alloc-r0drv-linux.c@ 28800

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1	/* $Id: alloc-r0drv-linux.c 28800 2010-04-27 08:22:32Z vboxsync $ */
2	/** @file
3	* IPRT - Memory Allocation, Ring-0 Driver, Linux.
4	*/
5
6	/*
7	* Copyright (C) 2006-2007 Oracle Corporation
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
27
28	/*******************************************************************************
29	* Header Files *
30	*******************************************************************************/
31	#include "the-linux-kernel.h"
32	#include "internal/iprt.h"
33
34	#include <iprt/mem.h>
35	#include <iprt/assert.h>
36	#include "r0drv/alloc-r0drv.h"
37
38	#if defined(RT_ARCH_AMD64) \|\| defined(DOXYGEN_RUNNING)
39	/**
40	* We need memory in the module range (~2GB to ~0) this can only be obtained
41	* thru APIs that are not exported (see module_alloc()).
42	*
43	* So, we'll have to create a quick and dirty heap here using BSS memory.
44	* Very annoying and it's going to restrict us!
45	*/
46	# define RTMEMALLOC_EXEC_HEAP
47	#endif
48	#ifdef RTMEMALLOC_EXEC_HEAP
49	# include <iprt/heap.h>
50	# include <iprt/spinlock.h>
51	# include <iprt/err.h>
52	#endif
53
54
55	/*******************************************************************************
56	* Global Variables *
57	*******************************************************************************/
58	#ifdef RTMEMALLOC_EXEC_HEAP
59	/** The heap. */
60	static RTHEAPSIMPLE g_HeapExec = NIL_RTHEAPSIMPLE;
61	/** Spinlock protecting the heap. */
62	static RTSPINLOCK g_HeapExecSpinlock = NIL_RTSPINLOCK;
63
64
65	/**
66	* API for cleaning up the heap spinlock on IPRT termination.
67	* This is as RTMemExecDonate specific to AMD64 Linux/GNU.
68	*/
69	void rtR0MemExecCleanup(void)
70	{
71	RTSpinlockDestroy(g_HeapExecSpinlock);
72	g_HeapExecSpinlock = NIL_RTSPINLOCK;
73	}
74
75
76	/**
77	* Donate read+write+execute memory to the exec heap.
78	*
79	* This API is specific to AMD64 and Linux/GNU. A kernel module that desires to
80	* use RTMemExecAlloc on AMD64 Linux/GNU will have to donate some statically
81	* allocated memory in the module if it wishes for GCC generated code to work.
82	* GCC can only generate modules that work in the address range ~2GB to ~0
83	* currently.
84	*
85	* The API only accept one single donation.
86	*
87	* @returns IPRT status code.
88	* @param pvMemory Pointer to the memory block.
89	* @param cb The size of the memory block.
90	*/
91	RTR0DECL(int) RTR0MemExecDonate(void *pvMemory, size_t cb)
92	{
93	int rc;
94	AssertReturn(g_HeapExec == NIL_RTHEAPSIMPLE, VERR_WRONG_ORDER);
95
96	rc = RTSpinlockCreate(&g_HeapExecSpinlock);
97	if (RT_SUCCESS(rc))
98	{
99	rc = RTHeapSimpleInit(&g_HeapExec, pvMemory, cb);
100	if (RT_FAILURE(rc))
101	rtR0MemExecCleanup();
102	}
103	return rc;
104	}
105	RT_EXPORT_SYMBOL(RTR0MemExecDonate);
106	#endif /* RTMEMALLOC_EXEC_HEAP */
107
108
109
110	/**
111	* OS specific allocation function.
112	*/
113	PRTMEMHDR rtR0MemAlloc(size_t cb, uint32_t fFlags)
114	{
115	/*
116	* Allocate.
