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authorKishon Vijay Abraham I <kishon@ti.com>2017-08-18 17:57:56 +0300
committerBjorn Helgaas <bhelgaas@google.com>2017-08-30 00:00:37 +0300
commit52c9285d47459cf241e144c7d8ef15941ba1b181 (patch)
tree2fb522bf05fb3227b9fba950ad9f31844afce158 /drivers/pci/endpoint
parent28daeff66990db85022c6a8b410e5b78dc78ff6a (diff)
downloadlinux-52c9285d47459cf241e144c7d8ef15941ba1b181.tar.xz
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: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/endpoint')
-rw-r--r--drivers/pci/endpoint/pci-epc-mem.c59
1 files changed, 50 insertions, 9 deletions
diff --git a/drivers/pci/endpoint/pci-epc-mem.c b/drivers/pci/endpoint/pci-epc-mem.c
index 3a94cc1caf22..83b7d5d3fc3e 100644
--- a/drivers/pci/endpoint/pci-epc-mem.c
+++ b/drivers/pci/endpoint/pci-epc-mem.c
@@ -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);