[v5,4/7] PCI: endpoint: Add support to handle multiple base for mapping outbound memory
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Message ID 20200228154122.14164-5-prabhakar.mahadev-lad.rj@bp.renesas.com
State New
Headers show
Series
  • Add support for PCIe controller to work in endpoint mode on R-Car SoCs
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Commit Message

Lad, Prabhakar Feb. 28, 2020, 3:41 p.m. UTC
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               | 167 ++++++++++++++++-------
 include/linux/pci-epc.h                          |  39 ++++--
 5 files changed, 169 insertions(+), 80 deletions(-)

Comments

Yoshihiro Shimoda March 17, 2020, 8:11 a.m. UTC | #1
Hi Prabhakar-san,

Thank you for the patch!

> From: Lad Prabhakar, Sent: Saturday, February 29, 2020 12:41 AM
> 
> 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               | 167 ++++++++++++++++-------

I could not apply this patch on the latest pci.git / next branch.
So, you need to rebase.

>  include/linux/pci-epc.h                          |  39 ++++--
>  5 files changed, 169 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);

I'm not sure my idea is acceptable or not but,
I think we can have compatible API for single window like below.
- In this patch, pci_epc_mem_init() and __pci_epc_mem_init() become the same behavior.
  So, for example, pci_epc_mem_init() is for simple, and __pci_epc_mem_init() is multiple windows.
-- In this case, pci_epc_mem_init() should have page_size argument.
- The original "mem" in the pci_epc can be the default window instead of
  PCI_EPC_DEFAULT_WINDOW.

>  	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..6c21957 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;

I could not understand why the window member is needed.
I think original members (just phys_base and size) are enough.
Also, this function doesn't store the page_size to mem->window.page_size.

> +		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);

If bitmap cannot be allocated, the epc->mem[i] is NULL.
So, freeing mem->bitmap anyway is not good.

> +		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 +182,23 @@ 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 (phys_addr >= mem->window.phys_base &&
> +		    phys_addr < (mem->window.phys_base + mem->window.size))
> +			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 +211,20 @@ 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

If my idea is acceptable, this should be "default address space ...".

> + * @mem: array of address space of the endpoint controller

And, this should be difference name.

> + * @mem_windows: number of windows supported by device

Perhaps, num_windows?

>   * @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)

As I mentioned above, pci_epc_mem_init() and __ pci_epc_mem_init() are the same behavior.

>  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);

Perhaps, this is not needed to change?

Best regards,
Yoshihiro Shimoda

>  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
Lad Prabhakar March 17, 2020, 10:03 a.m. UTC | #2
Hi Yoshihiro-san,

Thank you for the review,

> -----Original Message-----
> From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Sent: 17 March 2020 08:12
> To: Lad Prabhakar <prabhakar.csengg@gmail.com>
> Cc: Andrew Murray <andrew.murray@arm.com>; linux-pci@vger.kernel.org;
> linux-arm-kernel@lists.infradead.org; linux-renesas-soc@vger.kernel.org;
> linux-rockchip@lists.infradead.org; linux-kernel@vger.kernel.org;
> devicetree@vger.kernel.org; Prabhakar Mahadev Lad <prabhakar.mahadev-
> lad.rj@bp.renesas.com>; Bjorn Helgaas <bhelgaas@google.com>; Rob
> Herring <robh+dt@kernel.org>; Mark Rutland <mark.rutland@arm.com>;
> Catalin Marinas <catalin.marinas@arm.com>; Will Deacon <will@kernel.org>;
> Kishon Vijay Abraham I <kishon@ti.com>; Lorenzo Pieralisi
> <lorenzo.pieralisi@arm.com>; Arnd Bergmann <arnd@arndb.de>; Greg
> Kroah-Hartman <gregkh@linuxfoundation.org>; Jingoo Han
> <jingoohan1@gmail.com>; Gustavo Pimentel
> <gustavo.pimentel@synopsys.com>; Marek Vasut
> <marek.vasut+renesas@gmail.com>; Shawn Lin <shawn.lin@rock-
> chips.com>; Heiko Stuebner <heiko@sntech.de>
> Subject: RE: [PATCH v5 4/7] PCI: endpoint: Add support to handle multiple
> base for mapping outbound memory
>
> Hi Prabhakar-san,
>
> Thank you for the patch!
>
> > From: Lad Prabhakar, Sent: Saturday, February 29, 2020 12:41 AM
> >
> > 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               | 167 ++++++++++++++++-----
> --
>
> I could not apply this patch on the latest pci.git / next branch.
> So, you need to rebase.
>
Yes it needs rebasing on https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git/log/?h=pci/endpoint

> >  include/linux/pci-epc.h                          |  39 ++++--
> >  5 files changed, 169 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);
>
> I'm not sure my idea is acceptable or not but, I think we can have compatible
> API for single window like below.
> - In this patch, pci_epc_mem_init() and __pci_epc_mem_init() become the
> same behavior.
>   So, for example, pci_epc_mem_init() is for simple, and
> __pci_epc_mem_init() is multiple windows.
> -- In this case, pci_epc_mem_init() should have page_size argument.
> - The original "mem" in the pci_epc can be the default window instead of
>   PCI_EPC_DEFAULT_WINDOW.
>
OK

> >  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..6c21957 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;
>
> I could not understand why the window member is needed.
> I think original members (just phys_base and size) are enough.
> Also, this function doesn't store the page_size to mem->window.page_size.
>
Because,  for example on RZ/Gx platforms, following are the windows on endpoint device
where the root's address can be mapped, but where as on other platforms atm there
exists just single window to map. Also on RZ/Gx platforms if a window is allocated say of
size 1K, rest of the window cannot be used for other allocations.