117	*/
118	PRTMEMHDR pHdr;
119	if (fFlags & RTMEMHDR_FLAG_EXEC)
120	{
121	#if defined(RT_ARCH_AMD64)
122	# ifdef RTMEMALLOC_EXEC_HEAP
123	if (g_HeapExec != NIL_RTHEAPSIMPLE)
124	{
125	RTSPINLOCKTMP SpinlockTmp = RTSPINLOCKTMP_INITIALIZER;
126	RTSpinlockAcquireNoInts(g_HeapExecSpinlock, &SpinlockTmp);
127	pHdr = (PRTMEMHDR)RTHeapSimpleAlloc(g_HeapExec, cb + sizeof(*pHdr), 0);
128	RTSpinlockReleaseNoInts(g_HeapExecSpinlock, &SpinlockTmp);
129	fFlags \|= RTMEMHDR_FLAG_EXEC_HEAP;
130	}
131	else
132	pHdr = NULL;
133	# else /* !RTMEMALLOC_EXEC_HEAP */
134	pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL \| __GFP_HIGHMEM, MY_PAGE_KERNEL_EXEC);
135	# endif /* !RTMEMALLOC_EXEC_HEAP */
136
137	#elif defined(PAGE_KERNEL_EXEC) && defined(CONFIG_X86_PAE)
138	pHdr = (PRTMEMHDR)__vmalloc(cb + sizeof(*pHdr), GFP_KERNEL \| __GFP_HIGHMEM, MY_PAGE_KERNEL_EXEC);
139	#else
140	pHdr = (PRTMEMHDR)vmalloc(cb + sizeof(*pHdr));
141	#endif
142	}
143	else
144	{
145	if (cb <= PAGE_SIZE)
146	{
147	fFlags \|= RTMEMHDR_FLAG_KMALLOC;
148	pHdr = kmalloc(cb + sizeof(*pHdr), GFP_KERNEL);
149	}
150	else
151	pHdr = vmalloc(cb + sizeof(*pHdr));
152	}
153
154	/*
155	* Initialize.
156	*/
157	if (pHdr)
158	{
159	pHdr->u32Magic = RTMEMHDR_MAGIC;
160	pHdr->fFlags = fFlags;
161	pHdr->cb = cb;
162	pHdr->cbReq = cb;
163	}
164	return pHdr;
165	}
166
167
168	/**
169	* OS specific free function.
170	*/
171	void rtR0MemFree(PRTMEMHDR pHdr)
172	{
173	pHdr->u32Magic += 1;
174	if (pHdr->fFlags & RTMEMHDR_FLAG_KMALLOC)
175	kfree(pHdr);
176	#ifdef RTMEMALLOC_EXEC_HEAP
177	else if (pHdr->fFlags & RTMEMHDR_FLAG_EXEC_HEAP)
178	{
179	RTSPINLOCKTMP SpinlockTmp = RTSPINLOCKTMP_INITIALIZER;
180	RTSpinlockAcquireNoInts(g_HeapExecSpinlock, &SpinlockTmp);
181	RTHeapSimpleFree(g_HeapExec, pHdr);
182	RTSpinlockReleaseNoInts(g_HeapExecSpinlock, &SpinlockTmp);
183	}
184	#endif
185	else
186	vfree(pHdr);
187	}
188
189
190	/**
191	* Compute order. Some functions allocate 2^order pages.
192	*
193	* @returns order.
194	* @param cPages Number of pages.
195	*/
196	static int CalcPowerOf2Order(unsigned long cPages)
197	{
198	int iOrder;
199	unsigned long cTmp;
200
201	for (iOrder = 0, cTmp = cPages; cTmp >>= 1; ++iOrder)
202	;
203	if (cPages & ~(1 << iOrder))
204	++iOrder;
205
206	return iOrder;
207	}
208
209
210	/**
211	* Allocates physical contiguous memory (below 4GB).
212	* The allocation is page aligned and the content is undefined.
213	*
214	* @returns Pointer to the memory block. This is page aligned.
215	* @param pPhys Where to store the physical address.
216	* @param cb The allocation size in bytes. This is always
217	* rounded up to PAGE_SIZE.
218	*/
219	RTR0DECL(void *) RTMemContAlloc(PRTCCPHYS pPhys, size_t cb)
220	{
221	int cOrder;
222	unsigned cPages;
223	struct page *paPages;
224
225	/*
226	* validate input.
