264 lines
6.4 KiB
C
264 lines
6.4 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* PCI Endpoint *Controller* Address Space Management
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*
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* Copyright (C) 2017 Texas Instruments
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* Author: Kishon Vijay Abraham I <kishon@ti.com>
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*/
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/pci-epc.h>
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/**
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* pci_epc_mem_get_order() - determine the allocation order of a memory size
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* @mem: address space of the endpoint controller
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* @size: the size for which to get the order
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*
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* Reimplement get_order() for mem->page_size since the generic get_order
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* always gets order with a constant PAGE_SIZE.
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*/
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static int pci_epc_mem_get_order(struct pci_epc_mem *mem, size_t size)
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{
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int order;
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unsigned int page_shift = ilog2(mem->window.page_size);
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size--;
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size >>= page_shift;
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#if BITS_PER_LONG == 32
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order = fls(size);
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#else
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order = fls64(size);
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#endif
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return order;
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}
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/**
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* pci_epc_multi_mem_init() - initialize the pci_epc_mem structure
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* @epc: the EPC device that invoked pci_epc_mem_init
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* @windows: pointer to windows supported by the device
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* @num_windows: number of windows device supports
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*
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* Invoke to initialize the pci_epc_mem structure used by the
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* endpoint functions to allocate mapped PCI address.
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*/
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int pci_epc_multi_mem_init(struct pci_epc *epc,
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struct pci_epc_mem_window *windows,
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unsigned int num_windows)
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{
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struct pci_epc_mem *mem = NULL;
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unsigned long *bitmap = NULL;
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unsigned int page_shift;
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size_t page_size;
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int bitmap_size;
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int pages;
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int ret;
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int i;
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epc->num_windows = 0;
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if (!windows || !num_windows)
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return -EINVAL;
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epc->windows = kcalloc(num_windows, sizeof(*epc->windows), GFP_KERNEL);
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if (!epc->windows)
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return -ENOMEM;
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for (i = 0; i < num_windows; i++) {
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page_size = windows[i].page_size;
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if (page_size < PAGE_SIZE)
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page_size = PAGE_SIZE;
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page_shift = ilog2(page_size);
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pages = windows[i].size >> page_shift;
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bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
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mem = kzalloc(sizeof(*mem), GFP_KERNEL);
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if (!mem) {
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ret = -ENOMEM;
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i--;
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goto err_mem;
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}
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bitmap = kzalloc(bitmap_size, GFP_KERNEL);
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if (!bitmap) {
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ret = -ENOMEM;
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kfree(mem);
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i--;
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goto err_mem;
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}
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mem->window.phys_base = windows[i].phys_base;
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mem->window.size = windows[i].size;
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mem->window.page_size = page_size;
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mem->bitmap = bitmap;
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mem->pages = pages;
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mutex_init(&mem->lock);
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epc->windows[i] = mem;
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}
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epc->mem = epc->windows[0];
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epc->num_windows = num_windows;
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return 0;
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err_mem:
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for (; i >= 0; i--) {
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mem = epc->windows[i];
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kfree(mem->bitmap);
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kfree(mem);
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}
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kfree(epc->windows);
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return ret;
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}
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EXPORT_SYMBOL_GPL(pci_epc_multi_mem_init);
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int pci_epc_mem_init(struct pci_epc *epc, phys_addr_t base,
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size_t size, size_t page_size)
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{
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struct pci_epc_mem_window mem_window;
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mem_window.phys_base = base;
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mem_window.size = size;
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mem_window.page_size = page_size;
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return pci_epc_multi_mem_init(epc, &mem_window, 1);
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}
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EXPORT_SYMBOL_GPL(pci_epc_mem_init);
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/**
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* pci_epc_mem_exit() - cleanup the pci_epc_mem structure
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* @epc: the EPC device that invoked pci_epc_mem_exit
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*
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* Invoke to cleanup the pci_epc_mem structure allocated in
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* pci_epc_mem_init().
