--- /dev/null
+/*
+ * Low-level system-call handling, trap handlers and context-switching
+ *
+ * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2008-2009 PetaLogix
+ * Copyright (C) 2003 John Williams <jwilliams@itee.uq.edu.au>
+ * Copyright (C) 2001,2002 NEC Corporation
+ * Copyright (C) 2001,2002 Miles Bader <miles@gnu.org>
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file COPYING in the main directory of this
+ * archive for more details.
+ *
+ * Written by Miles Bader <miles@gnu.org>
+ * Heavily modified by John Williams for Microblaze
+ */
+
+#include <linux/sys.h>
+#include <linux/linkage.h>
+
+#include <asm/entry.h>
+#include <asm/current.h>
+#include <asm/processor.h>
+#include <asm/exceptions.h>
+#include <asm/asm-offsets.h>
+#include <asm/thread_info.h>
+
+#include <asm/page.h>
+#include <asm/unistd.h>
+
+#include <linux/errno.h>
+#include <asm/signal.h>
+
+/* The size of a state save frame. */
+#define STATE_SAVE_SIZE (PT_SIZE + STATE_SAVE_ARG_SPACE)
+
+/* The offset of the struct pt_regs in a `state save frame' on the stack. */
+#define PTO STATE_SAVE_ARG_SPACE /* 24 the space for args */
+
+#define C_ENTRY(name) .globl name; .align 4; name
+
+/*
+ * Various ways of setting and clearing BIP in flags reg.
+ * This is mucky, but necessary using microblaze version that
+ * allows msr ops to write to BIP
+ */
+#if CONFIG_XILINX_MICROBLAZE0_USE_MSR_INSTR
+ .macro clear_bip
+ msrclr r11, MSR_BIP
+ nop
+ .endm
+
+ .macro set_bip
+ msrset r11, MSR_BIP
+ nop
+ .endm
+
+ .macro clear_eip
+ msrclr r11, MSR_EIP
+ nop
+ .endm
+
+ .macro set_ee
+ msrset r11, MSR_EE
+ nop
+ .endm
+
+ .macro disable_irq
+ msrclr r11, MSR_IE
+ nop
+ .endm
+
+ .macro enable_irq
+ msrset r11, MSR_IE
+ nop
+ .endm
+
+ .macro set_ums
+ msrset r11, MSR_UMS
+ nop
+ msrclr r11, MSR_VMS
+ nop
+ .endm
+
+ .macro set_vms
+ msrclr r11, MSR_UMS
+ nop
+ msrset r11, MSR_VMS
+ nop
+ .endm
+
+ .macro clear_vms_ums
+ msrclr r11, MSR_VMS
+ nop
+ msrclr r11, MSR_UMS
+ nop
+ .endm
+#else
+ .macro clear_bip
+ mfs r11, rmsr
+ nop
+ andi r11, r11, ~MSR_BIP
+ mts rmsr, r11
+ nop
+ .endm
+
+ .macro set_bip
+ mfs r11, rmsr
+ nop
+ ori r11, r11, MSR_BIP
+ mts rmsr, r11
+ nop
+ .endm
+
+ .macro clear_eip
+ mfs r11, rmsr
+ nop
+ andi r11, r11, ~MSR_EIP
+ mts rmsr, r11
+ nop
+ .endm
+
+ .macro set_ee
+ mfs r11, rmsr
+ nop
+ ori r11, r11, MSR_EE
+ mts rmsr, r11
+ nop
+ .endm
+
+ .macro disable_irq
+ mfs r11, rmsr
+ nop
+ andi r11, r11, ~MSR_IE
+ mts rmsr, r11
+ nop
+ .endm
+
+ .macro enable_irq
+ mfs r11, rmsr
+ nop
+ ori r11, r11, MSR_IE
+ mts rmsr, r11
+ nop
+ .endm
+
+ .macro set_ums
+ mfs r11, rmsr
+ nop
+ ori r11, r11, MSR_VMS
+ andni r11, r11, MSR_UMS
+ mts rmsr, r11
+ nop
+ .endm
+
+ .macro set_vms
+ mfs r11, rmsr
+ nop
+ ori r11, r11, MSR_VMS
+ andni r11, r11, MSR_UMS
+ mts rmsr, r11
+ nop
+ .endm
+
+ .macro clear_vms_ums
+ mfs r11, rmsr
+ nop
+ andni r11, r11, (MSR_VMS|MSR_UMS)
+ mts rmsr,r11
+ nop
+ .endm
+#endif
+
+/* Define how to call high-level functions. With MMU, virtual mode must be
+ * enabled when calling the high-level function. Clobbers R11.
