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Kernel: Make contiguous VM objects use "user physical pages" by default

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If someone specifically wants contiguous memory in the low-physical-
address-for-DMA range ("super pages"), they can use the
allocate_dma_buffer_pages() helper.
This commit is contained in:
Andreas Kling 2022-02-11 12:20:26 +01:00
parent 5ff816abbf
commit 2ff9db0245
3 changed files with 24 additions and 1 deletions
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22
Kernel/Memory/MemoryManager.cpp
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@ -954,6 +954,28 @@ ErrorOr<NonnullRefPtr<PhysicalPage>> MemoryManager::allocate_user_physical_page(
return page.release_nonnull();
}
ErrorOr<NonnullRefPtrVector<PhysicalPage>> MemoryManager::allocate_contiguous_user_physical_pages(size_t size)
{
VERIFY(!(size % PAGE_SIZE));
SpinlockLocker lock(s_mm_lock);
size_t page_count = ceil_div(size, static_cast<size_t>(PAGE_SIZE));
for (auto& physical_region : m_user_physical_regions) {
auto physical_pages = physical_region.take_contiguous_free_pages(page_count);
if (!physical_pages.is_empty()) {
{
auto cleanup_region = TRY(MM.allocate_kernel_region(physical_pages[0].paddr(), PAGE_SIZE * page_count, "MemoryManager Allocation Sanitization", Region::Access::Read | Region::Access::Write));
memset(cleanup_region->vaddr().as_ptr(), 0, PAGE_SIZE * page_count);
}
m_system_memory_info.user_physical_pages_used += page_count;
return physical_pages;
}
}
dmesgln("MM: no contiguous user physical pages available");
return ENOMEM;
}
ErrorOr<NonnullRefPtrVector<PhysicalPage>> MemoryManager::allocate_contiguous_supervisor_physical_pages(size_t size)
{
VERIFY(!(size % PAGE_SIZE));