arch/tile/gxio/kiorpc.c

   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. */
  30 void __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
  61 EXPORT_SYMBOL(iorpc_ioremap);