APIC, HPET, virtual memory

aux/qemu_amd64.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+qemu-system-x86_64 -M q35 -m 4G -serial mon:stdio -cdrom mop3.iso

kernel/amd64/apic.c

@@ -0,0 +1,158 @@
+#include <amd64/apic.h>
+#include <libk/std.h>
+#include <limine/requests.h>
+#include <sys/debug.h>
+#include <sys/mm.h>
+#include <uacpi/acpi.h>
+#include <uacpi/status.h>
+#include <uacpi/tables.h>
+#include <uacpi/uacpi.h>
+
+#define IOAPICS_MAX                 24
+#define INTERRUPT_SRC_OVERRIDES_MAX 24
+
+static struct acpi_madt_ioapic apics[IOAPICS_MAX];
+/* clang-format off */
+static struct acpi_madt_interrupt_source_override intr_src_overrides[INTERRUPT_SRC_OVERRIDES_MAX];
+/* clang-format on */
+static size_t ioapic_entries = 0;
+static size_t intr_src_override_entries = 0;
+
+extern void amd64_spin (void);
+
+static uint32_t amd64_ioapic_read (uintptr_t vaddr, uint32_t reg) {
+  *(volatile uint32_t*)vaddr = reg;
+  return *(volatile uint32_t*)(vaddr + 0x10);
+}
+
+static void amd64_ioapic_write (uintptr_t vaddr, uint32_t reg, uint32_t value) {
+  *(volatile uint32_t*)vaddr = reg;
+  *(volatile uint32_t*)(vaddr + 0x10) = value;
+}
+
+static struct acpi_madt_ioapic* amd64_ioapic_find (uint8_t irq) {
+  struct acpi_madt_ioapic* apic = NULL;
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  for (size_t i = 0; i < ioapic_entries; i++) {
+    apic = &apics[i];
+    uint32_t version = amd64_ioapic_read (
+        (uintptr_t)hhdm->offset + (uintptr_t)apic->address, 1);
+    uint32_t max = (version >> 16);
+
+    if ((apic->gsi_base <= irq) && ((apic->gsi_base + max) > irq))
+      break;
+  }
+
+  return apic;
+}
+
+void amd64_ioapic_route_irq (uint8_t vec, uint8_t irq, uint64_t flags,
+                             uint64_t lapic_id) {
+  struct acpi_madt_ioapic* apic;
+  struct acpi_madt_interrupt_source_override* override;
+  bool found_override = false;
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  for (size_t i = 0; i < intr_src_override_entries; i++) {
+    override = &intr_src_overrides[i];
+    if (override->source == irq) {
+      found_override = true;
+      break;
+    }
+  }
+
+  uint64_t calc_flags = (lapic_id << 56) | (flags) | (vec & 0xFF);
+
+  if (found_override) {
+    uint8_t polarity = ((override->flags & 0x03) == 0x03) ? 1 : 0;
+    uint8_t mode = (((override->flags >> 2) & 0x03) == 0x03) ? 1 : 0;
+    calc_flags = (lapic_id << 56) | (mode << 15) | (polarity << 14) |
+        (vec & 0xFF) | flags;
+  }
+
+  apic = amd64_ioapic_find (irq);
+
+  if (apic == NULL)
+    return;
+
+  uint32_t irq_reg = ((irq - apic->gsi_base) * 2) + 0x10;
+