227	*/
228	Assert(VALID_PTR(pPhys));
229	Assert(cb > 0);
230
231	/*
232	* Allocate page pointer array.
233	*/
234	cb = RT_ALIGN_Z(cb, PAGE_SIZE);
235	cPages = cb >> PAGE_SHIFT;
236	cOrder = CalcPowerOf2Order(cPages);
237	#if (defined(RT_ARCH_AMD64) \|\| defined(CONFIG_X86_PAE)) && defined(GFP_DMA32)
238	/* ZONE_DMA32: 0-4GB */
239	paPages = alloc_pages(GFP_DMA32, cOrder);
240	if (!paPages)
241	#endif
242	#ifdef RT_ARCH_AMD64
243	/* ZONE_DMA; 0-16MB */
244	paPages = alloc_pages(GFP_DMA, cOrder);
245	#else
246	/* ZONE_NORMAL: 0-896MB */
247	paPages = alloc_pages(GFP_USER, cOrder);
248	#endif
249	if (paPages)
250	{
251	/*
252	* Reserve the pages and mark them executable.
253	*/
254	unsigned iPage;
255	for (iPage = 0; iPage < cPages; iPage++)
256	{
257	Assert(!PageHighMem(&paPages[iPage]));
258	if (iPage + 1 < cPages)
259	{
260	AssertMsg( (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage])) + PAGE_SIZE
261	== (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage + 1]))
262	&& page_to_phys(&paPages[iPage]) + PAGE_SIZE
263	== page_to_phys(&paPages[iPage + 1]),
264	("iPage=%i cPages=%u [0]=%#llx,%p [1]=%#llx,%p\n", iPage, cPages,
265	(long long)page_to_phys(&paPages[iPage]), phys_to_virt(page_to_phys(&paPages[iPage])),
266	(long long)page_to_phys(&paPages[iPage + 1]), phys_to_virt(page_to_phys(&paPages[iPage + 1])) ));
267	}
268
269	SetPageReserved(&paPages[iPage]);
270	#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 4, 20) /** @todo find the exact kernel where change_page_attr was introduced. */
271	MY_SET_PAGES_EXEC(&paPages[iPage], 1);
272	#endif
273	}
274	*pPhys = page_to_phys(paPages);
275	return phys_to_virt(page_to_phys(paPages));
276	}
277
278	return NULL;
279	}
280	RT_EXPORT_SYMBOL(RTMemContAlloc);
281
282
283	/**
284	* Frees memory allocated ysing RTMemContAlloc().
285	*
286	* @param pv Pointer to return from RTMemContAlloc().
287	* @param cb The cb parameter passed to RTMemContAlloc().
288	*/
289	RTR0DECL(void) RTMemContFree(void *pv, size_t cb)
290	{
291	if (pv)
292	{
293	int cOrder;
294	unsigned cPages;
295	unsigned iPage;
296	struct page *paPages;
297
298	/* validate */
299	AssertMsg(!((uintptr_t)pv & PAGE_OFFSET_MASK), ("pv=%p\n", pv));
300	Assert(cb > 0);
301
302	/* calc order and get pages */
303	cb = RT_ALIGN_Z(cb, PAGE_SIZE);
304	cPages = cb >> PAGE_SHIFT;
305	cOrder = CalcPowerOf2Order(cPages);
306	paPages = virt_to_page(pv);
307
308	/*
309	* Restore page attributes freeing the pages.
310	*/
311	for (iPage = 0; iPage < cPages; iPage++)
312	{
313	ClearPageReserved(&paPages[iPage]);
314	#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 4, 20) /** @todo find the exact kernel where change_page_attr was introduced. */
315	MY_SET_PAGES_NOEXEC(&paPages[iPage], 1);
316	#endif
317	}
318	__free_pages(paPages, cOrder);
319	}
320	}
321	RT_EXPORT_SYMBOL(RTMemContFree);
322

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source: vbox/trunk/src/VBox/Runtime/r0drv/linux/alloc-r0drv-linux.c@ 28800

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