sanchayanmaity/minix
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Wiki Activity
minix/kernel/arch/i386/mpx.S
Tomas Hruby 62c666566e SMP - We boot APs 
- kernel detects CPUs by searching ACPI tables for local apic nodes

- each CPU has its own TSS that points to its own stack. All cpus boot
  on the same boot stack (in sequence) but switch to its private stack
  as soon as they can.

- final booting code in main() placed in bsp_finish_booting() which is
  executed only after the BSP switches to its final stack

- apic functions to send startup interrupts

- assembler functions to handle CPU features not needed for single cpu
  mode like memory barries, HT detection etc.

- new files kernel/smp.[ch], kernel/arch/i386/arch_smp.c and
  kernel/arch/i386/include/arch_smp.h

- 16-bit trampoline code for the APs. It is executed by each AP after
  receiving startup IPIs it brings up the CPUs to 32bit mode and let
  them spin in an infinite loop so they don't do any damage.

- implementation of kernel spinlock

- CONFIG_SMP and CONFIG_MAX_CPUS set by the build system
2010-09-15 14:09:52 +00:00

681 lines
17 KiB
ArmAsm
Raw Blame History

/*
* This file is part of the lowest layer of the MINIX kernel. (The other part
* is "proc.c".) The lowest layer does process switching and message handling.
* Furthermore it contains the assembler startup code for Minix and the 32-bit
* interrupt handlers. It cooperates with the code in "start.c" to set up a
* good environment for main().
*
* Kernel is entered either because of kernel-calls, ipc-calls, interrupts or
* exceptions. TSS is set so that the kernel stack is loaded. The user context is
* saved to the proc table and the handler of the event is called. Once the
* handler is done, switch_to_user() function is called to pick a new process,
* finish what needs to be done for the next process to run, sets its context
* and switch to userspace.
*
* For communication with the boot monitor at startup time some constant
* data are compiled into the beginning of the text segment. This facilitates
* reading the data at the start of the boot process, since only the first
* sector of the file needs to be read.
*
* Some data storage is also allocated at the end of this file. This data
* will be at the start of the data segment of the kernel and will be read
* and modified by the boot monitor before the kernel starts.
*/
#include "kernel/kernel.h" /* configures the kernel */
/* sections */
#include <machine/vm.h>
#ifdef __ACK__
.text
begtext:
#ifdef __ACK__
.rom
#else
.data
#endif
begrom:
.data
begdata:
.bss
begbss:
#endif
#include "../../kernel.h"
#include <minix/config.h>
#include <minix/const.h>
#include <minix/com.h>
#include <machine/asm.h>
#include <machine/interrupt.h>
#include "archconst.h"
#include "kernel/const.h"
#include "kernel/proc.h"
#include "sconst.h"
#include "multiboot.h"
#include "arch_proto.h" /* K_STACK_SIZE */
#ifdef CONFIG_SMP
#include "kernel/smp.h"
#endif
/* Selected 386 tss offsets. */
#define TSS3_S_SP0 4
IMPORT(copr_not_available_handler)
IMPORT(params_size)
IMPORT(params_offset)
IMPORT(mon_ds)
IMPORT(switch_to_user)
/* Exported variables. */
.globl begbss
.globl begdata
.text
/*===========================================================================*/
/* MINIX */
/*===========================================================================*/
.global MINIX
MINIX:
/* this is the entry point for the MINIX kernel */
jmp over_flags /* skip over the next few bytes */
.short CLICK_SHIFT /* for the monitor: memory granularity */
