banan-os/kernel/kernel/APIC.cpp

260 lines
6.1 KiB
C++

#include <BAN/ScopeGuard.h>
#include <kernel/Debug.h>
#include <kernel/ACPI.h>
#include <kernel/APIC.h>
#include <kernel/CPUID.h>
#include <kernel/IDT.h>
#include <kernel/Memory/PageTable.h>
#include <string.h>
#define LAPIC_EIO_REG 0xB0
#define LAPIC_SIV_REG 0xF0
#define LAPIC_IS_REG 0x100
#define IOAPIC_MAX_REDIRS 0x01
#define IOAPIC_REDIRS 0x10
#define DEBUG_PRINT_PROCESSORS 0
// https://uefi.org/specs/ACPI/6.5/05_ACPI_Software_Programming_Model.html#multiple-apic-description-table-madt-format
struct MADT : public Kernel::ACPI::SDTHeader
{
uint32_t local_apic;
uint32_t flags;
} __attribute__((packed));
struct MADTEntry
{
uint8_t type;
uint8_t length;
union
{
struct
{
uint8_t acpi_processor_id;
uint8_t apic_id;
uint32_t flags;
} __attribute__((packed)) entry0;
struct
{
uint8_t ioapic_id;
uint8_t reserved;
uint32_t ioapic_address;
uint32_t gsi_base;
} __attribute__((packed)) entry1;
struct
{
uint8_t bus_source;
uint8_t irq_source;
uint32_t gsi;
uint16_t flags;
} __attribute__((packed)) entry2;
struct
{
uint16_t reserved;
uint64_t address;
} __attribute__((packed)) entry5;
};
} __attribute__((packed));
union RedirectionEntry
{
struct
{
uint64_t vector : 8;
uint64_t delivery_mode : 3;
uint64_t destination_mode : 1;
uint64_t delivery_status : 1;
uint64_t pin_polarity : 1;
uint64_t remote_irr : 1;
uint64_t trigger_mode : 1;
uint64_t mask : 1;
uint64_t reserved : 39;
uint64_t destination : 8;
};
struct
{
uint32_t lo_dword;
uint32_t hi_dword;
};
};
extern uint8_t g_kernel_end[];
using namespace Kernel;
APIC* APIC::create()
{
uint32_t ecx, edx;
CPUID::get_features(ecx, edx);
if (!(edx & CPUID::Features::EDX_APIC))
{
dprintln("Local APIC is not available");
return nullptr;
}
const MADT* madt = (const MADT*)Kernel::ACPI::get().get_header("APIC");
if (madt == nullptr)
{
dprintln("Could not find MADT header");
return nullptr;
}
APIC* apic = new APIC;
apic->m_local_apic_paddr = madt->local_apic;
for (uint32_t i = 0x00; i <= 0xFF; i++)
apic->m_irq_overrides[i] = i;
uintptr_t madt_entry_addr = (uintptr_t)madt + sizeof(MADT);
while (madt_entry_addr < (uintptr_t)madt + madt->length)
{
const MADTEntry* entry = (const MADTEntry*)madt_entry_addr;
switch (entry->type)
{
case 0:
Processor processor;
processor.processor_id = entry->entry0.acpi_processor_id;
processor.apic_id = entry->entry0.apic_id;
processor.flags = entry->entry0.flags & 0x03;
MUST(apic->m_processors.push_back(processor));
break;
case 1:
IOAPIC ioapic;
ioapic.id = entry->entry1.ioapic_id;
ioapic.paddr = entry->entry1.ioapic_address;
ioapic.gsi_base = entry->entry1.gsi_base;
ioapic.max_redirs = 0;
MUST(apic->m_io_apics.push_back(ioapic));
break;
case 2:
apic->m_irq_overrides[entry->entry2.irq_source] = entry->entry2.gsi;
break;
case 5:
apic->m_local_apic_paddr = entry->entry5.address;
break;
default:
dprintln("Unhandled madt entry, type {}", entry->type);
break;
}
madt_entry_addr += entry->length;
}
