#include <core/system.h>

Data Structures
struct	x86_regs
	The registers an interrupt or exception saved, on the kernel stack, as cpu.S's stubs push them: the general registers, the stub's vector and error code, then what the CPU pushed. More...
struct	x86_gdt_entry
	A segment descriptor, an entry of the GDT. More...
struct	x86_tss
struct	arch_cpu
	A CPU's aarch64 state (struct cpu's arch). More...

Macros
#define	X86_GDT_TSS 5
#define	X86_GDT_CPU 7
#define	X86_GDT_NR 8
#define	X86_SEL_CPU (X86_GDT_CPU << 3)
#define	CR0_PG _BV(31)
#define	CR0_WP _BV(16)
#define	CR0_MP _BV(1)
#define	CR0_EM _BV(2)
#define	CR0_TS _BV(3)
#define	CR0_NE _BV(5)
#define	CR4_PSE _BV(4)
#define	CR4_OSFXSR _BV(9)
#define	CR4_OSXMMEXCPT _BV(10)

Functions
static void	x86_dump_registers (struct x86_regs *regs)
static struct cpu *	curcpu (void)
static uintptr_t	read_cr0 (void)
static uintptr_t	read_cr1 (void)
static uintptr_t	read_cr2 (void)
static uintptr_t	read_cr3 (void)
static uintptr_t	read_cr4 (void)
static void	write_cr0 (uintptr_t val)
static void	write_cr1 (uintptr_t val)
static void	write_cr2 (uintptr_t val)
static void	write_cr3 (uintptr_t val)
static void	write_cr4 (uintptr_t val)
void	x86_gdt_setup (struct cpu *cpu, uintptr_t sp)
	Sets up and loads the running CPU's GDT and TSS, and points gs (or the GS base, on x86_64) at its struct cpu, so that curcpu() works.
void	x86_kernel_stack_set (uintptr_t sp)
	Sets the kernel stack that interrupts from user mode switch to, on the running CPU: the thread that is about to run's.
void	x86_idt_setup (void)
	Loads the IDT on the running CPU.
void	x86_idt_gate_set (uint32_t id, uintptr_t offset)
	Sets an interrupt gate that only the hardware (and the kernel) can raise: an exception or a device interrupt.
void	x86_idt_gate_user_set (uint32_t id, uintptr_t offset)
	Sets an interrupt gate that user mode may raise with int too: the system call vector.
void	x86_isr_setup (void)
	Sets the IDT's gates for the exceptions and the system call vector.
void	x86_fpu_setup (void)
	Sets up the FPU on the running CPU, at boot: CR0.TS set so that the first FPU or SSE instruction raises #NM (x86_fpu_trap()), SSE turned on if the CPU has it, and the clean starting state recorded.
void	x86_fpu_enable (void)
	Lets the running CPU use the FPU without trapping (clears CR0.TS).
void	x86_fpu_disable (void)
	Makes the next FPU instruction trap (sets CR0.TS).
void	x86_fpu_trap (void)
	Handles #NM, the current thread's first FPU or SSE instruction since it was switched in: it saves the previous owner's state, and gives the FPU to this thread, with its own state or a clean one.
void	x86_fpu_switch_out (void)
	Saves the current thread's FPU state when it is switched out, if the FPU holds it, because the thread may run on another CPU next.
int	x86_fpu_save_to (void *buf)
	Copies the current thread's FPU state, for a signal handler's frame (sys/signal.c).
void	x86_fpu_reset (void)
	Makes the current thread start with a clean FPU state at its next use of the FPU, as a signal handler does.
void	x86_fpu_load_from (const void *buf, int valid)
	Gives the current thread back the FPU state saved in a signal frame, at sigreturn.
void	x86_return_to_user (struct x86_regs *r, int syscall)
	Delivers the current process's pending signals on the way back to user mode: stops and default actions, a handler, and the restart (or EINTR) of a system call that a signal interrupted.

Macro Definition Documentation

◆ CR0_EM

#define CR0_EM _BV(2)

Definition at line 158 of file cpu.h.