+ * VM_ON, VM_OFF, DO_JUMP_BIPCLR, DO_CALL
+ */
+
+/* turn on virtual protected mode save */
+#define VM_ON \
+ set_ums; \
+ rted r0, 2f; \
+2: nop;
+
+/* turn off virtual protected mode save and user mode save*/
+#define VM_OFF \
+ clear_vms_ums; \
+ rted r0, TOPHYS(1f); \
+1: nop;
+
+#define SAVE_REGS \
+ swi r2, r1, PTO+PT_R2; /* Save SDA */ \
+ swi r5, r1, PTO+PT_R5; \
+ swi r6, r1, PTO+PT_R6; \
+ swi r7, r1, PTO+PT_R7; \
+ swi r8, r1, PTO+PT_R8; \
+ swi r9, r1, PTO+PT_R9; \
+ swi r10, r1, PTO+PT_R10; \
+ swi r11, r1, PTO+PT_R11; /* save clobbered regs after rval */\
+ swi r12, r1, PTO+PT_R12; \
+ swi r13, r1, PTO+PT_R13; /* Save SDA2 */ \
+ swi r14, r1, PTO+PT_PC; /* PC, before IRQ/trap */ \
+ swi r15, r1, PTO+PT_R15; /* Save LP */ \
+ swi r18, r1, PTO+PT_R18; /* Save asm scratch reg */ \
+ swi r19, r1, PTO+PT_R19; \
+ swi r20, r1, PTO+PT_R20; \
+ swi r21, r1, PTO+PT_R21; \
+ swi r22, r1, PTO+PT_R22; \
+ swi r23, r1, PTO+PT_R23; \
+ swi r24, r1, PTO+PT_R24; \
+ swi r25, r1, PTO+PT_R25; \
+ swi r26, r1, PTO+PT_R26; \
+ swi r27, r1, PTO+PT_R27; \
+ swi r28, r1, PTO+PT_R28; \
+ swi r29, r1, PTO+PT_R29; \
+ swi r30, r1, PTO+PT_R30; \
+ swi r31, r1, PTO+PT_R31; /* Save current task reg */ \
+ mfs r11, rmsr; /* save MSR */ \
+ nop; \
+ swi r11, r1, PTO+PT_MSR;
+
+#define RESTORE_REGS \
+ lwi r11, r1, PTO+PT_MSR; \
+ mts rmsr , r11; \
+ nop; \
+ lwi r2, r1, PTO+PT_R2; /* restore SDA */ \
+ lwi r5, r1, PTO+PT_R5; \
+ lwi r6, r1, PTO+PT_R6; \
+ lwi r7, r1, PTO+PT_R7; \
+ lwi r8, r1, PTO+PT_R8; \
+ lwi r9, r1, PTO+PT_R9; \
+ lwi r10, r1, PTO+PT_R10; \
+ lwi r11, r1, PTO+PT_R11; /* restore clobbered regs after rval */\
+ lwi r12, r1, PTO+PT_R12; \
+ lwi r13, r1, PTO+PT_R13; /* restore SDA2 */ \
+ lwi r14, r1, PTO+PT_PC; /* RESTORE_LINK PC, before IRQ/trap */\
+ lwi r15, r1, PTO+PT_R15; /* restore LP */ \
+ lwi r18, r1, PTO+PT_R18; /* restore asm scratch reg */ \
+ lwi r19, r1, PTO+PT_R19; \
+ lwi r20, r1, PTO+PT_R20; \
+ lwi r21, r1, PTO+PT_R21; \
+ lwi r22, r1, PTO+PT_R22; \
+ lwi r23, r1, PTO+PT_R23; \
+ lwi r24, r1, PTO+PT_R24; \
+ lwi r25, r1, PTO+PT_R25; \
+ lwi r26, r1, PTO+PT_R26; \
+ lwi r27, r1, PTO+PT_R27; \
+ lwi r28, r1, PTO+PT_R28; \
+ lwi r29, r1, PTO+PT_R29; \
+ lwi r30, r1, PTO+PT_R30; \
+ lwi r31, r1, PTO+PT_R31; /* Restore cur task reg */
+
+.text
+
+/*
+ * User trap.
+ *
+ * System calls are handled here.
+ *
+ * Syscall protocol:
+ * Syscall number in r12, args in r5-r10
+ * Return value in r3
+ *
+ * Trap entered via brki instruction, so BIP bit is set, and interrupts
+ * are masked. This is nice, means we don't have to CLI before state save
+ */
+C_ENTRY(_user_exception):
+ swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */
+ addi r14, r14, 4 /* return address is 4 byte after call */
+ swi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* Save r11 */
+
+ lwi r11, r0, TOPHYS(PER_CPU(KM));/* See if already in kernel mode.*/
+ beqi r11, 1f; /* Jump ahead if coming from user */
+/* Kernel-mode state save. */
+ lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/
+ tophys(r1,r11);
+ swi r11, r1, (PT_R1-PT_SIZE); /* Save original SP. */
+ lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */
+
+ addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */
+ SAVE_REGS
+
+ addi r11, r0, 1; /* Was in kernel-mode. */
+ swi r11, r1, PTO+PT_MODE; /* pt_regs -> kernel mode */
+ brid 2f;
+ nop; /* Fill delay slot */
+
+/* User-mode state save. */
+1:
+ lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */
+ lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */
+ tophys(r1,r1);
+ lwi r1, r1, TS_THREAD_INFO; /* get stack from task_struct */
+/* calculate kernel stack pointer from task struct 8k */
+ addik r1, r1, THREAD_SIZE;
+ tophys(r1,r1);
+
+ addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */
+ SAVE_REGS
+
+ swi r0, r1, PTO+PT_MODE; /* Was in user-mode. */
+ lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
+ swi r11, r1, PTO+PT_R1; /* Store user SP. */
+ addi r11, r0, 1;
+ swi r11, r0, TOPHYS(PER_CPU(KM)); /* Now we're in kernel-mode. */
+2: lwi r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */
+ /* Save away the syscall number. */
+ swi r12, r1, PTO+PT_R0;
+ tovirt(r1,r1)
+
+ la r15, r0, ret_from_trap-8
+/* where the trap should return need -8 to adjust for rtsd r15, 8*/
+/* Jump to the appropriate function for the system call number in r12
+ * (r12 is not preserved), or return an error if r12 is not valid. The LP
