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Move memory_manager and assert into kutil.

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Justin C. Miller
2018-05-08 01:11:03 -07:00
parent 712cd69242
commit 0f54630725
19 changed files with 140 additions and 84 deletions
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src/kernel/page_manager.h Normal file
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#pragma once
/// \file page_manager.h
/// The page memory manager and related definitions.
#include <stddef.h>
#include <stdint.h>
#include "kutil/memory.h"
#include "kutil/enum_bitfields.h"
struct page_block;
struct page_table;
struct free_page_header;
/// Manager for allocation of physical pages.
class page_manager
{
public:
/// Size of a single page.
static const size_t page_size = 0x1000;
/// Start of the higher half.
static const addr_t high_offset = 0xffff800000000000;
/// Offset from physical where page tables are mapped.
static const addr_t page_offset = 0xffffff8000000000;
page_manager();
/// Allocate and map pages into virtual memory.
/// \arg address The virtual address at which to map the pages
/// \arg count The number of pages to map
/// \returns A pointer to the start of the mapped region
void * map_pages(addr_t address, size_t count);
/// Unmap existing pages from memory.
/// \arg address The virtual address of the memory to unmap
/// \arg count The number of pages to unmap
void unmap_pages(addr_t address, size_t count);
/// Offset-map a pointer. No physical pages will be mapped.
/// \arg pointer Pointer to a pointer to the memory area to be mapped
/// \arg length Length of the memory area to be mapped
void map_offset_pointer(void **pointer, size_t length);
/// Log the current free/used block lists.
void dump_blocks();
/// Get the system page manager.
/// \returns A pointer to the system page manager
static page_manager * get();
private:
/// Set up the memory manager from bootstraped memory
void init(
page_block *free,
page_block *used,
page_block *block_cache);
/// Initialize the virtual memory manager based on this object's state
void init_memory_manager();
/// Create a `page_block` struct or pull one from the cache.
/// \returns An empty `page_block` struct
page_block * get_block();
/// Return a list of `page_block` structs to the cache.
/// \arg block A list of `page_block` structs
void free_blocks(page_block *block);
/// Allocate a page for a page table, or pull one from the cache
/// \returns An empty page mapped in page space
page_table * get_table_page();
/// Return a set of mapped contiguous pages to the page cache.
/// \arg pages Pointer to the first page to be returned
/// \arg count Number of pages in the range
void free_table_pages(void *pages, size_t count);
/// Consolidate the free and used block lists. Return freed blocks
/// to the cache.
void consolidate_blocks();
/// Helper to read the PML4 table from CR3.
/// \returns A pointer to the current PML4 table.
static inline page_table * get_pml4()
{
addr_t pml4 = 0;
__asm__ __volatile__ ( "mov %%cr3, %0" : "=r" (pml4) );
return reinterpret_cast<page_table *>((pml4 & ~0xfffull) + page_offset);
}
/// Helper to set the PML4 table pointer in CR3.
/// \arg pml4 A pointer to the PML4 table to install.
static inline void set_pml4(page_table *pml4)
{
addr_t p = reinterpret_cast<addr_t>(pml4) - page_offset;
__asm__ __volatile__ ( "mov %0, %%cr3" :: "r" (p & ~0xfffull) );
}
/// Helper function to allocate a new page table. If table entry `i` in
/// table `base` is empty, allocate a new page table and point `base[i]` at
/// it.
/// \arg base Existing page table being indexed into
/// \arg i Index into the existing table to check
void check_needs_page(page_table *base, unsigned i);
/// Low-level routine for mapping a number of pages into the given page table.
/// \arg pml4 The root page table to map into
/// \arg phys_addr The starting physical address of the pages to be mapped
/// \arg virt_addr The starting virtual address ot the memory to be mapped
/// \arg count The number of pages to map
void page_in(
page_table *pml4,
addr_t phys_addr,
addr_t virt_addr,
size_t count);
/// Low-level routine for unmapping a number of pages from the given page table.
/// \arg pml4 The root page table for this mapping
/// \arg virt_addr The starting virtual address ot the memory to be unmapped
/// \arg count The number of pages to unmap
void page_out(
page_table *pml4,
addr_t virt_addr,
size_t count);
/// Get free pages from the free list. Only pages from the first free block
/// are returned, so the number may be less than requested, but they will
/// be contiguous. Pages will not be mapped into virtual memory.
