Merge branch 'pci/endpoint'

- Add pci_epc_function_is_valid() to avoid repeating common validation
  checks (Damien Le Moal)

- Skip attempts to allocate from endpoint controller memory window if the
  requested size is larger than the window (Damien Le Moal)

- Add and document pci_epc_mem_map() and pci_epc_mem_unmap() to handle
  controller-specific size and alignment constraints, and add test cases to
  the endpoint test driver (Damien Le Moal)

- Implement dwc pci_epc_ops.align_addr() so pci_epc_mem_map() can observe
  DWC-specific alignment requirements (Damien Le Moal)

- Synchronously cancel command handler work in endpoint test before
  cleaning up DMA and BARs (Damien Le Moal)

- Respect endpoint page size in dw_pcie_ep_align_addr() (Niklas Cassel)

- Use dw_pcie_ep_align_addr() in dw_pcie_ep_raise_msi_irq() and
  dw_pcie_ep_raise_msix_irq() instead of open coding the equivalent (Niklas
  Cassel)

- Remove superfluous 'return' from pci_epf_test_clean_dma_chan() (Wang
  Jiang)

- Avoid NULL dereference if Modem Host Interface Endpoint lacks 'mmio' DT
  property (Zhongqiu Han)

- Release PCI domain ID of Endpoint controller parent (not controller
  itself) and before unregistering the controller, to avoid use-after-free
  (Zijun Hu)

- Clear secondary (not primary) EPC in pci_epc_remove_epf() when removing
  the secondary controller associated with an NTB (Zijun Hu)

- Fix pci_epc_map map_size kerneldoc (Rick Wertenbroek)

* pci/endpoint:
  PCI: endpoint: Fix pci_epc_map map_size kerneldoc string
  PCI: endpoint: Clear secondary (not primary) EPC in pci_epc_remove_epf()
  PCI: endpoint: Fix PCI domain ID release in pci_epc_destroy()
  PCI: endpoint: epf-mhi: Avoid NULL dereference if DT lacks 'mmio'
  PCI: endpoint: Remove surplus return statement from pci_epf_test_clean_dma_chan()
  PCI: dwc: ep: Use align addr function for dw_pcie_ep_raise_{msi,msix}_irq()
  PCI: endpoint: test: Synchronously cancel command handler work
  PCI: dwc: endpoint: Implement the pci_epc_ops::align_addr() operation
  PCI: endpoint: test: Use pci_epc_mem_map/unmap()
  PCI: endpoint: Update documentation
  PCI: endpoint: Introduce pci_epc_mem_map()/unmap()
  PCI: endpoint: Improve pci_epc_mem_alloc_addr()
  PCI: endpoint: Introduce pci_epc_function_is_valid()

Author: bjorn-helgaas

Documentation/PCI/endpoint/pci-endpoint.rst

@@ -117,6 +117,35 @@ by the PCI endpoint function driver.
    The PCI endpoint function driver should use pci_epc_mem_free_addr() to
    free the memory space allocated using pci_epc_mem_alloc_addr().
 