+ * register should point to the location where
+ * the called function should return. [note that MAKE_SYS_CALL uses label 1] */
+ /* See if the system call number is valid. */
+ addi r11, r12, -__NR_syscalls;
+ bgei r11,1f;
+ /* Figure out which function to use for this system call. */
+ /* Note Microblaze barrel shift is optional, so don't rely on it */
+ add r12, r12, r12; /* convert num -> ptr */
+ add r12, r12, r12;
+
+ /* Trac syscalls and stored them to r0_ram */
+ lwi r3, r12, 0x400 + TOPHYS(r0_ram)
+ addi r3, r3, 1
+ swi r3, r12, 0x400 + TOPHYS(r0_ram)
+
+ lwi r12, r12, TOPHYS(sys_call_table); /* Function ptr */
+ /* Make the system call. to r12*/
+ set_vms;
+ rtid r12, 0;
+ nop;
+ /* The syscall number is invalid, return an error. */
+1: VM_ON; /* RETURN() expects virtual mode*/
+ addi r3, r0, -ENOSYS;
+ rtsd r15,8; /* looks like a normal subroutine return */
+ or r0, r0, r0
+
+
+/* Entry point used to return from a syscall/trap. */
+/* We re-enable BIP bit before state restore */
+C_ENTRY(ret_from_trap):
+ set_bip; /* Ints masked for state restore*/
+ lwi r11, r1, PTO+PT_MODE;
+/* See if returning to kernel mode, if so, skip resched &c. */
+ bnei r11, 2f;
+
+ /* We're returning to user mode, so check for various conditions that
+ * trigger rescheduling. */
+ /* Get current task ptr into r11 */
+ add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
+ lwi r11, r11, TS_THREAD_INFO; /* get thread info */
+ lwi r11, r11, TI_FLAGS; /* get flags in thread info */
+ andi r11, r11, _TIF_NEED_RESCHED;
+ beqi r11, 5f;
+
+ swi r3, r1, PTO + PT_R3; /* store syscall result */
+ swi r4, r1, PTO + PT_R4;
+ bralid r15, schedule; /* Call scheduler */
+ nop; /* delay slot */
+ lwi r3, r1, PTO + PT_R3; /* restore syscall result */
+ lwi r4, r1, PTO + PT_R4;
+
+ /* Maybe handle a signal */
+5: add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
+ lwi r11, r11, TS_THREAD_INFO; /* get thread info */
+ lwi r11, r11, TI_FLAGS; /* get flags in thread info */
+ andi r11, r11, _TIF_SIGPENDING;
+ beqi r11, 1f; /* Signals to handle, handle them */
+
+ swi r3, r1, PTO + PT_R3; /* store syscall result */
+ swi r4, r1, PTO + PT_R4;
+ la r5, r1, PTO; /* Arg 1: struct pt_regs *regs */
+ add r6, r0, r0; /* Arg 2: sigset_t *oldset */
+ addi r7, r0, 1; /* Arg 3: int in_syscall */
+ bralid r15, do_signal; /* Handle any signals */
+ nop;
+ lwi r3, r1, PTO + PT_R3; /* restore syscall result */
+ lwi r4, r1, PTO + PT_R4;
+
+/* Finally, return to user state. */
+1: swi r0, r0, PER_CPU(KM); /* Now officially in user state. */
+ add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
+ swi r11, r0, PER_CPU(CURRENT_SAVE); /* save current */
+ VM_OFF;
+ tophys(r1,r1);
+ RESTORE_REGS;
+ addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
+ lwi r1, r1, PT_R1 - PT_SIZE;/* Restore user stack pointer. */
+ bri 6f;
+
+/* Return to kernel state. */
+2: VM_OFF;
+ tophys(r1,r1);
+ RESTORE_REGS;
+ addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
+ tovirt(r1,r1);
+6:
+TRAP_return: /* Make global symbol for debugging */
+ rtbd r14, 0; /* Instructions to return from an IRQ */
+ nop;
+
+
+/* These syscalls need access to the struct pt_regs on the stack, so we
+ implement them in assembly (they're basically all wrappers anyway). */
+
+C_ENTRY(sys_fork_wrapper):
+ addi r5, r0, SIGCHLD /* Arg 0: flags */
+ lwi r6, r1, PTO+PT_R1 /* Arg 1: child SP (use parent's) */
+ la r7, r1, PTO /* Arg 2: parent context */
+ add r8. r0, r0 /* Arg 3: (unused) */
+ add r9, r0, r0; /* Arg 4: (unused) */
+ add r10, r0, r0; /* Arg 5: (unused) */
+ brid do_fork /* Do real work (tail-call) */
+ nop;
+
+/* This the initial entry point for a new child thread, with an appropriate
+ stack in place that makes it look the the child is in the middle of an
+ syscall. This function is actually `returned to' from switch_thread
+ (copy_thread makes ret_from_fork the return address in each new thread's
+ saved context). */
+C_ENTRY(ret_from_fork):
+ bralid r15, schedule_tail; /* ...which is schedule_tail's arg */
+ add r3, r5, r0; /* switch_thread returns the prev task */
+ /* ( in the delay slot ) */
+ add r3, r0, r0; /* Child's fork call should return 0. */
+ brid ret_from_trap; /* Do normal trap return */
+ nop;
+
+C_ENTRY(sys_vfork_wrapper):
+ la r5, r1, PTO
+ brid sys_vfork /* Do real work (tail-call) */
+ nop
+
+C_ENTRY(sys_clone_wrapper):
+ bnei r6, 1f; /* See if child SP arg (arg 1) is 0. */
