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 struct osd_callback_struct {
  47         struct work_struct work;
  48         void (*callback)(void *);
  49         void *data;
  50 };
  51
  52 void *osd_VirtualAllocExec(unsigned int size)
  53 {
  54 #ifdef __x86_64__
  55         return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL_EXEC);
  56 #else
  57         return __vmalloc(size, GFP_KERNEL,
  58                          __pgprot(__PAGE_KERNEL & (~_PAGE_NX)));
  59 #endif
  60 }
  61
  62 /**
  63  * osd_PageAlloc() - Allocate pages
  64  * @count:      Total number of Kernel pages you want to allocate
  65  *
  66  * Tries to allocate @count number of consecutive free kernel pages.
  67  * And if successful, it will set the pages to 0 before returning.
  68  * If successfull it will return pointer to the @count pages.
  69  * Mainly used by Hyper-V drivers.
  70  */
  71 void *osd_PageAlloc(unsigned int count)
  72 {
  73         void *p;
  74
  75         p = (void *)__get_free_pages(GFP_KERNEL, get_order(count * PAGE_SIZE));
  76         if (p)
  77                 memset(p, 0, count * PAGE_SIZE);
  78         return p;
  79
  80         /* struct page* page = alloc_page(GFP_KERNEL|__GFP_ZERO); */
  81         /* void *p; */
  82
  83         /* BUGBUG: We need to use kmap in case we are in HIMEM region */
  84         /* p = page_address(page); */
  85         /* if (p) memset(p, 0, PAGE_SIZE); */
  86         /* return p; */
  87 }
  88 EXPORT_SYMBOL_GPL(osd_PageAlloc);
  89
  90 /**
  91  * osd_PageFree() - Free pages
  92  * @page:       Pointer to the first page to be freed
  93  * @count:      Total number of Kernel pages you free
  94  *
  95  * Frees the pages allocated by osd_PageAlloc()
  96  * Mainly used by Hyper-V drivers.
  97  */
  98 void osd_PageFree(void *page, unsigned int count)
  99 {
 100         free_pages((unsigned long)page, get_order(count * PAGE_SIZE));
 101         /*struct page* p = virt_to_page(page);
 102         __free_page(p);*/
 103 }
 104 EXPORT_SYMBOL_GPL(osd_PageFree);
 105
 106 /**
 107  * osd_WaitEventCreate() - Create the event queue
 108  *
 109  * Allocates memory for a &struct osd_waitevent. And then calls
 110  * init_waitqueue_head to set up the wait queue for the event.
 111  * This structure is usually part of a another structure that contains
 112  * the actual Hyper-V device driver structure.
 113  *
 114  * Returns pointer to &struct osd_waitevent
 115  * Mainly used by Hyper-V drivers.
 116  */
 117 struct osd_waitevent *osd_WaitEventCreate(void)
 118 {
 119         struct osd_waitevent *wait = kmalloc(sizeof(struct osd_waitevent),
 120                                              GFP_KERNEL);
 121         if (!wait)
 122                 return NULL;
 123
 124         wait->condition = 0;
 125         init_waitqueue_head(&wait->event);
 126         return wait;
 127 }
 128 EXPORT_SYMBOL_GPL(osd_WaitEventCreate);
 129
 130
 131 /**
 132  * osd_WaitEventSet() - Wake up the process
 133  * @waitEvent: Structure to event to be woken up
 134  *
 135  * @waitevent is of type &struct osd_waitevent
 136  *
 137  * Wake up the sleeping process so it can do some work.
 138  * And set condition indicator in &struct osd_waitevent to indicate
 139  * the process is in a woken state.
 140  *
 141  * Only used by Network and Storage Hyper-V drivers.
 142  */
 143 void osd_WaitEventSet(struct osd_waitevent *waitEvent)
 144 {
 145         waitEvent->condition = 1;
 146         wake_up_interruptible(&waitEvent->event);
 147 }
 148 EXPORT_SYMBOL_GPL(osd_WaitEventSet);
 149
 150 /**
 151  * osd_WaitEventWait() - Wait for event till condition is true
 152  * @waitEvent: Structure to event to be put to sleep
 153  *
 154  * @waitevent is of type &struct osd_waitevent
 155  *
 156  * Set up the process to sleep until waitEvent->condition get true.
 157  * And set condition indicator in &struct osd_waitevent to indicate
 158  * the process is in a sleeping state.
 159  *
 160  * Returns the status of 'wait_event_interruptible()' system call
 161  *
 162  * Mainly used by Hyper-V drivers.
 163  */
 164 int osd_WaitEventWait(struct osd_waitevent *waitEvent)
 165 {
 166         int ret = 0;
 167
 168         ret = wait_event_interruptible(waitEvent->event,
 169                                        waitEvent->condition);
 170         waitEvent->condition = 0;
 171         return ret;
 172 }
 173 EXPORT_SYMBOL_GPL(osd_WaitEventWait);
 174
 175 /**
 176  * osd_WaitEventWaitEx() - Wait for event or timeout for process wakeup
 177  * @waitEvent: Structure to event to be put to sleep
 178  * @TimeoutInMs:       Total number of Milliseconds to wait before waking up
 179  *
 180  * @waitevent is of type &struct osd_waitevent
 181  * Set up the process to sleep until @waitEvent->condition get true or
 182  * @TimeoutInMs (Time out in Milliseconds) has been reached.
 183  * And set condition indicator in &struct osd_waitevent to indicate
 184  * the process is in a sleeping state.
 185  *
 186  * Returns the status of 'wait_event_interruptible_timeout()' system call
 187  *
 188  * Mainly used by Hyper-V drivers.
 189  */
 190 int osd_WaitEventWaitEx(struct osd_waitevent *waitEvent, u32 TimeoutInMs)
 191 {
 192         int ret = 0;
 193
 194         ret = wait_event_interruptible_timeout(waitEvent->event,
 195                                                waitEvent->condition,
 196                                                msecs_to_jiffies(TimeoutInMs));
 197         waitEvent->condition = 0;
 198         return ret;
 199 }
 200 EXPORT_SYMBOL_GPL(osd_WaitEventWaitEx);
 201
 202 static void osd_callback_work(struct work_struct *work)
 203 {
 204         struct osd_callback_struct *cb = container_of(work,
 205                                                 struct osd_callback_struct,
 206                                                 work);
 207         (cb->callback)(cb->data);
 208         kfree(cb);
 209 }
 210
 211 int osd_schedule_callback(struct workqueue_struct *wq,
 212                           void (*func)(void *),
 213                           void *data)
 214 {
 215         struct osd_callback_struct *cb;
 216
 217         cb = kmalloc(sizeof(*cb), GFP_KERNEL);
 218         if (!cb) {
 219                 printk(KERN_ERR "unable to allocate memory in osd_schedule_callback\n");
 220                 return -1;
 221         }
 222
 223         cb->callback = func;
 224         cb->data = data;
 225         INIT_WORK(&cb->work, osd_callback_work);
 226         return queue_work(wq, &cb->work);
 227 }
 228