From e7ca83ecb2de85826e8dafdb9f81243ddf3ec760 Mon Sep 17 00:00:00 2001 From: Bananymous Date: Sun, 24 Sep 2023 01:29:34 +0300 Subject: [PATCH] Kernel: VirtualRange doesn't store physical addresses of pages This was unnecessarry allocation, since the page table allready contains virtual address -> physical address mappings. --- kernel/include/kernel/Memory/VirtualRange.h | 1 - kernel/kernel/Memory/VirtualRange.cpp | 89 +++++++++------------ 2 files changed, 39 insertions(+), 51 deletions(-) diff --git a/kernel/include/kernel/Memory/VirtualRange.h b/kernel/include/kernel/Memory/VirtualRange.h index c402294e59..502a9078ab 100644 --- a/kernel/include/kernel/Memory/VirtualRange.h +++ b/kernel/include/kernel/Memory/VirtualRange.h @@ -40,7 +40,6 @@ namespace Kernel vaddr_t m_vaddr { 0 }; size_t m_size { 0 }; PageTable::flags_t m_flags { 0 }; - BAN::Vector m_physical_pages; }; } \ No newline at end of file diff --git a/kernel/kernel/Memory/VirtualRange.cpp b/kernel/kernel/Memory/VirtualRange.cpp index a33c409041..2125b4c30c 100644 --- a/kernel/kernel/Memory/VirtualRange.cpp +++ b/kernel/kernel/Memory/VirtualRange.cpp @@ -1,4 +1,3 @@ -#include #include #include #include @@ -21,27 +20,25 @@ namespace Kernel result->m_vaddr = vaddr; result->m_size = size; result->m_flags = flags; - TRY(result->m_physical_pages.reserve(size / PAGE_SIZE)); ASSERT(page_table.reserve_range(vaddr, size)); - BAN::ScopeGuard unmapper([vaddr, size, &page_table] { page_table.unmap_range(vaddr, size); }); - TRY(result->m_physical_pages.reserve(size / PAGE_SIZE)); - for (size_t offset = 0; offset < size; offset += PAGE_SIZE) + size_t needed_pages = size / PAGE_SIZE; + + for (size_t i = 0; i < needed_pages; i++) { paddr_t paddr = Heap::get().take_free_page(); if (paddr == 0) { - for (paddr_t release : result->m_physical_pages) - Heap::get().release_page(release); + for (size_t j = 0; j < i; j++) + Heap::get().release_page(page_table.physical_address_of(vaddr + j * PAGE_SIZE)); + page_table.unmap_range(vaddr, size); + result->m_vaddr = 0; return BAN::Error::from_errno(ENOMEM); } - MUST(result->m_physical_pages.push_back(paddr)); - page_table.map_page_at(paddr, vaddr + offset, flags); + page_table.map_page_at(paddr, vaddr + i * PAGE_SIZE, flags); } - unmapper.disable(); - return result; } @@ -49,6 +46,7 @@ namespace Kernel { ASSERT(size % PAGE_SIZE == 0); ASSERT(vaddr_start > 0); + ASSERT(vaddr_start + size <= vaddr_end); // Align vaddr range to page boundaries if (size_t rem = vaddr_start % PAGE_SIZE) @@ -64,37 +62,32 @@ namespace Kernel auto result = BAN::UniqPtr::adopt(result_ptr); result->m_kmalloc = false; + result->m_vaddr = 0; result->m_size = size; result->m_flags = flags; - TRY(result->m_physical_pages.reserve(size / PAGE_SIZE)); vaddr_t vaddr = page_table.reserve_free_contiguous_pages(size / PAGE_SIZE, vaddr_start, vaddr_end); if (vaddr == 0) return BAN::Error::from_errno(ENOMEM); + ASSERT(vaddr + size <= vaddr_end); result->m_vaddr = vaddr; - BAN::ScopeGuard unmapper([vaddr, size, &page_table] { page_table.unmap_range(vaddr, size); }); - if (vaddr + size > vaddr_end) - return BAN::Error::from_errno(ENOMEM); + size_t needed_pages = size / PAGE_SIZE; - result->m_vaddr = vaddr; - - TRY(result->m_physical_pages.reserve(size / PAGE_SIZE)); - for (size_t offset = 0; offset < size; offset += PAGE_SIZE) + for (size_t i = 0; i < needed_pages; i++) { paddr_t paddr = Heap::get().take_free_page(); if (paddr == 0) { - for (paddr_t release : result->m_physical_pages) - Heap::get().release_page(release); + for (size_t j = 0; j < i; j++) + Heap::get().release_page(page_table.physical_address_of(vaddr + j * PAGE_SIZE)); + page_table.unmap_range(vaddr, size); + result->m_vaddr = 0; return BAN::Error::from_errno(ENOMEM); } - MUST(result->m_physical_pages.push_back(paddr)); - page_table.map_page_at(paddr, vaddr + offset, flags); + page_table.map_page_at(paddr, vaddr + i * PAGE_SIZE, flags); } - unmapper.disable(); - return result; } @@ -122,33 +115,34 @@ namespace Kernel VirtualRange::~VirtualRange() { - if (m_kmalloc) - { - kfree((void*)m_vaddr); + if (m_vaddr == 0) return; - } - m_page_table.unmap_range(vaddr(), size()); - for (paddr_t page : m_physical_pages) - Heap::get().release_page(page); + if (m_kmalloc) + kfree((void*)m_vaddr); + else + { + for (size_t offset = 0; offset < size(); offset += PAGE_SIZE) + Heap::get().release_page(m_page_table.physical_address_of(vaddr() + offset)); + m_page_table.unmap_range(vaddr(), size()); + } } BAN::ErrorOr> VirtualRange::clone(PageTable& page_table) { + ASSERT(&PageTable::current() == &m_page_table); + auto result = TRY(create_to_vaddr(page_table, vaddr(), size(), flags())); - m_page_table.lock(); - + LockGuard _(m_page_table); ASSERT(m_page_table.is_page_free(0)); - for (size_t i = 0; i < result->m_physical_pages.size(); i++) + for (size_t offset = 0; offset < size(); offset += PAGE_SIZE) { - m_page_table.map_page_at(result->m_physical_pages[i], 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present); - memcpy((void*)0, (void*)(vaddr() + i * PAGE_SIZE), PAGE_SIZE); + m_page_table.map_page_at(result->m_page_table.physical_address_of(vaddr() + offset), 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present); + memcpy((void*)0, (void*)(vaddr() + offset), PAGE_SIZE); } m_page_table.unmap_page(0); - m_page_table.unlock(); - return result; } @@ -162,17 +156,14 @@ namespace Kernel return; } - page_table.lock(); + LockGuard _(page_table); ASSERT(page_table.is_page_free(0)); - - for (size_t i = 0; i < m_physical_pages.size(); i++) + for (size_t offset = 0; offset < size(); offset += PAGE_SIZE) { - page_table.map_page_at(m_physical_pages[i], 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present); + page_table.map_page_at(m_page_table.physical_address_of(vaddr() + offset), 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present); memset((void*)0, 0, PAGE_SIZE); } page_table.unmap_page(0); - - page_table.unlock(); } void VirtualRange::copy_from(size_t offset, const uint8_t* buffer, size_t bytes) @@ -193,14 +184,14 @@ namespace Kernel return; } - page_table.lock(); + LockGuard _(page_table); ASSERT(page_table.is_page_free(0)); size_t off = offset % PAGE_SIZE; size_t i = offset / PAGE_SIZE; // NOTE: we map the first page separately since it needs extra calculations - page_table.map_page_at(m_physical_pages[i], 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present); + page_table.map_page_at(m_page_table.physical_address_of(vaddr() + i * PAGE_SIZE), 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present); memcpy((void*)off, buffer, PAGE_SIZE - off); @@ -212,7 +203,7 @@ namespace Kernel { size_t len = BAN::Math::min(PAGE_SIZE, bytes); - page_table.map_page_at(m_physical_pages[i], 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present); + page_table.map_page_at(m_page_table.physical_address_of(vaddr() + i * PAGE_SIZE), 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present); memcpy((void*)0, buffer, len); @@ -221,8 +212,6 @@ namespace Kernel i++; } page_table.unmap_page(0); - - page_table.unlock(); } } \ No newline at end of file