![Kishon Vijay Abraham I](/assets/img/avatar_default.png)
pci-epc-mem uses a page size equal to *PAGE_SIZE* (usually 4KB) to manage the address space. However certain platforms like TI's K2G have a restriction that this address space should be either divided into 1MB/2MB/4MB or 8MB sizes (Ref: 11.14.4.9.1 Outbound Address Translation in K2G TRM SPRUHY8F January 2016 – Revised May 2017). Add support to handle different page sizes here. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
185 lines
4.9 KiB
C
185 lines
4.9 KiB
C
/**
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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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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 of
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* the License as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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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->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_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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* @phys_base: the physical address of the base
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* @size: the size of the address space
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* @page_size: size of each page
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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_mem_init(struct pci_epc *epc, phys_addr_t phys_base, size_t size,
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size_t page_size)
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{
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int ret;
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struct pci_epc_mem *mem;
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unsigned long *bitmap;
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unsigned int page_shift;
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int pages;
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int bitmap_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 = 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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goto err;
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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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goto err_mem;
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}
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mem->bitmap = bitmap;
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mem->phys_base = phys_base;
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mem->page_size = page_size;
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mem->pages = pages;
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mem->size = size;
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epc->mem = mem;
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return 0;
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err_mem:
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kfree(mem);
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err:
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return ret;
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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 = epc->mem;
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epc->mem = NULL;
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kfree(mem->bitmap);
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kfree(mem);
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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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int pageno;
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void __iomem *virt_addr;
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struct pci_epc_mem *mem = epc->mem;
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unsigned int page_shift = ilog2(mem->page_size);
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int order;
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size = ALIGN(size, mem->page_size);
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order = pci_epc_mem_get_order(mem, size);
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pageno = bitmap_find_free_region(mem->bitmap, mem->pages, order);
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if (pageno < 0)
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return NULL;
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*phys_addr = mem->phys_base + (pageno << page_shift);
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virt_addr = ioremap(*phys_addr, size);
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if (!virt_addr)
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bitmap_release_region(mem->bitmap, pageno, order);
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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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/**
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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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int pageno;
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struct pci_epc_mem *mem = epc->mem;
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unsigned int page_shift = ilog2(mem->page_size);
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int order;
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iounmap(virt_addr);
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pageno = (phys_addr - mem->phys_base) >> page_shift;
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size = ALIGN(size, mem->page_size);
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order = pci_epc_mem_get_order(mem, size);
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bitmap_release_region(mem->bitmap, pageno, order);
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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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