1: 0xfe000000 0 0x80000
2: 0xfe100000 0 0x100000
3: 0xfe200000 0 0x200000
4: 0x30000000 0 0x8000000
5: 0x38000000 0 0x8000000

Struct pci_epc_mem_window, represents the above windows.

window.page_size is set by endpoint controller drivers as done in this patch.

> > +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);
>
> If bitmap cannot be allocated, the epc->mem[i] is NULL.
> So, freeing mem->bitmap anyway is not good.
>
Agreed shall fix it.

> > +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
> > +182,23 @@ 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 (phys_addr >= mem->window.phys_base &&
> > +    phys_addr < (mem->window.phys_base + mem-
> >window.size))
> > +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
> > +211,20 @@ 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_tphys_base;
> > +size_tsize;
> > +size_tpage_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_tphys_base;
> > -size_tsize;
> > +struct pci_epc_mem_window window;
> >  unsigned long*bitmap;
> >  size_tpage_size;
> >  intpages;
> > @@ -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
>
> If my idea is acceptable, this should be "default address space ...".
>
Could you please elaborate more on how you would like the structures to be organized.

> > + * @mem: array of address space of the endpoint controller
>
> And, this should be difference name.
>
OK

> > + * @mem_windows: number of windows supported by device
>
> Perhaps, num_windows?
>
OK

> >   * @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 devicedev;
> >  struct list_headpci_epf;
> >  const struct pci_epc_ops*ops;
> > -struct pci_epc_mem*mem;
> > +struct pci_epc_mem**mem;
> > +unsigned intmem_windows;
> >  u8max_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)
>
> As I mentioned above, pci_epc_mem_init() and __ pci_epc_mem_init() are
> the same behavior.
>
> >  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);
>
> Perhaps, this is not needed to change?
>
Yes my bad.

Cheers,
--Prabhakar

> Best regards,
> Yoshihiro Shimoda
>
> >  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



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Yoshihiro Shimoda March 17, 2020, 11:04 a.m. UTC | #3
Hi Prabhakar-san,

Just in my opinion though, automatically adding new line of email client
should be disabled or setting larger characters.
# In my side, I change the setting as 132 characters on Outlook :)

> From: Prabhakar Mahadev Lad, Sent: Tuesday, March 17, 2020 7:04 PM
<snip>
> > > -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;
> >
> > I could not understand why the window member is needed.
> > I think original members (just phys_base and size) are enough.
> > Also, this function doesn't store the page_size to mem->window.page_size.

I'm sorry, but I meant the window member is in the left side (mem->window.phys_base).
In other words, this patch changes the struct pci_epc_mem like below, but
I'm thinking this change is not needed because struct pci_epc will have
multiple windows as "array of address space of the endpoint controller".
---
struct pci_epc_mem {
-	phys_addr_t	phys_base;
-	size_t		size;
+	struct pci_epc_mem_window window;
---

> Because,  for example on RZ/Gx platforms, following are the windows on endpoint device
> where the root's address can be mapped, but where as on other platforms atm there
> exists just single window to map. Also on RZ/Gx platforms if a window is allocated say of
> size 1K, rest of the window cannot be used for other allocations.
> 
> 1: 0xfe000000 0 0x80000
> 2: 0xfe100000 0 0x100000
> 3: 0xfe200000 0 0x200000
> 4: 0x30000000 0 0x8000000
> 5: 0x38000000 0 0x8000000
> 
> Struct pci_epc_mem_window, represents the above windows.

Yes, I understood it.

> window.page_size is set by endpoint controller drivers as done in this patch.

I meant the left side. No one change the mem->window.page_size so that
the value seems to be 0. Of course, for now, this is no problem because
no one uses this value though.

<snip>
> > >  /**
> > >   * 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
> >
> > If my idea is acceptable, this should be "default address space ...".
> >
> Could you please elaborate more on how you would like the structures to be organized.

 * @mem: default address space of the endpoint controller.

And, if I assumed the "array of address space of the endpoint controller"
is renamed as struct pci_epc_mem **windows and when __pci_epc_mem_init() is succeeded,
the function should set the mem value right before return as the first window like below.

+	epc->mem = epc->windows[0];
+	epc->num_windows = num_windows;

	return 0;

Best regards,
Yoshihiro Shimoda

Patch
diff mbox series

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..6c21957 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 +182,23 @@  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 (phys_addr >= mem->window.phys_base &&
+		    phys_addr < (mem->window.phys_base + mem->window.size))
+			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 +211,20 @@  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);