Referenced by x86_fpu_setup().

◆ CR0_MP

#define CR0_MP _BV(1)

Definition at line 157 of file cpu.h.

Referenced by x86_fpu_setup().

◆ CR0_NE

#define CR0_NE _BV(5)

Definition at line 160 of file cpu.h.

Referenced by x86_fpu_setup().

◆ CR0_PG

#define CR0_PG _BV(31)

Definition at line 155 of file cpu.h.

Referenced by enable_paging().

◆ CR0_TS

#define CR0_TS _BV(3)

Definition at line 159 of file cpu.h.

Referenced by x86_fpu_disable(), and x86_fpu_setup().

◆ CR0_WP

#define CR0_WP _BV(16)

Definition at line 156 of file cpu.h.

Referenced by enable_paging().

◆ CR4_OSFXSR

#define CR4_OSFXSR _BV(9)

Definition at line 164 of file cpu.h.

Referenced by x86_fpu_setup().

◆ CR4_OSXMMEXCPT

#define CR4_OSXMMEXCPT _BV(10)

Definition at line 165 of file cpu.h.

Referenced by x86_fpu_setup().

◆ CR4_PSE

#define CR4_PSE _BV(4)

Definition at line 163 of file cpu.h.

◆ X86_GDT_CPU

#define X86_GDT_CPU 7

Definition at line 115 of file cpu.h.

Referenced by x86_gdt_setup().

◆ X86_GDT_NR

#define X86_GDT_NR 8

Definition at line 116 of file cpu.h.

◆ X86_GDT_TSS

#define X86_GDT_TSS 5

Definition at line 114 of file cpu.h.

Referenced by x86_gdt_setup().

◆ X86_SEL_CPU

#define X86_SEL_CPU (X86_GDT_CPU << 3)

Definition at line 118 of file cpu.h.

Referenced by x86_gdt_setup().

Function Documentation

◆ curcpu()

struct cpu * curcpu ( void )

inlinestatic

Definition at line 143 of file cpu.h.

◆ read_cr0()

uintptr_t read_cr0 ( void )

inlinestatic

Definition at line 168 of file cpu.h.

◆ read_cr1()

uintptr_t read_cr1 ( void )

inlinestatic

Definition at line 179 of file cpu.h.

References read_cr1().

Referenced by read_cr1().

◆ read_cr2()

uintptr_t read_cr2 ( void )

inlinestatic

Definition at line 190 of file cpu.h.

References read_cr2().

Referenced by isr_dispatch(), and read_cr2().

◆ read_cr3()

uintptr_t read_cr3 ( void )

inlinestatic

Definition at line 201 of file cpu.h.

References read_cr3().

Referenced by pmap_init(), read_cr3(), and tlb_flush().

◆ read_cr4()

uintptr_t read_cr4 ( void )

inlinestatic

Definition at line 212 of file cpu.h.

References read_cr4().

Referenced by read_cr4(), x86_fpu_setup(), and x86_smp_init().

◆ write_cr0()

void write_cr0 ( uintptr_t val )

inlinestatic

Definition at line 223 of file cpu.h.

◆ write_cr1()

void write_cr1 ( uintptr_t val )

inlinestatic

Definition at line 232 of file cpu.h.

References write_cr1().

Referenced by write_cr1().

◆ write_cr2()

void write_cr2 ( uintptr_t val )

inlinestatic

Definition at line 241 of file cpu.h.

References write_cr2().

Referenced by write_cr2().

◆ write_cr3()

void write_cr3 ( uintptr_t val )

inlinestatic

Definition at line 250 of file cpu.h.

◆ write_cr4()

void write_cr4 ( uintptr_t val )

inlinestatic

Definition at line 259 of file cpu.h.

References write_cr4().

Referenced by write_cr4(), and x86_fpu_setup().

◆ x86_dump_registers()

void x86_dump_registers ( struct x86_regs * regs )

inlinestatic

Definition at line 29 of file cpu.h.

