/* $Id: alloc-r0drv-linux.c $ */ /** @file * IPRT - Memory Allocation, Ring-0 Driver, Linux. */ /* * Copyright (C) 2006-2023 Oracle and/or its affiliates. * * This file is part of VirtualBox base platform packages, as * available from https://www.virtualbox.org. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation, in version 3 of the * License. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . * * The contents of this file may alternatively be used under the terms * of the Common Development and Distribution License Version 1.0 * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included * in the VirtualBox 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. * * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 */ /********************************************************************************************************************************* * Header Files * *********************************************************************************************************************************/ #include "the-linux-kernel.h" #include "internal/iprt.h" #include #include #include #include "r0drv/alloc-r0drv.h" #include "internal/initterm.h" /** * OS specific allocation function. */ DECLHIDDEN(int) rtR0MemAllocEx(size_t cb, uint32_t fFlags, PRTMEMHDR *ppHdr) { PRTMEMHDR pHdr; IPRT_LINUX_SAVE_EFL_AC(); /* * Allocate. */ if ( #if 1 /* vmalloc has serious performance issues, avoid it. */ cb <= PAGE_SIZE*16 - sizeof(*pHdr) #else cb <= PAGE_SIZE #endif || (fFlags & RTMEMHDR_FLAG_ANY_CTX) ) { fFlags |= RTMEMHDR_FLAG_KMALLOC; pHdr = kmalloc(cb + sizeof(*pHdr), fFlags & RTMEMHDR_FLAG_ANY_CTX_ALLOC ? GFP_ATOMIC | __GFP_NOWARN : GFP_KERNEL | __GFP_NOWARN); if (RT_UNLIKELY( !pHdr && cb > PAGE_SIZE && !(fFlags & RTMEMHDR_FLAG_ANY_CTX) )) { fFlags &= ~RTMEMHDR_FLAG_KMALLOC; pHdr = vmalloc(cb + sizeof(*pHdr)); } } else pHdr = vmalloc(cb + sizeof(*pHdr)); if (RT_LIKELY(pHdr)) { /* * Initialize. */ pHdr->u32Magic = RTMEMHDR_MAGIC; pHdr->fFlags = fFlags; pHdr->cb = cb; pHdr->cbReq = cb; *ppHdr = pHdr; IPRT_LINUX_RESTORE_EFL_AC(); return VINF_SUCCESS; } IPRT_LINUX_RESTORE_EFL_AC(); return VERR_NO_MEMORY; } /** * OS specific free function. */ DECLHIDDEN(void) rtR0MemFree(PRTMEMHDR pHdr) { IPRT_LINUX_SAVE_EFL_AC(); pHdr->u32Magic += 1; if (pHdr->fFlags & RTMEMHDR_FLAG_KMALLOC) kfree(pHdr); else vfree(pHdr); IPRT_LINUX_RESTORE_EFL_AC(); } /** * Compute order. Some functions allocate 2^order pages. * * @returns order. * @param cPages Number of pages. */ static int CalcPowerOf2Order(unsigned long cPages) { int iOrder; unsigned long cTmp; for (iOrder = 0, cTmp = cPages; cTmp >>= 1; ++iOrder) ; if (cPages & ~(1 << iOrder)) ++iOrder; return iOrder; } /** * Allocates physical contiguous memory (below 4GB). * The allocation is page aligned and the content is undefined. * * @returns Pointer to the memory block. This is page aligned. * @param pPhys Where to store the physical address. * @param cb The allocation size in bytes. This is always * rounded up to PAGE_SIZE. */ RTR0DECL(void *) RTMemContAlloc(PRTCCPHYS pPhys, size_t cb) { int cOrder; unsigned cPages; struct page *paPages; void *pvRet; IPRT_LINUX_SAVE_EFL_AC(); /* * validate input. */ AssertPtr(pPhys); Assert(cb > 0); /* * Allocate page pointer array. */ cb = RT_ALIGN_Z(cb, PAGE_SIZE); cPages = cb >> PAGE_SHIFT; cOrder = CalcPowerOf2Order(cPages); #if (defined(RT_ARCH_AMD64) || defined(CONFIG_X86_PAE)) && defined(GFP_DMA32) /* ZONE_DMA32: 0-4GB */ paPages = alloc_pages(GFP_DMA32 | __GFP_NOWARN, cOrder); if (!paPages) #endif #ifdef RT_ARCH_AMD64 /* ZONE_DMA; 0-16MB */ paPages = alloc_pages(GFP_DMA | __GFP_NOWARN, cOrder); #else /* ZONE_NORMAL: 0-896MB */ paPages = alloc_pages(GFP_USER | __GFP_NOWARN, cOrder); #endif if (paPages) { /* * Reserve the pages and mark them executable. */ unsigned iPage; for (iPage = 0; iPage < cPages; iPage++) { Assert(!PageHighMem(&paPages[iPage])); if (iPage + 1 < cPages) { AssertMsg( (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage])) + PAGE_SIZE == (uintptr_t)phys_to_virt(page_to_phys(&paPages[iPage + 1])) && page_to_phys(&paPages[iPage]) + PAGE_SIZE == page_to_phys(&paPages[iPage + 1]), ("iPage=%i cPages=%u [0]=%#llx,%p [1]=%#llx,%p\n", iPage, cPages, (long long)page_to_phys(&paPages[iPage]), phys_to_virt(page_to_phys(&paPages[iPage])), (long long)page_to_phys(&paPages[iPage + 1]), phys_to_virt(page_to_phys(&paPages[iPage + 1])) )); } SetPageReserved(&paPages[iPage]); } *pPhys = page_to_phys(paPages); pvRet = phys_to_virt(page_to_phys(paPages)); } else pvRet = NULL; IPRT_LINUX_RESTORE_EFL_AC(); return pvRet; } RT_EXPORT_SYMBOL(RTMemContAlloc); /** * Frees memory allocated using RTMemContAlloc(). * * @param pv Pointer to return from RTMemContAlloc(). * @param cb The cb parameter passed to RTMemContAlloc(). */ RTR0DECL(void) RTMemContFree(void *pv, size_t cb) { if (pv) { int cOrder; unsigned cPages; unsigned iPage; struct page *paPages; IPRT_LINUX_SAVE_EFL_AC(); /* validate */ AssertMsg(!((uintptr_t)pv & PAGE_OFFSET_MASK), ("pv=%p\n", pv)); Assert(cb > 0); /* calc order and get pages */ cb = RT_ALIGN_Z(cb, PAGE_SIZE); cPages = cb >> PAGE_SHIFT; cOrder = CalcPowerOf2Order(cPages); paPages = virt_to_page(pv); /* * Restore page attributes freeing the pages. */ for (iPage = 0; iPage < cPages; iPage++) { ClearPageReserved(&paPages[iPage]); } __free_pages(paPages, cOrder); IPRT_LINUX_RESTORE_EFL_AC(); } } RT_EXPORT_SYMBOL(RTMemContFree);