AHCI: Add very basic AHCI and some additional helper functions to mmu.c

Currently certain parts of the code are taken from osdev wiki as there
seems to be very little documentation that I can find on how H2D FIS is
structured. Those parts, especially some of the uglier parts of the
example code will be rewritten/changed.

1 files changed, 41 insertions, 9 deletions

diff --git a/kernel/arch/i386/mmu.c b/kernel/arch/i386/mmu.c
index 5d4252f..2b6c0b5 100644
--- a/kernel/arch/i386/mmu.c
+++ b/kernel/arch/i386/mmu.c
@@ -71,9 +71,7 @@ void *ksbrk_physical(size_t s, void **physical) {
   return r;
 }
 
-u32 mmu_get_number_of_allocated_frames(void) {
-  return num_allocated_frames;
-}
+u32 mmu_get_number_of_allocated_frames(void) { return num_allocated_frames; }
 
 Page *get_page(void *ptr, PageDirectory *directory, int create_new_page,
                int set_user) {
@@ -246,8 +244,7 @@ PageDirectory *clone_directory(PageDirectory *original) {
   u32 physical_address;
   PageDirectory *new_directory =
       ksbrk_physical(sizeof(PageDirectory), (void **)&physical_address);
-  u32 offset =
-      (u32)new_directory->physical_tables - (u32)new_directory;
+  u32 offset = (u32)new_directory->physical_tables - (u32)new_directory;
   new_directory->physical_address = physical_address + offset;
 
   for (int i = 0; i < 1024; i++) {
@@ -337,7 +334,6 @@ int mmu_allocate_region(void *ptr, size_t n, mmu_flags flags,
 
 void *mmu_map_frames(void *const ptr, size_t s) {
   void *const r = mmu_find_unallocated_virtual_range((void *)0xEF000000, s);
-  kprintf("r: %x\n", r);
   size_t num_pages = s / 0x1000;
   for (size_t i = 0; i <= num_pages; i++) {
     Page *p = get_page((void *)(r + i * 0x1000), NULL, PAGE_ALLOCATE, 1);
@@ -350,7 +346,6 @@ void *mmu_map_frames(void *const ptr, size_t s) {
     p->frame = (uintptr_t)(ptr + i * 0x1000) / 0x1000;
     write_to_frame((uintptr_t)ptr + i * 0x1000, 1);
   }
-  flush_tlb();
   return r;
 }
 
@@ -421,6 +416,44 @@ void mmu_map_physical(void *dst, PageDirectory *d, void *physical,
   flush_tlb();
 }
 
+struct PhysVirtMap {
+  u32 physical;
+  u32 virtual;
+  u32 length;
+  u8 in_use;
+};
+
+struct PhysVirtMap phys_to_virt_map[256] = {0};
+
+void create_physical_to_virtual_mapping(void *physical, void *virtual,
+                                        u32 length) {
+  for (u16 i = 0; i < 256; i++) {
+    if (phys_to_virt_map[i].in_use)
+      continue;
+    phys_to_virt_map[i].physical = (u32)physical;
+    phys_to_virt_map[i].virtual = (u32) virtual;
+    phys_to_virt_map[i].length = length;
+    phys_to_virt_map[i].in_use = 1;
+    return;
+  }
+  assert(0);
+}
+
+void *physical_to_virtual(void *address) {
+  for (u16 i = 0; i < 256; i++) {
+    if (!phys_to_virt_map[i].in_use)
+      continue;
+    if (phys_to_virt_map[i].physical + phys_to_virt_map[i].length <
+        (u32)address)
+      continue;
+    if (phys_to_virt_map[i].physical > (u32)address)
+      continue;
+    return (void *)phys_to_virt_map[i].virtual;
+  }
+  assert(0);
+  return NULL;
+}
+
 void *virtual_to_physical(void *address, PageDirectory *directory) {
   if (0 == directory)
     directory = get_active_pagedirectory();
@@ -448,8 +481,7 @@ void move_stack(u32 new_stack_address, u32 size) {
   // Copy the stack
   memcpy((void *)new_stack_pointer, (void *)old_stack_pointer,
          inital_esp - old_stack_pointer);
-  for (u32 i = (u32)new_stack_address; i > new_stack_address - size;
-       i -= 4) {
+  for (u32 i = (u32)new_stack_address; i > new_stack_address - size; i -= 4) {
     u32 tmp = *(u32 *)i;
     if (old_stack_pointer < tmp && tmp < inital_esp) {
       tmp = tmp + (new_stack_address - inital_esp);