+ lwi r6, r1, PTO+PT_R1; /* If so, use paret's stack ptr */
+1: la r7, r1, PTO; /* Arg 2: parent context */
+ add r8, r0, r0; /* Arg 3: (unused) */
+ add r9, r0, r0; /* Arg 4: (unused) */
+ add r10, r0, r0; /* Arg 5: (unused) */
+ brid do_fork /* Do real work (tail-call) */
+ nop;
+
+C_ENTRY(sys_execve_wrapper):
+ la r8, r1, PTO; /* add user context as 4th arg */
+ brid sys_execve; /* Do real work (tail-call).*/
+ nop;
+
+C_ENTRY(sys_sigsuspend_wrapper):
+ swi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
+ swi r4, r1, PTO+PT_R4;
+ la r6, r1, PTO; /* add user context as 2nd arg */
+ bralid r15, sys_sigsuspend; /* Do real work.*/
+ nop;
+ lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
+ lwi r4, r1, PTO+PT_R4;
+ bri ret_from_trap /* fall through will not work here due to align */
+ nop;
+
+C_ENTRY(sys_rt_sigsuspend_wrapper):
+ swi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
+ swi r4, r1, PTO+PT_R4;
+ la r7, r1, PTO; /* add user context as 3rd arg */
+ brlid r15, sys_rt_sigsuspend; /* Do real work.*/
+ nop;
+ lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
+ lwi r4, r1, PTO+PT_R4;
+ bri ret_from_trap /* fall through will not work here due to align */
+ nop;
+
+
+C_ENTRY(sys_sigreturn_wrapper):
+ swi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
+ swi r4, r1, PTO+PT_R4;
+ la r5, r1, PTO; /* add user context as 1st arg */
+ brlid r15, sys_sigreturn; /* Do real work.*/
+ nop;
+ lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
+ lwi r4, r1, PTO+PT_R4;
+ bri ret_from_trap /* fall through will not work here due to align */
+ nop;
+
+C_ENTRY(sys_rt_sigreturn_wrapper):
+ swi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
+ swi r4, r1, PTO+PT_R4;
+ la r5, r1, PTO; /* add user context as 1st arg */
+ brlid r15, sys_rt_sigreturn /* Do real work */
+ nop;
+ lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
+ lwi r4, r1, PTO+PT_R4;
+ bri ret_from_trap /* fall through will not work here due to align */
+ nop;
+
+/*
+ * HW EXCEPTION rutine start
+ */
+
+#define SAVE_STATE \
+ swi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* Save r11 */ \
+ set_bip; /*equalize initial state for all possible entries*/\
+ clear_eip; \
+ enable_irq; \
+ set_ee; \
+ /* See if already in kernel mode.*/ \
+ lwi r11, r0, TOPHYS(PER_CPU(KM)); \
+ beqi r11, 1f; /* Jump ahead if coming from user */\
+ /* Kernel-mode state save. */ \
+ /* Reload kernel stack-ptr. */ \
+ lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); \
+ tophys(r1,r11); \
+ swi r11, r1, (PT_R1-PT_SIZE); /* Save original SP. */ \
+ lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */\
+ addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */\
+ /* store return registers separately because \
+ * this macros is use for others exceptions */ \
+ swi r3, r1, PTO + PT_R3; \
+ swi r4, r1, PTO + PT_R4; \
+ SAVE_REGS \
+ /* PC, before IRQ/trap - this is one instruction above */ \
+ swi r17, r1, PTO+PT_PC; \
+ \
+ addi r11, r0, 1; /* Was in kernel-mode. */ \
+ swi r11, r1, PTO+PT_MODE; \
+ brid 2f; \
+ nop; /* Fill delay slot */ \
+1: /* User-mode state save. */ \
+ lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */\
+ lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */\
+ tophys(r1,r1); \
+ lwi r1, r1, TS_THREAD_INFO; /* get the thread info */ \
+ addik r1, r1, THREAD_SIZE; /* calculate kernel stack pointer */\
+ tophys(r1,r1); \
+ \
+ addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */\
+ /* store return registers separately because this macros \
+ * is use for others exceptions */ \
+ swi r3, r1, PTO + PT_R3; \
+ swi r4, r1, PTO + PT_R4; \
+ SAVE_REGS \
+ /* PC, before IRQ/trap - this is one instruction above FIXME*/ \
+ swi r17, r1, PTO+PT_PC; \
+ \
+ swi r0, r1, PTO+PT_MODE; /* Was in user-mode. */ \
+ lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); \
+ swi r11, r1, PTO+PT_R1; /* Store user SP. */ \
+ addi r11, r0, 1; \
+ swi r11, r0, TOPHYS(PER_CPU(KM)); /* Now we're in kernel-mode.*/\
+2: lwi r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */\
+ /* Save away the syscall number. */ \
+ swi r0, r1, PTO+PT_R0; \
+ tovirt(r1,r1)
+
+C_ENTRY(full_exception_trap):
+ swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */
+ /* adjust exception address for privileged instruction
+ * for finding where is it */
+ addik r17, r17, -4
+ SAVE_STATE /* Save registers */
+ /* FIXME this can be store directly in PT_ESR reg.