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*/
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void pci_epc_mem_exit(struct pci_epc *epc)
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{
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struct pci_epc_mem *mem;
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int i;
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if (!epc->num_windows)
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return;
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for (i = 0; i < epc->num_windows; i++) {
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mem = epc->windows[i];
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kfree(mem->bitmap);
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kfree(mem);
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}
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kfree(epc->windows);
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epc->windows = NULL;
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epc->mem = NULL;
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epc->num_windows = 0;
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}
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EXPORT_SYMBOL_GPL(pci_epc_mem_exit);
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/**
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* pci_epc_mem_alloc_addr() - allocate memory address from EPC addr space
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* @epc: the EPC device on which memory has to be allocated
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* @phys_addr: populate the allocated physical address here
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* @size: the size of the address space that has to be allocated
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*
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* Invoke to allocate memory address from the EPC address space. This
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* is usually done to map the remote RC address into the local system.
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*/
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void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
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phys_addr_t *phys_addr, size_t size)
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{
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void __iomem *virt_addr = NULL;
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struct pci_epc_mem *mem;
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unsigned int page_shift;
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size_t align_size;
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int pageno;
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int order;
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int i;
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for (i = 0; i < epc->num_windows; i++) {
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mem = epc->windows[i];
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mutex_lock(&mem->lock);
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align_size = ALIGN(size, mem->window.page_size);
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order = pci_epc_mem_get_order(mem, align_size);
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pageno = bitmap_find_free_region(mem->bitmap, mem->pages,
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order);
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if (pageno >= 0) {
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page_shift = ilog2(mem->window.page_size);
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*phys_addr = mem->window.phys_base +
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((phys_addr_t)pageno << page_shift);
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virt_addr = ioremap(*phys_addr, align_size);
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if (!virt_addr) {
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bitmap_release_region(mem->bitmap,
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pageno, order);
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mutex_unlock(&mem->lock);
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continue;
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}
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mutex_unlock(&mem->lock);
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return virt_addr;
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}
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mutex_unlock(&mem->lock);
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}
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return virt_addr;
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}
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EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr);
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static struct pci_epc_mem *pci_epc_get_matching_window(struct pci_epc *epc,
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phys_addr_t phys_addr)
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{
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struct pci_epc_mem *mem;
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int i;
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for (i = 0; i < epc->num_windows; i++) {
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mem = epc->windows[i];
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if (phys_addr >= mem->window.phys_base &&
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phys_addr < (mem->window.phys_base + mem->window.size))
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return mem;
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}
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return NULL;
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}
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/**
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* pci_epc_mem_free_addr() - free the allocated memory address
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* @epc: the EPC device on which memory was allocated
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* @phys_addr: the allocated physical address
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* @virt_addr: virtual address of the allocated mem space
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* @size: the size of the allocated address space
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*
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* Invoke to free the memory allocated using pci_epc_mem_alloc_addr.
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*/
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void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr,
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void __iomem *virt_addr, size_t size)
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{
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struct pci_epc_mem *mem;
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unsigned int page_shift;
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size_t page_size;
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int pageno;
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int order;
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mem = pci_epc_get_matching_window(epc, phys_addr);
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if (!mem) {
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pr_err("failed to get matching window\n");
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return;
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}
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page_size = mem->window.page_size;
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page_shift = ilog2(page_size);
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iounmap(virt_addr);
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pageno = (phys_addr - mem->window.phys_base) >> page_shift;
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size = ALIGN(size, page_size);
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order = pci_epc_mem_get_order(mem, size);
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mutex_lock(&mem->lock);
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bitmap_release_region(mem->bitmap, pageno, order);
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mutex_unlock(&mem->lock);
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}
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EXPORT_SYMBOL_GPL(pci_epc_mem_free_addr);
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MODULE_DESCRIPTION("PCI EPC Address Space Management");
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MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
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MODULE_LICENSE("GPL v2");
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