banan-os/kernel/kernel/APIC.cpp

354 lines
7.8 KiB
C++

#include <BAN/ScopeGuard.h>
#include <kernel/Debug.h>
#include <kernel/APIC.h>
#include <kernel/CPUID.h>
#include <kernel/IDT.h>
#include <kernel/MMU.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
// https://uefi.org/specs/ACPI/6.5/05_ACPI_Software_Programming_Model.html#multiple-apic-description-table-madt-format
static constexpr uint32_t RSPD_SIZE = 20;
static constexpr uint32_t RSPDv2_SIZE = 36;
struct RSDP
{
char signature[8];
uint8_t checksum;
char OEMID[6];
uint8_t revision;
uint32_t rsdt_address;
uint32_t v2_length;
uint64_t v2_xsdt_address;
uint8_t v2_extended_checksum;
uint8_t v2_reserved[3];
} __attribute__ ((packed));
struct SDTHeader
{
char signature[4];
uint32_t length;
uint8_t revision;
uint8_t checksum;
char OEMID[6];
char OEM_table_id[8];
uint32_t OEM_revision;
uint32_t creator_id;
uint32_t creator_revision;
} __attribute__((packed));
struct MADT
{
SDTHeader header;
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;
};
};
static bool IsRSDP(uintptr_t rsdp_addr)
{
const RSDP* rsdp = (const RSDP*)rsdp_addr;
if (memcmp(rsdp->signature, "RSD PTR ", 8) != 0)
return false;
{
uint8_t checksum = 0;
for (uint32_t i = 0; i < RSPD_SIZE; i++)
checksum += ((uint8_t*)rsdp)[i];
if (checksum != 0)
return false;
}
if (rsdp->revision == 2)
{
uint8_t checksum = 0;
for (uint32_t i = 0; i < RSPDv2_SIZE; i++)
checksum += ((uint8_t*)rsdp)[i];
if (checksum != 0)
return false;
}
return true;
}
static uintptr_t LocateRSDP()
{
// Look in main BIOS area below 1 MB
for (uintptr_t addr = 0x000E0000; addr < 0x000FFFFF; addr += 16)
if (IsRSDP(addr))
return addr;
return 0;
}
static bool IsValidSDTHeader(const SDTHeader* header)
{
uint8_t sum = 0;
for (uint32_t i = 0; i < header->length; i++)
sum += ((uint8_t*)header)[i];
return sum == 0;
}
uintptr_t LocateMADT(uintptr_t rsdp_addr)
{
uintptr_t entry_address_base = 0;
uintptr_t entry_address_mask = 0;
ptrdiff_t entry_pointer_size = 0;
uint32_t entry_count = 0;
const RSDP* rsdp = (const RSDP*)rsdp_addr;
if (rsdp->revision == 2)
{
uintptr_t xsdt_addr = rsdp->v2_xsdt_address;
MMU::Get().AllocatePage(xsdt_addr);
entry_address_base = xsdt_addr + sizeof(SDTHeader);
entry_address_mask = (uintptr_t)0xFFFFFFFFFFFFFFFF;
entry_count = (((const SDTHeader*)xsdt_addr)->length - sizeof(SDTHeader)) / 8;
entry_pointer_size = 8;
MMU::Get().UnAllocatePage(xsdt_addr);
}
else
{
uintptr_t rsdt_addr = rsdp->rsdt_address;
MMU::Get().AllocatePage(rsdt_addr);
entry_address_base = rsdt_addr + sizeof(SDTHeader);
entry_address_mask = 0xFFFFFFFF;
entry_count = (((const SDTHeader*)rsdt_addr)->length - sizeof(SDTHeader)) / 4;
entry_pointer_size = 4;
MMU::Get().UnAllocatePage(rsdt_addr);
}
for (uint32_t i = 0; i < entry_count; i++)
{
uintptr_t entry_addr_ptr = entry_address_base + i * entry_pointer_size;
