/** * PCI Endpoint *Controller* Address Space Management * * Copyright (C) 2017 Texas Instruments * Author: Kishon Vijay Abraham I * * 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 . */ #include #include #include #include /** * 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->page_size); size--; size >>= page_shift; #if BITS_PER_LONG == 32 order = fls(size); #else order = fls64(size); #endif return order; } /** * __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 * @page_size: size of each page * * 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, size_t page_size) { int ret; struct pci_epc_mem *mem; unsigned long *bitmap; unsigned int page_shift; int pages; int bitmap_size; if (page_size < PAGE_SIZE) page_size = PAGE_SIZE; page_shift = ilog2(page_size); pages = size >> page_shift; 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->page_size = page_size; 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; unsigned int page_shift = ilog2(mem->page_size); int order; size = ALIGN(size, mem->page_size); order = pci_epc_mem_get_order(mem, 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_wc_mem_alloc_addr() - allocate wc 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 wc memory address from the EPC address space. This * is usually done to map the remote RC address backed by RAM into the * local system. */ void __iomem *pci_epc_wc_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; unsigned int page_shift = ilog2(mem->page_size); int order; size = ALIGN(size, mem->page_size); order = pci_epc_mem_get_order(mem, 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_wc(*phys_addr, size); if (!virt_addr) bitmap_release_region(mem->bitmap, pageno, order); return virt_addr; } EXPORT_SYMBOL_GPL(pci_epc_wc_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 or * pci_epc_wc_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; struct pci_epc_mem *mem = epc->mem; unsigned int page_shift = ilog2(mem->page_size); int order; iounmap(virt_addr); pageno = (phys_addr - mem->phys_base) >> page_shift; size = ALIGN(size, mem->page_size); order = pci_epc_mem_get_order(mem, size); 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 "); MODULE_LICENSE("GPL v2");