source: vbox/trunk/include/iprt/memobj.h@ 30270

/** @file
 * IPRT - Memory Objects (Ring-0).
 */

/*
 * Copyright (C) 2006-2007 Oracle Corporation
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.virtualbox.org. This file is free software;
 * you can redistribute it and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software
 * Foundation, in version 2 as it comes in the "COPYING" file of the
 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 *
 * The contents of this file may alternatively be used under the terms
 * of the Common Development and Distribution License Version 1.0
 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
 * VirtualBox OSE distribution, in which case the provisions of the
 * CDDL are applicable instead of those of the GPL.
 *
 * You may elect to license modified versions of this file under the
 * terms and conditions of either the GPL or the CDDL or both.
 */

#ifndef ___iprt_memobj_h
#define ___iprt_memobj_h

#include <iprt/cdefs.h>
#include <iprt/types.h>

RT_C_DECLS_BEGIN

/** @defgroup grp_rt_memobj     RTMemObj - Memory Object Manipulation (Ring-0)
 * @ingroup grp_rt
 * @{
 */

#ifdef IN_RING0

/**
 * Checks if this is mapping or not.
 *
 * @returns true if it's a mapping, otherwise false.
 * @param   MemObj  The ring-0 memory object handle.
 */
RTR0DECL(bool) RTR0MemObjIsMapping(RTR0MEMOBJ MemObj);

/**
 * Gets the address of a ring-0 memory object.
 *
 * @returns The address of the memory object.
 * @returns NULL if the handle is invalid (asserts in strict builds) or if there isn't any mapping.
 * @param   MemObj  The ring-0 memory object handle.
 */
RTR0DECL(void *) RTR0MemObjAddress(RTR0MEMOBJ MemObj);

/**
 * Gets the ring-3 address of a ring-0 memory object.
 *
 * This only applies to ring-0 memory object with ring-3 mappings of some kind, i.e.
 * locked user memory, reserved user address space and user mappings. This API should
 * not be used on any other objects.
 *
 * @returns The address of the memory object.
 * @returns NIL_RTR3PTR if the handle is invalid or if it's not an object with a ring-3 mapping.
 *          Strict builds will assert in both cases.
 * @param   MemObj  The ring-0 memory object handle.
 */
RTR0DECL(RTR3PTR) RTR0MemObjAddressR3(RTR0MEMOBJ MemObj);

/**
 * Gets the size of a ring-0 memory object.
 *
 * @returns The address of the memory object.
 * @returns NULL if the handle is invalid (asserts in strict builds) or if there isn't any mapping.
 * @param   MemObj  The ring-0 memory object handle.
 */
RTR0DECL(size_t) RTR0MemObjSize(RTR0MEMOBJ MemObj);

/**
 * Get the physical address of an page in the memory object.
 *
 * @returns The physical address.
 * @returns NIL_RTHCPHYS if the object doesn't contain fixed physical pages.
 * @returns NIL_RTHCPHYS if the iPage is out of range.
 * @returns NIL_RTHCPHYS if the object handle isn't valid.
 * @param   MemObj  The ring-0 memory object handle.
 * @param   iPage   The page number within the object.
 */
RTR0DECL(RTHCPHYS) RTR0MemObjGetPagePhysAddr(RTR0MEMOBJ MemObj, size_t iPage);

/**
 * Frees a ring-0 memory object.
 *
 * @returns IPRT status code.
 * @retval  VERR_INVALID_HANDLE if
 * @param   MemObj          The ring-0 memory object to be freed. NULL is accepted.
 * @param   fFreeMappings   Whether or not to free mappings of the object.
 */
RTR0DECL(int) RTR0MemObjFree(RTR0MEMOBJ MemObj, bool fFreeMappings);

/**
 * Allocates page aligned virtual kernel memory.
 *
 * The memory is taken from a non paged (= fixed physical memory backing) pool.
 *
 * @returns IPRT status code.
 * @param   pMemObj         Where to store the ring-0 memory object handle.
 * @param   cb              Number of bytes to allocate. This is rounded up to nearest page.
 * @param   fExecutable     Flag indicating whether it should be permitted to executed code in the memory object.
 */
RTR0DECL(int) RTR0MemObjAllocPage(PRTR0MEMOBJ pMemObj, size_t cb, bool fExecutable);

