].start = &regs->type.unroll.ch[i].wr;
 		lim[0][i].end = &regs->type.unroll.ch[i].padding_1[0];
 	}
 }
 
-static void dw_edma_debugfs_regs_rd(struct dentry *dir)
+static void dw_edma_debugfs_regs_rd(struct dentry *dent)
 {
 	const struct dw_edma_debugfs_entry debugfs_regs[] = {
 		/* eDMA global registers */
@@ -236,27 +236,27 @@ static void dw_edma_debugfs_regs_rd(struct dentry *dir)
 		RD_REGISTER_UNROLL(ch6_pwr_en),
 		RD_REGISTER_UNROLL(ch7_pwr_en),
 	};
-	struct dentry *regs_dir, *ch_dir;
+	struct dentry *regs_dent, *ch_dent;
 	int nr_entries, i;
 	char name[16];
 
-	regs_dir = debugfs_create_dir(READ_STR, dir);
+	regs_dent = debugfs_create_dir(READ_STR, dent);
 
 	nr_entries = ARRAY_SIZE(debugfs_regs);
-	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, regs_dir);
+	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, regs_dent);
 
 	if (dw->chip->mf == EDMA_MF_HDMA_COMPAT) {
 		nr_entries = ARRAY_SIZE(debugfs_unroll_regs);
 		dw_edma_debugfs_create_x32(debugfs_unroll_regs, nr_entries,
-					   regs_dir);
+					   regs_dent);
 	}
 
 	for (i = 0; i < dw->rd_ch_cnt; i++) {
 		snprintf(name, sizeof(name), "%s:%d", CHANNEL_STR, i);
 
-		ch_dir = debugfs_create_dir(name, regs_dir);
+		ch_dent = debugfs_create_dir(name, regs_dent);
 
-		dw_edma_debugfs_regs_ch(&regs->type.unroll.ch[i].rd, ch_dir);
+		dw_edma_debugfs_regs_ch(&regs->type.unroll.ch[i].rd, ch_dent);
 
 		lim[1][i].start = &regs->type.unroll.ch[i].rd;
 		lim[1][i].end = &regs->type.unroll.ch[i].padding_2[0];
@@ -269,16 +269,16 @@ static void dw_edma_debugfs_regs(void)
 		REGISTER(ctrl_data_arb_prior),
 		REGISTER(ctrl),
 	};
-	struct dentry *regs_dir;
+	struct dentry *regs_dent;
 	int nr_entries;
 
-	regs_dir = debugfs_create_dir(REGISTERS_STR, dw->debugfs);
+	regs_dent = debugfs_create_dir(REGISTERS_STR, dw->debugfs);
 
 	nr_entries = ARRAY_SIZE(debugfs_regs);
-	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, regs_dir);
+	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, regs_dent);
 
-	dw_edma_debugfs_regs_wr(regs_dir);
-	dw_edma_debugfs_regs_rd(regs_dir);
+	dw_edma_debugfs_regs_wr(regs_dent);
+	dw_edma_debugfs_regs_rd(regs_dent);
 }
 
 void dw_edma_v0_debugfs_on(struct dw_edma *_dw)
-- 
2.38.1

[PATCH v7 15/25] dmaengine: dw-edma: Simplify the DebugFS context CSRs init procedure

[Serge Semin]

DW eDMA v4.70a and older have the read and write channels context CSRs
indirectly accessible. It means the CSRs like Channel Control, Xfer size,
SAR, DAR and LLP address are accessed over at a fixed MMIO address, but
their reference to the corresponding channel is determined by the Viewport
CSR. In order to have a coherent access to these registers the CSR IOs are
supposed to be protected with a spin-lock. DW eDMA v4.80a and newer
normally have unrolled Read/Write channel context registers. That is all
CSRs denoted before are directly mapped in the controller MMIO space.

Since both normal and viewport-based registers are exposed via the DebugFS
nodes, the original code author decided to implement an algorithm based on
the unrolled CSRs mapping with the viewport addresses recalculation if
it's required. The problem is that such implementation turned to be first
unscalable (supports a platform with only single eDMA available since a
base address statically preserved) and second needlessly overcomplicated
(it loops over all Rd/Wr context addresses and re-calculates the viewport
base address on each DebugFS node access). The algorithm can be greatly
simplified just by adding the channel ID and it's direction fields in the
eDMA DebugFS node descriptor. These new parameters can be used to find a
CSR offset within the corresponding channel registers space. The DW eDMA
DebugFS node getter afterwards will also use them in order to activate the
respective context CSRs viewport before reading data from the specified
register. In case of the unrolled version of the CSRs mapping there won't
be any spin-lock taken/released, no viewport activation as before this
modification.

Note this modification fixes the REGISTER() macros using an externally
defined local variable. The same problem with the rest of the macro will
be fixed in the next commit.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-v0-debugfs.c | 84 +++++++++++-------------
 1 file changed, 38 insertions(+), 46 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
index 7bb3363b40e4..1596eedf35c5 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
+++ b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
@@ -15,9 +15,27 @@
 
 #define REGS_ADDR(name) \
 	((void __iomem *)&regs->name)
+
+#define REGS_CH_ADDR(name, _dir, _ch)						\
+	({									\
+		struct dw_edma_v0_ch_regs __iomem *__ch_regs;			\
+										\
+		if ((dw)->chip->mf == EDMA_MF_EDMA_LEGACY)			\
+			__ch_regs = &regs->type.legacy.ch;			\
+		else if (_dir == EDMA_DIR_READ)					\
+			__ch_regs = &regs->type.unroll.ch[_ch].rd;		\
+		else								\
+			__ch_regs = &regs->type.unroll.ch[_ch].wr;		\
+										\
+		(void __iomem *)&__ch_regs->name;				\
+	})
+
 #define REGISTER(name) \
 	{ #name, REGS_ADDR(name) }
 
+#define CTX_REGISTER(name, dir, ch) \
+	{ #name, REGS_CH_ADDR(name, dir, ch), dir, ch }
+
 #define WR_REGISTER(name) \
 	{ #name, REGS_ADDR(wr_##name) }
 #define RD_REGISTER(name) \
@@ -41,14 +59,11 @@
 static struct dw_edma				*dw;
 static struct dw_edma_v0_regs			__iomem *regs;
 
-static struct {
-	void					__iomem *start;
-	void					__iomem *end;
-} lim[2][EDMA_V0_MAX_NR_CH];
-
 struct dw_edma_debugfs_entry {
 	const char				*name;
 	void __iomem				*reg;
+	enum dw_edma_dir			dir;
+	u16					ch;
 };
 
 static int dw_edma_debugfs_u32_get(void *data, u64 *val)
@@ -58,33 +73,16 @@ static int dw_edma_debugfs_u32_get(void *data, u64 *val)
 
 	if (dw->chip->mf == EDMA_MF_EDMA_LEGACY &&
 	    reg >= (void __iomem *)&regs->type.legacy.ch) {
-		void __iomem *ptr = &regs->type.legacy.ch;
-		u32 viewport_sel = 0;
 		unsigned long flags;
-		u16 ch;
-
-		for (ch = 0; ch < dw->wr_ch_cnt; ch++)
-			if (lim[0][ch].start >= reg && reg < lim[0][ch].end) {
-				ptr += (reg - lim[0][ch].start);
-				goto legacy_sel_wr;
-			}
-
-		for (ch = 0; ch < dw->rd_ch_cnt; ch++)
-			if (lim[1][ch].start >= reg && reg < lim[1][ch].end) {
-				ptr += (reg - lim[1][ch].start);
-				goto legacy_sel_rd;
-			}
-
-		return 0;
-legacy_sel_rd:
-		viewport_sel = BIT(31);
-legacy_sel_wr:
-		viewport_sel |= FIELD_PREP(EDMA_V0_VIEWPORT_MASK, ch);
+		u32 viewport_sel;
+
+		viewport_sel = entry->dir == EDMA_DIR_READ ? BIT(31) : 0;
+		viewport_sel |= FIELD_PREP(EDMA_V0_VIEWPORT_MASK, entry->ch);
 
 		raw_spin_lock_irqsave(&dw->lock, flags);
 
 		writel(viewport_sel, &regs->type.legacy.viewport_sel);
-		*val = readl(ptr);
+		*val = readl(reg);
 
 		raw_spin_unlock_irqrestore(&dw->lock, flags);
 	} else {
@@ -114,19 +112,19 @@ static void dw_edma_debugfs_create_x32(const struct dw_edma_debugfs_entry ini[],
 	}
 }
 
-static void dw_edma_debugfs_regs_ch(struct dw_edma_v0_ch_regs __iomem *regs,
+static void dw_edma_debugfs_regs_ch(enum dw_edma_dir dir, u16 ch,
 				    struct dentry *dent)
 {
-	const struct dw_edma_debugfs_entry debugfs_regs[] = {
-		REGISTER(ch_control1),
-		REGISTER(ch_control2),
-		REGISTER(transfer_size),
-		REGISTER(sar.lsb),
-		REGISTER(sar.msb),
-		REGISTER(dar.lsb),
-		REGISTER(dar.msb),
-		REGISTER(llp.lsb),
-		REGISTER(llp.msb),
+	struct dw_edma_debugfs_entry debugfs_regs[] = {
+		CTX_REGISTER(ch_control1, dir, ch),
+		CTX_REGISTER(ch_control2, dir, ch),
+		CTX_REGISTER(transfer_size, dir, ch),
+		CTX_REGISTER(sar.lsb, dir, ch),
+		CTX_REGISTER(sar.msb, dir, ch),
+		CTX_REGISTER(dar.lsb, dir, ch),
+		CTX_REGISTER(dar.msb, dir, ch),
+		CTX_REGISTER(llp.lsb, dir, ch),
+		CTX_REGISTER(llp.msb, dir, ch),
 	};
 	int nr_entries;
 
@@ -191,10 +189,7 @@ static void dw_edma_debugfs_regs_wr(struct dentry *dent)
 
 		ch_dent = debugfs_create_dir(name, regs_dent);
 
-		dw_edma_debugfs_regs_ch(&regs->type.unroll.ch[i].wr, ch_dent);
-
-		lim[0][i].start = &regs->type.unroll.ch[i].wr;
-		lim[0][i].end = &regs->type.unroll.ch[i].padding_1[0];
+		dw_edma_debugfs_regs_ch(EDMA_DIR_WRITE, i, ch_dent);
 	}
 }
 
@@ -256,10 +251,7 @@ static void dw_edma_debugfs_regs_rd(struct dentry *dent)
 
 		ch_dent = debugfs_create_dir(name, regs_dent);
 
-		dw_edma_debugfs_regs_ch(&regs->type.unroll.ch[i].rd, ch_dent);
-
-		lim[1][i].start = &regs->type.unroll.ch[i].rd;
-		lim[1][i].end = &regs->type.unroll.ch[i].padding_2[0];
+		dw_edma_debugfs_regs_ch(EDMA_DIR_READ, i, ch_dent);
 	}
 }
 
-- 
2.38.1

[PATCH v7 16/25] dmaengine: dw-edma: Move eDMA data pointer to DebugFS node descriptor

[Serge Semin]

The last thing that really stops the DebugFS part of the eDMA driver from
supporting the multi-eDMA platform in is keeping the eDMA private data
pointer in the static area of the DebugFS module. Since the DebugFS node
descriptors are now kz-allocated we can freely move that pointer to being
preserved in the descriptors. After the DebugFS initialization procedure
that pointer will be used in the DebugFS files getter to access the common
CSRs space and the context CSRs spin-lock. So the main part of this change
is connected with the DebugFS nodes descriptors initialization macros,
which aside with already defined prototypes now require to have the DW
eDMA private data pointer passed.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-v0-debugfs.c | 242 +++++++++++------------
 1 file changed, 117 insertions(+), 125 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
index 1596eedf35c5..e6cf608d121b 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
+++ b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
@@ -13,53 +13,55 @@
 #include "dw-edma-v0-regs.h"
 #include "dw-edma-core.h"
 
-#define REGS_ADDR(name) \
-	((void __iomem *)&regs->name)
+#define REGS_ADDR(dw, name)							\
+	({									\
+		struct dw_edma_v0_regs __iomem *__regs = (dw)->chip->reg_base;	\
+										\
+		(void __iomem *)&__regs->name;					\
+	})
 
-#define REGS_CH_ADDR(name, _dir, _ch)						\
+#define REGS_CH_ADDR(dw, name, _dir, _ch)					\
 	({									\
 		struct dw_edma_v0_ch_regs __iomem *__ch_regs;			\
 										\
 		if ((dw)->chip->mf == EDMA_MF_EDMA_LEGACY)			\
-			__ch_regs = &regs->type.legacy.ch;			\
+			__ch_regs = REGS_ADDR(dw, type.legacy.ch);		\
 		else if (_dir == EDMA_DIR_READ)					\
-			__ch_regs = &regs->type.unroll.ch[_ch].rd;		\
+			__ch_regs = REGS_ADDR(dw, type.unroll.ch[_ch].rd);	\
 		else								\
-			__ch_regs = &regs->type.unroll.ch[_ch].wr;		\
+			__ch_regs = REGS_ADDR(dw, type.unroll.ch[_ch].wr);	\
 										\
 		(void __iomem *)&__ch_regs->name;				\
 	})
 
-#define REGISTER(name) \
-	{ #name, REGS_ADDR(name) }
+#define REGISTER(dw, name) \
+	{ dw, #name, REGS_ADDR(dw, name) }
 
-#define CTX_REGISTER(name, dir, ch) \
-	{ #name, REGS_CH_ADDR(name, dir, ch), dir, ch }
+#define CTX_REGISTER(dw, name, dir, ch) \
+	{ dw, #name, REGS_CH_ADDR(dw, name, dir, ch), dir, ch }
 
-#define WR_REGISTER(name) \
-	{ #name, REGS_ADDR(wr_##name) }
-#define RD_REGISTER(name) \
-	{ #name, REGS_ADDR(rd_##name) }
+#define WR_REGISTER(dw, name) \
+	{ dw, #name, REGS_ADDR(dw, wr_##name) }
+#define RD_REGISTER(dw, name) \
+	{ dw, #name, REGS_ADDR(dw, rd_##name) }
 