+ * I tested it but there is a fault */
+ /* where the trap should return need -8 to adjust for rtsd r15, 8 */
+ la r15, r0, ret_from_exc - 8
+ la r5, r1, PTO /* parameter struct pt_regs * regs */
+ mfs r6, resr
+ nop
+ mfs r7, rfsr; /* save FSR */
+ nop
+ la r12, r0, full_exception
+ set_vms;
+ rtbd r12, 0;
+ nop;
+
+/*
+ * Unaligned data trap.
+ *
+ * Unaligned data trap last on 4k page is handled here.
+ *
+ * Trap entered via exception, so EE bit is set, and interrupts
+ * are masked. This is nice, means we don't have to CLI before state save
+ *
+ * The assembler routine is in "arch/microblaze/kernel/hw_exception_handler.S"
+ */
+C_ENTRY(unaligned_data_trap):
+ swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */
+ SAVE_STATE /* Save registers.*/
+ /* where the trap should return need -8 to adjust for rtsd r15, 8 */
+ la r15, r0, ret_from_exc-8
+ mfs r3, resr /* ESR */
+ nop
+ mfs r4, rear /* EAR */
+ nop
+ la r7, r1, PTO /* parameter struct pt_regs * regs */
+ la r12, r0, _unaligned_data_exception
+ set_vms;
+ rtbd r12, 0; /* interrupts enabled */
+ nop;
+
+/*
+ * Page fault traps.
+ *
+ * If the real exception handler (from hw_exception_handler.S) didn't find
+ * the mapping for the process, then we're thrown here to handle such situation.
+ *
+ * Trap entered via exceptions, so EE bit is set, and interrupts
+ * are masked. This is nice, means we don't have to CLI before state save
+ *
+ * Build a standard exception frame for TLB Access errors. All TLB exceptions
+ * will bail out to this point if they can't resolve the lightweight TLB fault.
+ *
+ * The C function called is in "arch/microblaze/mm/fault.c", declared as:
+ * void do_page_fault(struct pt_regs *regs,
+ * unsigned long address,
+ * unsigned long error_code)
+ */
+/* data and intruction trap - which is choose is resolved int fault.c */
+C_ENTRY(page_fault_data_trap):
+ swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */
+ SAVE_STATE /* Save registers.*/
+ /* where the trap should return need -8 to adjust for rtsd r15, 8 */
+ la r15, r0, ret_from_exc-8
+ la r5, r1, PTO /* parameter struct pt_regs * regs */
+ mfs r6, rear /* parameter unsigned long address */
+ nop
+ mfs r7, resr /* parameter unsigned long error_code */
+ nop
+ la r12, r0, do_page_fault
+ set_vms;
+ rtbd r12, 0; /* interrupts enabled */
+ nop;
+
+C_ENTRY(page_fault_instr_trap):
+ swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */
+ SAVE_STATE /* Save registers.*/
+ /* where the trap should return need -8 to adjust for rtsd r15, 8 */
+ la r15, r0, ret_from_exc-8
+ la r5, r1, PTO /* parameter struct pt_regs * regs */
+ mfs r6, rear /* parameter unsigned long address */
+ nop
+ ori r7, r0, 0 /* parameter unsigned long error_code */
+ la r12, r0, do_page_fault
+ set_vms;
+ rtbd r12, 0; /* interrupts enabled */
+ nop;
+
+/* Entry point used to return from an exception. */
+C_ENTRY(ret_from_exc):
+ set_bip; /* Ints masked for state restore*/
+ lwi r11, r1, PTO+PT_MODE;
+ bnei r11, 2f; /* See if returning to kernel mode, */
+ /* ... if so, skip resched &c. */
+
+ /* We're returning to user mode, so check for various conditions that
+ trigger rescheduling. */
+ /* Get current task ptr into r11 */
+ add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
+ lwi r11, r11, TS_THREAD_INFO; /* get thread info */
+ lwi r11, r11, TI_FLAGS; /* get flags in thread info */
+ andi r11, r11, _TIF_NEED_RESCHED;
+ beqi r11, 5f;
+
+/* Call the scheduler before returning from a syscall/trap. */
+ bralid r15, schedule; /* Call scheduler */
+ nop; /* delay slot */
+
+ /* Maybe handle a signal */
+5: add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
+ lwi r11, r11, TS_THREAD_INFO; /* get thread info */
+ lwi r11, r11, TI_FLAGS; /* get flags in thread info */
+ andi r11, r11, _TIF_SIGPENDING;
+ beqi r11, 1f; /* Signals to handle, handle them */
+
+ /*
+ * Handle a signal return; Pending signals should be in r18.
+ *
+ * Not all registers are saved by the normal trap/interrupt entry
+ * points (for instance, call-saved registers (because the normal
+ * C-compiler calling sequence in the kernel makes sure they're
+ * preserved), and call-clobbered registers in the case of
+ * traps), but signal handlers may want to examine or change the
+ * complete register state. Here we save anything not saved by
+ * the normal entry sequence, so that it may be safely restored
+ * (in a possibly modified form) after do_signal returns.