+  amd64_ioapic_write ((uintptr_t)hhdm->offset + (uintptr_t)apic->address,
+                      irq_reg, (uint32_t)calc_flags);
+
+  amd64_ioapic_write ((uintptr_t)hhdm->offset + (uintptr_t)apic->address,
+                      irq_reg + 1, (uint32_t)(calc_flags >> 32));
+}
+
+void amd64_ioapic_mask (uint8_t irq) {
+  struct acpi_madt_ioapic* apic;
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  apic = amd64_ioapic_find (irq);
+
+  if (apic == NULL)
+    return;
+
+  uint32_t irq_reg = ((irq - apic->gsi_base) * 2) + 0x10;
+
+  uint32_t value = amd64_ioapic_read (
+      (uintptr_t)hhdm->offset + (uintptr_t)apic->address, irq_reg);
+  amd64_ioapic_write ((uintptr_t)hhdm->offset + (uintptr_t)apic->address,
+                      irq_reg, value | (1 << 16));
+}
+
+void amd64_ioapic_unmask (uint8_t irq) {
+  struct acpi_madt_ioapic* apic;
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  apic = amd64_ioapic_find (irq);
+
+  if (apic == NULL)
+    return;
+
+  uint32_t irq_reg = ((irq - apic->gsi_base) * 2) + 0x10;
+
+  uint32_t value = amd64_ioapic_read (
+      (uintptr_t)hhdm->offset + (uintptr_t)apic->address, irq_reg);
+  amd64_ioapic_write ((uintptr_t)hhdm->offset + (uintptr_t)apic->address,
+                      irq_reg, value & ~(1 << 16));
+}
+
+void amd64_ioapic_init (void) {
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  struct uacpi_table apic_table;
+  uacpi_status status =
+      uacpi_table_find_by_signature (ACPI_MADT_SIGNATURE, &apic_table);
+  if (status != UACPI_STATUS_OK) {
+    DEBUG ("Could not find MADT table!\n");
+    amd64_spin ();
+  }
+
+  struct acpi_madt* apic = (struct acpi_madt*)apic_table.virt_addr;
+  struct acpi_entry_hdr* current = (struct acpi_entry_hdr*)apic->entries;
+
+  for (;;) {
+    if ((uintptr_t)current >= ((uintptr_t)apic->entries + apic->hdr.length -
+                               sizeof (struct acpi_madt)))
+      break;
+
+    switch (current->type) {
+    case ACPI_MADT_ENTRY_TYPE_IOAPIC: {
+      struct acpi_madt_ioapic* ioapic = (struct acpi_madt_ioapic*)current;
+      mm_map_kernel_page ((uintptr_t)ioapic->address,
+                          (uintptr_t)hhdm->offset + (uintptr_t)ioapic->address,
+                          MM_PG_USER | MM_PG_RW);
+      apics[ioapic_entries++] = *ioapic;
+    } break;
+    case ACPI_MADT_ENTRY_TYPE_INTERRUPT_SOURCE_OVERRIDE: {
+      struct acpi_madt_interrupt_source_override* override =
+          (struct acpi_madt_interrupt_source_override*)current;
+      intr_src_overrides[intr_src_override_entries++] = *override;
+    } break;
+    }
+
+    current = (struct acpi_entry_hdr*)((uintptr_t)current + current->length);
+  }
+}

