Some DesignWare PCIe endpoint controllers integrate a DesignWare eDMA
instance. Remote-eDMA providers (e.g. vNTB) need to expose the eDMA
register block to the host through a memory window so the host can
ioremap it and run dw_edma_probe() against the remote view.
Record the physical base and size of the eDMA register aperture and
export dwc_pcie_edma_get_reg_window() so higher-level code can query the
register window associated with a given PCI EPC device.
Keep the controller-side helper declarations in a dedicated header to
avoid pulling eDMA/dmaengine-specific interfaces into the generic
DesignWare PCIe header (include/linux/pcie-dwc.h).
Signed-off-by: Koichiro Den <den@valinux.co.jp>
---
MAINTAINERS | 2 +-
drivers/pci/controller/dwc/pcie-designware.c | 29 +++++++++++++++
drivers/pci/controller/dwc/pcie-designware.h | 2 +
include/linux/pcie-dwc-edma.h | 39 ++++++++++++++++++++
4 files changed, 71 insertions(+), 1 deletion(-)
create mode 100644 include/linux/pcie-dwc-edma.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 5b11839cba9d..fa0cb454744c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20066,7 +20066,7 @@ S: Maintained
F: Documentation/devicetree/bindings/pci/snps,dw-pcie-ep.yaml
F: Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml
F: drivers/pci/controller/dwc/*designware*
-F: include/linux/pcie-dwc.h
+F: include/linux/pcie-dwc*.h
PCI DRIVER FOR TI DRA7XX/J721E
M: Vignesh Raghavendra <vigneshr@ti.com>
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 18331d9e85be..bbaeecce199a 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -18,6 +18,7 @@
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/pcie-dwc.h>
+#include <linux/pcie-dwc-edma.h>
#include <linux/platform_device.h>
#include <linux/sizes.h>
#include <linux/types.h>
@@ -162,8 +163,12 @@ int dw_pcie_get_resources(struct dw_pcie *pci)
pci->edma.reg_base = devm_ioremap_resource(pci->dev, res);
if (IS_ERR(pci->edma.reg_base))
return PTR_ERR(pci->edma.reg_base);
+ pci->edma_reg_phys = res->start;
+ pci->edma_reg_size = resource_size(res);
} else if (pci->atu_size >= 2 * DEFAULT_DBI_DMA_OFFSET) {
pci->edma.reg_base = pci->atu_base + DEFAULT_DBI_DMA_OFFSET;
+ pci->edma_reg_phys = pci->atu_phys_addr + DEFAULT_DBI_DMA_OFFSET;
+ pci->edma_reg_size = pci->atu_size - DEFAULT_DBI_DMA_OFFSET;
}
}
@@ -1340,3 +1345,27 @@ resource_size_t dw_pcie_parent_bus_offset(struct dw_pcie *pci,
return cpu_phys_addr - reg_addr;
}
+
+int dwc_pcie_edma_get_reg_window(struct pci_epc *epc, phys_addr_t *phys,
+ resource_size_t *sz)
+{
+ struct dw_pcie_ep *ep;
+ struct dw_pcie *pci;
+
+ if (!epc || !phys || !sz)
+ return -EINVAL;
+
+ ep = epc_get_drvdata(epc);
+ if (!ep)
+ return -ENODEV;
+
+ pci = to_dw_pcie_from_ep(ep);
+ if (!pci->edma_reg_size)
+ return -ENODEV;
+
+ *phys = pci->edma_reg_phys;
+ *sz = pci->edma_reg_size;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dwc_pcie_edma_get_reg_window);
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index c3301b3aedb7..cd38147443bf 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -534,6 +534,8 @@ struct dw_pcie {
int max_link_speed;
u8 n_fts[2];
struct dw_edma_chip edma;
+ phys_addr_t edma_reg_phys;
+ resource_size_t edma_reg_size;
bool l1ss_support; /* L1 PM Substates support */
struct clk_bulk_data app_clks[DW_PCIE_NUM_APP_CLKS];
struct clk_bulk_data core_clks[DW_PCIE_NUM_CORE_CLKS];
diff --git a/include/linux/pcie-dwc-edma.h b/include/linux/pcie-dwc-edma.h
new file mode 100644
index 000000000000..a5b0595603f4
--- /dev/null
+++ b/include/linux/pcie-dwc-edma.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * DesignWare PCIe controller helpers for integrated DesignWare eDMA.