References x86_regs::cs, printk(), x86_regs::r10, x86_regs::r11, x86_regs::r12, x86_regs::r13, x86_regs::r14, x86_regs::r15, x86_regs::r8, x86_regs::r9, x86_regs::rax, x86_regs::rbp, x86_regs::rbx, x86_regs::rcx, x86_regs::rdi, x86_regs::rdx, x86_regs::rflags, x86_regs::rip, x86_regs::rsi, x86_regs::rsp, x86_regs::ss, and x86_dump_registers().

Referenced by isr_dispatch(), and x86_dump_registers().

◆ x86_fpu_disable()

void x86_fpu_disable ( void )

Makes the next FPU instruction trap (sets CR0.TS).

Definition at line 88 of file fpu.c.

References CR0_TS, and x86_fpu_disable().

Referenced by arch_thread_spawn(), arch_thread_switch(), x86_fpu_disable(), x86_fpu_reset(), and x86_fpu_setup().

◆ x86_fpu_enable()

void x86_fpu_enable ( void )

Lets the running CPU use the FPU without trapping (clears CR0.TS).

Definition at line 82 of file fpu.c.

References x86_fpu_enable().

Referenced by x86_fpu_enable(), x86_fpu_save_to(), x86_fpu_setup(), x86_fpu_switch_out(), and x86_fpu_trap().

◆ x86_fpu_load_from()

void x86_fpu_load_from	(	const void *	buf,
		int	valid )

Gives the current thread back the FPU state saved in a signal frame, at sigreturn.

It is loaded at the thread's next use of the FPU, with the MXCSR bits the CPU doesn't accept cleared.

Parameters

buf	the saved state: 512 bytes
valid	whether the frame has a state (the thread had used the FPU); if not, the thread starts afresh

Definition at line 239 of file fpu.c.

References curthread, x86_thread::fpu_context, x86_thread::fpu_enabled, fpu_fxsr, kmalloc(), memcpy(), mxcsr_mask, x86_fpu_load_from(), and x86_fpu_reset().

Referenced by arch_sigreturn(), and x86_fpu_load_from().

◆ x86_fpu_reset()

void x86_fpu_reset ( void )

Makes the current thread start with a clean FPU state at its next use of the FPU, as a signal handler does.

Definition at line 218 of file fpu.c.

References curthread, x86_thread::fpu_enabled, last_fpu_thread, NULL, x86_fpu_disable(), and x86_fpu_reset().

Referenced by deliver(), x86_fpu_load_from(), and x86_fpu_reset().

◆ x86_fpu_save_to()

int x86_fpu_save_to ( void * buf )

Copies the current thread's FPU state, for a signal handler's frame (sys/signal.c).

Parameters

buf	where to copy it: 512 bytes, 16-byte aligned

Returns: 1 if the state was copied, or 0 if the thread never used the FPU

Definition at line 198 of file fpu.c.

References curthread, fpu_context, x86_thread::fpu_context, x86_thread::fpu_enabled, fpu_save(), last_fpu_thread, memcpy(), x86_fpu_enable(), and x86_fpu_save_to().

Referenced by arch_proc_fork(), deliver(), and x86_fpu_save_to().

◆ x86_fpu_setup()

void x86_fpu_setup ( void )

Sets up the FPU on the running CPU, at boot: CR0.TS set so that the first FPU or SSE instruction raises #NM (x86_fpu_trap()), SSE turned on if the CPU has it, and the clean starting state recorded.

CR0.EM must stay clear, or SSE instructions would raise #UD instead.

Definition at line 50 of file fpu.c.

References CPUID_EDX_FXSR, CPUID_EDX_SSE, CR0_EM, CR0_MP, CR0_NE, CR0_TS, CR4_OSFXSR, CR4_OSXMMEXCPT, fpu_clean, fpu_fxsr, memset(), mxcsr_mask, read_cr4(), write_cr4(), x86_fpu_disable(), x86_fpu_enable(), and x86_fpu_setup().