-#define WR_REGISTER_LEGACY(name) \
-	{ #name, REGS_ADDR(type.legacy.wr_##name) }
+#define WR_REGISTER_LEGACY(dw, name) \
+	{ dw, #name, REGS_ADDR(dw, type.legacy.wr_##name) }
 #define RD_REGISTER_LEGACY(name) \
-	{ #name, REGS_ADDR(type.legacy.rd_##name) }
+	{ dw, #name, REGS_ADDR(dw, type.legacy.rd_##name) }
 
-#define WR_REGISTER_UNROLL(name) \
-	{ #name, REGS_ADDR(type.unroll.wr_##name) }
-#define RD_REGISTER_UNROLL(name) \
-	{ #name, REGS_ADDR(type.unroll.rd_##name) }
+#define WR_REGISTER_UNROLL(dw, name) \
+	{ dw, #name, REGS_ADDR(dw, type.unroll.wr_##name) }
+#define RD_REGISTER_UNROLL(dw, name) \
+	{ dw, #name, REGS_ADDR(dw, type.unroll.rd_##name) }
 
 #define WRITE_STR				"write"
 #define READ_STR				"read"
 #define CHANNEL_STR				"channel"
 #define REGISTERS_STR				"registers"
 
-static struct dw_edma				*dw;
-static struct dw_edma_v0_regs			__iomem *regs;
-
 struct dw_edma_debugfs_entry {
+	struct dw_edma				*dw;
 	const char				*name;
 	void __iomem				*reg;
 	enum dw_edma_dir			dir;
@@ -69,10 +71,11 @@ struct dw_edma_debugfs_entry {
 static int dw_edma_debugfs_u32_get(void *data, u64 *val)
 {
 	struct dw_edma_debugfs_entry *entry = data;
+	struct dw_edma *dw = entry->dw;
 	void __iomem *reg = entry->reg;
 
 	if (dw->chip->mf == EDMA_MF_EDMA_LEGACY &&
-	    reg >= (void __iomem *)&regs->type.legacy.ch) {
+	    reg >= REGS_ADDR(dw, type.legacy.ch)) {
 		unsigned long flags;
 		u32 viewport_sel;
 
@@ -81,7 +84,7 @@ static int dw_edma_debugfs_u32_get(void *data, u64 *val)
 
 		raw_spin_lock_irqsave(&dw->lock, flags);
 
-		writel(viewport_sel, &regs->type.legacy.viewport_sel);
+		writel(viewport_sel, REGS_ADDR(dw, type.legacy.viewport_sel));
 		*val = readl(reg);
 
 		raw_spin_unlock_irqrestore(&dw->lock, flags);
@@ -93,7 +96,8 @@ static int dw_edma_debugfs_u32_get(void *data, u64 *val)
 }
 DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, dw_edma_debugfs_u32_get, NULL, "0x%08llx\n");
 
-static void dw_edma_debugfs_create_x32(const struct dw_edma_debugfs_entry ini[],
+static void dw_edma_debugfs_create_x32(struct dw_edma *dw,
+				       const struct dw_edma_debugfs_entry ini[],
 				       int nr_entries, struct dentry *dent)
 {
 	struct dw_edma_debugfs_entry *entries;
@@ -112,62 +116,62 @@ static void dw_edma_debugfs_create_x32(const struct dw_edma_debugfs_entry ini[],
 	}
 }
 
-static void dw_edma_debugfs_regs_ch(enum dw_edma_dir dir, u16 ch,
-				    struct dentry *dent)
+static void dw_edma_debugfs_regs_ch(struct dw_edma *dw, enum dw_edma_dir dir,
+				    u16 ch, struct dentry *dent)
 {
 	struct dw_edma_debugfs_entry debugfs_regs[] = {
-		CTX_REGISTER(ch_control1, dir, ch),
-		CTX_REGISTER(ch_control2, dir, ch),
-		CTX_REGISTER(transfer_size, dir, ch),
-		CTX_REGISTER(sar.lsb, dir, ch),
-		CTX_REGISTER(sar.msb, dir, ch),
-		CTX_REGISTER(dar.lsb, dir, ch),
-		CTX_REGISTER(dar.msb, dir, ch),
-		CTX_REGISTER(llp.lsb, dir, ch),
-		CTX_REGISTER(llp.msb, dir, ch),
+		CTX_REGISTER(dw, ch_control1, dir, ch),
+		CTX_REGISTER(dw, ch_control2, dir, ch),
+		CTX_REGISTER(dw, transfer_size, dir, ch),
+		CTX_REGISTER(dw, sar.lsb, dir, ch),
+		CTX_REGISTER(dw, sar.msb, dir, ch),
+		CTX_REGISTER(dw, dar.lsb, dir, ch),
+		CTX_REGISTER(dw, dar.msb, dir, ch),
+		CTX_REGISTER(dw, llp.lsb, dir, ch),
+		CTX_REGISTER(dw, llp.msb, dir, ch),
 	};
 	int nr_entries;
 
 	nr_entries = ARRAY_SIZE(debugfs_regs);
-	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, dent);
+	dw_edma_debugfs_create_x32(dw, debugfs_regs, nr_entries, dent);
 }
 
-static void dw_edma_debugfs_regs_wr(struct dentry *dent)
+static void dw_edma_debugfs_regs_wr(struct dw_edma *dw, struct dentry *dent)
 {
 	const struct dw_edma_debugfs_entry debugfs_regs[] = {
 		/* eDMA global registers */
-		WR_REGISTER(engine_en),
-		WR_REGISTER(doorbell),
-		WR_REGISTER(ch_arb_weight.lsb),
-		WR_REGISTER(ch_arb_weight.msb),
+		WR_REGISTER(dw, engine_en),
+		WR_REGISTER(dw, doorbell),
+		WR_REGISTER(dw, ch_arb_weight.lsb),
+		WR_REGISTER(dw, ch_arb_weight.msb),
 		/* eDMA interrupts registers */
-		WR_REGISTER(int_status),
-		WR_REGISTER(int_mask),
-		WR_REGISTER(int_clear),
-		WR_REGISTER(err_status),
-		WR_REGISTER(done_imwr.lsb),
-		WR_REGISTER(done_imwr.msb),
-		WR_REGISTER(abort_imwr.lsb),
-		WR_REGISTER(abort_imwr.msb),
-		WR_REGISTER(ch01_imwr_data),
-		WR_REGISTER(ch23_imwr_data),
-		WR_REGISTER(ch45_imwr_data),
-		WR_REGISTER(ch67_imwr_data),
-		WR_REGISTER(linked_list_err_en),
+		WR_REGISTER(dw, int_status),
+		WR_REGISTER(dw, int_mask),
+		WR_REGISTER(dw, int_clear),
+		WR_REGISTER(dw, err_status),
+		WR_REGISTER(dw, done_imwr.lsb),
+		WR_REGISTER(dw, done_imwr.msb),
+		WR_REGISTER(dw, abort_imwr.lsb),
+		WR_REGISTER(dw, abort_imwr.msb),
+		WR_REGISTER(dw, ch01_imwr_data),
+		WR_REGISTER(dw, ch23_imwr_data),
+		WR_REGISTER(dw, ch45_imwr_data),
+		WR_REGISTER(dw, ch67_imwr_data),
+		WR_REGISTER(dw, linked_list_err_en),
 	};
 	const struct dw_edma_debugfs_entry debugfs_unroll_regs[] = {
 		/* eDMA channel context grouping */
-		WR_REGISTER_UNROLL(engine_chgroup),
-		WR_REGISTER_UNROLL(engine_hshake_cnt.lsb),
-		WR_REGISTER_UNROLL(engine_hshake_cnt.msb),
-		WR_REGISTER_UNROLL(ch0_pwr_en),
-		WR_REGISTER_UNROLL(ch1_pwr_en),
-		WR_REGISTER_UNROLL(ch2_pwr_en),
-		WR_REGISTER_UNROLL(ch3_pwr_en),
-		WR_REGISTER_UNROLL(ch4_pwr_en),
-		WR_REGISTER_UNROLL(ch5_pwr_en),
-		WR_REGISTER_UNROLL(ch6_pwr_en),
-		WR_REGISTER_UNROLL(ch7_pwr_en),
+		WR_REGISTER_UNROLL(dw, engine_chgroup),
+		WR_REGISTER_UNROLL(dw, engine_hshake_cnt.lsb),
+		WR_REGISTER_UNROLL(dw, engine_hshake_cnt.msb),
+		WR_REGISTER_UNROLL(dw, ch0_pwr_en),
+		WR_REGISTER_UNROLL(dw, ch1_pwr_en),
+		WR_REGISTER_UNROLL(dw, ch2_pwr_en),
+		WR_REGISTER_UNROLL(dw, ch3_pwr_en),
+		WR_REGISTER_UNROLL(dw, ch4_pwr_en),
+		WR_REGISTER_UNROLL(dw, ch5_pwr_en),
+		WR_REGISTER_UNROLL(dw, ch6_pwr_en),
+		WR_REGISTER_UNROLL(dw, ch7_pwr_en),
 	};
 	struct dentry *regs_dent, *ch_dent;
 	int nr_entries, i;
@@ -176,11 +180,11 @@ static void dw_edma_debugfs_regs_wr(struct dentry *dent)
 	regs_dent = debugfs_create_dir(WRITE_STR, dent);
 
 	nr_entries = ARRAY_SIZE(debugfs_regs);
-	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, regs_dent);
+	dw_edma_debugfs_create_x32(dw, debugfs_regs, nr_entries, regs_dent);
 
 	if (dw->chip->mf == EDMA_MF_HDMA_COMPAT) {
 		nr_entries = ARRAY_SIZE(debugfs_unroll_regs);
-		dw_edma_debugfs_create_x32(debugfs_unroll_regs, nr_entries,
+		dw_edma_debugfs_create_x32(dw, debugfs_unroll_regs, nr_entries,
 					   regs_dent);
 	}
 
@@ -189,47 +193,47 @@ static void dw_edma_debugfs_regs_wr(struct dentry *dent)
 
 		ch_dent = debugfs_create_dir(name, regs_dent);
 
-		dw_edma_debugfs_regs_ch(EDMA_DIR_WRITE, i, ch_dent);
+		dw_edma_debugfs_regs_ch(dw, EDMA_DIR_WRITE, i, ch_dent);
 	}
 }
 
-static void dw_edma_debugfs_regs_rd(struct dentry *dent)
+static void dw_edma_debugfs_regs_rd(struct dw_edma *dw, struct dentry *dent)
 {
 	const struct dw_edma_debugfs_entry debugfs_regs[] = {
 		/* eDMA global registers */
-		RD_REGISTER(engine_en),
-		RD_REGISTER(doorbell),
-		RD_REGISTER(ch_arb_weight.lsb),
-		RD_REGISTER(ch_arb_weight.msb),
+		RD_REGISTER(dw, engine_en),
+		RD_REGISTER(dw, doorbell),
+		RD_REGISTER(dw, ch_arb_weight.lsb),
+		RD_REGISTER(dw, ch_arb_weight.msb),
 		/* eDMA interrupts registers */
-		RD_REGISTER(int_status),
-		RD_REGISTER(int_mask),
-		RD_REGISTER(int_clear),
-		RD_REGISTER(err_status.lsb),
-		RD_REGISTER(err_status.msb),
-		RD_REGISTER(linked_list_err_en),
-		RD_REGISTER(done_imwr.lsb),
-		RD_REGISTER(done_imwr.msb),
-		RD_REGISTER(abort_imwr.lsb),
-		RD_REGISTER(abort_imwr.msb),
-		RD_REGISTER(ch01_imwr_data),
-		RD_REGISTER(ch23_imwr_data),
-		RD_REGISTER(ch45_imwr_data),
-		RD_REGISTER(ch67_imwr_data),
+		RD_REGISTER(dw, int_status),
+		RD_REGISTER(dw, int_mask),
+		RD_REGISTER(dw, int_clear),
+		RD_REGISTER(dw, err_status.lsb),
+		RD_REGISTER(dw, err_status.msb),
+		RD_REGISTER(dw, linked_list_err_en),
+		RD_REGISTER(dw, done_imwr.lsb),
+		RD_REGISTER(dw, done_imwr.msb),
+		RD_REGISTER(dw, abort_imwr.lsb),
+		RD_REGISTER(dw, abort_imwr.msb),
+		RD_REGISTER(dw, ch01_imwr_data),
+		RD_REGISTER(dw, ch23_imwr_data),
+		RD_REGISTER(dw, ch45_imwr_data),
+		RD_REGISTER(dw, ch67_imwr_data),
 	};
 	const struct dw_edma_debugfs_entry debugfs_unroll_regs[] = {
 		/* eDMA channel context grouping */
-		RD_REGISTER_UNROLL(engine_chgroup),
-		RD_REGISTER_UNROLL(engine_hshake_cnt.lsb),
-		RD_REGISTER_UNROLL(engine_hshake_cnt.msb),
-		RD_REGISTER_UNROLL(ch0_pwr_en),
-		RD_REGISTER_UNROLL(ch1_pwr_en),
-		RD_REGISTER_UNROLL(ch2_pwr_en),
-		RD_REGISTER_UNROLL(ch3_pwr_en),
-		RD_REGISTER_UNROLL(ch4_pwr_en),
-		RD_REGISTER_UNROLL(ch5_pwr_en),
-		RD_REGISTER_UNROLL(ch6_pwr_en),
-		RD_REGISTER_UNROLL(ch7_pwr_en),
+		RD_REGISTER_UNROLL(dw, engine_chgroup),
+		RD_REGISTER_UNROLL(dw, engine_hshake_cnt.lsb),
+		RD_REGISTER_UNROLL(dw, engine_hshake_cnt.msb),
+		RD_REGISTER_UNROLL(dw, ch0_pwr_en),
+		RD_REGISTER_UNROLL(dw, ch1_pwr_en),
+		RD_REGISTER_UNROLL(dw, ch2_pwr_en),
+		RD_REGISTER_UNROLL(dw, ch3_pwr_en),
+		RD_REGISTER_UNROLL(dw, ch4_pwr_en),
+		RD_REGISTER_UNROLL(dw, ch5_pwr_en),
+		RD_REGISTER_UNROLL(dw, ch6_pwr_en),
+		RD_REGISTER_UNROLL(dw, ch7_pwr_en),
 	};
 	struct dentry *regs_dent, *ch_dent;
 	int nr_entries, i;
@@ -238,11 +242,11 @@ static void dw_edma_debugfs_regs_rd(struct dentry *dent)
 	regs_dent = debugfs_create_dir(READ_STR, dent);
 
 	nr_entries = ARRAY_SIZE(debugfs_regs);
-	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, regs_dent);
+	dw_edma_debugfs_create_x32(dw, debugfs_regs, nr_entries, regs_dent);
 
 	if (dw->chip->mf == EDMA_MF_HDMA_COMPAT) {
 		nr_entries = ARRAY_SIZE(debugfs_unroll_regs);
-		dw_edma_debugfs_create_x32(debugfs_unroll_regs, nr_entries,
+		dw_edma_debugfs_create_x32(dw, debugfs_unroll_regs, nr_entries,
 					   regs_dent);
 	}
 