flags:
/* boot monitor flags:
* call in 386 mode, make bss, make stack,
* load high, don't patch, will return,
* uses generic INT, memory vector,
* new boot code return
*/
.short 0x03FD
nop /* extra byte to sync up disassembler */
/* Multiboot header here*/
.balign 8
multiboot_magic:
.long MULTIBOOT_HEADER_MAGIC
multiboot_flags:
.long MULTIBOOT_FLAGS
multiboot_checksum:
.long -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_FLAGS)
multiboot_header_addr:
.long (MULTIBOOT_LOAD_ADDRESS + MULTIBOOT_ENTRY_OFFSET + multiboot_magic)
multiboot_load_addr:
.long MULTIBOOT_LOAD_ADDRESS
multiboot_load_end_addr:
.long 0
multiboot_bss_end_addr:
.long 0
multiboot_entry_addr:
.long (MULTIBOOT_LOAD_ADDRESS + MULTIBOOT_ENTRY_OFFSET + multiboot_init)
/* Video mode */
multiboot_mode_type:
.long MULTIBOOT_VIDEO_MODE_EGA
multiboot_width:
.long MULTIBOOT_CONSOLE_COLS
multiboot_height:
.long MULTIBOOT_CONSOLE_LINES
multiboot_depth:
.long 0
over_flags:
/* Set up a C stack frame on the monitor stack. (The monitor sets cs and ds */
/* right. The ss descriptor still references the monitor data segment.) */
movzwl %sp, %esp /* monitor stack is a 16 bit stack */
.globl kernel_init
kernel_init: /* after pre-init*/
push %ebp
mov %esp, %ebp
push %esi
push %edi
cmp $0, 4(%ebp) /* monitor return vector is */
je noret /* nonzero if return possible */
incl _C_LABEL(mon_return)
noret:
movl %esp, _C_LABEL(mon_sp) /* save stack pointer for later return */
/* Copy the monitor global descriptor table to the address space of kernel and */
/* switch over to it. Prot_init() can then update it with immediate effect. */
sgdt _C_LABEL(gdt)+GDT_SELECTOR /* get the monitor gdtr */
movl _C_LABEL(gdt)+GDT_SELECTOR+2, %esi /* absolute address of GDT */
mov $_C_LABEL(gdt), %ebx /* address of kernel GDT */
mov $8*8, %ecx /* copying eight descriptors */
copygdt:
movb %es:(%esi), %al
movb %al, (%ebx)
inc %esi
inc %ebx
loop copygdt
movl _C_LABEL(gdt)+DS_SELECTOR+2, %eax /* base of kernel data */
and $0x00FFFFFF, %eax /* only 24 bits */
add $_C_LABEL(gdt), %eax /* eax = vir2phys(gdt) */
movl %eax, _C_LABEL(gdt)+GDT_SELECTOR+2 /* set base of GDT */
lgdt _C_LABEL(gdt)+GDT_SELECTOR /* switch over to kernel GDT */
/* Locate boot parameters, set up kernel segment registers and stack. */
mov 8(%ebp), %ebx /* boot parameters offset */
mov 12(%ebp), %edx /* boot parameters length */
mov 16(%ebp), %eax /* address of a.out headers */
movl %eax, _C_LABEL(aout)
mov %ds, %ax /* kernel data */
mov %ax, %es
mov %ax, %fs
mov %ax, %gs
mov %ax, %ss
mov $_C_LABEL(k_boot_stktop) - 4, %esp /* set sp to point to the top of kernel stack */
/* Save boot parameters into these global variables for i386 code */
movl %edx, _C_LABEL(params_size)
movl %ebx, _C_LABEL(params_offset)
movl $SS_SELECTOR, _C_LABEL(mon_ds)
/* Call C startup code to set up a proper environment to run main(). */
push %edx
push %ebx
push $SS_SELECTOR
push $DS_SELECTOR
push $CS_SELECTOR
call _C_LABEL(cstart) /* cstart(cs, ds, mds, parmoff, parmlen) */
add $5*4, %esp
/* Reload gdtr, idtr and the segment registers to global descriptor table set */
/* up by prot_init(). */
lgdt _C_LABEL(gdt)+GDT_SELECTOR
lidt _C_LABEL(gdt)+IDT_SELECTOR
ljmp $CS_SELECTOR, $csinit
csinit:
movw $DS_SELECTOR, %ax
mov %ax, %ds
mov %ax, %es
mov %ax, %fs
mov %ax, %gs
mov %ax, %ss
movw $TSS_SELECTOR_BOOT, %ax /* no other TSS is used */
ltr %ax
push $0 /* set flags to known good state */
popf /* esp, clear nested task and int enable */
jmp _C_LABEL(main) /* main() */
/*===========================================================================*/
