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path: root/drivers/pci/endpoint/pci-epc-mem.c
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Diffstat (limited to 'drivers/pci/endpoint/pci-epc-mem.c')
-rw-r--r--drivers/pci/endpoint/pci-epc-mem.c143
1 files changed, 143 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 000000000000..3a94cc1caf22
--- /dev/null
+++ b/drivers/pci/endpoint/pci-epc-mem.c
@@ -0,0 +1,143 @@
+/**
+ * PCI Endpoint *Controller* Address Space Management
+ *
+ * Copyright (C) 2017 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 of
+ * the License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/pci-epc.h>
+
+/**
+ * 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
+ *
+ * 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 ret;
+ struct pci_epc_mem *mem;
+ unsigned long *bitmap;
+ int pages = size >> PAGE_SHIFT;
+ int 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->pages = pages;
+ mem->size = size;
+
+ 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;
+ struct pci_epc_mem *mem = epc->mem;
+ int order = get_order(size);
+
+ pageno = bitmap_find_free_region(mem->bitmap, mem->pages, order);
+ if (pageno < 0)
+ return NULL;
+
+ *phys_addr = mem->phys_base + (pageno << PAGE_SHIFT);
+ virt_addr = ioremap(*phys_addr, size);
+ if (!virt_addr)
+ bitmap_release_region(mem->bitmap, pageno, order);
+
+ 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;
+ int order = get_order(size);
+ struct pci_epc_mem *mem = epc->mem;
+
+ iounmap(virt_addr);
+ pageno = (phys_addr - mem->phys_base) >> PAGE_SHIFT;
+ bitmap_release_region(mem->bitmap, pageno, order);
+}
+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");