@@ -251,15 +255,15 @@ static void dw_edma_debugfs_regs_rd(struct dentry *dent)
 
 		ch_dent = debugfs_create_dir(name, regs_dent);
 
-		dw_edma_debugfs_regs_ch(EDMA_DIR_READ, i, ch_dent);
+		dw_edma_debugfs_regs_ch(dw, EDMA_DIR_READ, i, ch_dent);
 	}
 }
 
-static void dw_edma_debugfs_regs(void)
+static void dw_edma_debugfs_regs(struct dw_edma *dw)
 {
 	const struct dw_edma_debugfs_entry debugfs_regs[] = {
-		REGISTER(ctrl_data_arb_prior),
-		REGISTER(ctrl),
+		REGISTER(dw, ctrl_data_arb_prior),
+		REGISTER(dw, ctrl),
 	};
 	struct dentry *regs_dent;
 	int nr_entries;
@@ -267,40 +271,28 @@ static void dw_edma_debugfs_regs(void)
 	regs_dent = debugfs_create_dir(REGISTERS_STR, dw->debugfs);
 
 	nr_entries = ARRAY_SIZE(debugfs_regs);
-	dw_edma_debugfs_create_x32(debugfs_regs, nr_entries, regs_dent);
+	dw_edma_debugfs_create_x32(dw, debugfs_regs, nr_entries, regs_dent);
 
-	dw_edma_debugfs_regs_wr(regs_dent);
-	dw_edma_debugfs_regs_rd(regs_dent);
+	dw_edma_debugfs_regs_wr(dw, regs_dent);
+	dw_edma_debugfs_regs_rd(dw, regs_dent);
 }
 
-void dw_edma_v0_debugfs_on(struct dw_edma *_dw)
+void dw_edma_v0_debugfs_on(struct dw_edma *dw)
 {
 	if (!debugfs_initialized())
 		return;
 
-	dw = _dw;
-	if (!dw)
-		return;
-
-	regs = dw->chip->reg_base;
-	if (!regs)
-		return;
-
 	dw->debugfs = debugfs_create_dir(dw->name, NULL);
 
 	debugfs_create_u32("mf", 0444, dw->debugfs, &dw->chip->mf);
 	debugfs_create_u16("wr_ch_cnt", 0444, dw->debugfs, &dw->wr_ch_cnt);
 	debugfs_create_u16("rd_ch_cnt", 0444, dw->debugfs, &dw->rd_ch_cnt);
 
-	dw_edma_debugfs_regs();
+	dw_edma_debugfs_regs(dw);
 }
 
-void dw_edma_v0_debugfs_off(struct dw_edma *_dw)
+void dw_edma_v0_debugfs_off(struct dw_edma *dw)
 {
-	dw = _dw;
-	if (!dw)
-		return;
-
 	debugfs_remove_recursive(dw->debugfs);
 	dw->debugfs = NULL;
 }
-- 
2.38.1

[PATCH v7 17/25] dmaengine: dw-edma: Join Write/Read channels into a single device

[Serge Semin]

Indeed there is no point in such split up because due to multiple reasons.
First of all eDMA read and write channels belong to one physical
controller. Splitting them up illogical. Secondly the channels
differentiating can be done by means of the filtering and the
dma_get_slave_caps() method. Finally having these channels handled
separately not only needlessly complicates the code, but also causes the
DebugFS error printed to console:

>> Debugfs: Directory '1f052000.pcie' with parent 'dmaengine' already present!

So to speak let's join the read/write channels into a single DMA device.
The client drivers will be able to choose the channel with required
capability by getting the DMA slave direction setting. It's default value
is overridden by the dw_edma_device_caps() callback in accordance with the
channel nature.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-core.c | 116 +++++++++++++++--------------
 drivers/dma/dw-edma/dw-edma-core.h |   5 +-
 2 files changed, 61 insertions(+), 60 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index ecd3e8f7ac5d..c3ecae4287d0 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -208,6 +208,24 @@ static void dw_edma_start_transfer(struct dw_edma_chan *chan)
 	desc->chunks_alloc--;
 }
 
+static void dw_edma_device_caps(struct dma_chan *dchan,
+				struct dma_slave_caps *caps)
+{
+	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
+
+	if (chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL) {
+		if (chan->dir == EDMA_DIR_READ)
+			caps->directions = BIT(DMA_DEV_TO_MEM);
+		else
+			caps->directions = BIT(DMA_MEM_TO_DEV);
+	} else {
+		if (chan->dir == EDMA_DIR_WRITE)
+			caps->directions = BIT(DMA_DEV_TO_MEM);
+		else
+			caps->directions = BIT(DMA_MEM_TO_DEV);
+	}
+}
+
 static int dw_edma_device_config(struct dma_chan *dchan,
 				 struct dma_slave_config *config)
 {
@@ -717,8 +735,7 @@ static void dw_edma_free_chan_resources(struct dma_chan *dchan)
 	}
 }
 
-static int dw_edma_channel_setup(struct dw_edma *dw, bool write,
-				 u32 wr_alloc, u32 rd_alloc)
+static int dw_edma_channel_setup(struct dw_edma *dw, u32 wr_alloc, u32 rd_alloc)
 {
 	struct dw_edma_chip *chip = dw->chip;
 	struct dw_edma_region *dt_region;
@@ -726,27 +743,15 @@ static int dw_edma_channel_setup(struct dw_edma *dw, bool write,
 	struct dw_edma_chan *chan;
 	struct dw_edma_irq *irq;
 	struct dma_device *dma;
-	u32 alloc, off_alloc;
-	u32 i, j, cnt;
-	int err = 0;
+	u32 i, ch_cnt;
 	u32 pos;
 
-	if (write) {
-		i = 0;
-		cnt = dw->wr_ch_cnt;
-		dma = &dw->wr_edma;
-		alloc = wr_alloc;
-		off_alloc = 0;
-	} else {
-		i = dw->wr_ch_cnt;
-		cnt = dw->rd_ch_cnt;
-		dma = &dw->rd_edma;
-		alloc = rd_alloc;
-		off_alloc = wr_alloc;
-	}
+	ch_cnt = dw->wr_ch_cnt + dw->rd_ch_cnt;
+	dma = &dw->dma;
 
 	INIT_LIST_HEAD(&dma->channels);
-	for (j = 0; (alloc || dw->nr_irqs == 1) && j < cnt; j++, i++) {
+
+	for (i = 0; i < ch_cnt; i++) {
 		chan = &dw->chan[i];
 
 		dt_region = devm_kzalloc(dev, sizeof(*dt_region), GFP_KERNEL);
@@ -756,52 +761,62 @@ static int dw_edma_channel_setup(struct dw_edma *dw, bool write,
 		chan->vc.chan.private = dt_region;
 
 		chan->dw = dw;
-		chan->id = j;
-		chan->dir = write ? EDMA_DIR_WRITE : EDMA_DIR_READ;
+
+		if (i < dw->wr_ch_cnt) {
+			chan->id = i;
+			chan->dir = EDMA_DIR_WRITE;
+		} else {
+			chan->id = i - dw->wr_ch_cnt;
+			chan->dir = EDMA_DIR_READ;
+		}
+
 		chan->configured = false;
 		chan->request = EDMA_REQ_NONE;
 		chan->status = EDMA_ST_IDLE;
 
-		if (write)
-			chan->ll_max = (chip->ll_region_wr[j].sz / EDMA_LL_SZ);
+		if (chan->dir == EDMA_DIR_WRITE)
+			chan->ll_max = (chip->ll_region_wr[chan->id].sz / EDMA_LL_SZ);
 		else
-			chan->ll_max = (chip->ll_region_rd[j].sz / EDMA_LL_SZ);
+			chan->ll_max = (chip->ll_region_rd[chan->id].sz / EDMA_LL_SZ);
 		chan->ll_max -= 1;
 
 		dev_vdbg(dev, "L. List:\tChannel %s[%u] max_cnt=%u\n",
-			 write ? "write" : "read", j, chan->ll_max);
+			 chan->dir == EDMA_DIR_WRITE ? "write" : "read",
+			 chan->id, chan->ll_max);
 
 		if (dw->nr_irqs == 1)
 			pos = 0;
+		else if (chan->dir == EDMA_DIR_WRITE)
+			pos = chan->id % wr_alloc;
 		else
-			pos = off_alloc + (j % alloc);
+			pos = wr_alloc + chan->id % rd_alloc;
 
 		irq = &dw->irq[pos];
 
-		if (write)
-			irq->wr_mask |= BIT(j);
+		if (chan->dir == EDMA_DIR_WRITE)
+			irq->wr_mask |= BIT(chan->id);
 		else
-			irq->rd_mask |= BIT(j);
+			irq->rd_mask |= BIT(chan->id);
 
 		irq->dw = dw;
 		memcpy(&chan->msi, &irq->msi, sizeof(chan->msi));
 
 		dev_vdbg(dev, "MSI:\t\tChannel %s[%u] addr=0x%.8x%.8x, data=0x%.8x\n",
-			 write ? "write" : "read", j,
+			 chan->dir == EDMA_DIR_WRITE  ? "write" : "read", chan->id,
 			 chan->msi.address_hi, chan->msi.address_lo,
 			 chan->msi.data);
 
 		chan->vc.desc_free = vchan_free_desc;
 		vchan_init(&chan->vc, dma);
 
-		if (write) {
-			dt_region->paddr = chip->dt_region_wr[j].paddr;
-			dt_region->vaddr = chip->dt_region_wr[j].vaddr;
-			dt_region->sz = chip->dt_region_wr[j].sz;
+		if (chan->dir == EDMA_DIR_WRITE) {
+			dt_region->paddr = chip->dt_region_wr[chan->id].paddr;
+			dt_region->vaddr = chip->dt_region_wr[chan->id].vaddr;
+			dt_region->sz = chip->dt_region_wr[chan->id].sz;
 		} else {
-			dt_region->paddr = chip->dt_region_rd[j].paddr;
-			dt_region->vaddr = chip->dt_region_rd[j].vaddr;
-			dt_region->sz = chip->dt_region_rd[j].sz;
+			dt_region->paddr = chip->dt_region_rd[chan->id].paddr;
+			dt_region->vaddr = chip->dt_region_rd[chan->id].vaddr;
+			dt_region->sz = chip->dt_region_rd[chan->id].sz;
 		}
 
 		dw_edma_v0_core_device_config(chan);
@@ -813,7 +828,7 @@ static int dw_edma_channel_setup(struct dw_edma *dw, bool write,
 	dma_cap_set(DMA_CYCLIC, dma->cap_mask);
 	dma_cap_set(DMA_PRIVATE, dma->cap_mask);
 	dma_cap_set(DMA_INTERLEAVE, dma->cap_mask);
-	dma->directions = BIT(write ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV);
+	dma->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
 	dma->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
 	dma->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
 	dma->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
@@ -822,6 +837,7 @@ static int dw_edma_channel_setup(struct dw_edma *dw, bool write,
 	dma->dev = chip->dev;
 	dma->device_alloc_chan_resources = dw_edma_alloc_chan_resources;
 	dma->device_free_chan_resources = dw_edma_free_chan_resources;
+	dma->device_caps = dw_edma_device_caps;
 	dma->device_config = dw_edma_device_config;
 	dma->device_pause = dw_edma_device_pause;
 	dma->device_resume = dw_edma_device_resume;
@@ -835,9 +851,7 @@ static int dw_edma_channel_setup(struct dw_edma *dw, bool write,
 	dma_set_max_seg_size(dma->dev, U32_MAX);
 
 	/* Register DMA device */
-	err = dma_async_device_register(dma);
-
-	return err;
+	return dma_async_device_register(dma);
 }
 
 static inline void dw_edma_dec_irq_alloc(int *nr_irqs, u32 *alloc, u16 cnt)
@@ -982,13 +996,8 @@ int dw_edma_probe(struct dw_edma_chip *chip)
 	if (err)
 		return err;
 
-	/* Setup write channels */
-	err = dw_edma_channel_setup(dw, true, wr_alloc, rd_alloc);
-	if (err)
-		goto err_irq_free;
-
-	/* Setup read channels */
-	err = dw_edma_channel_setup(dw, false, wr_alloc, rd_alloc);
+	/* Setup write/read channels */
+	err = dw_edma_channel_setup(dw, wr_alloc, rd_alloc);
 	if (err)
 		goto err_irq_free;
 
@@ -1022,15 +1031,8 @@ int dw_edma_remove(struct dw_edma_chip *chip)
 		free_irq(chip->ops->irq_vector(dev, i), &dw->irq[i]);
 