/* interrupt handlers */
/* interrupt handlers for 386 32-bit protected mode */
/*===========================================================================*/
#define PIC_IRQ_HANDLER(irq) \
push $irq ;\
call _C_LABEL(irq_handle) /* intr_handle(irq_handlers[irq]) */ ;\
add $4, %esp ;
/*===========================================================================*/
/* hwint00 - 07 */
/*===========================================================================*/
/* Note this is a macro, it just looks like a subroutine. */
#define hwint_master(irq) \
TEST_INT_IN_KERNEL(4, 0f) ;\
\
SAVE_PROCESS_CTX(0) ;\
push %ebp ;\
movl $0, %ebp /* for stack trace */ ;\
call _C_LABEL(context_stop) ;\
add $4, %esp ;\
PIC_IRQ_HANDLER(irq) ;\
movb $END_OF_INT, %al ;\
outb $INT_CTL /* reenable interrupts in master pic */ ;\
jmp _C_LABEL(switch_to_user) ;\
\
0: \
pusha ;\
call _C_LABEL(context_stop_idle) ;\
PIC_IRQ_HANDLER(irq) ;\
movb $END_OF_INT, %al ;\
outb $INT_CTL /* reenable interrupts in master pic */ ;\
CLEAR_IF(10*4(%esp)) ;\
popa ;\
iret ;
/* Each of these entry points is an expansion of the hwint_master macro */
ENTRY(hwint00)
/* Interrupt routine for irq 0 (the clock). */
hwint_master(0)
ENTRY(hwint01)
/* Interrupt routine for irq 1 (keyboard) */
hwint_master(1)
ENTRY(hwint02)
/* Interrupt routine for irq 2 (cascade!) */
hwint_master(2)
ENTRY(hwint03)
/* Interrupt routine for irq 3 (second serial) */
hwint_master(3)
ENTRY(hwint04)
/* Interrupt routine for irq 4 (first serial) */
hwint_master(4)
ENTRY(hwint05)
/* Interrupt routine for irq 5 (XT winchester) */
hwint_master(5)
ENTRY(hwint06)
/* Interrupt routine for irq 6 (floppy) */
hwint_master(6)
ENTRY(hwint07)
/* Interrupt routine for irq 7 (printer) */
hwint_master(7)
/*===========================================================================*/
/* hwint08 - 15 */
/*===========================================================================*/
/* Note this is a macro, it just looks like a subroutine. */
#define hwint_slave(irq) \
TEST_INT_IN_KERNEL(4, 0f) ;\
\
SAVE_PROCESS_CTX(0) ;\
push %ebp ;\
movl $0, %ebp /* for stack trace */ ;\
call _C_LABEL(context_stop) ;\
add $4, %esp ;\
PIC_IRQ_HANDLER(irq) ;\
movb $END_OF_INT, %al ;\
outb $INT_CTL /* reenable interrupts in master pic */ ;\
outb $INT2_CTL /* reenable slave 8259 */ ;\
jmp _C_LABEL(switch_to_user) ;\
\
0: \
pusha ;\
call _C_LABEL(context_stop_idle) ;\
PIC_IRQ_HANDLER(irq) ;\
movb $END_OF_INT, %al ;\
outb $INT_CTL /* reenable interrupts in master pic */ ;\
outb $INT2_CTL /* reenable slave 8259 */ ;\
CLEAR_IF(10*4(%esp)) ;\
popa ;\
iret ;
/* Each of these entry points is an expansion of the hwint_slave macro */
ENTRY(hwint08)
/* Interrupt routine for irq 8 (realtime clock) */
hwint_slave(8)
ENTRY(hwint09)
/* Interrupt routine for irq 9 (irq 2 redirected) */
hwint_slave(9)
ENTRY(hwint10)
/* Interrupt routine for irq 10 */
hwint_slave(10)
ENTRY(hwint11)
/* Interrupt routine for irq 11 */
hwint_slave(11)
ENTRY(hwint12)
/* Interrupt routine for irq 12 */
hwint_slave(12)
ENTRY(hwint13)
/* Interrupt routine for irq 13 (FPU exception) */
hwint_slave(13)
ENTRY(hwint14)
/* Interrupt routine for irq 14 (AT winchester) */
hwint_slave(14)
ENTRY(hwint15)
/* Interrupt routine for irq 15 */
hwint_slave(15)
/*
* IPC is only from a process to kernel
*/
ENTRY(ipc_entry)
SAVE_PROCESS_CTX(0)
/* save the pointer to the current process */
push %ebp
/*
* pass the syscall arguments from userspace to the handler.
* SAVE_PROCESS_CTX() does not clobber these registers, they are still