+* pci_epc_map_addr()
+
+  A PCI endpoint function driver should use pci_epc_map_addr() to map to a RC
+  PCI address the CPU address of local memory obtained with
+  pci_epc_mem_alloc_addr().
+
+* pci_epc_unmap_addr()
+
+  A PCI endpoint function driver should use pci_epc_unmap_addr() to unmap the
+  CPU address of local memory mapped to a RC address with pci_epc_map_addr().
+
+* pci_epc_mem_map()
+
+  A PCI endpoint controller may impose constraints on the RC PCI addresses that
+  can be mapped. The function pci_epc_mem_map() allows endpoint function
+  drivers to allocate and map controller memory while handling such
+  constraints. This function will determine the size of the memory that must be
+  allocated with pci_epc_mem_alloc_addr() for successfully mapping a RC PCI
+  address range. This function will also indicate the size of the PCI address
+  range that was actually mapped, which can be less than the requested size, as
+  well as the offset into the allocated memory to use for accessing the mapped
+  RC PCI address range.
+
+* pci_epc_mem_unmap()
+
+  A PCI endpoint function driver can use pci_epc_mem_unmap() to unmap and free
+  controller memory that was allocated and mapped using pci_epc_mem_map().
+
+
 Other EPC APIs
 ~~~~~~~~~~~~~~
 

drivers/pci/controller/dwc/pcie-designware-ep.c

@@ -268,6 +268,20 @@ static int dw_pcie_find_index(struct dw_pcie_ep *ep, phys_addr_t addr,
 	return -EINVAL;
 }
 
+static u64 dw_pcie_ep_align_addr(struct pci_epc *epc, u64 pci_addr,
+				 size_t *pci_size, size_t *offset)
+{
+	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	u64 mask = pci->region_align - 1;
+	size_t ofst = pci_addr & mask;
+
+	*pci_size = ALIGN(ofst + *pci_size, epc->mem->window.page_size);
+	*offset = ofst;
+
+	return pci_addr & ~mask;
+}
+
 static void dw_pcie_ep_unmap_addr(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
 				  phys_addr_t addr)
 {
@@ -444,6 +458,7 @@ static const struct pci_epc_ops epc_ops = {
 	.write_header		= dw_pcie_ep_write_header,
 	.set_bar		= dw_pcie_ep_set_bar,
 	.clear_bar		= dw_pcie_ep_clear_bar,
+	.align_addr		= dw_pcie_ep_align_addr,
 	.map_addr		= dw_pcie_ep_map_addr,
 	.unmap_addr		= dw_pcie_ep_unmap_addr,
 	.set_msi		= dw_pcie_ep_set_msi,
@@ -488,7 +503,8 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
 	u32 msg_addr_lower, msg_addr_upper, reg;
 	struct dw_pcie_ep_func *ep_func;
 	struct pci_epc *epc = ep->epc;
-	unsigned int aligned_offset;
+	size_t map_size = sizeof(u32);
+	size_t offset;
 	u16 msg_ctrl, msg_data;
 	bool has_upper;
 	u64 msg_addr;
@@ -516,14 +532,13 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
 	}
 	msg_addr = ((u64)msg_addr_upper) << 32 | msg_addr_lower;
 
-	aligned_offset = msg_addr & (epc->mem->window.page_size - 1);
-	msg_addr = ALIGN_DOWN(msg_addr, epc->mem->window.page_size);
+	msg_addr = dw_pcie_ep_align_addr(epc, msg_addr, &map_size, &offset);
 	ret = dw_pcie_ep_map_addr(epc, func_no, 0, ep->msi_mem_phys, msg_addr,
-				  epc->mem->window.page_size);
+				  map_size);
 	if (ret)
 		return ret;
 
-	writel(msg_data | (interrupt_num - 1), ep->msi_mem + aligned_offset);
+	writel(msg_data | (interrupt_num - 1), ep->msi_mem + offset);
 
 	dw_pcie_ep_unmap_addr(epc, func_no, 0, ep->msi_mem_phys);
 
@@ -574,8 +589,9 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
 	struct pci_epf_msix_tbl *msix_tbl;
 	struct dw_pcie_ep_func *ep_func;
 	struct pci_epc *epc = ep->epc;
+	size_t map_size = sizeof(u32);
+	size_t offset;
 	u32 reg, msg_data, vec_ctrl;
-	unsigned int aligned_offset;
 	u32 tbl_offset;
 	u64 msg_addr;
 	int ret;
@@ -600,14 +616,13 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
 		return -EPERM;
 	}
 
-	aligned_offset = msg_addr & (epc->mem->window.page_size - 1);
-	msg_addr = ALIGN_DOWN(msg_addr, epc->mem->window.page_size);
+	msg_addr = dw_pcie_ep_align_addr(epc, msg_addr, &map_size, &offset);
 	ret = dw_pcie_ep_map_addr(epc, func_no, 0, ep->msi_mem_phys, msg_addr,
-				  epc->mem->window.page_size);
+				  map_size);
 	if (ret)
 		return ret;
 
-	writel(msg_data, ep->msi_mem + aligned_offset);
+	writel(msg_data, ep->msi_mem + offset);
 
 	dw_pcie_ep_unmap_addr(epc, func_no, 0, ep->msi_mem_phys);
 

drivers/pci/endpoint/functions/pci-epf-mhi.c

@@ -867,12 +867,18 @@ static int pci_epf_mhi_bind(struct pci_epf *epf)
 {
 	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
 	struct pci_epc *epc = epf->epc;
+	struct device *dev = &epf->dev;
 	struct platform_device *pdev = to_platform_device(epc->dev.parent);
 	struct resource *res;
 	int ret;
 
 	/* Get MMIO base address from Endpoint controller */
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mmio");
+	if (!res) {
+		dev_err(dev, "Failed to get \"mmio\" resource\n");
+		return -ENODEV;
+	}
+
 	epf_mhi->mmio_phys = res->start;
 	epf_mhi->mmio_size = resource_size(res);