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Commit 52c9285d authored by Kishon Vijay Abraham I's avatar Kishon Vijay Abraham I Committed by Bjorn Helgaas
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PCI: endpoint: Add support for configurable page size 



pci-epc-mem uses a page size equal to *PAGE_SIZE* (usually 4KB) to manage
the address space. However certain platforms like TI's K2G have a
restriction that this address space should be either divided into
1MB/2MB/4MB or 8MB sizes (Ref: 11.14.4.9.1 Outbound Address Translation in
K2G TRM SPRUHY8F January 2016 – Revised May 2017).  Add support to handle
different page sizes here.

Signed-off-by: default avatarKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 28daeff6

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

+50 −9
Original line number Diff line number Diff line
@@ -24,21 +24,54 @@ 
#include <linux/pci-epc.h>



/**

 * pci_epc_mem_init() - initialize the pci_epc_mem structure

 * pci_epc_mem_get_order() - determine the allocation order of a memory size

 * @mem: address space of the endpoint controller

 * @size: the size for which to get the order

 *

 * Reimplement get_order() for mem->page_size since the generic get_order

 * always gets order with a constant PAGE_SIZE.

 */

static int pci_epc_mem_get_order(struct pci_epc_mem *mem, size_t size)

{

	int order;

	unsigned int page_shift = ilog2(mem->page_size);



	size--;

	size >>= page_shift;

#if BITS_PER_LONG == 32

	order = fls(size);

#else

	order = fls64(size);

#endif

	return order;

}



/**

 * __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

 *

 * 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)

int __pci_epc_mem_init(struct pci_epc *epc, phys_addr_t phys_base, size_t size,

		       size_t page_size)

{

	int ret;

	struct pci_epc_mem *mem;

	unsigned long *bitmap;

	int pages = size >> PAGE_SHIFT;

	int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);

	unsigned int page_shift;

	int pages;

	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) {
@@ -54,6 +87,7 @@ int pci_epc_mem_init(struct pci_epc *epc, phys_addr_t phys_base, size_t size) 


	mem->bitmap = bitmap;

	mem->phys_base = phys_base;

	mem->page_size = page_size;

	mem->pages = pages;

	mem->size = size;
@@ -67,7 +101,7 @@ int pci_epc_mem_init(struct pci_epc *epc, phys_addr_t phys_base, size_t size) 
err:

return ret;

}

EXPORT_SYMBOL_GPL(pci_epc_mem_init);

EXPORT_SYMBOL_GPL(__pci_epc_mem_init);



/**

 * pci_epc_mem_exit() - cleanup the pci_epc_mem structure
@@ -101,13 +135,17 @@ void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc, 
	int pageno;

	void __iomem *virt_addr;

	struct pci_epc_mem *mem = epc->mem;

	int order = get_order(size);

	unsigned int page_shift = ilog2(mem->page_size);

	int order;



	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)

		return NULL;



	*phys_addr = mem->phys_base + (pageno << PAGE_SHIFT);

	*phys_addr = mem->phys_base + (pageno << page_shift);

	virt_addr = ioremap(*phys_addr, size);

	if (!virt_addr)

		bitmap_release_region(mem->bitmap, pageno, order);
@@ -129,11 +167,14 @@ void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr, 
			   void __iomem *virt_addr, size_t size)

{

	int pageno;

	int order = get_order(size);

	struct pci_epc_mem *mem = epc->mem;

	unsigned int page_shift = ilog2(mem->page_size);

	int order;



	iounmap(virt_addr);

	pageno = (phys_addr - mem->phys_base) >> PAGE_SHIFT;

	pageno = (phys_addr - mem->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);

}

EXPORT_SYMBOL_GPL(pci_epc_mem_free_addr);

include/linux/pci-epc.h

+7 −1
Original line number Diff line number Diff line
@@ -62,11 +62,13 @@ struct pci_epc_ops { 
 * @size: the size of the PCI address space

 * @bitmap: bitmap to manage the PCI address space

 * @pages: number of bits representing the address region

 * @page_size: size of each page

 */

struct pci_epc_mem {

	phys_addr_t	phys_base;

	size_t		size;

	unsigned long	*bitmap;

	size_t		page_size;

	int		pages;

};
@@ -98,6 +100,9 @@ struct pci_epc { 
#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)



static inline void epc_set_drvdata(struct pci_epc *epc, void *data)

{

	dev_set_drvdata(&epc->dev, data);
@@ -135,7 +140,8 @@ void pci_epc_stop(struct pci_epc *epc); 
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);

int __pci_epc_mem_init(struct pci_epc *epc, phys_addr_t phys_addr, size_t size,

		       size_t page_size);

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);