/**
 * Allocates page aligned virtual kernel memory with physical backing below 4GB.
 *
 * The physical memory backing the allocation is fixed.
 *
 * @returns IPRT status code.
 * @param   pMemObj         Where to store the ring-0 memory object handle.
 * @param   cb              Number of bytes to allocate. This is rounded up to nearest page.
 * @param   fExecutable     Flag indicating whether it should be permitted to executed code in the memory object.
 */
RTR0DECL(int) RTR0MemObjAllocLow(PRTR0MEMOBJ pMemObj, size_t cb, bool fExecutable);

/**
 * Allocates page aligned virtual kernel memory with contiguous physical backing below 4GB.
 *
 * The physical memory backing the allocation is fixed.
 *
 * @returns IPRT status code.
 * @param   pMemObj         Where to store the ring-0 memory object handle.
 * @param   cb              Number of bytes to allocate. This is rounded up to nearest page.
 * @param   fExecutable     Flag indicating whether it should be permitted to executed code in the memory object.
 */
RTR0DECL(int) RTR0MemObjAllocCont(PRTR0MEMOBJ pMemObj, size_t cb, bool fExecutable);

/**
 * Locks a range of user virtual memory.
 *
 * @returns IPRT status code.
 * @param   pMemObj         Where to store the ring-0 memory object handle.
 * @param   R3Ptr           User virtual address. This is rounded down to a page
 *                          boundrary.
 * @param   cb              Number of bytes to lock. This is rounded up to
 *                          nearest page boundrary.
 * @param   fAccess         The desired access, a combination of RTMEM_PROT_READ
 *                          and RTMEM_PROT_WRITE.
 * @param   R0Process       The process to lock pages in. NIL_R0PROCESS is an
 *                          alias for the current one.
 *
 * @remarks RTR0MemGetAddressR3() and RTR0MemGetAddress() will return therounded
 *          down address.
 *
 * @remarks Linux: This API requires that the memory begin locked is in a memory
 *          mapping that is not required in any forked off child process. This
 *          is not intented as permanent restriction, feel free to help out
 *          lifting it.
 */
RTR0DECL(int) RTR0MemObjLockUser(PRTR0MEMOBJ pMemObj, RTR3PTR R3Ptr, size_t cb, uint32_t fAccess, RTR0PROCESS R0Process);

/**
 * Locks a range of kernel virtual memory.
 *
 * @returns IPRT status code.
 * @param   pMemObj         Where to store the ring-0 memory object handle.
 * @param   pv              Kernel virtual address. This is rounded down to a page boundrary.
 * @param   cb              Number of bytes to lock. This is rounded up to nearest page boundrary.
 * @param   fAccess         The desired access, a combination of RTMEM_PROT_READ
 *                          and RTMEM_PROT_WRITE.
 *
 * @remark  RTR0MemGetAddress() will return the rounded down address.
 */
RTR0DECL(int) RTR0MemObjLockKernel(PRTR0MEMOBJ pMemObj, void *pv, size_t cb, uint32_t fAccess);

/**
 * Allocates contiguous page aligned physical memory without (necessarily) any kernel mapping.
 *
 * @returns IPRT status code.
 * @param   pMemObj         Where to store the ring-0 memory object handle.
 * @param   cb              Number of bytes to allocate. This is rounded up to nearest page.
 * @param   PhysHighest     The highest permittable address (inclusive).
 *                          Pass NIL_RTHCPHYS if any address is acceptable.
 */
RTR0DECL(int) RTR0MemObjAllocPhys(PRTR0MEMOBJ pMemObj, size_t cb, RTHCPHYS PhysHighest);

/**
 * Allocates contiguous physical memory without (necessarily) any kernel mapping.
 *
 * @returns IPRT status code.
 * @param   pMemObj         Where to store the ring-0 memory object handle.
 * @param   cb              Number of bytes to allocate. This is rounded up to nearest page.
 * @param   PhysHighest     The highest permittable address (inclusive).
 *                          Pass NIL_RTHCPHYS if any address is acceptable.
 * @param   uAlignment      The alignment of the reserved memory.
 *                          Supported values are 0 (alias for PAGE_SIZE), PAGE_SIZE, _2M, _4M and _1G.
 */
RTR0DECL(int) RTR0MemObjAllocPhysEx(PRTR0MEMOBJ pMemObj, size_t cb, RTHCPHYS PhysHighest, size_t uAlignment);

