[PATCH v4 3/6] PCI: endpoint: Add support to handle multiple base for mapping outbound memory

[Lad Prabhakar <prabhakar.csengg@gmail.com>]

R-Car PCIe controller has support to map multiple memory regions for
mapping the outbound memory in local system also the controller limits
single allocation for each region (that is, once a chunk is used from the
region it cannot be used to allocate a new one). This features inspires to
add support for handling multiple memory bases in endpoint framework.

With this patch pci_epc_mem_init() now accepts multiple regions, also
page_size for each memory region is passed during initialization so as
to handle single allocation for each region by setting the page_size to
window_size.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
 drivers/pci/controller/cadence/pcie-cadence-ep.c |   7 +-
 drivers/pci/controller/dwc/pcie-designware-ep.c  |  29 ++--
 drivers/pci/controller/pcie-rockchip-ep.c        |   7 +-
 drivers/pci/endpoint/pci-epc-mem.c               | 166 ++++++++++++++++-------
 include/linux/pci-epc.h                          |  39 ++++--
 5 files changed, 168 insertions(+), 80 deletions(-)

diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c
index 1c173da..90e32438 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-ep.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c
@@ -401,6 +401,7 @@ int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
 	struct device *dev = ep->pcie.dev;
 	struct platform_device *pdev = to_platform_device(dev);
 	struct device_node *np = dev->of_node;
+	struct pci_epc_mem_window mem_window;
 	struct cdns_pcie *pcie = &ep->pcie;
 	struct resource *res;
 	struct pci_epc *epc;
@@ -449,8 +450,10 @@ int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
 	if (of_property_read_u8(np, "max-functions", &epc->max_functions) < 0)
 		epc->max_functions = 1;
 
-	ret = pci_epc_mem_init(epc, pcie->mem_res->start,
-			       resource_size(pcie->mem_res));
+	mem_window.phys_base = pcie->mem_res->start;
+	mem_window.size = resource_size(pcie->mem_res);
+	mem_window.page_size = PAGE_SIZE;
+	ret = pci_epc_mem_init(epc, &mem_window, 1);
 	if (ret < 0) {
 		dev_err(dev, "failed to initialize the memory space\n");
 		goto err_init;
diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index cfeccd7..b150ef3 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -195,8 +195,7 @@ static void dw_pcie_ep_unmap_addr(struct pci_epc *epc, u8 func_no,
 }
 
 static int dw_pcie_ep_map_addr(struct pci_epc *epc, u8 func_no,
-			       phys_addr_t addr,
-			       u64 pci_addr, size_t size)
+			       phys_addr_t addr, u64 pci_addr, size_t size)
 {
 	int ret;
 	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
@@ -367,6 +366,7 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
 	unsigned int aligned_offset;
 	u16 msg_ctrl, msg_data;
 	u32 msg_addr_lower, msg_addr_upper, reg;
+	int window = PCI_EPC_DEFAULT_WINDOW;
 	u64 msg_addr;
 	bool has_upper;
 	int ret;
@@ -390,11 +390,11 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
 		reg = ep->msi_cap + PCI_MSI_DATA_32;
 		msg_data = dw_pcie_readw_dbi(pci, reg);
 	}
-	aligned_offset = msg_addr_lower & (epc->mem->page_size - 1);
+	aligned_offset = msg_addr_lower & (epc->mem[window]->page_size - 1);
 	msg_addr = ((u64)msg_addr_upper) << 32 |
 			(msg_addr_lower & ~aligned_offset);
-	ret = dw_pcie_ep_map_addr(epc, func_no, ep->msi_mem_phys, msg_addr,
-				  epc->mem->page_size);
+	ret = dw_pcie_ep_map_addr(epc, func_no, ep->msi_mem_phys,
+				  msg_addr, epc->mem[window]->page_size);
 	if (ret)
 		return ret;
 
@@ -416,6 +416,7 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
 	u32 reg, msg_data, vec_ctrl;
 	u64 tbl_addr, msg_addr, reg_u64;
 	void __iomem *msix_tbl;
+	int window = PCI_EPC_DEFAULT_WINDOW;
 	int ret;
 
 	reg = ep->msix_cap + PCI_MSIX_TABLE;
@@ -452,8 +453,8 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
 		return -EPERM;
 	}
 
-	ret = dw_pcie_ep_map_addr(epc, func_no, ep->msi_mem_phys, msg_addr,
-				  epc->mem->page_size);
+	ret = dw_pcie_ep_map_addr(epc, func_no, ep->msi_mem_phys,
+				  msg_addr, epc->mem[window]->page_size);
 	if (ret)
 		return ret;
 
@@ -466,10 +467,11 @@ 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)
 {
+	int window = PCI_EPC_DEFAULT_WINDOW;
 	struct pci_epc *epc = ep->epc;
 
