linux/arch/tile/gxio/kiorpc.c
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   1/*
   2 * Copyright 2012 Tilera Corporation. All Rights Reserved.
   3 *
   4 *   This program is free software; you can redistribute it and/or
   5 *   modify it under the terms of the GNU General Public License
   6 *   as published by the Free Software Foundation, version 2.
   7 *
   8 *   This program is distributed in the hope that it will be useful, but
   9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11 *   NON INFRINGEMENT.  See the GNU General Public License for
  12 *   more details.
  13 *
  14 * TILE-Gx IORPC support for kernel I/O drivers.
  15 */
  16
  17#include <linux/mmzone.h>
  18#include <linux/module.h>
  19#include <linux/io.h>
  20#include <gxio/iorpc_globals.h>
  21#include <gxio/kiorpc.h>
  22
  23#ifdef DEBUG_IORPC
  24#define TRACE(FMT, ...) pr_info(SIMPLE_MSG_LINE FMT, ## __VA_ARGS__)
  25#else
  26#define TRACE(...)
  27#endif
  28
  29/* Create kernel-VA-space MMIO mapping for an on-chip IO device. */
  30void __iomem *iorpc_ioremap(int hv_fd, resource_size_t offset,
  31                            unsigned long size)
  32{
  33        pgprot_t mmio_base, prot = { 0 };
  34        unsigned long pfn;
  35        int err;
  36
  37        /* Look up the shim's lotar and base PA. */
  38        err = __iorpc_get_mmio_base(hv_fd, &mmio_base);
  39        if (err) {
  40                TRACE("get_mmio_base() failure: %d\n", err);
  41                return NULL;
  42        }
  43
  44        /* Make sure the HV driver approves of our offset and size. */
  45        err = __iorpc_check_mmio_offset(hv_fd, offset, size);
  46        if (err) {
  47                TRACE("check_mmio_offset() failure: %d\n", err);
  48                return NULL;
  49        }
  50
  51        /*
  52         * mmio_base contains a base pfn and homing coordinates.  Turn
  53         * it into an MMIO pgprot and offset pfn.
  54         */
  55        prot = hv_pte_set_lotar(prot, hv_pte_get_lotar(mmio_base));
  56        pfn = pte_pfn(mmio_base) + PFN_DOWN(offset);
  57
  58        return ioremap_prot(PFN_PHYS(pfn), size, prot);
  59}
  60
  61EXPORT_SYMBOL(iorpc_ioremap);
  62