+ */
+
+#ifndef LINUX_PCIE_DWC_EDMA_H
+#define LINUX_PCIE_DWC_EDMA_H
+
+#include <linux/errno.h>
+#include <linux/kconfig.h>
+#include <linux/pci-epc.h>
+#include <linux/types.h>
+
+#ifdef CONFIG_PCIE_DW
+/**
+ * dwc_pcie_edma_get_reg_window() - get integrated DW eDMA register window
+ * @epc: EPC device associated with the integrated eDMA instance
+ * @phys: pointer to receive the CPU-physical base address
+ * @sz: pointer to receive the size in bytes
+ *
+ * Some DesignWare PCIe endpoint controllers integrate a DesignWare eDMA
+ * instance. Higher-level code (e.g. BAR/window setup for remote use) may
+ * need the CPU-physical base and size of the eDMA register aperture.
+ *
+ * Return: 0 on success, -ENODEV if the EPC has no integrated eDMA register
+ * window, or -EINVAL if @epc is %NULL.
+ */
+int dwc_pcie_edma_get_reg_window(struct pci_epc *epc, phys_addr_t *phys,
+ resource_size_t *sz);
+#else
+static inline int
+dwc_pcie_edma_get_reg_window(struct pci_epc *epc, phys_addr_t *phys,
+ resource_size_t *sz)
+{
+ return -ENODEV;
+}
+#endif /* CONFIG_PCIE_DW */
+
+#endif /* LINUX_PCIE_DWC_EDMA_H */
--
2.51.0Hi Koichiro,
kernel test robot noticed the following build warnings:
[auto build test WARNING on pci/next]
[also build test WARNING on pci/for-linus linus/master v6.19-rc7 next-20260126]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Koichiro-Den/PCI-dwc-Add-helper-to-query-integrated-dw-edma-register-window/20260126-152209
base: https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link: https://lore.kernel.org/r/20260126071550.3233631-2-den%40valinux.co.jp
patch subject: [PATCH 1/2] PCI: dwc: Add helper to query integrated dw-edma register window
config: parisc-randconfig-001-20260127 (https://download.01.org/0day-ci/archive/20260127/202601271859.mmq8t4xv-lkp@intel.com/config)
compiler: hppa-linux-gcc (GCC) 11.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260127/202601271859.mmq8t4xv-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601271859.mmq8t4xv-lkp@intel.com/
All warnings (new ones prefixed by >>):
drivers/pci/controller/dwc/pcie-designware.c: In function 'dwc_pcie_edma_get_reg_window':
drivers/pci/controller/dwc/pcie-designware.c:1358:14: error: implicit declaration of function 'epc_get_drvdata'; did you mean 'epf_get_drvdata'? [-Werror=implicit-function-declaration]
1358 | ep = epc_get_drvdata(epc);
| ^~~~~~~~~~~~~~~
| epf_get_drvdata
>> drivers/pci/controller/dwc/pcie-designware.c:1358:12: warning: assignment to 'struct dw_pcie_ep *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
1358 | ep = epc_get_drvdata(epc);
| ^
cc1: some warnings being treated as errors
vim +1358 drivers/pci/controller/dwc/pcie-designware.c
1348
1349 int dwc_pcie_edma_get_reg_window(struct pci_epc *epc, phys_addr_t *phys,
1350 resource_size_t *sz)
1351 {
1352 struct dw_pcie_ep *ep;
1353 struct dw_pcie *pci;
1354
1355 if (!epc || !phys || !sz)
1356 return -EINVAL;
1357
> 1358 ep = epc_get_drvdata(epc);
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Hi Koichiro,
kernel test robot noticed the following build errors:
[auto build test ERROR on pci/next]
[also build test ERROR on pci/for-linus linus/master v6.19-rc7 next-20260126]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Koichiro-Den/PCI-dwc-Add-helper-to-query-integrated-dw-edma-register-window/20260126-152209
base: https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link: https://lore.kernel.org/r/20260126071550.3233631-2-den%40valinux.co.jp
patch subject: [PATCH 1/2] PCI: dwc: Add helper to query integrated dw-edma register window
config: riscv-defconfig (https://download.01.org/0day-ci/archive/20260127/202601271718.STDXKWdE-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 9b8addffa70cee5b2acc5454712d9cf78ce45710)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260127/202601271718.STDXKWdE-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601271718.STDXKWdE-lkp@intel.com/
All errors (new ones prefixed by >>):
>> drivers/pci/controller/dwc/pcie-designware.c:1358:7: error: call to undeclared function 'epc_get_drvdata'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
1358 | ep = epc_get_drvdata(epc);
| ^
drivers/pci/controller/dwc/pcie-designware.c:1358:7: note: did you mean 'epf_get_drvdata'?
