From 479817231a95033b233464f6566b408b4336bd34 Mon Sep 17 00:00:00 2001 From: Bananymous Date: Sun, 4 Jun 2023 01:20:47 +0300 Subject: [PATCH] Kernel: PhysicalRange maps its nodes to kernel vaddr space This keeps the lower half of address space cleaner --- kernel/include/kernel/Memory/PhysicalRange.h | 9 +++--- kernel/kernel/Memory/PhysicalRange.cpp | 33 +++++++++++--------- 2 files changed, 23 insertions(+), 19 deletions(-) diff --git a/kernel/include/kernel/Memory/PhysicalRange.h b/kernel/include/kernel/Memory/PhysicalRange.h index 317a052b..212ce37f 100644 --- a/kernel/include/kernel/Memory/PhysicalRange.h +++ b/kernel/include/kernel/Memory/PhysicalRange.h @@ -15,9 +15,9 @@ namespace Kernel paddr_t reserve_page(); void release_page(paddr_t); - paddr_t start() const { return m_start; } - paddr_t end() const { return m_start + m_size; } - bool contains(paddr_t addr) const { return m_start <= addr && addr < m_start + m_size; } + paddr_t start() const { return m_paddr; } + paddr_t end() const { return m_paddr + m_size; } + bool contains(paddr_t addr) const { return m_paddr <= addr && addr < m_paddr + m_size; } size_t usable_memory() const { return m_reservable_pages * PAGE_SIZE; } @@ -35,7 +35,8 @@ namespace Kernel node* node_address(paddr_t) const; private: - paddr_t m_start { 0 }; + paddr_t m_paddr { 0 }; + vaddr_t m_vaddr { 0 }; size_t m_size { 0 }; uint64_t m_total_pages { 0 }; diff --git a/kernel/kernel/Memory/PhysicalRange.cpp b/kernel/kernel/Memory/PhysicalRange.cpp index a0320206..3309ff31 100644 --- a/kernel/kernel/Memory/PhysicalRange.cpp +++ b/kernel/kernel/Memory/PhysicalRange.cpp @@ -15,15 +15,15 @@ namespace Kernel return; // Align start to page boundary and after the kernel memory - m_start = BAN::Math::max(start, V2P(g_kernel_end)); - if (auto rem = m_start % PAGE_SIZE) - m_start += PAGE_SIZE - rem; + m_paddr = BAN::Math::max(start, V2P(g_kernel_end)); + if (auto rem = m_paddr % PAGE_SIZE) + m_paddr += PAGE_SIZE - rem; - if (size <= m_start - start) + if (size <= m_paddr - start) return; // Align size to page boundary - m_size = size - (m_start - start); + m_size = size - (m_paddr - start); if (auto rem = m_size % PAGE_SIZE) m_size -= rem; @@ -40,12 +40,15 @@ namespace Kernel m_used_pages = 0; m_free_pages = m_reservable_pages; - PageTable::kernel().identity_map_range(m_start, m_list_pages * PAGE_SIZE, PageTable::Flags::ReadWrite | PageTable::Flags::Present); + PageTable::kernel().lock(); + m_vaddr = PageTable::kernel().get_free_contiguous_pages(m_list_pages, ((vaddr_t)g_kernel_end + PAGE_SIZE - 1) & PAGE_ADDR_MASK); + ASSERT(m_vaddr); + PageTable::kernel().map_range_at(m_paddr, m_vaddr, m_list_pages * PAGE_SIZE, PageTable::Flags::ReadWrite | PageTable::Flags::Present); + PageTable::kernel().unlock(); + // Initialize page list so that every page points to the next one - node* page_list = (node*)m_start; - - ASSERT((paddr_t)&page_list[m_reservable_pages - 1] <= m_start + m_size); + node* page_list = (node*)m_vaddr; for (uint64_t i = 0; i < m_reservable_pages; i++) page_list[i] = { page_list + i - 1, page_list + i + 1 }; @@ -108,17 +111,17 @@ namespace Kernel paddr_t PhysicalRange::page_address(const node* page) const { - ASSERT((paddr_t)page <= m_start + m_reservable_pages * sizeof(node)); - uint64_t page_index = page - (node*)m_start; - return m_start + (page_index + m_list_pages) * PAGE_SIZE; + ASSERT((vaddr_t)page <= m_vaddr + m_reservable_pages * sizeof(node)); + uint64_t page_index = page - (node*)m_vaddr; + return m_paddr + (page_index + m_list_pages) * PAGE_SIZE; } PhysicalRange::node* PhysicalRange::node_address(paddr_t page_address) const { ASSERT(page_address % PAGE_SIZE == 0); - ASSERT(m_start + m_list_pages * PAGE_SIZE <= page_address && page_address < m_start + m_size); - uint64_t page_offset = page_address - (m_start + m_list_pages * PAGE_SIZE); - return (node*)m_start + page_offset / PAGE_SIZE; + ASSERT(m_paddr + m_list_pages * PAGE_SIZE <= page_address && page_address < m_paddr + m_size); + uint64_t page_offset = page_address - (m_paddr + m_list_pages * PAGE_SIZE); + return (node*)m_vaddr + page_offset / PAGE_SIZE; } }