 	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
-			      epc->mem->page_size);
+			      epc->mem[window]->page_size);
 
 	pci_epc_mem_exit(epc);
 }
@@ -502,6 +504,8 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 	unsigned int nbars;
 	unsigned int offset;
 	struct pci_epc *epc;
+	size_t msi_page_size;
+	struct pci_epc_mem_window mem_window;
 	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
 	struct device *dev = pci->dev;
 	struct device_node *np = dev->of_node;
@@ -574,15 +578,18 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 	if (ret < 0)
 		epc->max_functions = 1;
 
-	ret = __pci_epc_mem_init(epc, ep->phys_base, ep->addr_size,
-				 ep->page_size);
+	mem_window.phys_base = ep->phys_base;
+	mem_window.size = ep->addr_size;
+	mem_window.page_size = ep->page_size;
+	ret = __pci_epc_mem_init(epc, &mem_window, 1);
 	if (ret < 0) {
 		dev_err(dev, "Failed to initialize address space\n");
 		return ret;
 	}
 
+	msi_page_size = epc->mem[PCI_EPC_DEFAULT_WINDOW]->page_size;
 	ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys,
-					     epc->mem->page_size);
+					     msi_page_size);
 	if (!ep->msi_mem) {
 		dev_err(dev, "Failed to reserve memory for MSI/MSI-X\n");
 		return -ENOMEM;
diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
index d743b0a..5a97390 100644
--- a/drivers/pci/controller/pcie-rockchip-ep.c
+++ b/drivers/pci/controller/pcie-rockchip-ep.c
@@ -562,6 +562,7 @@ static const struct of_device_id rockchip_pcie_ep_of_match[] = {
 
 static int rockchip_pcie_ep_probe(struct platform_device *pdev)
 {
+	struct pci_epc_mem_window mem_window;
 	struct device *dev = &pdev->dev;
 	struct rockchip_pcie_ep *ep;
 	struct rockchip_pcie *rockchip;
@@ -614,8 +615,10 @@ static int rockchip_pcie_ep_probe(struct platform_device *pdev)
 	/* Only enable function 0 by default */
 	rockchip_pcie_write(rockchip, BIT(0), PCIE_CORE_PHY_FUNC_CFG);
 
-	err = pci_epc_mem_init(epc, rockchip->mem_res->start,
-			       resource_size(rockchip->mem_res));
+	mem_window.phys_base = rockchip->mem_res->start;
+	mem_window.size = resource_size(rockchip->mem_res);
+	mem_window.page_size = PAGE_SIZE;
+	err = pci_epc_mem_init(epc, &mem_window, 1);
 	if (err < 0) {
 		dev_err(dev, "failed to initialize the memory space\n");
 		goto err_uninit_port;
diff --git a/drivers/pci/endpoint/pci-epc-mem.c b/drivers/pci/endpoint/pci-epc-mem.c
index d2b174c..b3eedee 100644
--- a/drivers/pci/endpoint/pci-epc-mem.c
+++ b/drivers/pci/endpoint/pci-epc-mem.c
@@ -38,57 +38,76 @@ static int pci_epc_mem_get_order(struct pci_epc_mem *mem, size_t size)
 /**
  * __pci_epc_mem_init() - initialize the pci_epc_mem structure
  * @epc: the EPC device that invoked pci_epc_mem_init
- * @phys_base: the physical address of the base
- * @size: the size of the address space
- * @page_size: size of each page
+ * @windows: pointer to windows supported by the device
+ * @num_windows: number of windows device supports
  *
  * Invoke to initialize the pci_epc_mem structure used by the
  * endpoint functions to allocate mapped PCI address.
  */
-int __pci_epc_mem_init(struct pci_epc *epc, phys_addr_t phys_base, size_t size,
-		       size_t page_size)
+int __pci_epc_mem_init(struct pci_epc *epc, struct pci_epc_mem_window *windows,
+		       int num_windows)
 {
-	int ret;
-	struct pci_epc_mem *mem;
-	unsigned long *bitmap;
+	struct pci_epc_mem *mem = NULL;
+	unsigned long *bitmap = NULL;
 	unsigned int page_shift;
-	int pages;
+	size_t page_size;
 	int bitmap_size;
-
-	if (page_size < PAGE_SIZE)
-		page_size = PAGE_SIZE;
-
-	page_shift = ilog2(page_size);
-	pages = size >> page_shift;
-	bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
-
-	mem = kzalloc(sizeof(*mem), GFP_KERNEL);
-	if (!mem) {
-		ret = -ENOMEM;
-		goto err;
-	}
-
-	bitmap = kzalloc(bitmap_size, GFP_KERNEL);
-	if (!bitmap) {
-		ret = -ENOMEM;
-		goto err_mem;
+	int pages;
+	int ret;
+	int i;
+
+	epc->mem_windows = 0;
+
+	if (!windows)
+		return -EINVAL;
+
+	if (num_windows <= 0)
+		return -EINVAL;
+
+	epc->mem = kcalloc(num_windows, sizeof(*mem), GFP_KERNEL);
+	if (!epc->mem)
+		return -EINVAL;
+
+	for (i = 0; i < num_windows; i++) {
+		page_size = windows[i].page_size;
+		if (page_size < PAGE_SIZE)
+			page_size = PAGE_SIZE;
+		page_shift = ilog2(page_size);
+		pages = windows[i].size >> page_shift;
+		bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
+
+		mem = kzalloc(sizeof(*mem), GFP_KERNEL);
+		if (!mem) {
+			ret = -ENOMEM;
+			goto err_mem;
+		}
+
+		bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+		if (!bitmap) {
+			ret = -ENOMEM;
+			goto err_mem;
+		}
+
+		mem->bitmap = bitmap;
+		mem->window.phys_base = windows[i].phys_base;
+		mem->page_size = page_size;
+		mem->pages = pages;
+		mem->window.size = windows[i].size;
+		epc->mem[i] = mem;
 	}
-
-	mem->bitmap = bitmap;
-	mem->phys_base = phys_base;
-	mem->page_size = page_size;
-	mem->pages = pages;
-	mem->size = size;
-
-	epc->mem = mem;
+	epc->mem_windows = num_windows;
 
