1 files changed, 54 insertions, 8 deletions

diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
index 394395c7f8de..d54e18872aef 100644
--- a/drivers/pci/endpoint/pci-epf-core.c
+++ b/drivers/pci/endpoint/pci-epf-core.c
@@ -236,12 +236,13 @@ void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar,
 	}
 
 	dev = epc->dev.parent;
-	dma_free_coherent(dev, epf_bar[bar].size, addr,
+	dma_free_coherent(dev, epf_bar[bar].aligned_size, addr,
 			  epf_bar[bar].phys_addr);
 
 	epf_bar[bar].phys_addr = 0;
 	epf_bar[bar].addr = NULL;
 	epf_bar[bar].size = 0;
+	epf_bar[bar].aligned_size = 0;
 	epf_bar[bar].barno = 0;
 	epf_bar[bar].flags = 0;
 }
@@ -264,7 +265,7 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
 			  enum pci_epc_interface_type type)
 {
 	u64 bar_fixed_size = epc_features->bar[bar].fixed_size;
-	size_t align = epc_features->align;
+	size_t aligned_size, align = epc_features->align;
 	struct pci_epf_bar *epf_bar;
 	dma_addr_t phys_addr;
 	struct pci_epc *epc;
@@ -285,12 +286,18 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
 			return NULL;
 		}
 		size = bar_fixed_size;
+	} else {
+		/* BAR size must be power of two */
+		size = roundup_pow_of_two(size);
 	}
 
-	if (align)
-		size = ALIGN(size, align);
-	else
-		size = roundup_pow_of_two(size);
+	/*
+	 * Allocate enough memory to accommodate the iATU alignment
+	 * requirement.  In most cases, this will be the same as .size but
+	 * it might be different if, for example, the fixed size of a BAR
+	 * is smaller than align.
+	 */
+	aligned_size = align ? ALIGN(size, align) : size;
 
 	if (type == PRIMARY_INTERFACE) {
 		epc = epf->epc;
@@ -301,7 +308,7 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
 	}
 
 	dev = epc->dev.parent;
-	space = dma_alloc_coherent(dev, size, &phys_addr, GFP_KERNEL);
+	space = dma_alloc_coherent(dev, aligned_size, &phys_addr, GFP_KERNEL);
 	if (!space) {
 		dev_err(dev, "failed to allocate mem space\n");
 		return NULL;
@@ -310,6 +317,7 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
 	epf_bar[bar].phys_addr = phys_addr;
 	epf_bar[bar].addr = space;
 	epf_bar[bar].size = size;
+	epf_bar[bar].aligned_size = aligned_size;
 	epf_bar[bar].barno = bar;
 	if (upper_32_bits(size) || epc_features->bar[bar].only_64bit)
 		epf_bar[bar].flags |= PCI_BASE_ADDRESS_MEM_TYPE_64;
@@ -330,7 +338,7 @@ static void pci_epf_remove_cfs(struct pci_epf_driver *driver)
 	mutex_lock(&pci_epf_mutex);
 	list_for_each_entry_safe(group, tmp, &driver->epf_group, group_entry)
 		pci_ep_cfs_remove_epf_group(group);
-	list_del(&driver->epf_group);
+	WARN_ON(!list_empty(&driver->epf_group));
 	mutex_unlock(&pci_epf_mutex);
 }
 
@@ -469,6 +477,44 @@ struct pci_epf *pci_epf_create(const char *name)
 }
 EXPORT_SYMBOL_GPL(pci_epf_create);
 
+/**
+ * pci_epf_align_inbound_addr() - Align the given address based on the BAR
+ *				  alignment requirement
+ * @epf: the EPF device
+ * @addr: inbound address to be aligned
+ * @bar: the BAR number corresponding to the given addr
+ * @base: base address matching the @bar alignment requirement
+ * @off: offset to be added to the @base address
+ *
+ * Helper function to align input @addr based on BAR's alignment requirement.
+ * The aligned base address and offset are returned via @base and @off.
+ *
+ * NOTE: The pci_epf_alloc_space() function already accounts for alignment.
+ * This API is primarily intended for use with other memory regions not
+ * allocated by pci_epf_alloc_space(), such as peripheral register spaces or
+ * the message address of a platform MSI controller.
+ *
+ * Return: 0 on success, errno otherwise.
+ */
+int pci_epf_align_inbound_addr(struct pci_epf *epf, enum pci_barno bar,
+			       u64 addr, dma_addr_t *base, size_t *off)
+{
+	/*
+	 * Most EP controllers require the BAR start address to be aligned to
+	 * the BAR size, because they mask off the lower bits.
+	 *
+	 * Alignment to BAR size also works for controllers that support
+	 * unaligned addresses.
+	 */
+	u64 align = epf->bar[bar].size;
+
+	*base = round_down(addr, align);
+	*off = addr & (align - 1);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_epf_align_inbound_addr);
+
 static void pci_epf_dev_release(struct device *dev)
 {
 	struct pci_epf *epf = to_pci_epf(dev);