/**
 * Allocates non-contiguous page aligned physical memory without (necessarily) any kernel mapping.
 *
 * This API is for allocating huge amounts of pages and will return
 * VERR_NOT_SUPPORTED if this cannot be implemented in a satisfactory
 * manner.
 *
 * @returns IPRT status code.
 * @retval  VERR_NOT_SUPPORTED if it's not possible to allocated unmapped
 *          physical memory on this platform. The caller should expect
 *          this error and have a fallback strategy for it.
 *
 * @param   pMemObj         Where to store the ring-0 memory object handle.
 * @param   cb              Number of bytes to allocate. This is rounded up to nearest page.
 * @param   PhysHighest     The highest permittable address (inclusive).
 *                          Pass NIL_RTHCPHYS if any address is acceptable.
 */
RTR0DECL(int) RTR0MemObjAllocPhysNC(PRTR0MEMOBJ pMemObj, size_t cb, RTHCPHYS PhysHighest);

/** Memory cache policy for RTR0MemObjEnterPhys.
 * @{
 */
/** Default caching policy -- don't care. */
#define RTMEM_CACHE_POLICY_DONT_CARE    UINT32_C(0)
/** MMIO caching policy -- uncachable. */
#define RTMEM_CACHE_POLICY_MMIO         UINT32_C(1)
/** @} */

/**
 * Creates a page aligned, contiguous, physical memory object.
 *
 * No physical memory is allocated, we trust you do know what you're doing.
 *
 * @returns IPRT status code.
 * @param   pMemObj         Where to store the ring-0 memory object handle.
 * @param   Phys            The physical address to start at. This is rounded down to the
 *                          nearest page boundrary.
 * @param   cb              The size of the object in bytes. This is rounded up to nearest page boundrary.
 * @param   uCachePolicy    One of the RTMEM_CACHE_XXX modes.
 */
RTR0DECL(int) RTR0MemObjEnterPhys(PRTR0MEMOBJ pMemObj, RTHCPHYS Phys, size_t cb, uint32_t uCachePolicy);

/**
 * Reserves kernel virtual address space.
 *
 * If this function fails with VERR_NOT_SUPPORTED, the idea is that you
 * can use RTR0MemObjEnterPhys() + RTR0MemObjMapKernel() as a fallback if
 * you have a safe physical address range to make use of...
 *
 * @returns IPRT status code.
 * @param   pMemObj         Where to store the ring-0 memory object handle.
 * @param   pvFixed         Requested address. (void *)-1 means any address. This must match the alignment.
 * @param   cb              The number of bytes to reserve. This is rounded up to nearest page.
 * @param   uAlignment      The alignment of the reserved memory.
 *                          Supported values are 0 (alias for PAGE_SIZE), PAGE_SIZE, _2M and _4M.
 */
RTR0DECL(int) RTR0MemObjReserveKernel(PRTR0MEMOBJ pMemObj, void *pvFixed, size_t cb, size_t uAlignment);

/**
 * Reserves user virtual address space in the current process.
 *
 * @returns IPRT status code.
 * @param   pMemObj         Where to store the ring-0 memory object handle.
 * @param   R3PtrFixed      Requested address. (RTR3PTR)-1 means any address. This must match the alignment.
 * @param   cb              The number of bytes to reserve. This is rounded up to nearest PAGE_SIZE.
 * @param   uAlignment      The alignment of the reserved memory.
 *                          Supported values are 0 (alias for PAGE_SIZE), PAGE_SIZE, _2M and _4M.
 * @param   R0Process       The process to reserve the memory in. NIL_R0PROCESS is an alias for the current one.
 */
RTR0DECL(int) RTR0MemObjReserveUser(PRTR0MEMOBJ pMemObj, RTR3PTR R3PtrFixed, size_t cb, size_t uAlignment, RTR0PROCESS R0Process);