 	return 0;
 
 err_mem:
-	kfree(mem);
+	for (; i >= 0; i--) {
+		mem = epc->mem[i];
+		kfree(mem->bitmap);
+		kfree(mem);
+	}
+	kfree(epc->mem);
 
-err:
-return ret;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(__pci_epc_mem_init);
 
@@ -101,11 +120,21 @@ EXPORT_SYMBOL_GPL(__pci_epc_mem_init);
  */
 void pci_epc_mem_exit(struct pci_epc *epc)
 {
-	struct pci_epc_mem *mem = epc->mem;
+	struct pci_epc_mem *mem;
+	int i;
+
+	if (!epc->mem_windows)
+		return;
+
+	for (i = 0; i <= epc->mem_windows; i++) {
+		mem = epc->mem[i];
+		kfree(mem->bitmap);
+		kfree(mem);
+	}
+	kfree(epc->mem);
 
 	epc->mem = NULL;
-	kfree(mem->bitmap);
-	kfree(mem);
+	epc->mem_windows = 0;
 }
 EXPORT_SYMBOL_GPL(pci_epc_mem_exit);
 
@@ -121,20 +150,30 @@ EXPORT_SYMBOL_GPL(pci_epc_mem_exit);
 void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
 				     phys_addr_t *phys_addr, size_t size)
 {
-	int pageno;
-	void __iomem *virt_addr;
-	struct pci_epc_mem *mem = epc->mem;
-	unsigned int page_shift = ilog2(mem->page_size);
+	void __iomem *virt_addr = NULL;
+	struct pci_epc_mem *mem;
+	unsigned int page_shift;
+	int pageno = -EINVAL;
 	int order;
+	int i;
 
-	size = ALIGN(size, mem->page_size);
-	order = pci_epc_mem_get_order(mem, size);
+	for (i = 0; i < epc->mem_windows; i++) {
+		mem = epc->mem[i];
+		size = ALIGN(size, mem->page_size);
+		order = pci_epc_mem_get_order(mem, size);
+
+		pageno = bitmap_find_free_region(mem->bitmap, mem->pages,
+						 order);
+		if (pageno >= 0)
+			break;
+	}
 
-	pageno = bitmap_find_free_region(mem->bitmap, mem->pages, order);
 	if (pageno < 0)
 		return NULL;
 
-	*phys_addr = mem->phys_base + ((phys_addr_t)pageno << page_shift);
+	page_shift = ilog2(mem->page_size);
+	*phys_addr = mem->window.phys_base +
+		     ((phys_addr_t)pageno << page_shift);
 	virt_addr = ioremap(*phys_addr, size);
 	if (!virt_addr)
 		bitmap_release_region(mem->bitmap, pageno, order);
@@ -143,6 +182,22 @@ void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
 }
 EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr);
 
+struct pci_epc_mem *pci_epc_get_matching_window(struct pci_epc *epc,
+						phys_addr_t phys_addr)
+{
+	struct pci_epc_mem *mem;
+	int i;
+
+	for (i = 0; i < epc->mem_windows; i++) {
+		mem = epc->mem[i];
+
+		if (mem->window.phys_base == phys_addr)
+			return mem;
+	}
+
+	return NULL;
+}
+
 /**
  * pci_epc_mem_free_addr() - free the allocated memory address
  * @epc: the EPC device on which memory was allocated
@@ -155,13 +210,20 @@ EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr);
 void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr,
 			   void __iomem *virt_addr, size_t size)
 {
+	struct pci_epc_mem *mem;
+	unsigned int page_shift;
 	int pageno;
-	struct pci_epc_mem *mem = epc->mem;
-	unsigned int page_shift = ilog2(mem->page_size);
 	int order;
 