 	/* Deregister eDMA device */
-	dma_async_device_unregister(&dw->wr_edma);
-	list_for_each_entry_safe(chan, _chan, &dw->wr_edma.channels,
-				 vc.chan.device_node) {
-		tasklet_kill(&chan->vc.task);
-		list_del(&chan->vc.chan.device_node);
-	}
-
-	dma_async_device_unregister(&dw->rd_edma);
-	list_for_each_entry_safe(chan, _chan, &dw->rd_edma.channels,
+	dma_async_device_unregister(&dw->dma);
+	list_for_each_entry_safe(chan, _chan, &dw->dma.channels,
 				 vc.chan.device_node) {
 		tasklet_kill(&chan->vc.task);
 		list_del(&chan->vc.chan.device_node);
diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h
index 85df2d511907..b576a8fff45a 100644
--- a/drivers/dma/dw-edma/dw-edma-core.h
+++ b/drivers/dma/dw-edma/dw-edma-core.h
@@ -98,10 +98,9 @@ struct dw_edma_irq {
 struct dw_edma {
 	char				name[20];
 
-	struct dma_device		wr_edma;
-	u16				wr_ch_cnt;
+	struct dma_device		dma;
 
-	struct dma_device		rd_edma;
+	u16				wr_ch_cnt;
 	u16				rd_ch_cnt;
 
 	struct dw_edma_irq		*irq;
-- 
2.38.1

[PATCH v7 18/25] dmaengine: dw-edma: Use DMA-engine device DebugFS subdirectory

[Serge Semin]

Since all DW eDMA read and write channels are now installed in a framework
of a single DMA-engine device, we can freely move all the DW eDMA-specific
DebugFS nodes into a ready-to-use DMA-engine DebugFS subdirectory. It's
created during the DMA-device registration and can be found in the
dma_device.dbg_dev_root field.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-core.c       |  3 ---
 drivers/dma/dw-edma/dw-edma-core.h       |  3 ---
 drivers/dma/dw-edma/dw-edma-v0-core.c    |  5 -----
 drivers/dma/dw-edma/dw-edma-v0-core.h    |  1 -
 drivers/dma/dw-edma/dw-edma-v0-debugfs.c | 16 ++++------------
 drivers/dma/dw-edma/dw-edma-v0-debugfs.h |  5 -----
 6 files changed, 4 insertions(+), 29 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index c3ecae4287d0..58808bec4148 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -1038,9 +1038,6 @@ int dw_edma_remove(struct dw_edma_chip *chip)
 		list_del(&chan->vc.chan.device_node);
 	}
 
-	/* Turn debugfs off */
-	dw_edma_v0_core_debugfs_off(dw);
-
 	return 0;
 }
 EXPORT_SYMBOL_GPL(dw_edma_remove);
diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h
index b576a8fff45a..e3ad3e372b55 100644
--- a/drivers/dma/dw-edma/dw-edma-core.h
+++ b/drivers/dma/dw-edma/dw-edma-core.h
@@ -111,9 +111,6 @@ struct dw_edma {
 	raw_spinlock_t			lock;		/* Only for legacy */
 
 	struct dw_edma_chip             *chip;
-#ifdef CONFIG_DEBUG_FS
-	struct dentry			*debugfs;
-#endif /* CONFIG_DEBUG_FS */
 };
 
 struct dw_edma_sg {
diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c
index 77e6cfe52e0a..66f296daac5a 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-core.c
+++ b/drivers/dma/dw-edma/dw-edma-v0-core.c
@@ -504,8 +504,3 @@ void dw_edma_v0_core_debugfs_on(struct dw_edma *dw)
 {
 	dw_edma_v0_debugfs_on(dw);
 }
-
-void dw_edma_v0_core_debugfs_off(struct dw_edma *dw)
-{
-	dw_edma_v0_debugfs_off(dw);
-}
diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.h b/drivers/dma/dw-edma/dw-edma-v0-core.h
index 75aec6d31b21..ab96a1f48080 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-core.h
+++ b/drivers/dma/dw-edma/dw-edma-v0-core.h
@@ -23,6 +23,5 @@ void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first);
 int dw_edma_v0_core_device_config(struct dw_edma_chan *chan);
 /* eDMA debug fs callbacks */
 void dw_edma_v0_core_debugfs_on(struct dw_edma *dw);
-void dw_edma_v0_core_debugfs_off(struct dw_edma *dw);
 
 #endif /* _DW_EDMA_V0_CORE_H */
diff --git a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
index e6cf608d121b..d12c607433bf 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
+++ b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
@@ -268,7 +268,7 @@ static void dw_edma_debugfs_regs(struct dw_edma *dw)
 	struct dentry *regs_dent;
 	int nr_entries;
 
-	regs_dent = debugfs_create_dir(REGISTERS_STR, dw->debugfs);
+	regs_dent = debugfs_create_dir(REGISTERS_STR, dw->dma.dbg_dev_root);
 
 	nr_entries = ARRAY_SIZE(debugfs_regs);
 	dw_edma_debugfs_create_x32(dw, debugfs_regs, nr_entries, regs_dent);
@@ -282,17 +282,9 @@ void dw_edma_v0_debugfs_on(struct dw_edma *dw)
 	if (!debugfs_initialized())
 		return;
 
-	dw->debugfs = debugfs_create_dir(dw->name, NULL);
-
-	debugfs_create_u32("mf", 0444, dw->debugfs, &dw->chip->mf);
-	debugfs_create_u16("wr_ch_cnt", 0444, dw->debugfs, &dw->wr_ch_cnt);
-	debugfs_create_u16("rd_ch_cnt", 0444, dw->debugfs, &dw->rd_ch_cnt);
+	debugfs_create_u32("mf", 0444, dw->dma.dbg_dev_root, &dw->chip->mf);
+	debugfs_create_u16("wr_ch_cnt", 0444, dw->dma.dbg_dev_root, &dw->wr_ch_cnt);
+	debugfs_create_u16("rd_ch_cnt", 0444, dw->dma.dbg_dev_root, &dw->rd_ch_cnt);
 
 	dw_edma_debugfs_regs(dw);
 }
-
-void dw_edma_v0_debugfs_off(struct dw_edma *dw)
-{
-	debugfs_remove_recursive(dw->debugfs);
-	dw->debugfs = NULL;
-}
diff --git a/drivers/dma/dw-edma/dw-edma-v0-debugfs.h b/drivers/dma/dw-edma/dw-edma-v0-debugfs.h
index 3391b86edf5a..fb3342d97d6d 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-debugfs.h
+++ b/drivers/dma/dw-edma/dw-edma-v0-debugfs.h
@@ -13,15 +13,10 @@
 
 #ifdef CONFIG_DEBUG_FS
 void dw_edma_v0_debugfs_on(struct dw_edma *dw);
-void dw_edma_v0_debugfs_off(struct dw_edma *dw);
 #else
 static inline void dw_edma_v0_debugfs_on(struct dw_edma *dw)
 {
 }
-
-static inline void dw_edma_v0_debugfs_off(struct dw_edma *dw)
-{
-}
 #endif /* CONFIG_DEBUG_FS */
 
 #endif /* _DW_EDMA_V0_DEBUG_FS_H */
-- 
2.38.1

[PATCH v7 19/25] dmaengine: dw-edma: Use non-atomic io-64 methods

[Serge Semin]

Instead of splitting the 64-bits IOs up into two 32-bits ones it's
possible to use the already available non-atomic readq/writeq methods
implemented exactly for such cases. They are defined in the dedicated
header files io-64-nonatomic-lo-hi.h/io-64-nonatomic-hi-lo.h. So in case
if the 64-bits readq/writeq methods are unavailable on some platforms at
consideration, the corresponding drivers can have any of these headers
included and stop locally re-implementing the 64-bits IO accessors taking
into account the non-atomic nature of the included methods. Let's do that
in the DW eDMA driver too. Note by doing so we can discard the
CONFIG_64BIT config ifdefs from the code.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-v0-core.c | 55 +++++++++------------------
 1 file changed, 18 insertions(+), 37 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c
index 66f296daac5a..51a34b43434c 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-core.c
+++ b/drivers/dma/dw-edma/dw-edma-v0-core.c
@@ -8,6 +8,8 @@
 
 #include <linux/bitfield.h>
 
+#include <linux/io-64-nonatomic-lo-hi.h>
+
 #include "dw-edma-core.h"
 #include "dw-edma-v0-core.h"
 #include "dw-edma-v0-regs.h"
@@ -53,8 +55,6 @@ static inline struct dw_edma_v0_regs __iomem *__dw_regs(struct dw_edma *dw)
 		SET_32(dw, rd_##name, value);		\
 	} while (0)
 
-#ifdef CONFIG_64BIT
-
 #define SET_64(dw, name, value)				\
 	writeq(value, &(__dw_regs(dw)->name))
 
@@ -80,8 +80,6 @@ static inline struct dw_edma_v0_regs __iomem *__dw_regs(struct dw_edma *dw)
 		SET_64(dw, rd_##name, value);		\
 	} while (0)
 
-#endif /* CONFIG_64BIT */
-
 #define SET_COMPAT(dw, name, value)			\
 	writel(value, &(__dw_regs(dw)->type.unroll.name))
 
@@ -164,14 +162,13 @@ static inline u32 readl_ch(struct dw_edma *dw, enum dw_edma_dir dir, u16 ch,
 #define SET_LL_32(ll, value) \
 	writel(value, ll)
 
-#ifdef CONFIG_64BIT
-
 static inline void writeq_ch(struct dw_edma *dw, enum dw_edma_dir dir, u16 ch,
 			     u64 value, void __iomem *addr)
 {
+	unsigned long flags;
+
 	if (dw->chip->mf == EDMA_MF_EDMA_LEGACY) {
 		u32 viewport_sel;
-		unsigned long flags;
 
 		raw_spin_lock_irqsave(&dw->lock, flags);
 
@@ -181,22 +178,22 @@ static inline void writeq_ch(struct dw_edma *dw, enum dw_edma_dir dir, u16 ch,
 
 		writel(viewport_sel,
 		       &(__dw_regs(dw)->type.legacy.viewport_sel));
-		writeq(value, addr);
+	}
+
+	writeq(value, addr);
 
+	if (dw->chip->mf == EDMA_MF_EDMA_LEGACY)
 		raw_spin_unlock_irqrestore(&dw->lock, flags);
-	} else {
-		writeq(value, addr);
-	}
 }
 
 static inline u64 readq_ch(struct dw_edma *dw, enum dw_edma_dir dir, u16 ch,
 			   const void __iomem *addr)
 {
-	u32 value;
+	unsigned long flags;
+	u64 value;
 
 	if (dw->chip->mf == EDMA_MF_EDMA_LEGACY) {
 		u32 viewport_sel;
-		unsigned long flags;
 
 		raw_spin_lock_irqsave(&dw->lock, flags);
 
@@ -206,12 +203,12 @@ static inline u64 readq_ch(struct dw_edma *dw, enum dw_edma_dir dir, u16 ch,
 
 		writel(viewport_sel,
 		       &(__dw_regs(dw)->type.legacy.viewport_sel));
-		value = readq(addr);
+	}
+
+	value = readq(addr);
 
+	if (dw->chip->mf == EDMA_MF_EDMA_LEGACY)
 		raw_spin_unlock_irqrestore(&dw->lock, flags);
-	} else {
-		value = readq(addr);
-	}
 
 	return value;
 }
@@ -225,8 +222,6 @@ static inline u64 readq_ch(struct dw_edma *dw, enum dw_edma_dir dir, u16 ch,
 #define SET_LL_64(ll, value) \
 	writeq(value, ll)
 
-#endif /* CONFIG_64BIT */
-
 /* eDMA management callbacks */
 void dw_edma_v0_core_off(struct dw_edma *dw)
 {
@@ -325,19 +320,10 @@ static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk)
 		/* Transfer size */
 		SET_LL_32(&lli[i].transfer_size, child->sz);
 		/* SAR */
-		#ifdef CONFIG_64BIT
-			SET_LL_64(&lli[i].sar.reg, child->sar);
-		#else /* CONFIG_64BIT */
-			SET_LL_32(&lli[i].sar.lsb, lower_32_bits(child->sar));
-			SET_LL_32(&lli[i].sar.msb, upper_32_bits(child->sar));
-		#endif /* CONFIG_64BIT */
+		SET_LL_64(&lli[i].sar.reg, child->sar);
 		/* DAR */
-		#ifdef CONFIG_64BIT
-			SET_LL_64(&lli[i].dar.reg, child->dar);
-		#else /* CONFIG_64BIT */
-			SET_LL_32(&lli[i].dar.lsb, lower_32_bits(child->dar));
-			SET_LL_32(&lli[i].dar.msb, upper_32_bits(child->dar));
-		#endif /* CONFIG_64BIT */
+		SET_LL_64(&lli[i].dar.reg, child->dar);
+
 		i++;
 	}
 
@@ -349,12 +335,7 @@ static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk)
 	/* Channel control */
 	SET_LL_32(&llp->control, control);
 	/* Linked list */
-	#ifdef CONFIG_64BIT
-		SET_LL_64(&llp->llp.reg, chunk->ll_region.paddr);
-	#else /* CONFIG_64BIT */
-		SET_LL_32(&llp->llp.lsb, lower_32_bits(chunk->ll_region.paddr));
-		SET_LL_32(&llp->llp.msb, upper_32_bits(chunk->ll_region.paddr));
-	#endif /* CONFIG_64BIT */
+	SET_LL_64(&llp->llp.reg, chunk->ll_region.paddr);
 }
 
 void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
-- 
2.38.1

[PATCH v7 20/25] dmaengine: dw-edma: Drop DT-region allocation

[Serge Semin]

There is no point in allocating an additional memory for the data target
regions passed then to the client drivers. Just use the already available
structures defined in the dw_edma_chip instance.