include/linux/pci-epf.h:229:21: note: 'epf_get_drvdata' declared here
229 | static inline void *epf_get_drvdata(struct pci_epf *epf)
| ^
>> drivers/pci/controller/dwc/pcie-designware.c:1358:5: error: incompatible integer to pointer conversion assigning to 'struct dw_pcie_ep *' from 'int' [-Wint-conversion]
1358 | ep = epc_get_drvdata(epc);
| ^ ~~~~~~~~~~~~~~~~~~~~
2 errors generated.
vim +/epc_get_drvdata +1358 drivers/pci/controller/dwc/pcie-designware.c
1348
1349 int dwc_pcie_edma_get_reg_window(struct pci_epc *epc, phys_addr_t *phys,
1350 resource_size_t *sz)
1351 {
1352 struct dw_pcie_ep *ep;
1353 struct dw_pcie *pci;
1354
1355 if (!epc || !phys || !sz)
1356 return -EINVAL;
1357
> 1358 ep = epc_get_drvdata(epc);
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Hi Koichiro,
kernel test robot noticed the following build errors:
[auto build test ERROR on pci/next]
[also build test ERROR on pci/for-linus linus/master v6.19-rc7 next-20260126]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Koichiro-Den/PCI-dwc-Add-helper-to-query-integrated-dw-edma-register-window/20260126-152209
base: https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link: https://lore.kernel.org/r/20260126071550.3233631-2-den%40valinux.co.jp
patch subject: [PATCH 1/2] PCI: dwc: Add helper to query integrated dw-edma register window
config: um-randconfig-r071-20260127 (https://download.01.org/0day-ci/archive/20260127/202601271506.INKGUWyt-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
smatch version: v0.5.0-8994-gd50c5a4c
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260127/202601271506.INKGUWyt-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601271506.INKGUWyt-lkp@intel.com/
All errors (new ones prefixed by >>):
drivers/pci/controller/dwc/pcie-designware.c: In function 'dwc_pcie_edma_get_reg_window':
>> drivers/pci/controller/dwc/pcie-designware.c:1358:14: error: implicit declaration of function 'epc_get_drvdata'; did you mean 'epf_get_drvdata'? [-Wimplicit-function-declaration]
1358 | ep = epc_get_drvdata(epc);
| ^~~~~~~~~~~~~~~
| epf_get_drvdata
>> drivers/pci/controller/dwc/pcie-designware.c:1358:12: error: assignment to 'struct dw_pcie_ep *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
1358 | ep = epc_get_drvdata(epc);
| ^
vim +1358 drivers/pci/controller/dwc/pcie-designware.c
1348
1349 int dwc_pcie_edma_get_reg_window(struct pci_epc *epc, phys_addr_t *phys,
1350 resource_size_t *sz)
1351 {
1352 struct dw_pcie_ep *ep;
1353 struct dw_pcie *pci;
1354
1355 if (!epc || !phys || !sz)
1356 return -EINVAL;
1357
> 1358 ep = epc_get_drvdata(epc);
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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