alloc-r0drv-linux.c@ 13476

Last change on this file since 13476 was 12360, checked in by vboxsync, 16 years ago
2.6.27 vboxdrv compile fix
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File size: 9.3 KB

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1	/* $Id: alloc-r0drv-linux.c 12360 2008-09-10 15:02:01Z vboxsync $ */
2	/** @file
3	* IPRT - Memory Allocation, Ring-0 Driver, Linux.
4	*/
5
6	/*
7	* Copyright (C) 2006-2007 Sun Microsystems, Inc.
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*
17	* The contents of this file may alternatively be used under the terms
18	* of the Common Development and Distribution License Version 1.0
19	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20	* VirtualBox OSE distribution, in which case the provisions of the
21	* CDDL are applicable instead of those of the GPL.
22	*
23	* You may elect to license modified versions of this file under the
24	* terms and conditions of either the GPL or the CDDL or both.
25	*
26	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
27	* Clara, CA 95054 USA or visit http://www.sun.com if you need
28	* additional information or have any questions.
29	*/
30
31
32	/*******************************************************************************
33	* Header Files *
34	*******************************************************************************/
35	#include "the-linux-kernel.h"
36	#include <iprt/mem.h>
37	#include <iprt/assert.h>
38	#include "r0drv/alloc-r0drv.h"
39
40	#if defined(RT_ARCH_AMD64) \|\| defined(__DOXYGEN__)
41	/**
42	* We need memory in the module range (~2GB to ~0) this can only be obtained
43	* thru APIs that are not exported (see module_alloc()).
44	*
45	* So, we'll have to create a quick and dirty heap here using BSS memory.
46	* Very annoying and it's going to restrict us!
47	*/
48	# define RTMEMALLOC_EXEC_HEAP
49	#endif
50	#ifdef RTMEMALLOC_EXEC_HEAP
51	# include <iprt/heap.h>
52	# include <iprt/spinlock.h>
53	# include <iprt/err.h>
54	#endif
55
56
57	/*******************************************************************************
58	* Global Variables *
59	*******************************************************************************/
60	#ifdef RTMEMALLOC_EXEC_HEAP
61	/** The heap. */
62	static RTHEAPSIMPLE g_HeapExec = NIL_RTHEAPSIMPLE;
63	/** Spinlock protecting the heap. */
64	static RTSPINLOCK g_HeapExecSpinlock = NIL_RTSPINLOCK;
65
66
67	/**
68	* API for cleaning up the heap spinlock on IPRT termination.
69	* This is as RTMemExecDonate specific to AMD64 Linux/GNU.
70	*/
71	void rtR0MemExecCleanup(void)
72	{
73	RTSpinlockDestroy(g_HeapExecSpinlock);
74	g_HeapExecSpinlock = NIL_RTSPINLOCK;
75	}
76
77
78	/**
79	* Donate read+write+execute memory to the exec heap.
80	*
81	* This API is specific to AMD64 and Linux/GNU. A kernel module that desires to
82	* use RTMemExecAlloc on AMD64 Linux/GNU will have to donate some statically
83	* allocated memory in the module if it wishes for GCC generated code to work.
84	* GCC can only generate modules that work in the address range ~2GB to ~0
85	* currently.
86	*
87	* The API only accept one single donation.
88	*
89	* @returns IPRT status code.
90	* @param pvMemory Pointer to the memory block.
91	* @param cb The size of the memory block.
92	*/
93	RTR0DECL(int) RTR0MemExecDonate(void *pvMemory, size_t cb)
94	{
95	int rc;
96	AssertReturn(g_HeapExec == NIL_RTHEAPSIMPLE, VERR_WRONG_ORDER);
97
98	rc = RTSpinlockCreate(&g_HeapExecSpinlock);
99	if (RT_SUCCESS(rc))
100	{
101	rc = RTHeapSimpleInit(&g_HeapExec, pvMemory, cb);
102	if (RT_FAILURE(rc))
103	rtR0MemExecCleanup();
104	}
105	return rc;
106	}
107	#endif /* RTMEMALLOC_EXEC_HEAP */
108
109
110
111	/**
112	* OS specific allocation function.
