1 /** 2 * PCI Endpoint *Controller* Address Space Management 3 * 4 * Copyright (C) 2017 Texas Instruments 5 * Author: Kishon Vijay Abraham I <kishon@ti.com> 6 * 7 * This program is free software: you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 of 9 * the License as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #include <linux/io.h> 21 #include <linux/module.h> 22 #include <linux/slab.h> 23 24 #include <linux/pci-epc.h> 25 26 /** 27 * pci_epc_mem_init() - initialize the pci_epc_mem structure 28 * @epc: the EPC device that invoked pci_epc_mem_init 29 * @phys_base: the physical address of the base 30 * @size: the size of the address space 31 * 32 * Invoke to initialize the pci_epc_mem structure used by the 33 * endpoint functions to allocate mapped PCI address. 34 */ 35 int pci_epc_mem_init(struct pci_epc *epc, phys_addr_t phys_base, size_t size) 36 { 37 int ret; 38 struct pci_epc_mem *mem; 39 unsigned long *bitmap; 40 int pages = size >> PAGE_SHIFT; 41 int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long); 42 43 mem = kzalloc(sizeof(*mem), GFP_KERNEL); 44 if (!mem) { 45 ret = -ENOMEM; 46 goto err; 47 } 48 49 bitmap = kzalloc(bitmap_size, GFP_KERNEL); 50 if (!bitmap) { 51 ret = -ENOMEM; 52 goto err_mem; 53 } 54 55 mem->bitmap = bitmap; 56 mem->phys_base = phys_base; 57 mem->pages = pages; 58 mem->size = size; 59 60 epc->mem = mem; 61 62 return 0; 63 64 err_mem: 65 kfree(mem); 66 67 err: 68 return ret; 69 } 70 EXPORT_SYMBOL_GPL(pci_epc_mem_init); 71 72 /** 73 * pci_epc_mem_exit() - cleanup the pci_epc_mem structure 74 * @epc: the EPC device that invoked pci_epc_mem_exit 75 * 76 * Invoke to cleanup the pci_epc_mem structure allocated in 77 * pci_epc_mem_init(). 78 */ 79 void pci_epc_mem_exit(struct pci_epc *epc) 80 { 81 struct pci_epc_mem *mem = epc->mem; 82 83 epc->mem = NULL; 84 kfree(mem->bitmap); 85 kfree(mem); 86 } 87 EXPORT_SYMBOL_GPL(pci_epc_mem_exit); 88 89 /** 90 * pci_epc_mem_alloc_addr() - allocate memory address from EPC addr space 91 * @epc: the EPC device on which memory has to be allocated 92 * @phys_addr: populate the allocated physical address here 93 * @size: the size of the address space that has to be allocated 94 * 95 * Invoke to allocate memory address from the EPC address space. This 96 * is usually done to map the remote RC address into the local system. 97 */ 98 void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc, 99 phys_addr_t *phys_addr, size_t size) 100 { 101 int pageno; 102 void __iomem *virt_addr; 103 struct pci_epc_mem *mem = epc->mem; 104 int order = get_order(size); 105 106 pageno = bitmap_find_free_region(mem->bitmap, mem->pages, order); 107 if (pageno < 0) 108 return NULL; 109 110 *phys_addr = mem->phys_base + (pageno << PAGE_SHIFT); 111 virt_addr = ioremap(*phys_addr, size); 112 if (!virt_addr) 113 bitmap_release_region(mem->bitmap, pageno, order); 114 115 return virt_addr; 116 } 117 EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr); 118 119 /** 120 * pci_epc_mem_free_addr() - free the allocated memory address 121 * @epc: the EPC device on which memory was allocated 122 * @phys_addr: the allocated physical address 123 * @virt_addr: virtual address of the allocated mem space 124 * @size: the size of the allocated address space 125 * 126 * Invoke to free the memory allocated using pci_epc_mem_alloc_addr. 127 */ 128 void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr, 129 void __iomem *virt_addr, size_t size) 130 { 131 int pageno; 132 int order = get_order(size); 133 struct pci_epc_mem *mem = epc->mem; 134 135 iounmap(virt_addr); 136 pageno = (phys_addr - mem->phys_base) >> PAGE_SHIFT; 137 bitmap_release_region(mem->bitmap, pageno, order); 138 } 139 EXPORT_SYMBOL_GPL(pci_epc_mem_free_addr); 140 141 MODULE_DESCRIPTION("PCI EPC Address Space Management"); 142 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>"); 143 MODULE_LICENSE("GPL v2"); 144