Note these regions are unused in normal circumstances since they are
specific to the case of eDMA being embedded into the DW PCIe End-point and
having it's CSRs accessible over a End-point' BAR. This case is only known
to be implemented as a part of the Synopsys PCIe EndPoint IP prototype
kit.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-core.c | 21 ++++-----------------
 1 file changed, 4 insertions(+), 17 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 58808bec4148..040a88cfe070 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -738,7 +738,6 @@ static void dw_edma_free_chan_resources(struct dma_chan *dchan)
 static int dw_edma_channel_setup(struct dw_edma *dw, u32 wr_alloc, u32 rd_alloc)
 {
 	struct dw_edma_chip *chip = dw->chip;
-	struct dw_edma_region *dt_region;
 	struct device *dev = chip->dev;
 	struct dw_edma_chan *chan;
 	struct dw_edma_irq *irq;
@@ -754,12 +753,6 @@ static int dw_edma_channel_setup(struct dw_edma *dw, u32 wr_alloc, u32 rd_alloc)
 	for (i = 0; i < ch_cnt; i++) {
 		chan = &dw->chan[i];
 
-		dt_region = devm_kzalloc(dev, sizeof(*dt_region), GFP_KERNEL);
-		if (!dt_region)
-			return -ENOMEM;
-
-		chan->vc.chan.private = dt_region;
-
 		chan->dw = dw;
 
 		if (i < dw->wr_ch_cnt) {
@@ -807,17 +800,11 @@ static int dw_edma_channel_setup(struct dw_edma *dw, u32 wr_alloc, u32 rd_alloc)
 			 chan->msi.data);
 
 		chan->vc.desc_free = vchan_free_desc;
-		vchan_init(&chan->vc, dma);
+		chan->vc.chan.private = chan->dir == EDMA_DIR_WRITE ?
+					&dw->chip->dt_region_wr[chan->id] :
+					&dw->chip->dt_region_rd[chan->id];
 
-		if (chan->dir == EDMA_DIR_WRITE) {
-			dt_region->paddr = chip->dt_region_wr[chan->id].paddr;
-			dt_region->vaddr = chip->dt_region_wr[chan->id].vaddr;
-			dt_region->sz = chip->dt_region_wr[chan->id].sz;
-		} else {
-			dt_region->paddr = chip->dt_region_rd[chan->id].paddr;
-			dt_region->vaddr = chip->dt_region_rd[chan->id].vaddr;
-			dt_region->sz = chip->dt_region_rd[chan->id].sz;
-		}
+		vchan_init(&chan->vc, dma);
 
 		dw_edma_v0_core_device_config(chan);
 	}
-- 
2.38.1

[PATCH v7 21/25] dmaengine: dw-edma: Replace chip ID number with device name

[Serge Semin]

Using some abstract number as the DW eDMA chip identifier isn't really
practical. First of all there can be more than one DW eDMA controller on
the platform some of them can be detected as the PCIe end-points, some of
them can be embedded into the DW PCIe Root Port/End-point controllers.
Seeing some abstract number in for instance IRQ handlers list doesn't give
a notion regarding their reference to the particular DMA controller.
Secondly current DW eDMA chip id implementation doesn't provide the
multi-eDMA platforms support for same reason of possibly having eDMA
detected on different system buses. At the same time re-implementing
something ida-based won't give much benefits especially seeing the DW eDMA
chip ID is only used in the IRQ request procedure. So to speak in order to
preserve the code simplicity and get to have the multi-eDMA platforms
support let's just use the parental device name to create the DW eDMA
controller name.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>

---

Changelog v2:
- Slightly extend the eDMA name array. (@Manivannan)
---
 drivers/dma/dw-edma/dw-edma-core.c | 3 ++-
 drivers/dma/dw-edma/dw-edma-core.h | 2 +-
 drivers/dma/dw-edma/dw-edma-pcie.c | 1 -
 include/linux/dma/edma.h           | 1 -
 4 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 040a88cfe070..e3671bfbe186 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -973,7 +973,8 @@ int dw_edma_probe(struct dw_edma_chip *chip)
 	if (!dw->chan)
 		return -ENOMEM;
 
-	snprintf(dw->name, sizeof(dw->name), "dw-edma-core:%d", chip->id);
+	snprintf(dw->name, sizeof(dw->name), "dw-edma-core:%s",
+		 dev_name(chip->dev));
 
 	/* Disable eDMA, only to establish the ideal initial conditions */
 	dw_edma_v0_core_off(dw);
diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h
index e3ad3e372b55..0ab2b6dba880 100644
--- a/drivers/dma/dw-edma/dw-edma-core.h
+++ b/drivers/dma/dw-edma/dw-edma-core.h
@@ -96,7 +96,7 @@ struct dw_edma_irq {
 };
 
 struct dw_edma {
-	char				name[20];
+	char				name[32];
 
 	struct dma_device		dma;
 
diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c b/drivers/dma/dw-edma/dw-edma-pcie.c
index f530bacfd716..3f9dadc73854 100644
--- a/drivers/dma/dw-edma/dw-edma-pcie.c
+++ b/drivers/dma/dw-edma/dw-edma-pcie.c
@@ -222,7 +222,6 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
 
 	/* Data structure initialization */
 	chip->dev = dev;
-	chip->id = pdev->devfn;
 
 	chip->mf = vsec_data.mf;
 	chip->nr_irqs = nr_irqs;
diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
index 380a0a3e251f..9d44da4aa59d 100644
--- a/include/linux/dma/edma.h
+++ b/include/linux/dma/edma.h
@@ -76,7 +76,6 @@ enum dw_edma_chip_flags {
  */
 struct dw_edma_chip {
 	struct device		*dev;
-	int			id;
 	int			nr_irqs;
 	const struct dw_edma_core_ops   *ops;
 	u32			flags;
-- 
2.38.1

[PATCH v7 22/25] dmaengine: dw-edma: Skip cleanup procedure if no private data found

[Serge Semin]

DW eDMA driver private data is preserved in the passed DW eDMA chip info
structure. If either probe procedure failed or for some reason the passed
info object doesn't have private data pointer initialized we need to halt
the DMA device cleanup procedure in order to prevent possible system
crashes.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index e3671bfbe186..1906a836f0aa 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -1011,6 +1011,10 @@ int dw_edma_remove(struct dw_edma_chip *chip)
 	struct dw_edma *dw = chip->dw;
 	int i;
 
+	/* Skip removal if no private data found */
+	if (!dw)
+		return -ENODEV;
+
 	/* Disable eDMA */
 	dw_edma_v0_core_off(dw);
 
-- 
2.38.1

[PATCH v7 23/25] PCI: dwc: Restore DMA-mask after MSI-data allocation

[Serge Semin]

DW PCIe Root Ports and End-points can be equipped with the DW eDMA engine.
In that case it is critical to have the platform device pre-initialized
with a valid DMA-mask so the drivers using the eDMA-engine would be able
to allocate the DMA-able buffers. The MSI-capable data requires to be
allocated from the lowest 4GB region. Since that procedure implies the
DMA-mask change we need to restore the mask set by the low-level drivers
after the MSI-data allocation is done.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>

---

Changelog v7:
- This is a new patch added on v7 stage of the series. (@Robin)
---
 drivers/pci/controller/dwc/pcie-designware-host.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 5762bd306261..1a3dae1f6aa2 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -326,7 +326,7 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp)
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct device *dev = pci->dev;
 	struct platform_device *pdev = to_platform_device(dev);
-	u64 *msi_vaddr;
+	u64 *msi_vaddr, dma_mask;
 	int ret;
 	u32 ctrl, num_ctrls;
 
@@ -366,6 +366,13 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp)
 						    dw_chained_msi_isr, pp);
 	}
 
+	/*
+	 * Save and then restore the DMA-mask pre-set by the low-level drivers
+	 * after allocating the MSI-capable region. The mask might be useful for
+	 * the controllers with the embedded eDMA engine.
+	 */
+	dma_mask = dma_get_mask(dev);
+
 	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
 	if (ret)
 		dev_warn(dev, "Failed to set DMA mask to 32-bit. Devices with only 32-bit MSI support may not work properly\n");
@@ -378,6 +385,10 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp)
 		return -ENOMEM;
 	}
 
+	ret = dma_set_mask_and_coherent(dev, dma_mask);
+	if (ret)
+		dev_warn(dev, "Failed to re-store DMA-mask\n");
+
 	return 0;
 }
 
-- 
2.38.1

[PATCH v7 24/25] PCI: bt1: Set 64-bit DMA-mask

[Serge Semin]

The DW PCIe RC IP-core is synthesized with the 64-bits AXI address bus.
Since the device is also equipped with the eDMA engine we need to
explicitly set the device DMA-mask so the DMA-engine clients would be able
to allocate the data buffers from the DMA-able memory space.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>

---

Changelog v7:
- This is a new patch added on v7 stage of the series. (@Robin)
---
 drivers/pci/controller/dwc/pcie-bt1.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-bt1.c b/drivers/pci/controller/dwc/pcie-bt1.c
index 8b6c7d544d9a..04aa58348aa5 100644
--- a/drivers/pci/controller/dwc/pcie-bt1.c
+++ b/drivers/pci/controller/dwc/pcie-bt1.c
@@ -583,6 +583,10 @@ static int bt1_pcie_add_port(struct bt1_pcie *btpci)
 	struct device *dev = &btpci->pdev->dev;
 	int ret;
 
+	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+	if (ret)
+		return ret;
+
 	btpci->dw.version = DW_PCIE_VER_460A;
 	btpci->dw.dev = dev;
 	btpci->dw.ops = &bt1_pcie_ops;
-- 
2.38.1

[PATCH v7 25/25] PCI: dwc: Add DW eDMA engine support

[Serge Semin]

Since the DW eDMA driver now supports eDMA controllers embedded into the
locally accessible DW PCIe Root Ports and Endpoints, we can use the
updated interface to register DW eDMA as DMA engine device if it's
available. In order to successfully do that the DW PCIe core driver need
to perform some preparations first. First of all it needs to find out the
eDMA controller CSRs base address, whether they are accessible over the
Port Logic or iATU unrolled space. Afterwards it can try to auto-detect
the eDMA controller availability and number of read/write channels.
If none was found the procedure will just silently halt with no error
returned. Secondly the platform is supposed to provide either combined or
per-channel IRQ signals. If no valid IRQs set is found the procedure will
also halt with no error returned so to be backward compatible with the
platforms where DW PCIe controllers have eDMA embedded but lack of the
IRQs defined for them. Finally before actually probing the eDMA device we
need to allocate LLP items buffers. After that the DW eDMA can be
registered. If registration is successful the info-message regarding the
number of detected Read/Write eDMA channels will be printed to the system
as is done for the iATU settings.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>

---

Changelog v2:
- Don't fail eDMA detection procedure if the DW eDMA driver couldn't probe
  device. That happens if the driver is disabled. (@Manivannan)
- Add "dma" registers resource mapping procedure. (@Manivannan)
- Move the eDMA CSRs space detection into the dw_pcie_map_detect() method.
- Remove eDMA on the dw_pcie_ep_init() internal errors. (@Manivannan)
- Remove eDMA in the dw_pcie_ep_exit() method.
- Move the dw_pcie_edma_detect() method execution to the tail of the
  dw_pcie_ep_init() function.

Changelog v3:
- Add more comprehensive and less regression prune eDMA block detection
  procedure.
- Remove Manivannan tb tag since the patch content has been changed.

Changelog v6:
- Fix some patchlog and in-line comments misspells. (@Bjorn)

Changelog v7:
- Activate the mapping auto-detection procedure for IP-cores older than
  5.40a since the viewport-based access has been removed since that
  version. (@Yoshihiro)
---
 .../pci/controller/dwc/pcie-designware-ep.c   |  12 +-
 .../pci/controller/dwc/pcie-designware-host.c |  13 +-
 drivers/pci/controller/dwc/pcie-designware.c  | 195 ++++++++++++++++++
 drivers/pci/controller/dwc/pcie-designware.h  |  21 ++
 4 files changed, 238 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index f68d1ab83bb3..1a9956692a97 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -612,8 +612,11 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
 
 void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
 {
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
 	struct pci_epc *epc = ep->epc;
 
+	dw_pcie_edma_remove(pci);
+
 	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
 			      epc->mem->window.page_size);
 
@@ -768,6 +771,10 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 		goto err_exit_epc_mem;
 	}
 
+	ret = dw_pcie_edma_detect(pci);
+	if (ret)
+		goto err_free_epc_mem;
+
 	if (ep->ops->get_features) {
 		epc_features = ep->ops->get_features(ep);
 		if (epc_features->core_init_notifier)
@@ -776,10 +783,13 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 
 	ret = dw_pcie_ep_init_complete(ep);
 	if (ret)
-		goto err_free_epc_mem;
+		goto err_remove_edma;
 
 	return 0;
 
+err_remove_edma:
+	dw_pcie_edma_remove(pci);
+
 err_free_epc_mem:
 	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
 			      epc->mem->window.page_size);
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 1a3dae1f6aa2..4733cbdb3d6e 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -478,14 +478,18 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp)
 
 	dw_pcie_iatu_detect(pci);
 
-	ret = dw_pcie_setup_rc(pp);
+	ret = dw_pcie_edma_detect(pci);
 	if (ret)
 		goto err_free_msi;
 
+	ret = dw_pcie_setup_rc(pp);
+	if (ret)
+		goto err_remove_edma;
+
 	if (!dw_pcie_link_up(pci)) {
 		ret = dw_pcie_start_link(pci);
 		if (ret)
-			goto err_free_msi;
+			goto err_remove_edma;
 	}
 
 	/* Ignore errors, the link may come up later */
@@ -502,6 +506,9 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp)
 err_stop_link:
 	dw_pcie_stop_link(pci);
 
+err_remove_edma:
+	dw_pcie_edma_remove(pci);
+
 err_free_msi:
 	if (pp->has_msi_ctrl)
 		dw_pcie_free_msi(pp);
@@ -523,6 +530,8 @@ void dw_pcie_host_deinit(struct dw_pcie_rp *pp)
 
 	dw_pcie_stop_link(pci);
 
+	dw_pcie_edma_remove(pci);
+
 	if (pp->has_msi_ctrl)
 		dw_pcie_free_msi(pp);
 
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 1e06ccf2dc9e..825cabde67a4 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -12,6 +12,7 @@
 #include <linux/bitops.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/dma/edma.h>
 #include <linux/gpio/consumer.h>
 #include <linux/ioport.h>
 #include <linux/of.h>
@@ -142,6 +143,18 @@ int dw_pcie_get_resources(struct dw_pcie *pci)
 	if (!pci->atu_size)
 		pci->atu_size = SZ_4K;
 