Referenced by x86_cpu_init(), and x86_fpu_setup().

◆ x86_fpu_switch_out()

void x86_fpu_switch_out ( void )

Saves the current thread's FPU state when it is switched out, if the FPU holds it, because the thread may run on another CPU next.

Afterwards, the FPU belongs to no thread.

Definition at line 178 of file fpu.c.

References curthread, fpu_context, x86_thread::fpu_context, fpu_save(), last_fpu_thread, memcpy(), NULL, x86_fpu_enable(), and x86_fpu_switch_out().

Referenced by x86_fpu_switch_out(), and x86_thread_saved().

◆ x86_fpu_trap()

void x86_fpu_trap ( void )

Handles #NM, the current thread's first FPU or SSE instruction since it was switched in: it saves the previous owner's state, and gives the FPU to this thread, with its own state or a clean one.

If there's no memory for the thread's save area, the process is killed.

Definition at line 131 of file fpu.c.

References curproc, curthread, fpu_context, x86_thread::fpu_context, x86_thread::fpu_enabled, fpu_restore(), fpu_save(), kmalloc(), last_fpu_thread, memcpy(), panic, signal_proc_send(), x86_fpu_enable(), x86_fpu_init(), and x86_fpu_trap().

Referenced by isr_dispatch(), and x86_fpu_trap().

◆ x86_gdt_setup()

void x86_gdt_setup	(	struct cpu *	cpu,
		uintptr_t	sp )

Sets up and loads the running CPU's GDT and TSS, and points gs (or the GS base, on x86_64) at its struct cpu, so that curcpu() works.

Parameters

cpu	the running CPU
sp	the kernel stack that interrupts from user mode switch to (each thread sets its own later, x86_kernel_stack_set())

Definition at line 79 of file gdt.c.

References x86_tss::_, x86_tss::__, cpu::arch, assert_alignof, assert_sizeof, x86_gdt_entry::db, x86_gdt_entry::dpl, DPL0, DPL3, arch_cpu::gdt, gdt_template, memcpy(), memset(), MSR_GS_BASE, MSR_KERNEL_GS_BASE, x86_gdt_entry::p, RW_DATA, x86_gdt_entry::s, segment_set(), cpu::self, x86_tss::sp, arch_cpu::tss, TSS_AVL, x86_gdt_entry::type, X86_GDT_CPU, x86_gdt_setup(), X86_GDT_TSS, x86_lgdt(), x86_ltr(), and X86_SEL_CPU.

Referenced by x86_ap_start(), x86_cpu_init(), and x86_gdt_setup().

◆ x86_idt_gate_set()

void x86_idt_gate_set	(	uint32_t	id,
		uintptr_t	offset )

Sets an interrupt gate that only the hardware (and the kernel) can raise: an exception or a device interrupt.

The handler runs in the kernel's code segment, with interrupts disabled.

Parameters

id	the vector
offset	the handler's address

Definition at line 45 of file idt.c.

References idt_entry::dpl, DPL0, idt_entry::flags, idt, idt_entry::offset_ext, idt_entry::offset_hi, idt_entry::offset_lo, idt_entry::p, idt_entry::selector, and x86_idt_gate_set().

Referenced by x86_idt_gate_set(), x86_irq_gates_setup(), and x86_isr_setup().

◆ x86_idt_gate_user_set()

void x86_idt_gate_user_set	(	uint32_t	id,
		uintptr_t	offset )

Sets an interrupt gate that user mode may raise with int too: the system call vector.

The handler still runs in the kernel's code segment.

Parameters

id	the vector
offset	the handler's address

Definition at line 67 of file idt.c.

References idt_entry::dpl, DPL3, idt_entry::flags, idt, idt_entry::offset_ext, idt_entry::offset_hi, idt_entry::offset_lo, idt_entry::p, idt_entry::selector, and x86_idt_gate_user_set().

Referenced by x86_idt_gate_user_set(), and x86_isr_setup().

◆ x86_idt_setup()

void x86_idt_setup ( void )

Loads the IDT on the running CPU.