113	*/
114	PRTMEMHDR rtMemAlloc(size_t cb, uint32_t fFlags)
115	{
116	/*
117	* Allocate.
118	*/
119	PRTMEMHDR pHdr;
120	if (fFlags & RTMEMHDR_FLAG_EXEC)
121	{
122	#if defined(RT_ARCH_AMD64)
123	# ifdef RTMEMALLOC_EXEC_HEAP
124	if (g_HeapExec != NIL_RTHEAPSIMPLE)
125	{
126	RTSPINLOCKTMP SpinlockTmp = RTSPINLOCKTMP_INITIALIZER;
127	RTSpinlockAcquireNoInts(g_HeapExecSpinlock, &SpinlockTmp);
128	pHdr = (PRTMEMHDR)RTHeapSimpleAlloc(g_HeapExec, cb + sizeof(*pHdr), 0);
129	RTSpinlockReleaseNoInts(g_HeapExecSpinlock, &SpinlockTmp);
130	fFlags \|= RTMEMHDR_FLAG_EXEC_HEAP;
131	}
132	else
133	# endif
134	pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL \| __GFP_HIGHMEM, MY_PAGE_KERNEL_EXEC);
135
136	#elif defined(PAGE_KERNEL_EXEC) && defined(CONFIG_X86_PAE)
137	pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL \| __GFP_HIGHMEM, MY_PAGE_KERNEL_EXEC);
138	#else
139	pHdr = (PRTMEMHDR)vmalloc(cb + sizeof(*pHdr));
140	#endif
141	}
142	else
143	{
144	if (cb <= PAGE_SIZE)
145	{
146	fFlags \|= RTMEMHDR_FLAG_KMALLOC;
147	pHdr = kmalloc(cb + sizeof(*pHdr), GFP_KERNEL);
148	}
149	else
150	pHdr = vmalloc(cb + sizeof(*pHdr));
151	}
152
153	/*
154	* Initialize.
155	*/
156	if (pHdr)
157	{
158	pHdr->u32Magic = RTMEMHDR_MAGIC;
159	pHdr->fFlags = fFlags;
160	pHdr->cb = cb;
161	pHdr->cbReq = cb;
162	}
163	return pHdr;
164	}
165
166
167	/**
168	* OS specific free function.
169	*/
170	void rtMemFree(PRTMEMHDR pHdr)
171	{
172	pHdr->u32Magic += 1;
173	if (pHdr->fFlags & RTMEMHDR_FLAG_KMALLOC)
174	kfree(pHdr);
175	#ifdef RTMEMALLOC_EXEC_HEAP
176	else if (pHdr->fFlags & RTMEMHDR_FLAG_EXEC_HEAP)
177	{
178	RTSPINLOCKTMP SpinlockTmp = RTSPINLOCKTMP_INITIALIZER;
179	RTSpinlockAcquireNoInts(g_HeapExecSpinlock, &SpinlockTmp);
180	RTHeapSimpleFree(g_HeapExec, pHdr);
181	RTSpinlockReleaseNoInts(g_HeapExecSpinlock, &SpinlockTmp);
182	}
183	#endif
184	else
185	vfree(pHdr);
186	}
187
188
189	/**
190	* Compute order. Some functions allocate 2^order pages.
191	*
192	* @returns order.
193	* @param cPages Number of pages.
194	*/
195	static int CalcPowerOf2Order(unsigned long cPages)
196	{
197	int iOrder;
198	unsigned long cTmp;
199
200	for (iOrder = 0, cTmp = cPages; cTmp >>= 1; ++iOrder)
201	;
202	if (cPages & ~(1 << iOrder))
203	++iOrder;
204
205	return iOrder;
206	}
207
208
209	/**
210	* Allocates physical contiguous memory (below 4GB).
211	* The allocation is page aligned and the content is undefined.
