Merge branch 'pci/endpoint'

- Destroy the EPC device in devm_pci_epc_destroy(), which previously didn't
  call devres_release() (Zijun Hu)

- Simplify pci_epc_get() with class_find_device_by_name() (Zijun Hu)

- Finish virtual EP removal in pci_epf_remove_vepf(), which previously
  caused a subsequent pci_epf_add_vepf() to fail with -EBUSY (Zijun Hu)

- Write BAR_MASK before iATU registers in pci_epc_set_bar() so we don't
  depend on the BAR_MASK reset value being larger than the requested BAR
  size (Niklas Cassel)

- Prevent changing BAR size/flags in pci_epc_set_bar() to prevent reads
  from bypassing the iATU if we reduced the BAR size (Niklas Cassel)

- Verify address alignment when programming iATU so we don't attempt to
  write bits that are read-only because of the BAR size, which could lead
  to directing accesses to the wrong address (Niklas Cassel)

- Implement artpec6 pci_epc_features so we can rely on all drivers
  supporting it so we can use it in EPC core code (Niklas Cassel)

- Check for BARs of fixed size to prevent endpoint drivers from trying to
  change their size (Niklas Cassel)

- Verify that requested BAR size is a power of two when endpoint driver
  sets the BAR (Niklas Cassel)

* pci/endpoint:
  PCI: endpoint: Verify that requested BAR size is a power of two
  PCI: endpoint: Add size check for fixed size BARs in pci_epc_set_bar()
  PCI: artpec6: Implement dw_pcie_ep operation get_features
  PCI: dwc: ep: Add 'address' alignment to 'size' check in dw_pcie_prog_ep_inbound_atu()
  PCI: dwc: ep: Prevent changing BAR size/flags in pci_epc_set_bar()
  PCI: dwc: ep: Write BAR_MASK before iATU registers in pci_epc_set_bar()
  PCI: endpoint: Finish virtual EP removal in pci_epf_remove_vepf()
  PCI: endpoint: Simplify pci_epc_get()
  PCI: endpoint: Destroy the EPC device in devm_pci_epc_destroy()
  PCI: endpoint: Replace magic number '6' by PCI_STD_NUM_BARS

Author: bjorn-helgaas

drivers/pci/controller/dwc/pcie-artpec6.c

@@ -369,9 +369,22 @@ static int artpec6_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
 	return 0;
 }
 
+static const struct pci_epc_features artpec6_pcie_epc_features = {
+	.linkup_notifier = false,
+	.msi_capable = true,
+	.msix_capable = false,
+};
+
+static const struct pci_epc_features *
+artpec6_pcie_get_features(struct dw_pcie_ep *ep)
+{
+	return &artpec6_pcie_epc_features;
+}
+
 static const struct dw_pcie_ep_ops pcie_ep_ops = {
 	.init = artpec6_pcie_ep_init,
 	.raise_irq = artpec6_pcie_raise_irq,
+	.get_features = artpec6_pcie_get_features,
 };
 
 static int artpec6_pcie_probe(struct platform_device *pdev)

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

@@ -128,7 +128,8 @@ static int dw_pcie_ep_write_header(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
 }
 
 static int dw_pcie_ep_inbound_atu(struct dw_pcie_ep *ep, u8 func_no, int type,
-				  dma_addr_t cpu_addr, enum pci_barno bar)
+				  dma_addr_t cpu_addr, enum pci_barno bar,
+				  size_t size)
 {
 	int ret;
 	u32 free_win;
@@ -145,7 +146,7 @@ static int dw_pcie_ep_inbound_atu(struct dw_pcie_ep *ep, u8 func_no, int type,
 	}
 
 	ret = dw_pcie_prog_ep_inbound_atu(pci, func_no, free_win, type,
-					  cpu_addr, bar);
+					  cpu_addr, bar, size);
 	if (ret < 0) {
 		dev_err(pci->dev, "Failed to program IB window\n");
 		return ret;
@@ -222,19 +223,30 @@ static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
 	if ((flags & PCI_BASE_ADDRESS_MEM_TYPE_64) && (bar & 1))
 		return -EINVAL;
 
-	reg = PCI_BASE_ADDRESS_0 + (4 * bar);
-
-	if (!(flags & PCI_BASE_ADDRESS_SPACE))
-		type = PCIE_ATU_TYPE_MEM;
-	else
-		type = PCIE_ATU_TYPE_IO;
+	/*
+	 * Certain EPF drivers dynamically change the physical address of a BAR
+	 * (i.e. they call set_bar() twice, without ever calling clear_bar(), as
+	 * calling clear_bar() would clear the BAR's PCI address assigned by the
+	 * host).
+	 */
+	if (ep->epf_bar[bar]) {
+		/*
+		 * We can only dynamically change a BAR if the new BAR size and
+		 * BAR flags do not differ from the existing configuration.
+		 */
+		if (ep->epf_bar[bar]->barno != bar ||
+		    ep->epf_bar[bar]->size != size ||
+		    ep->epf_bar[bar]->flags != flags)
+			return -EINVAL;
 
-	ret = dw_pcie_ep_inbound_atu(ep, func_no, type, epf_bar->phys_addr, bar);
-	if (ret)
-		return ret;
+		/*
+		 * When dynamically changing a BAR, skip writing the BAR reg, as
+		 * that would clear the BAR's PCI address assigned by the host.
+		 */
+		goto config_atu;
+	}
 
-	if (ep->epf_bar[bar])
-		return 0;
+	reg = PCI_BASE_ADDRESS_0 + (4 * bar);
 
 	dw_pcie_dbi_ro_wr_en(pci);
 
@@ -246,9 +258,21 @@ static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
 		dw_pcie_ep_writel_dbi(ep, func_no, reg + 4, 0);
 	}
 
