From 23a2f8b90314b9597640e5bc2ed8fc2b6277e8f7 Mon Sep 17 00:00:00 2001 From: Bananymous Date: Thu, 7 Mar 2024 16:57:39 +0200 Subject: [PATCH] Kernel: Cleanup multiprocessor startup by removing magic numbers --- kernel/kernel/APIC.cpp | 66 ++++++++++++++++++++++++++++++++++++++---- 1 file changed, 60 insertions(+), 6 deletions(-) diff --git a/kernel/kernel/APIC.cpp b/kernel/kernel/APIC.cpp index ef0b6072cc..274449c3a5 100644 --- a/kernel/kernel/APIC.cpp +++ b/kernel/kernel/APIC.cpp @@ -31,6 +31,35 @@ extern volatile uint8_t g_ap_stack_loaded[]; namespace Kernel { + enum ICR_LO : uint32_t + { + ICR_LO_reserved_mask = 0xFFF32000, + + ICR_LO_delivery_mode_fixed = 0b000 << 8, + ICR_LO_delivery_mode_lowest_priority = 0b001 << 8, + ICR_LO_delivery_mode_smi = 0b010 << 8, + ICR_LO_delivery_mode_nmi = 0b100 << 8, + ICR_LO_delivery_mode_init = 0b101 << 8, + ICR_LO_delivery_mode_start_up = 0b110 << 8, + + ICR_LO_destination_mode_physical = 0 << 11, + ICR_LO_destination_mode_logical = 1 << 11, + + ICR_LO_delivery_status_idle = 0 << 12, + ICR_LO_delivery_status_send_pending = 1 << 12, + + ICR_LO_level_deassert = 0 << 14, + ICR_LO_level_assert = 1 << 14, + + ICR_LO_trigger_mode_edge = 0 << 15, + ICR_LO_trigger_mode_level = 1 << 15, + + ICR_LO_destination_shorthand_none = 0b00 << 18, + ICR_LO_destination_shorthand_self = 0b01 << 18, + ICR_LO_destination_shorthand_all_including_self = 0b10 << 18, + ICR_LO_destination_shorthand_all_excluding_self = 0b11 << 18, + }; + struct MADT : public Kernel::ACPI::SDTHeader { uint32_t local_apic; @@ -208,7 +237,7 @@ namespace Kernel write_to_local_apic(LAPIC_ICR_HI_REG, (read_from_local_apic(LAPIC_ICR_HI_REG) & 0x00FFFFFF) | (processor << 24)); write_to_local_apic(LAPIC_ICR_LO_REG, data); udelay(ud); - while (read_from_local_apic(LAPIC_ICR_LO_REG) & (1 << 12)) + while ((read_from_local_apic(LAPIC_ICR_LO_REG) & ICR_LO_delivery_status_send_pending) == ICR_LO_delivery_status_send_pending) __builtin_ia32_pause(); }; @@ -232,30 +261,55 @@ namespace Kernel dprintln("Trying to enable processor (lapic id {})", processor.apic_id); - auto& proc = Kernel::Processor::create(processor.processor_id); + auto& proc = Kernel::Processor::create(processor.apic_id); PageTable::with_fast_page((paddr_t)g_ap_init_addr, [&] { PageTable::fast_page_as_sized(2) = V2P(proc.stack_top()); }); *g_ap_stack_loaded = 0; write_to_local_apic(LAPIC_ERROR_REG, 0x00); - send_ipi(processor.processor_id, (read_from_local_apic(LAPIC_ICR_LO_REG) & 0xFFF00000) | 0x0000C500, 0); - send_ipi(processor.processor_id, (read_from_local_apic(LAPIC_ICR_LO_REG) & 0xFFF0F800) | 0x00008500, 0); + + // send INIT IPI + send_ipi(processor.apic_id, + (read_from_local_apic(LAPIC_ICR_LO_REG) & ICR_LO_reserved_mask) + | ICR_LO_delivery_mode_init + | ICR_LO_destination_mode_physical + | ICR_LO_level_assert + | ICR_LO_trigger_mode_edge + | ICR_LO_destination_shorthand_none + , 0 + ); + + // TODO: If we are on processor predating Pentium, we need to send deassert udelay(10 * 1000); for (int i = 0; i < 2; i++) { write_to_local_apic(LAPIC_ERROR_REG, 0x00); - send_ipi(processor.processor_id, (read_from_local_apic(LAPIC_ICR_LO_REG) & 0xFFF0F800) | 0x00000600 | ap_init_page, 200); + + // send 2 SETUP IPIs with 200 us delay + send_ipi(processor.apic_id, + (read_from_local_apic(LAPIC_ICR_LO_REG) & ICR_LO_reserved_mask) + | ICR_LO_delivery_mode_start_up + | ICR_LO_destination_mode_physical + | ICR_LO_level_assert + | ICR_LO_trigger_mode_edge + | ICR_LO_destination_shorthand_none + | ap_init_page + , 200 + ); } - // give processor upto 100 * 100 us (10 ms to boot) + // give processor upto 100 * 100 us + 200 us to boot for (int i = 0; *g_ap_stack_loaded == 0 && i < 100; i++) udelay(100); } *g_ap_startup_done = 1; + + // give processors 100 us time to increment running count + udelay(100); dprintln("{} processors started", *g_ap_running_count); }