212	*
213	* @returns Pointer to the memory block. This is page aligned.
214	* @param pPhys Where to store the physical address.
215	* @param cb The allocation size in bytes. This is always
216	* rounded up to PAGE_SIZE.
217	*/
218	RTR0DECL(void *) RTMemContAlloc(PRTCCPHYS pPhys, size_t cb)
219	{
220	int cOrder;
221	unsigned cPages;
222	struct page *paPages;
223
224	/*
225	* validate input.
226	*/
227	Assert(VALID_PTR(pPhys));
228	Assert(cb > 0);
229
230	/*
231	* Allocate page pointer array.
232	*/
233	cb = RT_ALIGN_Z(cb, PAGE_SIZE);
234	cPages = cb >> PAGE_SHIFT;
235	cOrder = CalcPowerOf2Order(cPages);
236	#ifdef RT_ARCH_AMD64 /** @todo check out if there is a correct way of getting memory below 4GB (physically). */
237	paPages = alloc_pages(GFP_DMA, cOrder);
238	#else
239	paPages = alloc_pages(GFP_USER, cOrder);
240	#endif
241	if (paPages)
242	{
243	/*
244	* Reserve the pages and mark them executable.
245	*/
246	unsigned iPage;
247	for (iPage = 0; iPage < cPages; iPage++)
248	{
249	Assert(!PageHighMem(&paPages[iPage]));
250	if (iPage + 1 < cPages)
251	{
252	AssertMsg( (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage])) + PAGE_SIZE
253	== (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage + 1]))
254	&& page_to_phys(&paPages[iPage]) + PAGE_SIZE
255	== page_to_phys(&paPages[iPage + 1]),
256	("iPage=%i cPages=%u [0]=%#llx,%p [1]=%#llx,%p\n", iPage, cPages,
257	(long long)page_to_phys(&paPages[iPage]), phys_to_virt(page_to_phys(&paPages[iPage])),
258	(long long)page_to_phys(&paPages[iPage + 1]), phys_to_virt(page_to_phys(&paPages[iPage + 1])) ));
259	}
260
261	SetPageReserved(&paPages[iPage]);
262	#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 4, 20) /** @todo find the exact kernel where change_page_attr was introduced. */
263	MY_SET_PAGES_EXEC(&paPages[iPage], 1);
264	#endif
265	}
266	*pPhys = page_to_phys(paPages);
267	return phys_to_virt(page_to_phys(paPages));
268	}
269
270	return NULL;
271	}
272
273
274	/**
275	* Frees memory allocated ysing RTMemContAlloc().
276	*
277	* @param pv Pointer to return from RTMemContAlloc().
278	* @param cb The cb parameter passed to RTMemContAlloc().
279	*/
280	RTR0DECL(void) RTMemContFree(void *pv, size_t cb)
281	{
282	if (pv)
283	{
284	int cOrder;
285	unsigned cPages;
286	unsigned iPage;
287	struct page *paPages;
288
289	/* validate */
290	AssertMsg(!((uintptr_t)pv & PAGE_OFFSET_MASK), ("pv=%p\n", pv));
291	Assert(cb > 0);
292
293	/* calc order and get pages */
294	cb = RT_ALIGN_Z(cb, PAGE_SIZE);
295	cPages = cb >> PAGE_SHIFT;
296	cOrder = CalcPowerOf2Order(cPages);
297	paPages = virt_to_page(pv);
298
299	/*
300	* Restore page attributes freeing the pages.
301	*/
302	for (iPage = 0; iPage < cPages; iPage++)
303	{
304	ClearPageReserved(&paPages[iPage]);
305	#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 4, 20) /** @todo find the exact kernel where change_page_attr was introduced. */
306	MY_SET_PAGES_NOEXEC(&paPages[iPage], 1);
307	#endif
308	}
309	__free_pages(paPages, cOrder);
310	}
311	}
312

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source: vbox/trunk/src/VBox/Runtime/r0drv/linux/alloc-r0drv-linux.c@ 13476

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