+	mem = pci_epc_get_matching_window(epc, phys_addr);
+	if (!mem) {
+		pr_err("failed to get matching window\n");
+		return;
+	}
+
+	page_shift = ilog2(mem->page_size);
 	iounmap(virt_addr);
-	pageno = (phys_addr - mem->phys_base) >> page_shift;
+	pageno = (phys_addr - mem->window.phys_base) >> page_shift;
 	size = ALIGN(size, mem->page_size);
 	order = pci_epc_mem_get_order(mem, size);
 	bitmap_release_region(mem->bitmap, pageno, order);
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 56f1846..dde42e5 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -64,17 +64,29 @@ struct pci_epc_ops {
 	struct module *owner;
 };
 
+#define PCI_EPC_DEFAULT_WINDOW         0
+
+/**
+ * struct pci_epc_mem_window - address window of the endpoint controller
+ * @phys_base: physical base address of the PCI address window
+ * @size: the size of the PCI address window
+ * @page_size: size of each page
+ */
+struct pci_epc_mem_window {
+	phys_addr_t	phys_base;
+	size_t		size;
+	size_t		page_size;
+};
+
 /**
  * struct pci_epc_mem - address space of the endpoint controller
- * @phys_base: physical base address of the PCI address space
- * @size: the size of the PCI address space
+ * @window: address window of the endpoint controller
  * @bitmap: bitmap to manage the PCI address space
- * @pages: number of bits representing the address region
  * @page_size: size of each page
+ * @pages: number of bits representing the address region
  */
 struct pci_epc_mem {
-	phys_addr_t	phys_base;
-	size_t		size;
+	struct pci_epc_mem_window window;
 	unsigned long	*bitmap;
 	size_t		page_size;
 	int		pages;
@@ -85,7 +97,8 @@ struct pci_epc_mem {
  * @dev: PCI EPC device
  * @pci_epf: list of endpoint functions present in this EPC device
  * @ops: function pointers for performing endpoint operations
- * @mem: address space of the endpoint controller
+ * @mem: array of address space of the endpoint controller
+ * @mem_windows: number of windows supported by device
  * @max_functions: max number of functions that can be configured in this EPC
  * @group: configfs group representing the PCI EPC device
  * @lock: spinlock to protect pci_epc ops
@@ -94,7 +107,8 @@ struct pci_epc {
 	struct device			dev;
 	struct list_head		pci_epf;
 	const struct pci_epc_ops	*ops;
-	struct pci_epc_mem		*mem;
+	struct pci_epc_mem		**mem;
+	unsigned int			mem_windows;
 	u8				max_functions;
 	struct config_group		*group;
 	/* spinlock to protect against concurrent access of EP controller */
@@ -128,8 +142,8 @@ struct pci_epc_features {
 #define devm_pci_epc_create(dev, ops)    \
 		__devm_pci_epc_create((dev), (ops), THIS_MODULE)
 
-#define pci_epc_mem_init(epc, phys_addr, size)	\
-		__pci_epc_mem_init((epc), (phys_addr), (size), PAGE_SIZE)
+#define pci_epc_mem_init(epc, windows, num_windows)	\
+		__pci_epc_mem_init((epc), windows, num_windows)
 
 static inline void epc_set_drvdata(struct pci_epc *epc, void *data)
 {
@@ -159,8 +173,7 @@ int pci_epc_set_bar(struct pci_epc *epc, u8 func_no,
 void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no,
 		       struct pci_epf_bar *epf_bar);
 int pci_epc_map_addr(struct pci_epc *epc, u8 func_no,
-		     phys_addr_t phys_addr,
-		     u64 pci_addr, size_t size);
+		     phys_addr_t phys_addr, u64 pci_addr, size_t size);
 void pci_epc_unmap_addr(struct pci_epc *epc, u8 func_no,
 			phys_addr_t phys_addr);
 int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts);
@@ -178,8 +191,8 @@ unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
 struct pci_epc *pci_epc_get(const char *epc_name);
 void pci_epc_put(struct pci_epc *epc);
 
-int __pci_epc_mem_init(struct pci_epc *epc, phys_addr_t phys_addr, size_t size,
-		       size_t page_size);
+int __pci_epc_mem_init(struct pci_epc *epc, struct pci_epc_mem_window *window,
+		       int num_windows);
 void pci_epc_mem_exit(struct pci_epc *epc);
 void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
 				     phys_addr_t *phys_addr, size_t size);
-- 
2.7.4