+	/* eDMA region can be mapped to a custom base address */
+	if (!pci->edma.reg_base) {
+		res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dma");
+		if (res) {
+			pci->edma.reg_base = devm_ioremap_resource(pci->dev, res);
+			if (IS_ERR(pci->edma.reg_base))
+				return PTR_ERR(pci->edma.reg_base);
+		} else if (pci->atu_size >= 2 * DEFAULT_DBI_DMA_OFFSET) {
+			pci->edma.reg_base = pci->atu_base + DEFAULT_DBI_DMA_OFFSET;
+		}
+	}
+
 	/* LLDD is supposed to manually switch the clocks and resets state */
 	if (dw_pcie_cap_is(pci, REQ_RES)) {
 		ret = dw_pcie_get_clocks(pci);
@@ -782,6 +795,188 @@ void dw_pcie_iatu_detect(struct dw_pcie *pci)
 		 pci->region_align / SZ_1K, (pci->region_limit + 1) / SZ_1G);
 }
 
+static u32 dw_pcie_readl_dma(struct dw_pcie *pci, u32 reg)
+{
+	u32 val = 0;
+	int ret;
+
+	if (pci->ops && pci->ops->read_dbi)
+		return pci->ops->read_dbi(pci, pci->edma.reg_base, reg, 4);
+
+	ret = dw_pcie_read(pci->edma.reg_base + reg, 4, &val);
+	if (ret)
+		dev_err(pci->dev, "Read DMA address failed\n");
+
+	return val;
+}
+
+static int dw_pcie_edma_irq_vector(struct device *dev, unsigned int nr)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	char name[6];
+	int ret;
+
+	if (nr >= EDMA_MAX_WR_CH + EDMA_MAX_RD_CH)
+		return -EINVAL;
+
+	ret = platform_get_irq_byname_optional(pdev, "dma");
+	if (ret > 0)
+		return ret;
+
+	snprintf(name, sizeof(name), "dma%u", nr);
+
+	return platform_get_irq_byname_optional(pdev, name);
+}
+
+static struct dw_edma_core_ops dw_pcie_edma_ops = {
+	.irq_vector = dw_pcie_edma_irq_vector,
+};
+
+static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
+{
+	u32 val;
+
+	/*
+	 * Indirect eDMA CSRs access has been completely removed since v5.40a
+	 * thus no space is now reserved for the eDMA channels viewport and
+	 * former DMA CTRL register is no longer fixed to FFs.
+	 */
+	if (dw_pcie_ver_is_ge(pci, 540A))
+		val = 0xFFFFFFFF;
+	else
+		val = dw_pcie_readl_dbi(pci, PCIE_DMA_VIEWPORT_BASE + PCIE_DMA_CTRL);
+
+	if (val == 0xFFFFFFFF && pci->edma.reg_base) {
+		pci->edma.mf = EDMA_MF_EDMA_UNROLL;
+
+		val = dw_pcie_readl_dma(pci, PCIE_DMA_CTRL);
+	} else if (val != 0xFFFFFFFF) {
+		pci->edma.mf = EDMA_MF_EDMA_LEGACY;
+
+		pci->edma.reg_base = pci->dbi_base + PCIE_DMA_VIEWPORT_BASE;
+	} else {
+		return -ENODEV;
+	}
+
+	pci->edma.dev = pci->dev;
+
+	if (!pci->edma.ops)
+		pci->edma.ops = &dw_pcie_edma_ops;
+
+	pci->edma.flags |= DW_EDMA_CHIP_LOCAL;
+
+	pci->edma.ll_wr_cnt = FIELD_GET(PCIE_DMA_NUM_WR_CHAN, val);
+	pci->edma.ll_rd_cnt = FIELD_GET(PCIE_DMA_NUM_RD_CHAN, val);
+
+	/* Sanity check the channels count if the mapping was incorrect */
+	if (!pci->edma.ll_wr_cnt || pci->edma.ll_wr_cnt > EDMA_MAX_WR_CH ||
+	    !pci->edma.ll_rd_cnt || pci->edma.ll_rd_cnt > EDMA_MAX_RD_CH)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int dw_pcie_edma_irq_verify(struct dw_pcie *pci)
+{
+	struct platform_device *pdev = to_platform_device(pci->dev);
+	u16 ch_cnt = pci->edma.ll_wr_cnt + pci->edma.ll_rd_cnt;
+	char name[6];
+	int ret;
+
+	if (pci->edma.nr_irqs == 1)
+		return 0;
+	else if (pci->edma.nr_irqs > 1)
+		return pci->edma.nr_irqs != ch_cnt ? -EINVAL : 0;
+
+	ret = platform_get_irq_byname_optional(pdev, "dma");
+	if (ret > 0) {
+		pci->edma.nr_irqs = 1;
+		return 0;
+	}
+
+	for (; pci->edma.nr_irqs < ch_cnt; pci->edma.nr_irqs++) {
+		snprintf(name, sizeof(name), "dma%d", pci->edma.nr_irqs);
+
+		ret = platform_get_irq_byname_optional(pdev, name);
+		if (ret <= 0)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int dw_pcie_edma_ll_alloc(struct dw_pcie *pci)
+{
+	struct dw_edma_region *ll;
+	dma_addr_t paddr;
+	int i;
+
+	for (i = 0; i < pci->edma.ll_wr_cnt; i++) {
+		ll = &pci->edma.ll_region_wr[i];
+		ll->sz = DMA_LLP_MEM_SIZE;
+		ll->vaddr = dmam_alloc_coherent(pci->dev, ll->sz,
+						&paddr, GFP_KERNEL);
+		if (!ll->vaddr)
+			return -ENOMEM;
+
+		ll->paddr = paddr;
+	}
+
+	for (i = 0; i < pci->edma.ll_rd_cnt; i++) {
+		ll = &pci->edma.ll_region_rd[i];
+		ll->sz = DMA_LLP_MEM_SIZE;
+		ll->vaddr = dmam_alloc_coherent(pci->dev, ll->sz,
+						&paddr, GFP_KERNEL);
+		if (!ll->vaddr)
+			return -ENOMEM;
+
+		ll->paddr = paddr;
+	}
+
+	return 0;
+}
+
+int dw_pcie_edma_detect(struct dw_pcie *pci)
+{
+	int ret;
+
+	/* Don't fail if no eDMA was found (for the backward compatibility) */
+	ret = dw_pcie_edma_find_chip(pci);
+	if (ret)
+		return 0;
+
+	/* Don't fail on the IRQs verification (for the backward compatibility) */
+	ret = dw_pcie_edma_irq_verify(pci);
+	if (ret) {
+		dev_err(pci->dev, "Invalid eDMA IRQs found\n");
+		return 0;
+	}
+
+	ret = dw_pcie_edma_ll_alloc(pci);
+	if (ret) {
+		dev_err(pci->dev, "Couldn't allocate LLP memory\n");
+		return ret;
+	}
+
+	/* Don't fail if the DW eDMA driver can't find the device */
+	ret = dw_edma_probe(&pci->edma);
+	if (ret && ret != -ENODEV) {
+		dev_err(pci->dev, "Couldn't register eDMA device\n");
+		return ret;
+	}
+
+	dev_info(pci->dev, "eDMA: unroll %s, %hu wr, %hu rd\n",
+		 pci->edma.mf == EDMA_MF_EDMA_UNROLL ? "T" : "F",
+		 pci->edma.ll_wr_cnt, pci->edma.ll_rd_cnt);
+
+	return 0;
+}
+
+void dw_pcie_edma_remove(struct dw_pcie *pci)
+{
+	dw_edma_remove(&pci->edma);
+}
+
 void dw_pcie_setup(struct dw_pcie *pci)
 {
 	u32 val;
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 393dfb931df6..79713ce075cc 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -15,6 +15,7 @@
 #include <linux/bitops.h>
 #include <linux/clk.h>
 #include <linux/dma-mapping.h>
+#include <linux/dma/edma.h>
 #include <linux/gpio/consumer.h>
 #include <linux/irq.h>
 #include <linux/msi.h>
@@ -31,6 +32,7 @@
 #define DW_PCIE_VER_480A		0x3438302a
 #define DW_PCIE_VER_490A		0x3439302a
 #define DW_PCIE_VER_520A		0x3532302a
+#define DW_PCIE_VER_540A		0x3534302a
 
 #define __dw_pcie_ver_cmp(_pci, _ver, _op) \
 	((_pci)->version _op DW_PCIE_VER_ ## _ver)
@@ -167,6 +169,18 @@
 #define PCIE_MSIX_DOORBELL		0x948
 #define PCIE_MSIX_DOORBELL_PF_SHIFT	24
 
+/*
+ * eDMA CSRs. DW PCIe IP-core v4.70a and older had the eDMA registers accessible
+ * over the Port Logic registers space. Afterwards the unrolled mapping was
+ * introduced so eDMA and iATU could be accessed via a dedicated registers
+ * space.
+ */
+#define PCIE_DMA_VIEWPORT_BASE		0x970
+#define PCIE_DMA_UNROLL_BASE		0x80000
+#define PCIE_DMA_CTRL			0x008
+#define PCIE_DMA_NUM_WR_CHAN		GENMASK(3, 0)
+#define PCIE_DMA_NUM_RD_CHAN		GENMASK(19, 16)
+
 #define PCIE_PL_CHK_REG_CONTROL_STATUS			0xB20
 #define PCIE_PL_CHK_REG_CHK_REG_START			BIT(0)
 #define PCIE_PL_CHK_REG_CHK_REG_CONTINUOUS		BIT(1)
@@ -215,6 +229,7 @@
  * this offset, if atu_base not set.
  */
 #define DEFAULT_DBI_ATU_OFFSET (0x3 << 20)
+#define DEFAULT_DBI_DMA_OFFSET PCIE_DMA_UNROLL_BASE
 
 #define MAX_MSI_IRQS			256
 #define MAX_MSI_IRQS_PER_CTRL		32
@@ -226,6 +241,9 @@
 #define MAX_IATU_IN			256
 #define MAX_IATU_OUT			256
 
+/* Default eDMA LLP memory size */
+#define DMA_LLP_MEM_SIZE		PAGE_SIZE
+
 struct dw_pcie;
 struct dw_pcie_rp;
 struct dw_pcie_ep;
@@ -369,6 +387,7 @@ struct dw_pcie {
 	int			num_lanes;
 	int			link_gen;
 	u8			n_fts[2];
+	struct dw_edma_chip	edma;
 	struct clk_bulk_data	app_clks[DW_PCIE_NUM_APP_CLKS];
 	struct clk_bulk_data	core_clks[DW_PCIE_NUM_CORE_CLKS];
 	struct reset_control_bulk_data	app_rsts[DW_PCIE_NUM_APP_RSTS];
@@ -408,6 +427,8 @@ int dw_pcie_prog_ep_inbound_atu(struct dw_pcie *pci, u8 func_no, int index,
 void dw_pcie_disable_atu(struct dw_pcie *pci, u32 dir, int index);
 void dw_pcie_setup(struct dw_pcie *pci);
 void dw_pcie_iatu_detect(struct dw_pcie *pci);
+int dw_pcie_edma_detect(struct dw_pcie *pci);
+void dw_pcie_edma_remove(struct dw_pcie *pci);
 
 static inline void dw_pcie_writel_dbi(struct dw_pcie *pci, u32 reg, u32 val)
 {
-- 
2.38.1

Re: [PATCH v7 23/25] PCI: dwc: Restore DMA-mask after MSI-data allocation

[Serge Semin]

Hi Robin

On Thu, Dec 15, 2022 at 02:53:03AM +0300, Serge Semin wrote:
> DW PCIe Root Ports and End-points can be equipped with the DW eDMA engine.
> In that case it is critical to have the platform device pre-initialized
> with a valid DMA-mask so the drivers using the eDMA-engine would be able
> to allocate the DMA-able buffers. The MSI-capable data requires to be
> allocated from the lowest 4GB region. Since that procedure implies the
> DMA-mask change we need to restore the mask set by the low-level drivers
> after the MSI-data allocation is done.

I dropped the patch
[PATCH v6 22/24] dmaengine: dw-edma: Bypass dma-ranges mapping for the local setup
Link: https://lore.kernel.org/linux-pci/20221107210438.1515-23-Sergey.Semin@baikalelectronics.ru/
from the series. It has turned to be useless since your commit
f1ad5338a4d5 ("of: Fix "dma-ranges" handling for bus controllers").
Instead I added the patches
[PATCH v7 23/25] PCI: dwc: Restore DMA-mask after MSI-data allocation
and
[PATCH v7 24/25] PCI: bt1: Set 64-bit DMA-mask
to this patchset in order to properly handle the DMA-mask.

Could you please give your opinion on these patches?

-Serge(y)

> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> 
> ---
> 
> Changelog v7:
> - This is a new patch added on v7 stage of the series. (@Robin)
> ---
>  drivers/pci/controller/dwc/pcie-designware-host.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 5762bd306261..1a3dae1f6aa2 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -326,7 +326,7 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp)
>  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>  	struct device *dev = pci->dev;
>  	struct platform_device *pdev = to_platform_device(dev);
> -	u64 *msi_vaddr;
> +	u64 *msi_vaddr, dma_mask;
>  	int ret;
>  	u32 ctrl, num_ctrls;
>  
> @@ -366,6 +366,13 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp)
>  						    dw_chained_msi_isr, pp);
>  	}
>  
> +	/*
> +	 * Save and then restore the DMA-mask pre-set by the low-level drivers
> +	 * after allocating the MSI-capable region. The mask might be useful for
> +	 * the controllers with the embedded eDMA engine.
> +	 */
> +	dma_mask = dma_get_mask(dev);
> +
>  	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
>  	if (ret)
>  		dev_warn(dev, "Failed to set DMA mask to 32-bit. Devices with only 32-bit MSI support may not work properly\n");
> @@ -378,6 +385,10 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp)
>  		return -ENOMEM;
>  	}
>  
> +	ret = dma_set_mask_and_coherent(dev, dma_mask);
> +	if (ret)
> +		dev_warn(dev, "Failed to re-store DMA-mask\n");
> +
>  	return 0;
>  }
>  
> -- 
> 2.38.1
> 
> 

Re: [PATCH v7 23/25] PCI: dwc: Restore DMA-mask after MSI-data allocation

[Christoph Hellwig]

On Thu, Dec 15, 2022 at 02:53:03AM +0300, Serge Semin wrote:
> DW PCIe Root Ports and End-points can be equipped with the DW eDMA engine.
> In that case it is critical to have the platform device pre-initialized
> with a valid DMA-mask so the drivers using the eDMA-engine would be able
> to allocate the DMA-able buffers. The MSI-capable data requires to be
> allocated from the lowest 4GB region. Since that procedure implies the
> DMA-mask change we need to restore the mask set by the low-level drivers
> after the MSI-data allocation is done.