+ * store return registers separately because this macros is use
+ * for others exceptions */
+ swi r3, r1, PTO + PT_R3;
+ swi r4, r1, PTO + PT_R4;
+ la r5, r1, PTO; /* Arg 1: struct pt_regs *regs */
+ add r6, r0, r0; /* Arg 2: sigset_t *oldset */
+ addi r7, r0, 0; /* Arg 3: int in_syscall */
+ bralid r15, do_signal; /* Handle any signals */
+ nop;
+ lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
+ lwi r4, r1, PTO+PT_R4;
+
+/* Finally, return to user state. */
+1: swi r0, r0, PER_CPU(KM); /* Now officially in user state. */
+ add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
+ swi r11, r0, PER_CPU(CURRENT_SAVE); /* save current */
+ VM_OFF;
+ tophys(r1,r1);
+
+ lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
+ lwi r4, r1, PTO+PT_R4;
+ RESTORE_REGS;
+ addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
+
+ lwi r1, r1, PT_R1 - PT_SIZE; /* Restore user stack pointer. */
+ bri 6f;
+/* Return to kernel state. */
+2: VM_OFF;
+ tophys(r1,r1);
+ lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
+ lwi r4, r1, PTO+PT_R4;
+ RESTORE_REGS;
+ addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
+
+ tovirt(r1,r1);
+6:
+EXC_return: /* Make global symbol for debugging */
+ rtbd r14, 0; /* Instructions to return from an IRQ */
+ nop;
+
+/*
+ * HW EXCEPTION rutine end
+ */
+
+/*
+ * Hardware maskable interrupts.
+ *
+ * The stack-pointer (r1) should have already been saved to the memory
+ * location PER_CPU(ENTRY_SP).
+ */
+C_ENTRY(_interrupt):
+/* MS: we are in physical address */
+/* Save registers, switch to proper stack, convert SP to virtual.*/
+ swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP))
+ swi r11, r0, TOPHYS(PER_CPU(R11_SAVE));
+ /* MS: See if already in kernel mode. */
+ lwi r11, r0, TOPHYS(PER_CPU(KM));
+ beqi r11, 1f; /* MS: Jump ahead if coming from user */
+
+/* Kernel-mode state save. */
+ or r11, r1, r0
+ tophys(r1,r11); /* MS: I have in r1 physical address where stack is */
+/* MS: Save original SP - position PT_R1 to next stack frame 4 *1 - 152*/
+ swi r11, r1, (PT_R1 - PT_SIZE);
+/* MS: restore r11 because of saving in SAVE_REGS */
+ lwi r11, r0, TOPHYS(PER_CPU(R11_SAVE));
+ /* save registers */
+/* MS: Make room on the stack -> activation record */
+ addik r1, r1, -STATE_SAVE_SIZE;
+/* MS: store return registers separately because
+ * this macros is use for others exceptions */
+ swi r3, r1, PTO + PT_R3;
+ swi r4, r1, PTO + PT_R4;
+ SAVE_REGS
+ /* MS: store mode */
+ addi r11, r0, 1; /* MS: Was in kernel-mode. */
+ swi r11, r1, PTO + PT_MODE; /* MS: and save it */
+ brid 2f;
+ nop; /* MS: Fill delay slot */
+
+1:
+/* User-mode state save. */
+/* MS: restore r11 -> FIXME move before SAVE_REG */
+ lwi r11, r0, TOPHYS(PER_CPU(R11_SAVE));
+ /* MS: get the saved current */
+ lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
+ tophys(r1,r1);
+ lwi r1, r1, TS_THREAD_INFO;
+ addik r1, r1, THREAD_SIZE;
+ tophys(r1,r1);
+ /* save registers */
+ addik r1, r1, -STATE_SAVE_SIZE;
+ swi r3, r1, PTO+PT_R3;
+ swi r4, r1, PTO+PT_R4;
+ SAVE_REGS
+ /* calculate mode */
+ swi r0, r1, PTO + PT_MODE;
+ lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
+ swi r11, r1, PTO+PT_R1;
+ /* setup kernel mode to KM */
+ addi r11, r0, 1;
+ swi r11, r0, TOPHYS(PER_CPU(KM));
+
+2:
+ lwi r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
+ swi r0, r1, PTO + PT_R0;
+ tovirt(r1,r1)
+ la r5, r1, PTO;
+ set_vms;
+ la r11, r0, do_IRQ;
+ la r15, r0, irq_call;
+irq_call:rtbd r11, 0;
+ nop;
+
+/* MS: we are in virtual mode */
+ret_from_irq:
+ lwi r11, r1, PTO + PT_MODE;
+ bnei r11, 2f;
+
+ add r11, r0, CURRENT_TASK;
+ lwi r11, r11, TS_THREAD_INFO;
+ lwi r11, r11, TI_FLAGS; /* MS: get flags from thread info */
+ andi r11, r11, _TIF_NEED_RESCHED;
+ beqi r11, 5f
+ bralid r15, schedule;
+ nop; /* delay slot */
+
+ /* Maybe handle a signal */
+5: add r11, r0, CURRENT_TASK;
+ lwi r11, r11, TS_THREAD_INFO; /* MS: get thread info */
+ lwi r11, r11, TI_FLAGS; /* get flags in thread info */
+ andi r11, r11, _TIF_SIGPENDING;
+ beqid r11, no_intr_resched
+/* Handle a signal return; Pending signals should be in r18. */
+ addi r7, r0, 0; /* Arg 3: int in_syscall */
+ la r5, r1, PTO; /* Arg 1: struct pt_regs *regs */
+ bralid r15, do_signal; /* Handle any signals */
+ add r6, r0, r0; /* Arg 2: sigset_t *oldset */
+
+/* Finally, return to user state. */
+no_intr_resched:
+ /* Disable interrupts, we are now committed to the state restore */
+ disable_irq
+ swi r0, r0, PER_CPU(KM); /* MS: Now officially in user state. */
+ add r11, r0, CURRENT_TASK;
+ swi r11, r0, PER_CPU(CURRENT_SAVE);
+ VM_OFF;
+ tophys(r1,r1);
+ lwi r3, r1, PTO + PT_R3; /* MS: restore saved r3, r4 registers */
+ lwi r4, r1, PTO + PT_R4;
+ RESTORE_REGS
+ addik r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */
+ lwi r1, r1, PT_R1 - PT_SIZE;
+ bri 6f;
+/* MS: Return to kernel state. */
+2: VM_OFF /* MS: turn off MMU */
+ tophys(r1,r1)
+ lwi r3, r1, PTO + PT_R3; /* MS: restore saved r3, r4 registers */
+ lwi r4, r1, PTO + PT_R4;
+ RESTORE_REGS
+ addik r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */
+ tovirt(r1,r1);
+6:
+IRQ_return: /* MS: Make global symbol for debugging */
+ rtid r14, 0
+ nop
+
+/*
+ * `Debug' trap
+ * We enter dbtrap in "BIP" (breakpoint) mode.
