1 files changed, 179 insertions, 0 deletions
diff --git a/drivers/pci/endpoint/pci-epc-mem.c b/drivers/pci/endpoint/pci-epc-mem.c
new file mode 100644
index 000000000..0471643cf
--- /dev/null
+++ b/drivers/pci/endpoint/pci-epc-mem.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * PCI Endpoint *Controller* Address Space Management
+ *
+ * Copyright (C) 2017 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/pci-epc.h>
+
+/**
+ * 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,
+		       size_t page_size)
+{
+	int ret;
+	struct pci_epc_mem *mem;
+	unsigned long *bitmap;
+	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) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+	if (!bitmap) {
+		ret = -ENOMEM;
+		goto err_mem;
+	}
+
+	mem->bitmap = bitmap;
+	mem->phys_base = phys_base;
+	mem->page_size = page_size;
+	mem->pages = pages;
+	mem->size = size;
+	mutex_init(&mem->lock);
+
+	epc->mem = mem;
+
+	return 0;
+
+err_mem:
+	kfree(mem);
+
+err:
+return ret;
+}
+EXPORT_SYMBOL_GPL(__pci_epc_mem_init);
+
+/**
+ * pci_epc_mem_exit() - cleanup the pci_epc_mem structure
+ * @epc: the EPC device that invoked pci_epc_mem_exit
+ *
+ * Invoke to cleanup the pci_epc_mem structure allocated in
+ * pci_epc_mem_init().
+ */
+void pci_epc_mem_exit(struct pci_epc *epc)
+{
+	struct pci_epc_mem *mem = epc->mem;
+
+	epc->mem = NULL;
+	kfree(mem->bitmap);
+	kfree(mem);
+}
+EXPORT_SYMBOL_GPL(pci_epc_mem_exit);
+
+/**
+ * pci_epc_mem_alloc_addr() - allocate memory address from EPC addr space
+ * @epc: the EPC device on which memory has to be allocated
+ * @phys_addr: populate the allocated physical address here
+ * @size: the size of the address space that has to be allocated
+ *
+ * Invoke to allocate memory address from the EPC address space. This
+ * is usually done to map the remote RC address into the local system.
+ */
+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 = NULL;
+	struct pci_epc_mem *mem = epc->mem;
+	unsigned int page_shift = ilog2(mem->page_size);
+	int order;
+
+	size = ALIGN(size, mem->page_size);
+	order = pci_epc_mem_get_order(mem, size);
+
+	mutex_lock(&mem->lock);
+	pageno = bitmap_find_free_region(mem->bitmap, mem->pages, order);
+	if (pageno < 0)
+		goto ret;
+
+	*phys_addr = mem->phys_base + (pageno << page_shift);
+	virt_addr = ioremap(*phys_addr, size);
+	if (!virt_addr)
+		bitmap_release_region(mem->bitmap, pageno, order);
+
+ret:
+	mutex_unlock(&mem->lock);
+	return virt_addr;
+}
+EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr);
+
+/**
+ * pci_epc_mem_free_addr() - free the allocated memory address
+ * @epc: the EPC device on which memory was allocated
+ * @phys_addr: the allocated physical address
+ * @virt_addr: virtual address of the allocated mem space
+ * @size: the size of the allocated address space
+ *
+ * Invoke to free the memory allocated using 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)
+{
+	int pageno;
+	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;
+	size = ALIGN(size, mem->page_size);
+	order = pci_epc_mem_get_order(mem, size);
+	mutex_lock(&mem->lock);
+	bitmap_release_region(mem->bitmap, pageno, order);
+	mutex_unlock(&mem->lock);
+}
+EXPORT_SYMBOL_GPL(pci_epc_mem_free_addr);
+
+MODULE_DESCRIPTION("PCI EPC Address Space Management");
+MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
+MODULE_LICENSE("GPL v2");