kernel/amd64/apic.h

@@ -0,0 +1,12 @@
+#ifndef _KERNEL_AMD64_APIC_H
+#define _KERNEL_AMD64_APIC_H
+
+#include <libk/std.h>
+
+void amd64_ioapic_route_irq (uint8_t vec, uint8_t irq, uint64_t flags,
+                             uint64_t lapic_id);
+void amd64_ioapic_mask (uint8_t irq);
+void amd64_ioapic_unmask (uint8_t irq);
+void amd64_ioapic_init (void);
+
+#endif // _KERNEL_AMD64_APIC_H

kernel/amd64/bootmain.c

@@ -1,9 +1,12 @@
+#include <amd64/apic.h>
+#include <amd64/hpet.h>
 #include <amd64/init.h>
 #include <aux/compiler.h>
 #include <limine/limine.h>
 #include <mm/liballoc.h>
 #include <mm/pmm.h>
 #include <sys/debug.h>
+#include <sys/mm.h>
 #include <uacpi/uacpi.h>
 
 #define UACPI_MEMORY_BUFFER_MAX 4096
@@ -13,14 +16,22 @@ ALIGNED (16) static uint8_t uacpi_memory_buffer[UACPI_MEMORY_BUFFER_MAX];
 void bootmain (void) {
   amd64_init ();
   pmm_init ();
+  mm_init ();
 
   uacpi_setup_early_table_access ((void*)uacpi_memory_buffer,
                                   sizeof (uacpi_memory_buffer));
 
+  amd64_ioapic_init ();
+  amd64_hpet_init ();
+
   int* a = malloc (sizeof (int));
   *a = 6969;
   DEBUG ("a=%p, *a=%d\n", a, *a);
 
+  amd64_hpet_sleep_micro (3000000);
+
+  DEBUG ("woke up!!!\n");
+
   for (;;)
     ;
 }

kernel/amd64/hpet.c

@@ -0,0 +1,73 @@
+#include <amd64/hpet.h>
+#include <libk/std.h>
+#include <limine/requests.h>
+#include <sys/debug.h>
+#include <sys/mm.h>
+#include <uacpi/acpi.h>
+#include <uacpi/status.h>
+#include <uacpi/tables.h>
+#include <uacpi/uacpi.h>
+
+#define HPET_MCVR  0xF0 /* Main Counter Value Register            */
+#define HPET_GCR   0x10 /* General Configuration Register         */
+#define HPET_GCIDR 0x00 /* General Capabilities and ID Register   */
+
+static bool hpet_32bits = 1;
+static uintptr_t hpet_paddr;
+static uint64_t hpet_clock_nano;
+
+extern void amd64_spin (void);
+
+static uint64_t amd64_hpet_read (uint32_t reg) {
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+  uintptr_t hpet_vaddr = hpet_paddr + (uintptr_t)hhdm->offset;
+  return (hpet_32bits ? *(volatile uint32_t*)(hpet_vaddr + reg)
+                      : *(volatile uint64_t*)(hpet_vaddr + reg));
+}
+
+static void amd64_hpet_write (uint32_t reg, uint64_t value) {
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+  uintptr_t hpet_vaddr = hpet_paddr + (uintptr_t)hhdm->offset;
+  if (hpet_32bits)
+    *(volatile uint32_t*)(hpet_vaddr + reg) = (value & 0xFFFFFFFF);
+  else
+    *(volatile uint64_t*)(hpet_vaddr + reg) = value;
+}
+
+static uint64_t amd64_hpet_timestamp (void) {
+  return amd64_hpet_read (HPET_MCVR);
+}
+
+uint64_t amd64_hpet_current_nano (void) {
+  return amd64_hpet_timestamp () * hpet_clock_nano;
+}
+
+void amd64_hpet_sleep_micro (uint64_t us) {
+  uint64_t start = amd64_hpet_timestamp ();
+  uint64_t conv = us * 1000;
+  while (((amd64_hpet_timestamp () - start) * hpet_clock_nano) < conv)
+    __asm__ volatile ("pause" ::: "memory");
+}
+
+void amd64_hpet_init (void) {
+  struct uacpi_table hpet_table;
+  uacpi_status status =
+      uacpi_table_find_by_signature (ACPI_HPET_SIGNATURE, &hpet_table);
+  if (status != UACPI_STATUS_OK) {
+    DEBUG ("Could not find HPET table!\n");
+    amd64_spin ();
+  }
+
+  struct acpi_hpet* hpet = (struct acpi_hpet*)hpet_table.virt_addr;
+  hpet_paddr = (uintptr_t)hpet->address.address;
+
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+  mm_map_kernel_page (hpet_paddr, (uintptr_t)hhdm->offset + hpet_paddr,
+                      MM_PG_PRESENT | MM_PG_RW);
+
+  hpet_32bits = (amd64_hpet_read (HPET_GCIDR) & (1 << 13)) ? 0 : 1;
+
+  amd64_hpet_write (HPET_GCR, amd64_hpet_read (HPET_GCR) | 0x01);
+
+  hpet_clock_nano = amd64_hpet_read (HPET_GCIDR + 4) / 1000000;
+}