+ * So we exit the breakpoint mode with an 'rtbd' and proceed with the
+ * original dbtrap.
+ * however, wait to save state first
+ */
+C_ENTRY(_debug_exception):
+ /* BIP bit is set on entry, no interrupts can occur */
+ swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP))
+
+ swi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* Save r11 */
+ set_bip; /*equalize initial state for all possible entries*/
+ clear_eip;
+ enable_irq;
+ lwi r11, r0, TOPHYS(PER_CPU(KM));/* See if already in kernel mode.*/
+ beqi r11, 1f; /* Jump ahead if coming from user */
+ /* Kernel-mode state save. */
+ lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/
+ tophys(r1,r11);
+ swi r11, r1, (PT_R1-PT_SIZE); /* Save original SP. */
+ lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */
+
+ addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */
+ swi r3, r1, PTO + PT_R3;
+ swi r4, r1, PTO + PT_R4;
+ SAVE_REGS;
+
+ addi r11, r0, 1; /* Was in kernel-mode. */
+ swi r11, r1, PTO + PT_MODE;
+ brid 2f;
+ nop; /* Fill delay slot */
+1: /* User-mode state save. */
+ lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */
+ lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */
+ tophys(r1,r1);
+ lwi r1, r1, TS_THREAD_INFO; /* get the thread info */
+ addik r1, r1, THREAD_SIZE; /* calculate kernel stack pointer */
+ tophys(r1,r1);
+
+ addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */
+ swi r3, r1, PTO + PT_R3;
+ swi r4, r1, PTO + PT_R4;
+ SAVE_REGS;
+
+ swi r0, r1, PTO+PT_MODE; /* Was in user-mode. */
+ lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
+ swi r11, r1, PTO+PT_R1; /* Store user SP. */
+ addi r11, r0, 1;
+ swi r11, r0, TOPHYS(PER_CPU(KM)); /* Now we're in kernel-mode. */
+2: lwi r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */
+ /* Save away the syscall number. */
+ swi r0, r1, PTO+PT_R0;
+ tovirt(r1,r1)
+
+ addi r5, r0, SIGTRAP /* send the trap signal */
+ add r6, r0, CURRENT_TASK; /* Get current task ptr into r11 */
+ addk r7, r0, r0 /* 3rd param zero */
+
+ set_vms;
+ la r11, r0, send_sig;
+ la r15, r0, dbtrap_call;
+dbtrap_call: rtbd r11, 0;
+ nop;
+
+ set_bip; /* Ints masked for state restore*/
+ lwi r11, r1, PTO+PT_MODE;
+ bnei r11, 2f;
+
+ /* Get current task ptr into r11 */
+ add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
+ lwi r11, r11, TS_THREAD_INFO; /* get thread info */
+ lwi r11, r11, TI_FLAGS; /* get flags in thread info */
+ andi r11, r11, _TIF_NEED_RESCHED;
+ beqi r11, 5f;
+
+/* Call the scheduler before returning from a syscall/trap. */
+
+ bralid r15, schedule; /* Call scheduler */
+ nop; /* delay slot */
+ /* XXX Is PT_DTRACE handling needed here? */
+ /* XXX m68knommu also checks TASK_STATE & TASK_COUNTER here. */
+
+ /* Maybe handle a signal */
+5: add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
+ lwi r11, r11, TS_THREAD_INFO; /* get thread info */
+ lwi r11, r11, TI_FLAGS; /* get flags in thread info */
+ andi r11, r11, _TIF_SIGPENDING;
+ beqi r11, 1f; /* Signals to handle, handle them */
+
+/* Handle a signal return; Pending signals should be in r18. */
+ /* Not all registers are saved by the normal trap/interrupt entry
+ points (for instance, call-saved registers (because the normal
+ C-compiler calling sequence in the kernel makes sure they're
+ preserved), and call-clobbered registers in the case of
+ traps), but signal handlers may want to examine or change the
+ complete register state. Here we save anything not saved by
+ the normal entry sequence, so that it may be safely restored
+ (in a possibly modified form) after do_signal returns. */
+
+ la r5, r1, PTO; /* Arg 1: struct pt_regs *regs */
+ add r6, r0, r0; /* Arg 2: sigset_t *oldset */
+ addi r7, r0, 0; /* Arg 3: int in_syscall */
+ bralid r15, do_signal; /* Handle any signals */
+ nop;
+
+
+/* Finally, return to user state. */
+1: swi r0, r0, PER_CPU(KM); /* Now officially in user state. */
+ add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
+ swi r11, r0, PER_CPU(CURRENT_SAVE); /* save current */
+ VM_OFF;
+ tophys(r1,r1);
+
+ lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
+ lwi r4, r1, PTO+PT_R4;
+ RESTORE_REGS
+ addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
+
+
+ lwi r1, r1, PT_R1 - PT_SIZE;
+ /* Restore user stack pointer. */
+ bri 6f;
+
+/* Return to kernel state. */
+2: VM_OFF;
+ tophys(r1,r1);
+ lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
+ lwi r4, r1, PTO+PT_R4;
+ RESTORE_REGS
+ addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
+
+ tovirt(r1,r1);
+6:
+DBTRAP_return: /* Make global symbol for debugging */
+ rtbd r14, 0; /* Instructions to return from an IRQ */
+ nop;
+
+
+
+ENTRY(_switch_to)
+ /* prepare return value */
+ addk r3, r0, r31
+
+ /* save registers in cpu_context */
+ /* use r11 and r12, volatile registers, as temp register */
+ /* give start of cpu_context for previous process */
+ addik r11, r5, TI_CPU_CONTEXT
+ swi r1, r11, CC_R1
+ swi r2, r11, CC_R2
+ /* skip volatile registers.
