drivers/staging/hv/osd.c

   1 /*
   2  *
   3  * Copyright (c) 2009, Microsoft Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  16  * Place - Suite 330, Boston, MA 02111-1307 USA.
  17  *
  18  * Authors:
  19  *   Haiyang Zhang <haiyangz@microsoft.com>
  20  *   Hank Janssen  <hjanssen@microsoft.com>
  21  *
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/types.h>
  27 #include <linux/mm.h>
  28 #include <linux/highmem.h>
  29 #include <linux/vmalloc.h>
  30 #include <linux/ioport.h>
  31 #include <linux/irq.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/sched.h>
  34 #include <linux/wait.h>
  35 #include <linux/spinlock.h>
  36 #include <linux/workqueue.h>
  37 #include <linux/kernel.h>
  38 #include <linux/jiffies.h>
  39 #include <linux/delay.h>
  40 #include <linux/time.h>
  41 #include <linux/io.h>
  42 #include <linux/bitops.h>
  43 #include <linux/slab.h>
  44 #include "osd.h"
  45
  46 void *osd_virtual_alloc_exec(unsigned int size)
  47 {
  48 #ifdef __x86_64__
  49         return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL_EXEC);
  50 #else
  51         return __vmalloc(size, GFP_KERNEL,
  52                          __pgprot(__PAGE_KERNEL & (~_PAGE_NX)));
  53 #endif
  54 }
  55
  56 /**
  57  * osd_page_alloc() - Allocate pages
  58  * @count:      Total number of Kernel pages you want to allocate
  59  *
  60  * Tries to allocate @count number of consecutive free kernel pages.
  61  * And if successful, it will set the pages to 0 before returning.
  62  * If successfull it will return pointer to the @count pages.
  63  * Mainly used by Hyper-V drivers.
  64  */
  65 void *osd_page_alloc(unsigned int count)
  66 {
  67         void *p;
  68
  69         p = (void *)__get_free_pages(GFP_KERNEL, get_order(count * PAGE_SIZE));
  70         if (p)
  71                 memset(p, 0, count * PAGE_SIZE);
  72         return p;
  73
  74         /* struct page* page = alloc_page(GFP_KERNEL|__GFP_ZERO); */
  75         /* void *p; */
  76
  77         /* BUGBUG: We need to use kmap in case we are in HIMEM region */
  78         /* p = page_address(page); */
  79         /* if (p) memset(p, 0, PAGE_SIZE); */
  80         /* return p; */
  81 }
  82 EXPORT_SYMBOL_GPL(osd_page_alloc);
  83
  84 /**
  85  * osd_page_free() - Free pages
  86  * @page:       Pointer to the first page to be freed
  87  * @count:      Total number of Kernel pages you free
  88  *
  89  * Frees the pages allocated by osd_page_alloc()
  90  * Mainly used by Hyper-V drivers.
  91  */
  92 void osd_page_free(void *page, unsigned int count)
  93 {
  94         free_pages((unsigned long)page, get_order(count * PAGE_SIZE));
  95         /*struct page* p = virt_to_page(page);
  96         __free_page(p);*/
  97 }
  98 EXPORT_SYMBOL_GPL(osd_page_free);
  99
 100 /**
 101  * osd_waitevent_create() - Create the event queue
 102  *
 103  * Allocates memory for a &struct osd_waitevent. And then calls
 104  * init_waitqueue_head to set up the wait queue for the event.
 105  * This structure is usually part of a another structure that contains
 106  * the actual Hyper-V device driver structure.
 107  *
 108  * Returns pointer to &struct osd_waitevent
 109  * Mainly used by Hyper-V drivers.
 110  */
 111 struct osd_waitevent *osd_waitevent_create(void)
 112 {
 113         struct osd_waitevent *wait = kmalloc(sizeof(struct osd_waitevent),
 114                                              GFP_KERNEL);
 115         if (!wait)
 116                 return NULL;
 117
 118         wait->condition = 0;
 119         init_waitqueue_head(&wait->event);
 120         return wait;
 121 }
 122 EXPORT_SYMBOL_GPL(osd_waitevent_create);
 123
 124
 125 /**
 126  * osd_waitevent_set() - Wake up the process
 127  * @wait_event: Structure to event to be woken up
 128  *
 129  * @wait_event is of type &struct osd_waitevent
 130  *
 131  * Wake up the sleeping process so it can do some work.
 132  * And set condition indicator in &struct osd_waitevent to indicate
 133  * the process is in a woken state.
 134  *
 135  * Only used by Network and Storage Hyper-V drivers.
 136  */
 137 void osd_waitevent_set(struct osd_waitevent *wait_event)
 138 {
 139         wait_event->condition = 1;
 140         wake_up_interruptible(&wait_event->event);
 141 }
 142 EXPORT_SYMBOL_GPL(osd_waitevent_set);
 143
 144 /**
 145  * osd_waitevent_wait() - Wait for event till condition is true
 146  * @wait_event: Structure to event to be put to sleep
 147  *
 148  * @wait_event is of type &struct osd_waitevent
 149  *
 150  * Set up the process to sleep until waitEvent->condition get true.
 151  * And set condition indicator in &struct osd_waitevent to indicate
 152  * the process is in a sleeping state.
 153  *
 154  * Returns the status of 'wait_event_interruptible()' system call
 155  *
 156  * Mainly used by Hyper-V drivers.
 157  */
 158 int osd_waitevent_wait(struct osd_waitevent *wait_event)
 159 {
 160         int ret = 0;
 161
 162         ret = wait_event_interruptible(wait_event->event,
 163                                        wait_event->condition);
 164         wait_event->condition = 0;
 165         return ret;
 166 }
 167 EXPORT_SYMBOL_GPL(osd_waitevent_wait);
 168
 169 /**
 170  * osd_waitevent_waitex() - Wait for event or timeout for process wakeup
 171  * @wait_event: Structure to event to be put to sleep
 172  * @timeout_in_ms:       Total number of Milliseconds to wait before waking up
 173  *
 174  * @wait_event is of type &struct osd_waitevent
 175  * Set up the process to sleep until @waitEvent->condition get true or
 176  * @timeout_in_ms (Time out in Milliseconds) has been reached.
 177  * And set condition indicator in &struct osd_waitevent to indicate
 178  * the process is in a sleeping state.
 179  *
 180  * Returns the status of 'wait_event_interruptible_timeout()' system call
 181  *
 182  * Mainly used by Hyper-V drivers.
 183  */
 184 int osd_waitevent_waitex(struct osd_waitevent *wait_event, u32 timeout_in_ms)
 185 {
 186         int ret = 0;
 187
 188         ret = wait_event_interruptible_timeout(wait_event->event,
 189                                                wait_event->condition,
 190                                                msecs_to_jiffies(timeout_in_ms));
 191         wait_event->condition = 0;
 192         return ret;
 193 }
 194 EXPORT_SYMBOL_GPL(osd_waitevent_waitex);