Linux Kernel  3.7.1
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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. */
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