/**
 * Maps a memory object into kernel virtual address space.
 *
 * This is the same as calling RTR0MemObjMapKernelEx with cbSub and offSub set
 * to zero.
 *
 * @returns IPRT status code.
 * @param   pMemObj         Where to store the ring-0 memory object handle of the mapping object.
 * @param   MemObjToMap     The object to be map.
 * @param   pvFixed         Requested address. (void *)-1 means any address. This must match the alignment.
 * @param   uAlignment      The alignment of the reserved memory.
 *                          Supported values are 0 (alias for PAGE_SIZE), PAGE_SIZE, _2M and _4M.
 * @param   fProt           Combination of RTMEM_PROT_* flags (except RTMEM_PROT_NONE).
 */
RTR0DECL(int) RTR0MemObjMapKernel(PRTR0MEMOBJ pMemObj, RTR0MEMOBJ MemObjToMap, void *pvFixed, size_t uAlignment, unsigned fProt);

/**
 * Maps a memory object into kernel virtual address space.
 *
 * The ability to map subsections of the object into kernel space is currently
 * not implemented on all platforms. All/Most of platforms supports mapping the
 * whole object into  kernel space.
 *
 * @returns IPRT status code.
 * @retval  VERR_NOT_SUPPORTED if it's not possible to map a subsection of a
 *          memory object on this platform. When you hit this, try implement it.
 *
 * @param   pMemObj         Where to store the ring-0 memory object handle of the mapping object.
 * @param   MemObjToMap     The object to be map.
 * @param   pvFixed         Requested address. (void *)-1 means any address. This must match the alignment.
 * @param   uAlignment      The alignment of the reserved memory.
 *                          Supported values are 0 (alias for PAGE_SIZE), PAGE_SIZE, _2M and _4M.
 * @param   fProt           Combination of RTMEM_PROT_* flags (except RTMEM_PROT_NONE).
 * @param   offSub          Where in the object to start mapping. If non-zero
 *                          the value must be page aligned and cbSub must be
 *                          non-zero as well.
 * @param   cbSub           The size of the part of the object to be mapped. If
 *                          zero the entire object is mapped. The value must be
 *                          page aligned.
 */
RTR0DECL(int) RTR0MemObjMapKernelEx(PRTR0MEMOBJ pMemObj, RTR0MEMOBJ MemObjToMap, void *pvFixed, size_t uAlignment,
                                    unsigned fProt, size_t offSub, size_t cbSub);

/**
 * Maps a memory object into user virtual address space in the current process.
 *
 * @returns IPRT status code.
 * @param   pMemObj         Where to store the ring-0 memory object handle of the mapping object.
 * @param   MemObjToMap     The object to be map.
 * @param   R3PtrFixed      Requested address. (RTR3PTR)-1 means any address. This must match the alignment.
 * @param   uAlignment      The alignment of the reserved memory.
 *                          Supported values are 0 (alias for PAGE_SIZE), PAGE_SIZE, _2M and _4M.
 * @param   fProt           Combination of RTMEM_PROT_* flags (except RTMEM_PROT_NONE).
 * @param   R0Process       The process to map the memory into. NIL_R0PROCESS is an alias for the current one.
 */
RTR0DECL(int) RTR0MemObjMapUser(PRTR0MEMOBJ pMemObj, RTR0MEMOBJ MemObjToMap, RTR3PTR R3PtrFixed, size_t uAlignment, unsigned fProt, RTR0PROCESS R0Process);

/**
 * Change the page level protection of one or more pages in a memory object.
 *
 * @returns IPRT status code.
 * @retval  VERR_NOT_SUPPORTED if the OS doesn't provide any way to manipulate
 *          page level protection. The caller must handle this status code
 *          gracefully. (Note that it may also occur if the implementation is
 *          missing, in which case just go ahead and implement it.)
 *
 * @param   hMemObj         Memory object handle.
 * @param   offSub          Offset into the memory object. Must be page aligned.
 * @param   cbSub           Number of bytes to change the protection of. Must be
 *                          page aligned.
 * @param   fProt           Combination of RTMEM_PROT_* flags.
 */
RTR0DECL(int) RTR0MemObjProtect(RTR0MEMOBJ hMemObj, size_t offSub, size_t cbSub, uint32_t fProt);

#endif /* IN_RING0 */

/** @} */

RT_C_DECLS_END

#endif