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PCI: endpoint: Add support for configurable page size

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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: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Kishon Vijay Abraham I 2017-08-18 20:27:56 +05:30 committed by Bjorn Helgaas
parent 28daeff669
commit 52c9285d47
2 changed files with 57 additions and 10 deletions
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59
drivers/pci/endpoint/pci-epc-mem.c
View File

@ -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 @@ err_mem:
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);

8
include/linux/pci-epc.h
View File

@ -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);