MMU::Get().AllocatePage(entry_addr_ptr);
uintptr_t entry_addr = *(uintptr_t*)entry_addr_ptr & entry_address_mask;
MMU::Get().AllocatePage(entry_addr);
BAN::ScopeGuard _([&]() {
MMU::Get().UnAllocatePage(entry_addr);
MMU::Get().UnAllocatePage(entry_addr_ptr);
});
const SDTHeader* entry = (const SDTHeader*)entry_addr;
if (memcmp(entry->signature, "APIC", 4) == 0 && IsValidSDTHeader(entry))
return entry_addr;
}
return 0;
}
APIC* APIC::Create()
{
uint32_t ecx, edx;
CPUID::GetFeatures(ecx, edx);
if (!(edx & CPUID::Features::EDX_APIC))
{
dprintln("Local APIC is not available");
return nullptr;
}
uintptr_t rsdp_addr = LocateRSDP();
if (!rsdp_addr)
{
dprintln("Could not locate RSDP");
return nullptr;
}
uintptr_t madt_addr = LocateMADT(rsdp_addr);
if (!madt_addr)
{
dprintln("Could not find MADT in RSDP");
return nullptr;
}
MMU::Get().AllocatePage(madt_addr);
const MADT* madt = (const MADT*)madt_addr;
APIC* apic = new APIC;
apic->m_local_apic = 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->header.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.PushBack(processor));
break;
case 1:
IOAPIC ioapic;
ioapic.id = entry->entry1.ioapic_id;
ioapic.address = entry->entry1.ioapic_address;
ioapic.gsi_base = entry->entry1.gsi_base;
ioapic.max_redirs = 0;
MUST(apic->m_io_apics.PushBack(ioapic));
break;
case 2:
apic->m_irq_overrides[entry->entry2.irq_source] = entry->entry2.gsi;
break;
case 5:
apic->m_local_apic = entry->entry5.address;
break;
default:
dprintln("Unhandled madt entry, type {}", entry->type);
break;
}
madt_entry_addr += entry->length;
}
MMU::Get().UnAllocatePage((uintptr_t)madt);
if (apic->m_local_apic == 0 || apic->m_io_apics.Empty())
{
dprintln("MADT did not provide necessary information");
delete apic;
return nullptr;
}
MMU::Get().AllocatePage(apic->m_local_apic);
for (auto& io_apic : apic->m_io_apics)
{
MMU::Get().AllocatePage(io_apic.address);
io_apic.max_redirs = io_apic.Read(IOAPIC_MAX_REDIRS);
}
// Mask all interrupts
uint32_t sivr = apic->ReadFromLocalAPIC(LAPIC_SIV_REG);
apic->WriteToLocalAPIC(LAPIC_SIV_REG, sivr | 0x1FF);
return apic;
}
uint32_t APIC::ReadFromLocalAPIC(ptrdiff_t offset)
{
return *(uint32_t*)(m_local_apic + offset);
}
void APIC::WriteToLocalAPIC(ptrdiff_t offset, uint32_t data)
{
*(uint32_t*)(m_local_apic + offset) = data;
}
uint32_t APIC::IOAPIC::Read(uint8_t offset)
{
volatile uint32_t* ioapic = (volatile uint32_t*)address;
ioapic[0] = offset;
return ioapic[4];
}
void APIC::IOAPIC::Write(uint8_t offset, uint32_t data)
{
volatile uint32_t* ioapic = (volatile uint32_t*)address;
ioapic[0] = offset;
ioapic[4] = data;
}
void APIC::EOI(uint8_t)
{
WriteToLocalAPIC(LAPIC_EIO_REG, 0);
}
void APIC::EnableIrq(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);
}
void APIC::GetISR(uint32_t out[8])
{
for (uint32_t i = 0; i < 8; i++)
out[i] = ReadFromLocalAPIC(LAPIC_IS_REG + i * 0x10);
}