kernel/amd64/hpet.h

@@ -0,0 +1,10 @@
+#ifndef _KERNEL_AMD64_HPET_H
+#define _KERNEL_AMD64_HPET_H
+
+#include <libk/std.h>
+
+uint64_t amd64_hpet_current_nano (void);
+void amd64_hpet_sleep_micro (uint64_t us);
+void amd64_hpet_init (void);
+
+#endif // _KERNEL_AMD64_HPET_H

kernel/amd64/mm.c

@@ -0,0 +1,163 @@
+#include <aux/compiler.h>
+#include <libk/std.h>
+#include <libk/string.h>
+#include <limine/requests.h>
+#include <mm/pmm.h>
+#include <sync/spin_lock.h>
+#include <sys/mm.h>
+
+#define AMD64_PG_PRESENT (1 << 0)
+#define AMD64_PG_RW      (1 << 1)
+#define AMD64_PG_USER    (1 << 2)
+
+#define AMD64_PG_TABLE_ENTRIES_MAX 512
+
+struct pg_index {
+  uint16_t pml4, pml3, pml2, pml1;
+} PACKED;
+
+struct pd kernel_pd = {.lock = SPIN_LOCK_INIT};
+
+static uintptr_t amd64_current_cr3 (void) {
+  uintptr_t cr3;
+  __asm__ volatile ("movq %%cr3, %0" : "=r"(cr3)::"memory");
+  return cr3;
+}
+
+static struct pg_index amd64_mm_page_index (uint64_t vaddr) {
+  struct pg_index ret;
+
+  ret.pml4 = ((vaddr >> 39) & 0x1FF);
+  ret.pml3 = ((vaddr >> 30) & 0x1FF);
+  ret.pml2 = ((vaddr >> 21) & 0x1FF);
+  ret.pml1 = ((vaddr >> 12) & 0x1FF);
+
+  return ret;
+}
+
+static uint64_t* amd64_mm_next_table (uint64_t* table, uint64_t entry_idx,
+                                      bool alloc) {
+  uint64_t entry = table[entry_idx];
+  uint64_t paddr;
+
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  if (entry & AMD64_PG_PRESENT)
+    paddr = entry & ~0xFFFULL;
+  else {
+    if (!alloc)
+      return NULL;
+
+    paddr = pmm_alloc (1);
+
+    if (paddr == 0)
+      return NULL;
+
+    memset ((void*)((uintptr_t)hhdm->offset + (uintptr_t)paddr), 0, PAGE_SIZE);
+    table[entry_idx] = paddr | AMD64_PG_PRESENT | AMD64_PG_RW;
+  }
+
+  return (uint64_t*)((uintptr_t)hhdm->offset + (uintptr_t)paddr);
+}
+
+static uint64_t amd64_mm_resolve_flags (uint32_t generic) {
+  uint64_t flags = 0;
+
+  flags |= ((generic & MM_PG_PRESENT) ? AMD64_PG_PRESENT : 0);
+  flags |= ((generic & MM_PG_RW) ? AMD64_PG_RW : 0);
+  flags |= ((generic & MM_PG_USER) ? AMD64_PG_USER : 0);
+
+  return flags;
+}
+
+static void amd64_reload_cr3 (void) {
+  uint64_t cr3;
+  __asm__ volatile ("movq %%cr3, %0; movq %0, %%cr3" : "=r"(cr3)::"memory");
+}
+
+void mm_map_page (struct pd* pd, uintptr_t paddr, uintptr_t vaddr,