You can't change the DMA mask when there are existing allocations.

Re: [PATCH v7 23/25] PCI: dwc: Restore DMA-mask after MSI-data allocation

[Serge Semin]

Hi Christoph

On Wed, Dec 14, 2022 at 11:13:41PM -0800, Christoph Hellwig wrote:
> On Thu, Dec 15, 2022 at 02:53:03AM +0300, Serge Semin wrote:
> > DW PCIe Root Ports and End-points can be equipped with the DW eDMA engine.
> > In that case it is critical to have the platform device pre-initialized
> > with a valid DMA-mask so the drivers using the eDMA-engine would be able
> > to allocate the DMA-able buffers. The MSI-capable data requires to be
> > allocated from the lowest 4GB region. Since that procedure implies the
> > DMA-mask change we need to restore the mask set by the low-level drivers
> > after the MSI-data allocation is done.
> 
> You can't change the DMA mask when there are existing allocations.

Em, what do you guys suggest for the DW PCIe devices with the embedded
DMA-engine then? To live forever with the SWIOTLBs? I can't drop the
DMA-mask update due to this commit 423511ec23e2 ("PCI: dwc: Drop
dependency on ZONE_DMA32") and I can't change the mask after it's
updated. Note it's updated for the memory allocation to which actually
no DMA will be performed, see
https://lore.kernel.org/linux-pci/20220825185026.3816331-2-willmcvicker@google.com/.
My patches imply adding the real DMA operations support.

We've discussed this a lot with Robin in various threads and I thought
a workable solution was found. I was going to update the mask in
another place, but basically it would still mean to have first setting
the 32-bit mask here, and then change it to 64-bit one in the
framework of the DW eDMA driver.

So to speak I don't see a proper way out from the situation. Nothing I
suggested was accepted and now we'll have to live with the SWIOTLBs
used for the memory above 4GB. So please suggest a workable solution
then. We need the next things:
1. Somehow preserve a single DWORD of the PCIe bus memory for the
iMSI-RX engine. (That's what is currently done the
dw_pcie_msi_host_init() method by allocating the coherent memory.)
2. Set the actual DMA-mask to the DW PCIe platform device so the
DMA-engine clients would be able to allocate actually DMA-able memory.

@Robin, please join the discussion.

-Serge(y)

Re: [PATCH v7 23/25] PCI: dwc: Restore DMA-mask after MSI-data allocation

[Robin Murphy]

On 2022-12-15 09:27, Serge Semin wrote:
> Hi Christoph
> 
> On Wed, Dec 14, 2022 at 11:13:41PM -0800, Christoph Hellwig wrote:
>> On Thu, Dec 15, 2022 at 02:53:03AM +0300, Serge Semin wrote:
>>> DW PCIe Root Ports and End-points can be equipped with the DW eDMA engine.
>>> In that case it is critical to have the platform device pre-initialized
>>> with a valid DMA-mask so the drivers using the eDMA-engine would be able
>>> to allocate the DMA-able buffers. The MSI-capable data requires to be
>>> allocated from the lowest 4GB region. Since that procedure implies the
>>> DMA-mask change we need to restore the mask set by the low-level drivers
>>> after the MSI-data allocation is done.
>>
>> You can't change the DMA mask when there are existing allocations.
> 
> Em, what do you guys suggest for the DW PCIe devices with the embedded
> DMA-engine then? To live forever with the SWIOTLBs? I can't drop the
> DMA-mask update due to this commit 423511ec23e2 ("PCI: dwc: Drop
> dependency on ZONE_DMA32") and I can't change the mask after it's
> updated. Note it's updated for the memory allocation to which actually
> no DMA will be performed, see
> https://lore.kernel.org/linux-pci/20220825185026.3816331-2-willmcvicker@google.com/.
> My patches imply adding the real DMA operations support.
> 
> We've discussed this a lot with Robin in various threads and I thought
> a workable solution was found. I was going to update the mask in
> another place, but basically it would still mean to have first setting
> the 32-bit mask here, and then change it to 64-bit one in the
> framework of the DW eDMA driver.
> 
> So to speak I don't see a proper way out from the situation. Nothing I
> suggested was accepted and now we'll have to live with the SWIOTLBs
> used for the memory above 4GB. So please suggest a workable solution
> then. We need the next things:
> 1. Somehow preserve a single DWORD of the PCIe bus memory for the
> iMSI-RX engine. (That's what is currently done the
> dw_pcie_msi_host_init() method by allocating the coherent memory.)
> 2. Set the actual DMA-mask to the DW PCIe platform device so the
> DMA-engine clients would be able to allocate actually DMA-able memory.
> 
> @Robin, please join the discussion.

Basically just don't touch the coherent mask. The eDMA drivers can still 
set the streaming mask to something larger, and that's the one that's 
going to matter for most dmaengine clients anyway. Even if someone does 
call dma_alloc_coherent() for their eDMA channel, it's not going to make 
much practical difference if that has to come from a DMA zone, unless 
the system is under severe memory pressure anyway.

Thanks,
Robin.

Re: [PATCH v7 23/25] PCI: dwc: Restore DMA-mask after MSI-data allocation

[Serge Semin]

On Thu, Dec 15, 2022 at 10:26:08AM +0000, Robin Murphy wrote:
> On 2022-12-15 09:27, Serge Semin wrote:
> > Hi Christoph
> > 
> > On Wed, Dec 14, 2022 at 11:13:41PM -0800, Christoph Hellwig wrote:
> > > On Thu, Dec 15, 2022 at 02:53:03AM +0300, Serge Semin wrote:
> > > > DW PCIe Root Ports and End-points can be equipped with the DW eDMA engine.
> > > > In that case it is critical to have the platform device pre-initialized
> > > > with a valid DMA-mask so the drivers using the eDMA-engine would be able
> > > > to allocate the DMA-able buffers. The MSI-capable data requires to be
> > > > allocated from the lowest 4GB region. Since that procedure implies the
> > > > DMA-mask change we need to restore the mask set by the low-level drivers
> > > > after the MSI-data allocation is done.
> > > 
> > > You can't change the DMA mask when there are existing allocations.
> > 
> > Em, what do you guys suggest for the DW PCIe devices with the embedded
> > DMA-engine then? To live forever with the SWIOTLBs? I can't drop the
> > DMA-mask update due to this commit 423511ec23e2 ("PCI: dwc: Drop
> > dependency on ZONE_DMA32") and I can't change the mask after it's
> > updated. Note it's updated for the memory allocation to which actually
> > no DMA will be performed, see
> > https://lore.kernel.org/linux-pci/20220825185026.3816331-2-willmcvicker@google.com/.
> > My patches imply adding the real DMA operations support.
> > 
> > We've discussed this a lot with Robin in various threads and I thought
> > a workable solution was found. I was going to update the mask in
> > another place, but basically it would still mean to have first setting
> > the 32-bit mask here, and then change it to 64-bit one in the
> > framework of the DW eDMA driver.
> > 
> > So to speak I don't see a proper way out from the situation. Nothing I
> > suggested was accepted and now we'll have to live with the SWIOTLBs
> > used for the memory above 4GB. So please suggest a workable solution
> > then. We need the next things:
> > 1. Somehow preserve a single DWORD of the PCIe bus memory for the
> > iMSI-RX engine. (That's what is currently done the
> > dw_pcie_msi_host_init() method by allocating the coherent memory.)
> > 2. Set the actual DMA-mask to the DW PCIe platform device so the
> > DMA-engine clients would be able to allocate actually DMA-able memory.
> > 
> > @Robin, please join the discussion.
> 

> Basically just don't touch the coherent mask. The eDMA drivers can still set
> the streaming mask to something larger, and that's the one that's going to
> matter for most dmaengine clients anyway. Even if someone does call
> dma_alloc_coherent() for their eDMA channel, it's not going to make much
> practical difference if that has to come from a DMA zone, unless the system
> is under severe memory pressure anyway.

Got it. Thanks for clarification. I'll resubmit the series with only
the streaming DMA mask restoration.

-Serge(y)

> 
> Thanks,
> Robin.

Re: [PATCH v7 23/25] PCI: dwc: Restore DMA-mask after MSI-data allocation

[Christoph Hellwig]

On Fri, Dec 16, 2022 at 02:52:18AM +0300, Serge Semin wrote:
> Got it. Thanks for clarification. I'll resubmit the series with only
> the streaming DMA mask restoration.

Note that even for that we need to make sure there are no outstanding
mappings when you change the mask.

Re: [PATCH v7 23/25] PCI: dwc: Restore DMA-mask after MSI-data allocation

[Serge Semin]

On Thu, Dec 15, 2022 at 11:39:41PM -0800, Christoph Hellwig wrote:
> On Fri, Dec 16, 2022 at 02:52:18AM +0300, Serge Semin wrote:
> > Got it. Thanks for clarification. I'll resubmit the series with only
> > the streaming DMA mask restoration.
> 
> Note that even for that we need to make sure there are no outstanding
> mappings when you change the mask.
> 

What about instead of save/restore pattern I'll just change the
dma_set_mask_and_coherent() method with the dma_set_coherent_mask()
function call? It seems cleaner. Like this:

< --- a/drivers/pci/controller/dwc/pcie-designware-host.c
< +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
< @@ -366,10 +366,10 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp)
<  						    dw_chained_msi_isr, pp);
<  	}
<  
< -	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
< +	ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
<  	if (ret)
<  		dev_warn(dev, "Failed to set DMA mask to 32-bit. Devices with only 32-bit MSI support may not work properly\n");
<  
<  	msi_vaddr = dmam_alloc_coherent(dev, sizeof(u64), &pp->msi_data,
<  					GFP_KERNEL);

Thus the platform-specific streaming DMA mask would be preserved.
Since it's PCIe then having the streaming DMA-mask less than 32-bits
wide is very much improbable. Moreover DW PCIe AXI-interface can be
synthesize only with one out of two address bus widths: 32 and 64.

-Serge(y)

Re: [PATCH v7 23/25] PCI: dwc: Restore DMA-mask after MSI-data allocation

[Christoph Hellwig]

On Fri, Dec 16, 2022 at 12:34:23PM +0300, Serge Semin wrote:
> What about instead of save/restore pattern I'll just change the
> dma_set_mask_and_coherent() method with the dma_set_coherent_mask()
> function call? It seems cleaner. Like this:

> Thus the platform-specific streaming DMA mask would be preserved.
> Since it's PCIe then having the streaming DMA-mask less than 32-bits
> wide is very much improbable. Moreover DW PCIe AXI-interface can be
> synthesize only with one out of two address bus widths: 32 and 64.

Where platform-specific means the dwc subdriver?  Yes, that seems
to work.  Alternatively have a flag that says which streaming mask
to set.

Re: [PATCH v7 23/25] PCI: dwc: Restore DMA-mask after MSI-data allocation

[Serge Semin]

On Fri, Dec 16, 2022 at 01:49:38AM -0800, Christoph Hellwig wrote:
> On Fri, Dec 16, 2022 at 12:34:23PM +0300, Serge Semin wrote:
> > What about instead of save/restore pattern I'll just change the
> > dma_set_mask_and_coherent() method with the dma_set_coherent_mask()
> > function call? It seems cleaner. Like this:
> 
> > Thus the platform-specific streaming DMA mask would be preserved.
> > Since it's PCIe then having the streaming DMA-mask less than 32-bits
> > wide is very much improbable. Moreover DW PCIe AXI-interface can be
> > synthesize only with one out of two address bus widths: 32 and 64.
> 

> Where platform-specific means the dwc subdriver? 

Right. I meant the streaming DMA-mask set by the low-level DWC PCIe drivers
(like pcie-qcom(-ep)?.c, pcie-bt1.c, etc). It's very much important to
have the real DMA-mask (at least the streaming one) set for the eDMA-capable
controllers so the DMA-engine clients would work with the best performance.

> Yes, that seems to work. 

Ok. I'll just use the direct dma_set_coherent_mask() method here then.

> Alternatively have a flag that says which streaming mask
> to set.

I'd prefer to have more flexibility here relying on the low-level
drivers to set the mask(s) instead of adding the new flag, just in case
if there is vendor-specific IP-core/platform changes in the address
bus width.

-Serge(y)

Re: [PATCH v7 23/25] PCI: dwc: Restore DMA-mask after MSI-data allocation

[Robin Murphy]

On 2022-12-16 10:18, Serge Semin wrote:
> On Fri, Dec 16, 2022 at 01:49:38AM -0800, Christoph Hellwig wrote:
>> On Fri, Dec 16, 2022 at 12:34:23PM +0300, Serge Semin wrote:
>>> What about instead of save/restore pattern I'll just change the
>>> dma_set_mask_and_coherent() method with the dma_set_coherent_mask()
>>> function call? It seems cleaner. Like this:
>>
>>> Thus the platform-specific streaming DMA mask would be preserved.
>>> Since it's PCIe then having the streaming DMA-mask less than 32-bits
>>> wide is very much improbable. Moreover DW PCIe AXI-interface can be
>>> synthesize only with one out of two address bus widths: 32 and 64.
>>
> 
>> Where platform-specific means the dwc subdriver?
> 
> Right. I meant the streaming DMA-mask set by the low-level DWC PCIe drivers
> (like pcie-qcom(-ep)?.c, pcie-bt1.c, etc). It's very much important to
> have the real DMA-mask (at least the streaming one) set for the eDMA-capable
> controllers so the DMA-engine clients would work with the best performance.
> 
>> Yes, that seems to work.
> 
> Ok. I'll just use the direct dma_set_coherent_mask() method here then.
> 
>> Alternatively have a flag that says which streaming mask
>> to set.
> 
> I'd prefer to have more flexibility here relying on the low-level
> drivers to set the mask(s) instead of adding the new flag, just in case
> if there is vendor-specific IP-core/platform changes in the address
> bus width.