* set as the userspace have set them
*/
push %ebx
push %eax
push %ecx
/* stop user process cycles */
push %ebp
/* for stack trace */
movl $0, %ebp
call _C_LABEL(context_stop)
add $4, %esp
call _C_LABEL(do_ipc)
/* restore the current process pointer and save the return value */
add $3 * 4, %esp
pop %esi
mov %eax, AXREG(%esi)
jmp _C_LABEL(switch_to_user)
/*
* kernel call is only from a process to kernel
*/
ENTRY(kernel_call_entry)
SAVE_PROCESS_CTX(0)
/* save the pointer to the current process */
push %ebp
/*
* pass the syscall arguments from userspace to the handler.
* SAVE_PROCESS_CTX() does not clobber these registers, they are still
* set as the userspace have set them
*/
push %eax
/* stop user process cycles */
push %ebp
/* for stack trace */
movl $0, %ebp
call _C_LABEL(context_stop)
add $4, %esp
call _C_LABEL(kernel_call)
/* restore the current process pointer and save the return value */
add $8, %esp
jmp _C_LABEL(switch_to_user)
.balign 16
/*
* called by the exception interrupt vectors. If the exception does not push
* errorcode, we assume that the vector handler pushed 0 instead. Next pushed
* thing is the vector number. From this point on we can continue as if every
* exception pushes an error code
*/
exception_entry:
/*
* check if it is a nested trap by comparing the saved code segment
* descriptor with the kernel CS first
*/
TEST_INT_IN_KERNEL(12, exception_entry_nested)
exception_entry_from_user:
SAVE_PROCESS_CTX(8)
/* stop user process cycles */
push %ebp
/* for stack trace clear %ebp */
movl $0, %ebp
call _C_LABEL(context_stop)
add $4, %esp
/*
* push a pointer to the interrupt state pushed by the cpu and the
* vector number pushed by the vector handler just before calling
* exception_entry and call the exception handler.
*/
push %esp
push $0 /* it's not a nested exception */
call _C_LABEL(exception_handler)
jmp _C_LABEL(switch_to_user)
exception_entry_nested:
pusha
mov %esp, %eax
add $(8 * 4), %eax
push %eax
pushl $1 /* it's a nested exception */
call _C_LABEL(exception_handler)
add $8, %esp
popa
/* clear the error code and the exception number */
add $8, %esp
/* resume execution at the point of exception */
iret
/*===========================================================================*/
/* restart */
/*===========================================================================*/
ENTRY(restore_user_context)
mov 4(%esp), %ebp /* will assume P_STACKBASE == 0 */
/* reconstruct the stack for iret */
movl SSREG(%ebp), %eax
push %eax
movl SPREG(%ebp), %eax
push %eax
movl PSWREG(%ebp), %eax
push %eax
movl CSREG(%ebp), %eax
push %eax
movl PCREG(%ebp), %eax
push %eax
RESTORE_GP_REGS(%ebp)
RESTORE_SEGS(%ebp)
movl %ss:BPREG(%ebp), %ebp
iret /* continue process */
/*===========================================================================*/
/* exception handlers */
/*===========================================================================*/
#define EXCEPTION_ERR_CODE(vector) \
push $vector ;\
jmp exception_entry
#define EXCEPTION_NO_ERR_CODE(vector) \
pushl $0 ;\
EXCEPTION_ERR_CODE(vector)
LABEL(divide_error)
EXCEPTION_NO_ERR_CODE(DIVIDE_VECTOR)
LABEL(single_step_exception)
EXCEPTION_NO_ERR_CODE(DEBUG_VECTOR)
LABEL(nmi)
#ifndef CONFIG_WATCHDOG
EXCEPTION_NO_ERR_CODE(NMI_VECTOR)
#else
/*
* We have to be very careful as this interrupt can occur anytime. On
* the other hand, if it interrupts a user process, we will resume the
* same process which makes things a little simpler. We know that we are
* already on kernel stack whenever it happened and we can be