+ * they are saved on stack when we jumped to _switch_to() */
+ /* dedicated registers */
+ swi r13, r11, CC_R13
+ swi r14, r11, CC_R14
+ swi r15, r11, CC_R15
+ swi r16, r11, CC_R16
+ swi r17, r11, CC_R17
+ swi r18, r11, CC_R18
+ /* save non-volatile registers */
+ swi r19, r11, CC_R19
+ swi r20, r11, CC_R20
+ swi r21, r11, CC_R21
+ swi r22, r11, CC_R22
+ swi r23, r11, CC_R23
+ swi r24, r11, CC_R24
+ swi r25, r11, CC_R25
+ swi r26, r11, CC_R26
+ swi r27, r11, CC_R27
+ swi r28, r11, CC_R28
+ swi r29, r11, CC_R29
+ swi r30, r11, CC_R30
+ /* special purpose registers */
+ mfs r12, rmsr
+ nop
+ swi r12, r11, CC_MSR
+ mfs r12, rear
+ nop
+ swi r12, r11, CC_EAR
+ mfs r12, resr
+ nop
+ swi r12, r11, CC_ESR
+ mfs r12, rfsr
+ nop
+ swi r12, r11, CC_FSR
+
+ /* update r31, the current */
+ lwi r31, r6, TI_TASK/* give me pointer to task which will be next */
+ /* stored it to current_save too */
+ swi r31, r0, PER_CPU(CURRENT_SAVE)
+
+ /* get new process' cpu context and restore */
+ /* give me start where start context of next task */
+ addik r11, r6, TI_CPU_CONTEXT
+
+ /* non-volatile registers */
+ lwi r30, r11, CC_R30
+ lwi r29, r11, CC_R29
+ lwi r28, r11, CC_R28
+ lwi r27, r11, CC_R27
+ lwi r26, r11, CC_R26
+ lwi r25, r11, CC_R25
+ lwi r24, r11, CC_R24
+ lwi r23, r11, CC_R23
+ lwi r22, r11, CC_R22
+ lwi r21, r11, CC_R21
+ lwi r20, r11, CC_R20
+ lwi r19, r11, CC_R19
+ /* dedicated registers */
+ lwi r18, r11, CC_R18
+ lwi r17, r11, CC_R17
+ lwi r16, r11, CC_R16
+ lwi r15, r11, CC_R15
+ lwi r14, r11, CC_R14
+ lwi r13, r11, CC_R13
+ /* skip volatile registers */
+ lwi r2, r11, CC_R2
+ lwi r1, r11, CC_R1
+
+ /* special purpose registers */
+ lwi r12, r11, CC_FSR
+ mts rfsr, r12
+ nop
+ lwi r12, r11, CC_MSR
+ mts rmsr, r12
+ nop
+
+ rtsd r15, 8
+ nop
+
+ENTRY(_reset)
+ brai 0x70; /* Jump back to FS-boot */
+
+ENTRY(_break)
+ mfs r5, rmsr
+ nop
+ swi r5, r0, 0x250 + TOPHYS(r0_ram)
+ mfs r5, resr
+ nop
+ swi r5, r0, 0x254 + TOPHYS(r0_ram)
+ bri 0
+
+ /* These are compiled and loaded into high memory, then
+ * copied into place in mach_early_setup */
+ .section .init.ivt, "ax"
+ .org 0x0
+ /* this is very important - here is the reset vector */
+ /* in current MMU branch you don't care what is here - it is
+ * used from bootloader site - but this is correct for FS-BOOT */
+ brai 0x70
+ nop
+ brai TOPHYS(_user_exception); /* syscall handler */
+ brai TOPHYS(_interrupt); /* Interrupt handler */
+ brai TOPHYS(_break); /* nmi trap handler */
+ brai TOPHYS(_hw_exception_handler); /* HW exception handler */
+
+ .org 0x60
+ brai TOPHYS(_debug_exception); /* debug trap handler*/
+
+.section .rodata,"a"
+#include "syscall_table.S"
+
+syscall_table_size=(.-sys_call_table)
+
git://ftp.safe.ca / safe / jmp / linux-2.6 / commitdiff