Presumably the low-level glue drivers could pass a bus size or mask 
value in struct dw_pcie_rp/dw_pcie, so the actual dma_set_mask() call 
itself could be centralised? I guess there's also an argument that only 
glue drivers which care about eDMA need to care about setting a mask at 
all, so I don't have a string preference either way. If you'd rather 
stick with that approach then it might be worth a brief comment at each 
site to clarify why the other mask is being set from an entirely 
different place, just in case anyone comes along and tries to "fix" it.

Cheers,
Robin.

Re: [PATCH v7 23/25] PCI: dwc: Restore DMA-mask after MSI-data allocation

[Serge Semin]

On Fri, Dec 16, 2022 at 02:01:20PM +0000, Robin Murphy wrote:
> On 2022-12-16 10:18, Serge Semin wrote:
> > On Fri, Dec 16, 2022 at 01:49:38AM -0800, Christoph Hellwig wrote:
> > > On Fri, Dec 16, 2022 at 12:34:23PM +0300, Serge Semin wrote:
> > > > What about instead of save/restore pattern I'll just change the
> > > > dma_set_mask_and_coherent() method with the dma_set_coherent_mask()
> > > > function call? It seems cleaner. Like this:
> > > 
> > > > Thus the platform-specific streaming DMA mask would be preserved.
> > > > Since it's PCIe then having the streaming DMA-mask less than 32-bits
> > > > wide is very much improbable. Moreover DW PCIe AXI-interface can be
> > > > synthesize only with one out of two address bus widths: 32 and 64.
> > > 
> > 
> > > Where platform-specific means the dwc subdriver?
> > 
> > Right. I meant the streaming DMA-mask set by the low-level DWC PCIe drivers
> > (like pcie-qcom(-ep)?.c, pcie-bt1.c, etc). It's very much important to
> > have the real DMA-mask (at least the streaming one) set for the eDMA-capable
> > controllers so the DMA-engine clients would work with the best performance.
> > 
> > > Yes, that seems to work.
> > 
> > Ok. I'll just use the direct dma_set_coherent_mask() method here then.
> > 
> > > Alternatively have a flag that says which streaming mask
> > > to set.
> > 
> > I'd prefer to have more flexibility here relying on the low-level
> > drivers to set the mask(s) instead of adding the new flag, just in case
> > if there is vendor-specific IP-core/platform changes in the address
> > bus width.
> 

> Presumably the low-level glue drivers could pass a bus size or mask value in
> struct dw_pcie_rp/dw_pcie, so the actual dma_set_mask() call itself could be
> centralised? I guess there's also an argument that only glue drivers which
> care about eDMA need to care about setting a mask at all, so I don't have a
> string preference either way.

There is another peculiarity here due to which the centralized
approach turns to be less suitable. The dw_pcie_msi_host_init()
method, which currently updates the mask, isn't always executed. It's
run only if pci_msi_enabled() returns true and there is no
platform-specific dw_pci_rp.msi_host_init callback specified. Thus if
we got to implement the centralized DMA-mask setting up procedure then
it should have been done in the always executed place. That code would
have also implied the 32-bit coherent DMA-mask if the generic iMSI-RX
config is required. Thus the iMSI-RX-specific setups (data allocation
and the mask settings) would have been split up into different places
which would be less maintainable.

Moreover as you correctly noted the real DMA-mask setting up is only
needed for the eDMA-capable controllers. Meanwhile in the most of the
cases there is no eDMA embedded in the PCIe controller, but due to the
centralized approach we would need to set some mask anyway. Since I
don't know the real address bus width of all the already available DW
PCIe platforms  we'll have to fallback to using some default mask
value, which might incorrectly describe the actual device capability
(and possible cause some side-effects/regressions).

To sum up weighing up pros and cons the centralized approach seems to
me more complex, less maintainable and less flexible. In my opinion
relying on the glue-drivers to set the mask if it's needed to be set
(that is there is the embedded eDMA) is the best and the simplest
choice.

> If you'd rather stick with that approach then
> it might be worth a brief comment at each site to clarify why the other mask
> is being set from an entirely different place, just in case anyone comes
> along and tries to "fix" it.

Exactly what I was going to do. I'll add a brief comment why the
coherent DMA-mask is updated in the dw_pcie_msi_host_init() method.

-Serge(y)
> 
> Cheers,
> Robin.

Re: [PATCH v7 24/25] PCI: bt1: Set 64-bit DMA-mask

[Lorenzo Pieralisi]

On Thu, Dec 15, 2022 at 02:53:04AM +0300, Serge Semin wrote:
> The DW PCIe RC IP-core is synthesized with the 64-bits AXI address bus.
> Since the device is also equipped with the eDMA engine we need to
> explicitly set the device DMA-mask so the DMA-engine clients would be able
> to allocate the data buffers from the DMA-able memory space.
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> 
> ---
> 
> Changelog v7:
> - This is a new patch added on v7 stage of the series. (@Robin)
> ---
>  drivers/pci/controller/dwc/pcie-bt1.c | 4 ++++
>  1 file changed, 4 insertions(+)

Hi Robin,

are you OK with this change ? I think that's the last (PCI) bit we
need to take the series.

Thanks,
Lorenzo

> diff --git a/drivers/pci/controller/dwc/pcie-bt1.c b/drivers/pci/controller/dwc/pcie-bt1.c
> index 8b6c7d544d9a..04aa58348aa5 100644
> --- a/drivers/pci/controller/dwc/pcie-bt1.c
> +++ b/drivers/pci/controller/dwc/pcie-bt1.c
> @@ -583,6 +583,10 @@ static int bt1_pcie_add_port(struct bt1_pcie *btpci)
>  	struct device *dev = &btpci->pdev->dev;
>  	int ret;
>  
> +	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
> +	if (ret)
> +		return ret;
> +
>  	btpci->dw.version = DW_PCIE_VER_460A;
>  	btpci->dw.dev = dev;
>  	btpci->dw.ops = &bt1_pcie_ops;
> -- 
> 2.38.1
> 
> 

Re: [PATCH v7 24/25] PCI: bt1: Set 64-bit DMA-mask

[Serge Semin]

Hi Lorenzo

On Fri, Jan 13, 2023 at 01:04:46PM +0100, Lorenzo Pieralisi wrote:
> On Thu, Dec 15, 2022 at 02:53:04AM +0300, Serge Semin wrote:
> > The DW PCIe RC IP-core is synthesized with the 64-bits AXI address bus.
> > Since the device is also equipped with the eDMA engine we need to
> > explicitly set the device DMA-mask so the DMA-engine clients would be able
> > to allocate the data buffers from the DMA-able memory space.
> > 
> > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> > 
> > ---
> > 
> > Changelog v7:
> > - This is a new patch added on v7 stage of the series. (@Robin)
> > ---
> >  drivers/pci/controller/dwc/pcie-bt1.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> 
> Hi Robin,
> 
> are you OK with this change ? I think that's the last (PCI) bit we
> need to take the series.

There is a sparse warning raised by the last patch in this series:
> drivers/pci/controller/dwc/pcie-designware.c:917:27: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected void [noderef] __iomem *vaddr @@     got void * @@
   drivers/pci/controller/dwc/pcie-designware.c:917:27: sparse:     expected void [noderef] __iomem *vaddr
   drivers/pci/controller/dwc/pcie-designware.c:917:27: sparse:     got void *
   drivers/pci/controller/dwc/pcie-designware.c:928:27: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected void [noderef] __iomem *vaddr @@     got void * @@
   drivers/pci/controller/dwc/pcie-designware.c:928:27: sparse:     expected void [noderef] __iomem *vaddr
   drivers/pci/controller/dwc/pcie-designware.c:928:27: sparse:     got void *

See it full text in the oe-kbuild-all list:
https://lore.kernel.org/oe-kbuild-all/202212201019.zbdcz1of-lkp@intel.com/

I'll resubmit the patchset v9 today with that warning fixed. So please
hold on with merging the series in.

-Serge(y)

> 
> Thanks,
> Lorenzo
> 
> > diff --git a/drivers/pci/controller/dwc/pcie-bt1.c b/drivers/pci/controller/dwc/pcie-bt1.c
> > index 8b6c7d544d9a..04aa58348aa5 100644
> > --- a/drivers/pci/controller/dwc/pcie-bt1.c
> > +++ b/drivers/pci/controller/dwc/pcie-bt1.c
> > @@ -583,6 +583,10 @@ static int bt1_pcie_add_port(struct bt1_pcie *btpci)
> >  	struct device *dev = &btpci->pdev->dev;
> >  	int ret;
> >  
> > +	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
> > +	if (ret)
> > +		return ret;
> > +
> >  	btpci->dw.version = DW_PCIE_VER_460A;
> >  	btpci->dw.dev = dev;
> >  	btpci->dw.ops = &bt1_pcie_ops;
> > -- 
> > 2.38.1
> > 
> > 

Re: [PATCH v7 24/25] PCI: bt1: Set 64-bit DMA-mask

[Robin Murphy]

On 2023-01-13 12:04, Lorenzo Pieralisi wrote:
> On Thu, Dec 15, 2022 at 02:53:04AM +0300, Serge Semin wrote:
>> The DW PCIe RC IP-core is synthesized with the 64-bits AXI address bus.
>> Since the device is also equipped with the eDMA engine we need to
>> explicitly set the device DMA-mask so the DMA-engine clients would be able
>> to allocate the data buffers from the DMA-able memory space.
>>
>> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
>>
>> ---
>>
>> Changelog v7:
>> - This is a new patch added on v7 stage of the series. (@Robin)
>> ---
>>   drivers/pci/controller/dwc/pcie-bt1.c | 4 ++++
>>   1 file changed, 4 insertions(+)
> 
> Hi Robin,
> 
> are you OK with this change ? I think that's the last (PCI) bit we
> need to take the series.

Yup, having gone and double-checked the context this seems fine too - 
I've slightly lost track of all the circles we've been round in by now, 
but it looks like the way things all end up after v8 (and now v9) should 
be uncontentious.

Thanks,
Robin.

> 
> Thanks,
> Lorenzo
> 
>> diff --git a/drivers/pci/controller/dwc/pcie-bt1.c b/drivers/pci/controller/dwc/pcie-bt1.c
>> index 8b6c7d544d9a..04aa58348aa5 100644
>> --- a/drivers/pci/controller/dwc/pcie-bt1.c
>> +++ b/drivers/pci/controller/dwc/pcie-bt1.c
>> @@ -583,6 +583,10 @@ static int bt1_pcie_add_port(struct bt1_pcie *btpci)
>>   	struct device *dev = &btpci->pdev->dev;
>>   	int ret;
>>   
>> +	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
>> +	if (ret)
>> +		return ret;
>> +
>>   	btpci->dw.version = DW_PCIE_VER_460A;
>>   	btpci->dw.dev = dev;
>>   	btpci->dw.ops = &bt1_pcie_ops;
>> -- 
>> 2.38.1
>>
>>

Re: [PATCH v7 24/25] PCI: bt1: Set 64-bit DMA-mask

[Serge Semin]

On Fri, Jan 13, 2023 at 05:40:38PM +0000, Robin Murphy wrote:
> On 2023-01-13 12:04, Lorenzo Pieralisi wrote:
> > On Thu, Dec 15, 2022 at 02:53:04AM +0300, Serge Semin wrote:
> > > The DW PCIe RC IP-core is synthesized with the 64-bits AXI address bus.
> > > Since the device is also equipped with the eDMA engine we need to
> > > explicitly set the device DMA-mask so the DMA-engine clients would be able
> > > to allocate the data buffers from the DMA-able memory space.
> > > 
> > > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> > > 
> > > ---
> > > 
> > > Changelog v7:
> > > - This is a new patch added on v7 stage of the series. (@Robin)
> > > ---
> > >   drivers/pci/controller/dwc/pcie-bt1.c | 4 ++++
> > >   1 file changed, 4 insertions(+)
> > 
> > Hi Robin,
> > 
> > are you OK with this change ? I think that's the last (PCI) bit we
> > need to take the series.
> 

> Yup, having gone and double-checked the context this seems fine too - I've
> slightly lost track of all the circles we've been round in by now, but it
> looks like the way things all end up after v8 (and now v9) should be
> uncontentious.

Yes, v9 has just been submitted with your Rb-tag preserved in the
coherent-DMA-mask modification patch (patch #25/27).
Please find the last version of the series here:
https://lore.kernel.org/linux-pci/20230113171409.30470-1-Sergey.Semin@baikalelectronics.ru/

-Serge(y)

> 
> Thanks,
> Robin.
> 
> > 
> > Thanks,
> > Lorenzo
> > 
> > > diff --git a/drivers/pci/controller/dwc/pcie-bt1.c b/drivers/pci/controller/dwc/pcie-bt1.c
> > > index 8b6c7d544d9a..04aa58348aa5 100644
> > > --- a/drivers/pci/controller/dwc/pcie-bt1.c
> > > +++ b/drivers/pci/controller/dwc/pcie-bt1.c
> > > @@ -583,6 +583,10 @@ static int bt1_pcie_add_port(struct bt1_pcie *btpci)
> > >   	struct device *dev = &btpci->pdev->dev;
> > >   	int ret;
> > > +	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
> > > +	if (ret)
> > > +		return ret;
> > > +
> > >   	btpci->dw.version = DW_PCIE_VER_460A;
> > >   	btpci->dw.dev = dev;
> > >   	btpci->dw.ops = &bt1_pcie_ops;
> > > -- 
> > > 2.38.1
> > > 
> > >