* conservative and save everything as we don't need to be extremely
* efficient as the interrupt is infrequent and some overhead is already
* expected.
*/
/*
* save the important registers. We don't save %cs and %ss and they are
* saved and restored by CPU
*/
pushw %ds
pushw %es
pushw %fs
pushw %gs
pusha
/*
* We cannot be sure about the state of the kernel segment register,
* however, we always set %ds and %es to the same as %ss
*/
mov %ss, %si
mov %si, %ds
mov %si, %es
push %esp
call _C_LABEL(nmi_watchdog_handler)
add $4, %esp
/* restore all the important registers as they were before the trap */
popa
popw %gs
popw %fs
popw %es
popw %ds
iret
#endif
LABEL(breakpoint_exception)
EXCEPTION_NO_ERR_CODE(BREAKPOINT_VECTOR)
LABEL(overflow)
EXCEPTION_NO_ERR_CODE(OVERFLOW_VECTOR)
LABEL(bounds_check)
EXCEPTION_NO_ERR_CODE(BOUNDS_VECTOR)
LABEL(inval_opcode)
EXCEPTION_NO_ERR_CODE(INVAL_OP_VECTOR)
LABEL(copr_not_available)
TEST_INT_IN_KERNEL(4, copr_not_available_in_kernel)
cld /* set direction flag to a known value */
SAVE_PROCESS_CTX(0)
/* stop user process cycles */
push %ebp
mov $0, %ebp
call _C_LABEL(context_stop)
jmp _C_LABEL(copr_not_available_handler)
copr_not_available_in_kernel:
pushl $0
pushl $COPROC_NOT_VECTOR
jmp exception_entry_nested
LABEL(double_fault)
EXCEPTION_ERR_CODE(DOUBLE_FAULT_VECTOR)
LABEL(copr_seg_overrun)
EXCEPTION_NO_ERR_CODE(COPROC_SEG_VECTOR)
LABEL(inval_tss)
EXCEPTION_ERR_CODE(INVAL_TSS_VECTOR)
LABEL(segment_not_present)
EXCEPTION_ERR_CODE(SEG_NOT_VECTOR)
LABEL(stack_exception)
EXCEPTION_ERR_CODE(STACK_FAULT_VECTOR)
LABEL(general_protection)
EXCEPTION_ERR_CODE(PROTECTION_VECTOR)
LABEL(page_fault)
EXCEPTION_ERR_CODE(PAGE_FAULT_VECTOR)
LABEL(copr_error)
EXCEPTION_NO_ERR_CODE(COPROC_ERR_VECTOR)
LABEL(alignment_check)
EXCEPTION_NO_ERR_CODE(ALIGNMENT_CHECK_VECTOR)
LABEL(machine_check)
EXCEPTION_NO_ERR_CODE(MACHINE_CHECK_VECTOR)
LABEL(simd_exception)
EXCEPTION_NO_ERR_CODE(SIMD_EXCEPTION_VECTOR)
/*===========================================================================*/
/* reload_cr3 */
/*===========================================================================*/
/* PUBLIC void reload_cr3(void); */
ENTRY(reload_cr3)
push %ebp
mov %esp, %ebp
mov %cr3, %eax
mov %eax, %cr3
pop %ebp
ret
#ifdef CONFIG_SMP
ENTRY(startup_ap_32)
/*
* we are in protected mode now, %cs is correct and we need to set the
* data descriptors before we can touch anything
*/
movw $DS_SELECTOR, %ax
mov %ax, %ds
mov %ax, %ss
mov %ax, %es
movw $0, %ax
mov %ax, %fs
mov %ax, %gs
/* load TSS for this cpu which was prepared by BSP */
movl _C_LABEL(__ap_id), %ecx
shl $3, %cx
mov $TSS_SELECTOR(0), %eax
add %cx, %ax
ltr %ax
/*
* use the boot stack for now. The running CPUs are already using their
* own stack, the rest is still waiting to be booted
*/
mov $_C_LABEL(k_boot_stktop) - 4, %esp
jmp _C_LABEL(smp_ap_boot)
hlt
#endif
/*===========================================================================*/
/* data */
/*===========================================================================*/
#ifdef __ACK__
.rom /* Before the string table please */
#else
.data
#endif
.short 0x526F /* this must be the first data entry (magic #) */
.bss
/*
* the kernel stack
*/
k_boot_stack:
.space K_STACK_SIZE /* kernel stack */ /* FIXME use macro here */
LABEL(k_boot_stktop) /* top of kernel stack */
.balign K_STACK_SIZE
LABEL(k_stacks_start)
/* two pages for each stack, one for data, other as a sandbox */
.space 2 * (K_STACK_SIZE * (CONFIG_MAX_CPUS + 1))
LABEL(k_stacks_end)
/* top of kernel stack */
Reference in a new issue View git blame Copy permalink