/**
* 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.
*/
Assert(VALID_PTR(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]);
#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 4, 20) /** @todo find the exact kernel where change_page_attr was introduced. */
MY_SET_PAGES_EXEC(&paPages[iPage], 1);
#endif
}
*pPhys = page_to_phys(paPages);
pvRet = phys_to_virt(page_to_phys(paPages));
}
else
pvRet = NULL;
IPRT_LINUX_RESTORE_EFL_AC();
return pvRet;
}
/**
* Internal worker that allocates physical pages and creates the memory object for them.
*
* @returns IPRT status code.
* @param ppMemLnx Where to store the memory object pointer.
* @param enmType The object type.
* @param cb The number of bytes to allocate.
* @param uAlignment The alignment of the phyiscal memory.
* Only valid if fContiguous == true, ignored otherwise.
* @param fFlagsLnx The page allocation flags (GPFs).
* @param fContiguous Whether the allocation must be contiguous.
*/
static int rtR0MemObjLinuxAllocPages(PRTR0MEMOBJLNX *ppMemLnx, RTR0MEMOBJTYPE enmType, size_t cb,
size_t uAlignment, unsigned fFlagsLnx, bool fContiguous)
{
size_t iPage;
size_t const cPages = cb >> PAGE_SHIFT;
struct page *paPages;
/*
* Allocate a memory object structure that's large enough to contain
* the page pointer array.
*/
PRTR0MEMOBJLNX pMemLnx = (PRTR0MEMOBJLNX)rtR0MemObjNew(RT_OFFSETOF(RTR0MEMOBJLNX, apPages[cPages]), enmType, NULL, cb);
if (!pMemLnx)
return VERR_NO_MEMORY;
pMemLnx->cPages = cPages;
/*
* Allocate the pages.
* For small allocations we'll try contiguous first and then fall back on page by page.
*/
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 22)
if ( fContiguous
|| cb <= PAGE_SIZE * 2)
{
# ifdef VBOX_USE_INSERT_PAGE
paPages = alloc_pages(fFlagsLnx | __GFP_COMP, rtR0MemObjLinuxOrder(cPages));
# else
paPages = alloc_pages(fFlagsLnx, rtR0MemObjLinuxOrder(cPages));
# endif
if (paPages)
{
fContiguous = true;
for (iPage = 0; iPage < cPages; iPage++)
pMemLnx->apPages[iPage] = &paPages[iPage];
}
else if (fContiguous)
{
rtR0MemObjDelete(&pMemLnx->Core);
return VERR_NO_MEMORY;
}
}
if (!fContiguous)
{
for (iPage = 0; iPage < cPages; iPage++)
{
pMemLnx->apPages[iPage] = alloc_page(fFlagsLnx);
if (RT_UNLIKELY(!pMemLnx->apPages[iPage]))
{
while (iPage-- > 0)
__free_page(pMemLnx->apPages[iPage]);
rtR0MemObjDelete(&pMemLnx->Core);
return VERR_NO_MEMORY;
}
}
}
#else /* < 2.4.22 */
/** @todo figure out why we didn't allocate page-by-page on 2.4.21 and older... */
paPages = alloc_pages(fFlagsLnx, rtR0MemObjLinuxOrder(cPages));
if (!paPages)
{
rtR0MemObjDelete(&pMemLnx->Core);
return VERR_NO_MEMORY;
}
for (iPage = 0; iPage < cPages; iPage++)
{
pMemLnx->apPages[iPage] = &paPages[iPage];
MY_SET_PAGES_EXEC(pMemLnx->apPages[iPage], 1);
if (PageHighMem(pMemLnx->apPages[iPage]))
BUG();
}
fContiguous = true;
#endif /* < 2.4.22 */
pMemLnx->fContiguous = fContiguous;
/*
* Reserve the pages.
*/
for (iPage = 0; iPage < cPages; iPage++)
SetPageReserved(pMemLnx->apPages[iPage]);
/*
* Note that the physical address of memory allocated with alloc_pages(flags, order)
* is always 2^(PAGE_SHIFT+order)-aligned.
*/
if ( fContiguous
&& uAlignment > PAGE_SIZE)
{
/*
* Check for alignment constraints. The physical address of memory allocated with
* alloc_pages(flags, order) is always 2^(PAGE_SHIFT+order)-aligned.
*/
if (RT_UNLIKELY(page_to_phys(pMemLnx->apPages[0]) & ~(uAlignment - 1)))
{
/*
* This should never happen!
*/
printk("rtR0MemObjLinuxAllocPages(cb=%ld, uAlignment=%ld): alloc_pages(..., %d) returned physical memory at %lu!\n",
(unsigned long)cb, (unsigned long)uAlignment, rtR0MemObjLinuxOrder(cPages), (unsigned long)page_to_phys(pMemLnx->apPages[0]));
rtR0MemObjLinuxFreePages(pMemLnx);
return VERR_NO_MEMORY;
}
}
*ppMemLnx = pMemLnx;
return VINF_SUCCESS;
}