+                  uint32_t flags) {
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+  bool do_reload = false;
+
+  if (flags & MM_PD_LOCK)
+    spin_lock (&pd->lock);
+
+  uint64_t amd64_flags = amd64_mm_resolve_flags (flags);
+
+  uint64_t* pml4 = (uint64_t*)(pd->cr3_paddr + (uintptr_t)hhdm->offset);
+  struct pg_index pg_index = amd64_mm_page_index (vaddr);
+
+  uint64_t* pml3 = amd64_mm_next_table (pml4, pg_index.pml4, true);
+  if (pml3 == NULL)
+    goto done;
+
+  uint64_t* pml2 = amd64_mm_next_table (pml3, pg_index.pml3, true);
+  if (pml2 == NULL)
+    goto done;
+
+  uint64_t* pml1 = amd64_mm_next_table (pml2, pg_index.pml2, true);
+  if (pml1 == NULL)
+    goto done;
+
+  uint64_t* pte = &pml1[pg_index.pml1];
+
+  *pte = ((paddr & ~0xFFFULL) | (amd64_flags & 0x7ULL));
+  do_reload = true;
+
+done:
+  if (do_reload)
+    amd64_reload_cr3 ();
+
+  if (flags & MM_PD_LOCK)
+    spin_unlock (&pd->lock);
+}
+
+void mm_map_kernel_page (uintptr_t paddr, uintptr_t vaddr, uint32_t flags) {
+  mm_map_page (&kernel_pd, paddr, vaddr, flags);
+}
+
+void mm_unmap_page (struct pd* pd, uintptr_t vaddr, uint32_t flags) {
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+  bool do_reload = false;
+
+  if (flags & MM_PD_LOCK)
+    spin_lock (&pd->lock);
+
+  uint64_t* pml4 = (uint64_t*)(pd->cr3_paddr + (uintptr_t)hhdm->offset);
+  struct pg_index pg_index = amd64_mm_page_index (vaddr);
+
+  uint64_t* pml3 = amd64_mm_next_table (pml4, pg_index.pml4, true);
+  if (pml3 == NULL)
+    goto done;
+
+  uint64_t* pml2 = amd64_mm_next_table (pml3, pg_index.pml3, true);
+  if (pml2 == NULL)
+    goto done;
+
+  uint64_t* pml1 = amd64_mm_next_table (pml2, pg_index.pml2, true);
+  if (pml1 == NULL)
+    goto done;
+
+  uint64_t* pte = &pml1[pg_index.pml1];
+
+  *pte &= ~AMD64_PG_PRESENT;
+  do_reload = true;
+
+done:
+  if (do_reload)
+    amd64_reload_cr3 ();
+
+  if (flags & MM_PD_LOCK)
+    spin_unlock (&pd->lock);
+}
+
+void mm_unmap_kernel_page (uintptr_t vaddr, uint32_t flags) {
+  mm_unmap_page (&kernel_pd, vaddr, flags);
+}
+
+void mm_lock_kernel (void) { spin_lock (&kernel_pd.lock); }
+
+void mm_unlock_kernel (void) { spin_unlock (&kernel_pd.lock); }
+
+void mm_init (void) { kernel_pd.cr3_paddr = amd64_current_cr3 (); }

