1 files changed, 263 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..a97b56a6d
--- /dev/null
+++ b/drivers/pci/endpoint/pci-epc-mem.c
@@ -0,0 +1,263 @@
+// 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->window.page_size);
+
+	size--;
+	size >>= page_shift;
+#if BITS_PER_LONG == 32
+	order = fls(size);
+#else
+	order = fls64(size);
+#endif
+	return order;
+}
+
+/**
+ * pci_epc_multi_mem_init() - initialize the pci_epc_mem structure
+ * @epc: the EPC device that invoked pci_epc_mem_init
+ * @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_multi_mem_init(struct pci_epc *epc,
+			   struct pci_epc_mem_window *windows,
+			   unsigned int num_windows)
+{
+	struct pci_epc_mem *mem = NULL;
+	unsigned long *bitmap = NULL;
+	unsigned int page_shift;
+	size_t page_size;
+	int bitmap_size;
+	int pages;
+	int ret;
+	int i;
+
+	epc->num_windows = 0;
+
+	if (!windows || !num_windows)
+		return -EINVAL;
+
+	epc->windows = kcalloc(num_windows, sizeof(*epc->windows), GFP_KERNEL);
+	if (!epc->windows)
+		return -ENOMEM;
+
+	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;
+			i--;
+			goto err_mem;
+		}
+
+		bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+		if (!bitmap) {
+			ret = -ENOMEM;
+			kfree(mem);
+			i--;
+			goto err_mem;
+		}
+
+		mem->window.phys_base = windows[i].phys_base;
+		mem->window.size = windows[i].size;
+		mem->window.page_size = page_size;
+		mem->bitmap = bitmap;
+		mem->pages = pages;
+		mutex_init(&mem->lock);
+		epc->windows[i] = mem;
+	}
+
+	epc->mem = epc->windows[0];
+	epc->num_windows = num_windows;
+
+	return 0;
+
+err_mem:
+	for (; i >= 0; i--) {
+		mem = epc->windows[i];
+		kfree(mem->bitmap);
+		kfree(mem);
+	}
+	kfree(epc->windows);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pci_epc_multi_mem_init);
+
+int pci_epc_mem_init(struct pci_epc *epc, phys_addr_t base,
+		     size_t size, size_t page_size)
+{
+	struct pci_epc_mem_window mem_window;
+
+	mem_window.phys_base = base;
+	mem_window.size = size;
+	mem_window.page_size = page_size;
+
+	return pci_epc_multi_mem_init(epc, &mem_window, 1);
+}
+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;
+	int i;
+
+	if (!epc->num_windows)
+		return;
+
+	for (i = 0; i < epc->num_windows; i++) {
+		mem = epc->windows[i];
+		kfree(mem->bitmap);
+		kfree(mem);
+	}
+	kfree(epc->windows);
+
+	epc->windows = NULL;
+	epc->mem = NULL;
+	epc->num_windows = 0;
+}
+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)
+{
+	void __iomem *virt_addr = NULL;
+	struct pci_epc_mem *mem;
+	unsigned int page_shift;
+	size_t align_size;
+	int pageno;
+	int order;
+	int i;
+
+	for (i = 0; i < epc->num_windows; i++) {
+		mem = epc->windows[i];
+		mutex_lock(&mem->lock);
+		align_size = ALIGN(size, mem->window.page_size);
+		order = pci_epc_mem_get_order(mem, align_size);
+
+		pageno = bitmap_find_free_region(mem->bitmap, mem->pages,
+						 order);
+		if (pageno >= 0) {
+			page_shift = ilog2(mem->window.page_size);
+			*phys_addr = mem->window.phys_base +
+				((phys_addr_t)pageno << page_shift);
+			virt_addr = ioremap(*phys_addr, align_size);
+			if (!virt_addr) {
+				bitmap_release_region(mem->bitmap,
+						      pageno, order);
+				mutex_unlock(&mem->lock);
+				continue;
+			}
+			mutex_unlock(&mem->lock);
+			return virt_addr;
+		}
+		mutex_unlock(&mem->lock);
+	}
+
+	return virt_addr;
+}
+EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr);
+
+static 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->num_windows; i++) {
+		mem = epc->windows[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
+ * @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)
+{
+	struct pci_epc_mem *mem;
+	unsigned int page_shift;
+	size_t page_size;
+	int pageno;
+	int order;
+
+	mem = pci_epc_get_matching_window(epc, phys_addr);
+	if (!mem) {
+		pr_err("failed to get matching window\n");
+		return;
+	}
+
+	page_size = mem->window.page_size;
+	page_shift = ilog2(page_size);
+	iounmap(virt_addr);
+	pageno = (phys_addr - mem->window.phys_base) >> page_shift;
+	size = ALIGN(size, 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");