Definition at line 82 of file idt.c.

References idt_ptr::base, idt, idt_pointer, idt_ptr::limit, x86_idt_setup(), and x86_lidt().

Referenced by x86_ap_start(), x86_cpu_init(), and x86_idt_setup().

◆ x86_isr_setup()

void x86_isr_setup ( void )

Sets the IDT's gates for the exceptions and the system call vector.

Definition at line 253 of file isr.c.

References __x86_isr0(), __x86_isr1(), __x86_isr10(), __x86_isr11(), __x86_isr12(), __x86_isr128(), __x86_isr13(), __x86_isr14(), __x86_isr15(), __x86_isr16(), __x86_isr17(), __x86_isr18(), __x86_isr19(), __x86_isr2(), __x86_isr20(), __x86_isr21(), __x86_isr22(), __x86_isr23(), __x86_isr24(), __x86_isr25(), __x86_isr26(), __x86_isr27(), __x86_isr28(), __x86_isr29(), __x86_isr3(), __x86_isr30(), __x86_isr31(), __x86_isr4(), __x86_isr5(), __x86_isr6(), __x86_isr7(), __x86_isr8(), __x86_isr9(), x86_idt_gate_set(), x86_idt_gate_user_set(), and x86_isr_setup().

Referenced by x86_cpu_init(), and x86_isr_setup().

◆ x86_kernel_stack_set()

void x86_kernel_stack_set ( uintptr_t sp )

Sets the kernel stack that interrupts from user mode switch to, on the running CPU: the thread that is about to run's.

Parameters

sp	the top of the stack

Definition at line 152 of file gdt.c.

References x86_kernel_stack_set().

Referenced by arch_idle(), arch_thread_kill(), arch_thread_spawn(), arch_thread_switch(), and x86_kernel_stack_set().

◆ x86_return_to_user()

void x86_return_to_user	(	struct x86_regs *	r,
		int	syscall )

Delivers the current process's pending signals on the way back to user mode: stops and default actions, a handler, and the restart (or EINTR) of a system call that a signal interrupted.

Parameters

r	the user context about to be returned to
syscall	whether r is returning from a system call (one that may need restarting)

Definition at line 246 of file signal.c.

References thread::arch, x86_regs::cs, curthread, deliver(), ERESTARTNOHAND, ERESTARTSYS, thread::owner, REG_AX, REG_IP, thread::restarting, thread::sig_oldmask, thread::sig_oldmask_set, proc::sigaction, proc::sigmask, signal_take(), thread::syscall_nr, and x86_return_to_user().

Referenced by arch_syscall(), irq_dispatch(), isr_dispatch(), and x86_return_to_user().

Data Structures

Macros

Functions

Macro Definition Documentation

◆ CR0_EM

◆ CR0_MP

◆ CR0_NE

◆ CR0_PG

◆ CR0_TS

◆ CR0_WP

◆ CR4_OSFXSR

◆ CR4_OSXMMEXCPT

◆ CR4_PSE

◆ X86_GDT_CPU

◆ X86_GDT_NR

◆ X86_GDT_TSS

◆ X86_SEL_CPU

Function Documentation

◆ curcpu()

◆ read_cr0()

◆ read_cr1()

◆ read_cr2()

◆ read_cr3()

◆ read_cr4()

◆ write_cr0()

◆ write_cr1()

◆ write_cr2()

◆ write_cr3()

◆ write_cr4()

◆ x86_dump_registers()

◆ x86_fpu_disable()

◆ x86_fpu_enable()

◆ x86_fpu_load_from()

◆ x86_fpu_reset()

◆ x86_fpu_save_to()

◆ x86_fpu_setup()

◆ x86_fpu_switch_out()

◆ x86_fpu_trap()

◆ x86_gdt_setup()

◆ x86_idt_gate_set()

◆ x86_idt_gate_user_set()

◆ x86_idt_setup()

◆ x86_isr_setup()

◆ x86_kernel_stack_set()

◆ x86_return_to_user()