kernel/amd64/mm.h

@@ -1,6 +1,14 @@
 #ifndef _KERNEL_AMD64_MM_H
 #define _KERNEL_AMD64_MM_H
 
+#include <libk/std.h>
+#include <sync/spin_lock.h>
+
 #define PAGE_SIZE 4096
 
+struct pd {
+  spin_lock_t lock;
+  uintptr_t cr3_paddr;
+};
+
 #endif // _KERNEL_AMD64_MM_H

kernel/amd64/msr.c

@@ -0,0 +1,14 @@
+#include <amd64/msr.h>
+#include <libk/std.h>
+
+uint64_t amd64_rdmsr (uint32_t msr) {
+  uint32_t low, high;
+  __asm__ volatile ("rdmsr" : "=a"(low), "=d"(high) : "c"(msr));
+  return ((uint64_t)high << 32 | (uint64_t)low);
+}
+
+void amd64_wrmsr (uint32_t msr, uint64_t value) {
+  uint32_t low = (uint32_t)(value & 0xFFFFFFFF);
+  uint32_t high = (uint32_t)(value >> 32);
+  __asm__ volatile ("wrmsr" ::"c"(msr), "a"(low), "d"(high));
+}

kernel/amd64/msr.h

@@ -0,0 +1,9 @@
+#ifndef _KERNEL_AMD64_MSR_H
+#define _KERNEL_AMD64_MSR_H
+
+#include <libk/std.h>
+
+uint64_t amd64_rdmsr (uint32_t msr);
+void amd64_wrmsr (uint32_t msr, uint64_t value);
+
+#endif // _KERNEL_AMD64_MSR_H

kernel/amd64/src.mk

@@ -4,7 +4,11 @@ c += amd64/bootmain.c \
 		 amd64/io.c \
 		 amd64/debug.c \
 		 amd64/spin_lock.c \
-		 amd64/intr.c
+		 amd64/intr.c \
+		 amd64/apic.c \
+		 amd64/msr.c \
+		 amd64/hpet.c \
+		 amd64/mm.c
 
 S += amd64/intr_stub.S \
 		 amd64/spin.S
@@ -17,4 +21,8 @@ o += amd64/bootmain.o \
 		 amd64/spin_lock.o \
 		 amd64/intr.o \
 		 amd64/intr_stub.o \
-		 amd64/spin.o
+		 amd64/spin.o \
+		 amd64/apic.o \
+		 amd64/msr.o \
+		 amd64/hpet.o \
+		 amd64/mm.o

kernel/sys/mm.h

@@ -1,8 +1,24 @@
 #ifndef _KERNEL_SYS_MM_H
 #define _KERNEL_SYS_MM_H
 
+#include <libk/std.h>
+
 #if defined(__x86_64__)
 #include <amd64/mm.h>
 #endif
 
+#define MM_PG_PRESENT (1 << 0)
+#define MM_PG_RW      (1 << 1)
+#define MM_PG_USER    (1 << 2)
+#define MM_PD_LOCK    (1 << 31)
+
+void mm_map_page (struct pd* pd, uintptr_t paddr, uintptr_t vaddr,
+                  uint32_t flags);
+void mm_map_kernel_page (uintptr_t paddr, uintptr_t vaddr, uint32_t flags);
+void mm_unmap_page (struct pd* pd, uintptr_t vaddr, uint32_t flags);
+void mm_unmap_kernel_page (uintptr_t vaddr, uint32_t flags);
+void mm_lock_kernel (void);
+void mm_unlock_kernel (void);
+void mm_init (void);
+
 #endif // _KERNEL_SYS_MM_H

kernel/uACPI/platform_mop3.c

@@ -1,7 +1,9 @@
+#include <libk/align.h>
 #include <libk/std.h>
 #include <limine/requests.h>
 #include <mm/liballoc.h>
 #include <sys/debug.h>
+#include <sys/mm.h>
 #include <uacpi/kernel_api.h>
 #include <uacpi/status.h>
 
@@ -17,11 +19,16 @@ uacpi_status uacpi_kernel_get_rsdp (uacpi_phys_addr* out_rsdp_address) {
 
 void* uacpi_kernel_map (uacpi_phys_addr addr, uacpi_size len) {
   (void)len;
+
   struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
   return (void*)((uintptr_t)hhdm->offset + (uintptr_t)addr);
 }
 
-void uacpi_kernel_unmap (void* addr, uacpi_size len) { (void)addr, (void)len; }
+void uacpi_kernel_unmap (void* addr, uacpi_size len) {
+  (void)addr;
+  (void)len;
+}
 
 void uacpi_kernel_log (uacpi_log_level level, const uacpi_char* msg) {
   const char* prefix = NULL;