if (apic->m_local_apic_paddr == 0 || apic->m_io_apics.empty())
{
dprintln("MADT did not provide necessary information");
delete apic;
return nullptr;
}
// Map the local apic to kernel memory
{
vaddr_t vaddr = PageTable::kernel().get_free_page((vaddr_t)g_kernel_end);
ASSERT(vaddr);
dprintln("lapic paddr {8H}", apic->m_local_apic_paddr);
apic->m_local_apic_vaddr = vaddr + (apic->m_local_apic_paddr % PAGE_SIZE);
dprintln("lapic vaddr {8H}", apic->m_local_apic_vaddr);
PageTable::kernel().map_page_at(
apic->m_local_apic_paddr & PAGE_ADDR_MASK,
apic->m_local_apic_vaddr & PAGE_ADDR_MASK,
PageTable::Flags::ReadWrite | PageTable::Flags::Present
);
}
// Map io apics to kernel memory
for (auto& io_apic : apic->m_io_apics)
{
vaddr_t vaddr = PageTable::kernel().get_free_page((vaddr_t)g_kernel_end);
ASSERT(vaddr);
io_apic.vaddr = vaddr + (io_apic.paddr % PAGE_SIZE);
PageTable::kernel().map_page_at(
io_apic.paddr & PAGE_ADDR_MASK,
io_apic.vaddr & PAGE_ADDR_MASK,
PageTable::Flags::ReadWrite | PageTable::Flags::Present
);
io_apic.max_redirs = io_apic.read(IOAPIC_MAX_REDIRS);
}
// Mask all interrupts
uint32_t sivr = apic->read_from_local_apic(LAPIC_SIV_REG);
apic->write_to_local_apic(LAPIC_SIV_REG, sivr | 0x1FF);
#if DEBUG_PRINT_PROCESSORS
for (auto& processor : apic->m_processors)
{
dprintln("Processor{}", processor.processor_id);
dprintln(" lapic id: {}", processor.apic_id);
dprintln(" status: {}", (processor.flags & Processor::Flags::Enabled) ? "enabled" : (processor.flags & Processor::Flags::OnlineCapable) ? "can be enabled" : "disabled");
}
#endif
return apic;
}
uint32_t APIC::read_from_local_apic(ptrdiff_t offset)
{
return *(uint32_t*)(m_local_apic_vaddr + offset);
}
void APIC::write_to_local_apic(ptrdiff_t offset, uint32_t data)
{
*(uint32_t*)(m_local_apic_vaddr + offset) = data;
}
uint32_t APIC::IOAPIC::read(uint8_t offset)
{
volatile uint32_t* ioapic = (volatile uint32_t*)vaddr;
ioapic[0] = offset;
return ioapic[4];
}
void APIC::IOAPIC::write(uint8_t offset, uint32_t data)
{
volatile uint32_t* ioapic = (volatile uint32_t*)vaddr;
ioapic[0] = offset;
ioapic[4] = data;
}
void APIC::eoi(uint8_t)
{
write_to_local_apic(LAPIC_EIO_REG, 0);
}
void APIC::enable_irq(uint8_t irq)
{
uint32_t gsi = m_irq_overrides[irq];
IOAPIC* ioapic = nullptr;
for (IOAPIC& io : m_io_apics)
{
if (io.gsi_base <= gsi && gsi <= io.gsi_base + io.max_redirs)
{
ioapic = &io;
break;
}
}
ASSERT(ioapic);
RedirectionEntry redir;
redir.lo_dword = ioapic->read(IOAPIC_REDIRS + gsi * 2);
redir.hi_dword = ioapic->read(IOAPIC_REDIRS + gsi * 2 + 1);
redir.vector = IRQ_VECTOR_BASE + irq;
redir.mask = 0;
redir.destination = m_processors.front().apic_id;
ioapic->write(IOAPIC_REDIRS + gsi * 2, redir.lo_dword);
ioapic->write(IOAPIC_REDIRS + gsi * 2 + 1, redir.hi_dword);
}
bool APIC::is_in_service(uint8_t irq)
{
uint32_t dword = (irq + IRQ_VECTOR_BASE) / 32;
uint32_t bit = (irq + IRQ_VECTOR_BASE) % 32;
uint32_t isr = read_from_local_apic(LAPIC_IS_REG + dword * 0x10);
return isr & (1 << bit);
}