-	ep->epf_bar[bar] = epf_bar;
 	dw_pcie_dbi_ro_wr_dis(pci);
 
+config_atu:
+	if (!(flags & PCI_BASE_ADDRESS_SPACE))
+		type = PCIE_ATU_TYPE_MEM;
+	else
+		type = PCIE_ATU_TYPE_IO;
+
+	ret = dw_pcie_ep_inbound_atu(ep, func_no, type, epf_bar->phys_addr, bar,
+				     size);
+	if (ret)
+		return ret;
+
+	ep->epf_bar[bar] = epf_bar;
+
 	return 0;
 }
 

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

@@ -597,11 +597,12 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int index, int type,
 }
 
 int dw_pcie_prog_ep_inbound_atu(struct dw_pcie *pci, u8 func_no, int index,
-				int type, u64 cpu_addr, u8 bar)
+				int type, u64 cpu_addr, u8 bar, size_t size)
 {
 	u32 retries, val;
 
-	if (!IS_ALIGNED(cpu_addr, pci->region_align))
+	if (!IS_ALIGNED(cpu_addr, pci->region_align) ||
+	    !IS_ALIGNED(cpu_addr, size))
 		return -EINVAL;
 
 	dw_pcie_writel_atu_ib(pci, index, PCIE_ATU_LOWER_TARGET,

drivers/pci/controller/dwc/pcie-designware.h

@@ -491,7 +491,7 @@ int dw_pcie_prog_outbound_atu(struct dw_pcie *pci,
 int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int index, int type,
 			     u64 cpu_addr, u64 pci_addr, u64 size);
 int dw_pcie_prog_ep_inbound_atu(struct dw_pcie *pci, u8 func_no, int index,
-				int type, u64 cpu_addr, u8 bar);
+				int type, u64 cpu_addr, u8 bar, size_t size);
 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);

drivers/pci/endpoint/pci-epc-core.c

@@ -60,26 +60,17 @@ struct pci_epc *pci_epc_get(const char *epc_name)
 	int ret = -EINVAL;
 	struct pci_epc *epc;
 	struct device *dev;
-	struct class_dev_iter iter;
 
-	class_dev_iter_init(&iter, &pci_epc_class, NULL, NULL);
-	while ((dev = class_dev_iter_next(&iter))) {
-		if (strcmp(epc_name, dev_name(dev)))
-			continue;
+	dev = class_find_device_by_name(&pci_epc_class, epc_name);
+	if (!dev)
+		goto err;
 
-		epc = to_pci_epc(dev);
-		if (!try_module_get(epc->ops->owner)) {
-			ret = -EINVAL;
-			goto err;
-		}
-
-		class_dev_iter_exit(&iter);
-		get_device(&epc->dev);
+	epc = to_pci_epc(dev);
+	if (try_module_get(epc->ops->owner))
 		return epc;
-	}
 
 err:
-	class_dev_iter_exit(&iter);
+	put_device(dev);
 	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(pci_epc_get);
@@ -609,10 +600,20 @@ EXPORT_SYMBOL_GPL(pci_epc_clear_bar);
 int pci_epc_set_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
 		    struct pci_epf_bar *epf_bar)
 {
-	int ret;
+	const struct pci_epc_features *epc_features;
+	enum pci_barno bar = epf_bar->barno;
 	int flags = epf_bar->flags;
+	int ret;
 
-	if (!pci_epc_function_is_valid(epc, func_no, vfunc_no))
+	epc_features = pci_epc_get_features(epc, func_no, vfunc_no);
+	if (!epc_features)
+		return -EINVAL;
+
+	if (epc_features->bar[bar].type == BAR_FIXED &&
+	    (epc_features->bar[bar].fixed_size != epf_bar->size))
+		return -EINVAL;
+
+	if (!is_power_of_2(epf_bar->size))
 		return -EINVAL;
 
 	if ((epf_bar->barno == BAR_5 && flags & PCI_BASE_ADDRESS_MEM_TYPE_64) ||
@@ -942,7 +943,7 @@ void devm_pci_epc_destroy(struct device *dev, struct pci_epc *epc)
 {
 	int r;
 
-	r = devres_destroy(dev, devm_pci_epc_release, devm_pci_epc_match,
+	r = devres_release(dev, devm_pci_epc_release, devm_pci_epc_match,
 			   epc);
 	dev_WARN_ONCE(dev, r, "couldn't find PCI EPC resource\n");
 }

drivers/pci/endpoint/pci-epf-core.c

@@ -202,6 +202,7 @@ void pci_epf_remove_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf)
 
 	mutex_lock(&epf_pf->lock);
 	clear_bit(epf_vf->vfunc_no, &epf_pf->vfunction_num_map);
+	epf_vf->epf_pf = NULL;
 	list_del(&epf_vf->list);
 	mutex_unlock(&epf_pf->lock);
 }

include/linux/pci-epf.h

@@ -157,7 +157,7 @@ struct pci_epf {
 	struct device		dev;
 	const char		*name;
 	struct pci_epf_header	*header;
-	struct pci_epf_bar	bar[6];
+	struct pci_epf_bar	bar[PCI_STD_NUM_BARS];
 	u8			msi_interrupts;
 	u16			msix_interrupts;
 	u8			func_no;
@@ -174,7 +174,7 @@ struct pci_epf {
 	/* Below members are to attach secondary EPC to an endpoint function */
 	struct pci_epc		*sec_epc;
 	struct list_head	sec_epc_list;
-	struct pci_epf_bar	sec_epc_bar[6];
+	struct pci_epf_bar	sec_epc_bar[PCI_STD_NUM_BARS];
 	u8			sec_epc_func_no;
 	struct config_group	*group;
 	unsigned int		is_bound;