/// \arg count The maximum number of pages to get
/// \arg address [out] The address of the first page
/// \returns The number of pages retrieved
size_t pop_pages(size_t count, addr_t *address);
page_block *m_free; ///< Free pages list
page_block *m_used; ///< In-use pages list
page_block *m_block_cache; ///< Cache of unused page_block structs
free_page_header *m_page_cache; ///< Cache of free pages to use for tables
friend void memory_initialize(const void *, size_t, size_t);
page_manager(const page_manager &) = delete;
};
/// Global page manager.
extern page_manager g_page_manager;
inline page_manager * page_manager::get() { return &g_page_manager; }
/// Flags used by `page_block`.
enum class page_block_flags : uint32_t
{
free = 0x00000000, ///< Not a flag, value for free memory
used = 0x00000001, ///< Memory is in use
mapped = 0x00000002, ///< Memory is mapped to virtual address
mmio = 0x00000010, ///< Memory is a MMIO region
nonvolatile = 0x00000020, ///< Memory is non-volatile storage
pending_free = 0x10000000, ///< Memory should be freed
acpi_wait = 0x40000000, ///< Memory should be freed after ACPI init
permanent = 0x80000000, ///< Memory is permanently unusable
max_flags
};
IS_BITFIELD(page_block_flags);
/// A block of contiguous pages. Each `page_block` represents contiguous
/// physical pages with the same attributes. A `page_block *` is also a
/// linked list of such structures.
struct page_block
{
addr_t physical_address;
addr_t virtual_address;
uint32_t count;
page_block_flags flags;
page_block *next;
inline bool has_flag(page_block_flags f) const { return bitfield_contains(flags, f); }
inline addr_t physical_end() const { return physical_address + (count * page_manager::page_size); }
inline addr_t virtual_end() const { return virtual_address + (count * page_manager::page_size); }
inline bool contains(addr_t vaddr) const { return vaddr >= virtual_address && vaddr < virtual_end(); }
inline bool contains_physical(addr_t addr) const { return addr >= physical_address && addr < physical_end(); }
/// Helper to zero out a block and optionally set the next pointer.
/// \arg next [optional] The value for the `next` pointer
void zero(page_block *set_next = nullptr);
/// Helper to copy a bock from another block
/// \arg other The block to copy from
void copy(page_block *other);
/// \name Page block linked list functions
/// Functions to act on a `page_block *` as a linked list
/// @{
/// Count the items in the given linked list.
/// \arg list The list to count
/// \returns The number of entries in the list.
static size_t length(page_block *list);
/// Append a block or list to the given list.
/// \arg list The list to append to
/// \arg extra The list or block to be appended
/// \returns The new list head
static page_block * append(page_block *list, page_block *extra);
/// Sorted-insert of a block into the list by address.
/// \arg list The list to insert into
/// \arg block The single block to insert
/// \returns The new list head
static page_block * insert(page_block *list, page_block *block);
/// Compare two blocks by address.
/// \arg lhs The left-hand comparator
/// \arg rhs The right-hand comparator
/// \returns <0 if lhs is sorts earlier, >0 if lhs sorts later, 0 for equal
static int compare(const page_block *lhs, const page_block *rhs);
/// Traverse the list, joining adjacent blocks where possible.
/// \arg list The list to consolidate
/// \returns A linked list of freed page_block structures.
static page_block * consolidate(page_block *list);
/// Traverse the list, printing debug info on this list.
/// \arg list The list to print
/// \arg name [optional] String to print as the name of this list
/// \arg show_permanent [optional] If false, hide unmapped blocks
static void dump(page_block *list, const char *name = nullptr, bool show_unmapped = false);
/// @}
};
/// Struct to allow easy accessing of a memory page being used as a page table.
struct page_table
{
using pm = page_manager;
uint64_t entries[512];
inline page_table * get(int i) const {
uint64_t entry = entries[i];
if ((entry & 0x1) == 0) return nullptr;
return reinterpret_cast<page_table *>((entry & ~0xfffull) + pm::page_offset);
}
inline void set(int i, page_table *p, uint16_t flags) {
entries[i] = (reinterpret_cast<uint64_t>(p) - pm::page_offset) | (flags & 0xfff);
}
void dump(int level = 4, uint64_t offset = page_manager::page_offset);
};
/// Helper struct for computing page table indices of a given address.
struct page_table_indices
{
page_table_indices(uint64_t v = 0) :
index{
(v >> 39) & 0x1ff,
(v >> 30) & 0x1ff,
(v >> 21) & 0x1ff,
(v >> 12) & 0x1ff }
{}
/// Get the index for a given level of page table.
uint64_t & operator[](size_t i) { return index[i]; }
uint64_t index[4]; ///< Indices for each level of tables.
};
/// Calculate a page-aligned address.
/// \arg p The address to align.
/// \returns The next page-aligned address _after_ `p`.
template <typename T> inline T page_align(T p)
{
return ((p - 1) & ~(page_manager::page_size - 1)) + page_manager::page_size;
}
/// Calculate a page-table-aligned address. That is, an address that is
/// page-aligned to the first page in a page table.
/// \arg p The address to align.
/// \returns The next page-table-aligned address _after_ `p`.
template <typename T> inline T page_table_align(T p) { return ((p - 1) & ~0x1fffffull) + 0x200000; }
/// Bootstrap the memory managers.
void memory_initialize(const void *memory_map, size_t map_length, size_t desc_length);