1 // SPDX-License-Identifier: GPL-2.0
3 * PCI Endpoint *Controller* Address Space Management
5 * Copyright (C) 2017 Texas Instruments
6 * Author: Kishon Vijay Abraham I <kishon@ti.com>
10 #include <linux/module.h>
11 #include <linux/slab.h>
13 #include <linux/pci-epc.h>
16 * pci_epc_mem_get_order() - determine the allocation order of a memory size
17 * @mem: address space of the endpoint controller
18 * @size: the size for which to get the order
20 * Reimplement get_order() for mem->page_size since the generic get_order
21 * always gets order with a constant PAGE_SIZE.
23 static int pci_epc_mem_get_order(struct pci_epc_mem *mem, size_t size)
26 unsigned int page_shift = ilog2(mem->window.page_size);
30 #if BITS_PER_LONG == 32
39 * pci_epc_multi_mem_init() - initialize the pci_epc_mem structure
40 * @epc: the EPC device that invoked pci_epc_mem_init
41 * @windows: pointer to windows supported by the device
42 * @num_windows: number of windows device supports
44 * Invoke to initialize the pci_epc_mem structure used by the
45 * endpoint functions to allocate mapped PCI address.
47 int pci_epc_multi_mem_init(struct pci_epc *epc,
48 struct pci_epc_mem_window *windows,
49 unsigned int num_windows)
51 struct pci_epc_mem *mem = NULL;
52 unsigned long *bitmap = NULL;
53 unsigned int page_shift;
62 if (!windows || !num_windows)
65 epc->windows = kcalloc(num_windows, sizeof(*epc->windows), GFP_KERNEL);
69 for (i = 0; i < num_windows; i++) {
70 page_size = windows[i].page_size;
71 if (page_size < PAGE_SIZE)
72 page_size = PAGE_SIZE;
73 page_shift = ilog2(page_size);
74 pages = windows[i].size >> page_shift;
75 bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
77 mem = kzalloc(sizeof(*mem), GFP_KERNEL);
84 bitmap = kzalloc(bitmap_size, GFP_KERNEL);
92 mem->window.phys_base = windows[i].phys_base;
93 mem->window.size = windows[i].size;
94 mem->window.page_size = page_size;
97 mutex_init(&mem->lock);
98 epc->windows[i] = mem;
101 epc->mem = epc->windows[0];
102 epc->num_windows = num_windows;
107 for (; i >= 0; i--) {
108 mem = epc->windows[i];
116 EXPORT_SYMBOL_GPL(pci_epc_multi_mem_init);
119 * pci_epc_mem_init() - Initialize the pci_epc_mem structure
120 * @epc: the EPC device that invoked pci_epc_mem_init
121 * @base: Physical address of the window region
122 * @size: Total Size of the window region
123 * @page_size: Page size of the window region
125 * Invoke to initialize a single pci_epc_mem structure used by the
126 * endpoint functions to allocate memory for mapping the PCI host memory
128 int pci_epc_mem_init(struct pci_epc *epc, phys_addr_t base,
129 size_t size, size_t page_size)
131 struct pci_epc_mem_window mem_window;
133 mem_window.phys_base = base;
134 mem_window.size = size;
135 mem_window.page_size = page_size;
137 return pci_epc_multi_mem_init(epc, &mem_window, 1);
139 EXPORT_SYMBOL_GPL(pci_epc_mem_init);
142 * pci_epc_mem_exit() - cleanup the pci_epc_mem structure
143 * @epc: the EPC device that invoked pci_epc_mem_exit
145 * Invoke to cleanup the pci_epc_mem structure allocated in
146 * pci_epc_mem_init().
148 void pci_epc_mem_exit(struct pci_epc *epc)
150 struct pci_epc_mem *mem;
153 if (!epc->num_windows)
156 for (i = 0; i < epc->num_windows; i++) {
157 mem = epc->windows[i];
165 epc->num_windows = 0;
167 EXPORT_SYMBOL_GPL(pci_epc_mem_exit);
170 * pci_epc_mem_alloc_addr() - allocate memory address from EPC addr space
171 * @epc: the EPC device on which memory has to be allocated
172 * @phys_addr: populate the allocated physical address here
173 * @size: the size of the address space that has to be allocated
175 * Invoke to allocate memory address from the EPC address space. This
176 * is usually done to map the remote RC address into the local system.
178 void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
179 phys_addr_t *phys_addr, size_t size)
181 void __iomem *virt_addr = NULL;
182 struct pci_epc_mem *mem;
183 unsigned int page_shift;
189 for (i = 0; i < epc->num_windows; i++) {
190 mem = epc->windows[i];
191 mutex_lock(&mem->lock);
192 align_size = ALIGN(size, mem->window.page_size);
193 order = pci_epc_mem_get_order(mem, align_size);
195 pageno = bitmap_find_free_region(mem->bitmap, mem->pages,
198 page_shift = ilog2(mem->window.page_size);
199 *phys_addr = mem->window.phys_base +
200 ((phys_addr_t)pageno << page_shift);
201 virt_addr = ioremap(*phys_addr, align_size);
203 bitmap_release_region(mem->bitmap,
205 mutex_unlock(&mem->lock);
208 mutex_unlock(&mem->lock);
211 mutex_unlock(&mem->lock);
216 EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr);
218 static struct pci_epc_mem *pci_epc_get_matching_window(struct pci_epc *epc,
219 phys_addr_t phys_addr)
221 struct pci_epc_mem *mem;
224 for (i = 0; i < epc->num_windows; i++) {
225 mem = epc->windows[i];
227 if (phys_addr >= mem->window.phys_base &&
228 phys_addr < (mem->window.phys_base + mem->window.size))
236 * pci_epc_mem_free_addr() - free the allocated memory address
237 * @epc: the EPC device on which memory was allocated
238 * @phys_addr: the allocated physical address
239 * @virt_addr: virtual address of the allocated mem space
240 * @size: the size of the allocated address space
242 * Invoke to free the memory allocated using pci_epc_mem_alloc_addr.
244 void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr,
245 void __iomem *virt_addr, size_t size)
247 struct pci_epc_mem *mem;
248 unsigned int page_shift;
253 mem = pci_epc_get_matching_window(epc, phys_addr);
255 pr_err("failed to get matching window\n");
259 page_size = mem->window.page_size;
260 page_shift = ilog2(page_size);
262 pageno = (phys_addr - mem->window.phys_base) >> page_shift;
263 size = ALIGN(size, page_size);
264 order = pci_epc_mem_get_order(mem, size);
265 mutex_lock(&mem->lock);
266 bitmap_release_region(mem->bitmap, pageno, order);
267 mutex_unlock(&mem->lock);
269 EXPORT_SYMBOL_GPL(pci_epc_mem_free_addr);
271 MODULE_DESCRIPTION("PCI EPC Address Space Management");
272 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");