diff options
Diffstat (limited to 'arch/unicore32/kernel')
-rw-r--r-- | arch/unicore32/kernel/entry.S | 824 | ||||
-rw-r--r-- | arch/unicore32/kernel/head.S | 252 | ||||
-rw-r--r-- | arch/unicore32/kernel/setup.c | 360 | ||||
-rw-r--r-- | arch/unicore32/kernel/setup.h | 30 | ||||
-rw-r--r-- | arch/unicore32/kernel/traps.c | 333 |
5 files changed, 1799 insertions, 0 deletions
diff --git a/arch/unicore32/kernel/entry.S b/arch/unicore32/kernel/entry.S new file mode 100644 index 000000000000..83698b7c8f5b --- /dev/null +++ b/arch/unicore32/kernel/entry.S @@ -0,0 +1,824 @@ +/* + * linux/arch/unicore32/kernel/entry.S + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Low-level vector interface routines + */ +#include <linux/init.h> +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/errno.h> +#include <asm/thread_info.h> +#include <asm/memory.h> +#include <asm/unistd.h> +#include <generated/asm-offsets.h> +#include "debug-macro.S" + +@ +@ Most of the stack format comes from struct pt_regs, but with +@ the addition of 8 bytes for storing syscall args 5 and 6. +@ +#define S_OFF 8 + +/* + * The SWI code relies on the fact that R0 is at the bottom of the stack + * (due to slow/fast restore user regs). + */ +#if S_R0 != 0 +#error "Please fix" +#endif + + .macro zero_fp +#ifdef CONFIG_FRAME_POINTER + mov fp, #0 +#endif + .endm + + .macro alignment_trap, rtemp +#ifdef CONFIG_ALIGNMENT_TRAP + ldw \rtemp, .LCcralign + ldw \rtemp, [\rtemp] + movc p0.c1, \rtemp, #0 +#endif + .endm + + .macro load_user_sp_lr, rd, rtemp, offset = 0 + mov \rtemp, asr + xor \rtemp, \rtemp, #(PRIV_MODE ^ SUSR_MODE) + mov.a asr, \rtemp @ switch to the SUSR mode + + ldw sp, [\rd+], #\offset @ load sp_user + ldw lr, [\rd+], #\offset + 4 @ load lr_user + + xor \rtemp, \rtemp, #(PRIV_MODE ^ SUSR_MODE) + mov.a asr, \rtemp @ switch back to the PRIV mode + .endm + + .macro priv_exit, rpsr + mov.a bsr, \rpsr + ldm.w (r0 - r15), [sp]+ + ldm.b (r16 - pc), [sp]+ @ load r0 - pc, asr + .endm + + .macro restore_user_regs, fast = 0, offset = 0 + ldw r1, [sp+], #\offset + S_PSR @ get calling asr + ldw lr, [sp+], #\offset + S_PC @ get pc + mov.a bsr, r1 @ save in bsr_priv + .if \fast + add sp, sp, #\offset + S_R1 @ r0 is syscall return value + ldm.w (r1 - r15), [sp]+ @ get calling r1 - r15 + ldur (r16 - lr), [sp]+ @ get calling r16 - lr + .else + ldm.w (r0 - r15), [sp]+ @ get calling r0 - r15 + ldur (r16 - lr), [sp]+ @ get calling r16 - lr + .endif + nop + add sp, sp, #S_FRAME_SIZE - S_R16 + mov.a pc, lr @ return + @ and move bsr_priv into asr + .endm + + .macro get_thread_info, rd + mov \rd, sp >> #13 + mov \rd, \rd << #13 + .endm + + .macro get_irqnr_and_base, irqnr, irqstat, base, tmp + ldw \base, =(io_p2v(PKUNITY_INTC_BASE)) + ldw \irqstat, [\base+], #0xC @ INTC_ICIP + ldw \tmp, [\base+], #0x4 @ INTC_ICMR + and.a \irqstat, \irqstat, \tmp + beq 1001f + cntlz \irqnr, \irqstat + rsub \irqnr, \irqnr, #31 +1001: /* EQ will be set if no irqs pending */ + .endm + +#ifdef CONFIG_DEBUG_LL + .macro printreg, reg, temp + adr \temp, 901f + stm (r0-r3), [\temp]+ + stw lr, [\temp+], #0x10 + mov r0, \reg + b.l printhex8 + mov r0, #':' + b.l printch + mov r0, pc + b.l printhex8 + adr r0, 902f + b.l printascii + adr \temp, 901f + ldm (r0-r3), [\temp]+ + ldw lr, [\temp+], #0x10 + b 903f +901: .word 0, 0, 0, 0, 0 @ r0-r3, lr +902: .asciz ": epip4d\n" + .align +903: + .endm +#endif + +/* + * These are the registers used in the syscall handler, and allow us to + * have in theory up to 7 arguments to a function - r0 to r6. + * + * Note that tbl == why is intentional. + * + * We must set at least "tsk" and "why" when calling ret_with_reschedule. + */ +scno .req r21 @ syscall number +tbl .req r22 @ syscall table pointer +why .req r22 @ Linux syscall (!= 0) +tsk .req r23 @ current thread_info + +/* + * Interrupt handling. Preserves r17, r18, r19 + */ + .macro intr_handler +1: get_irqnr_and_base r0, r6, r5, lr + beq 2f + mov r1, sp + @ + @ routine called with r0 = irq number, r1 = struct pt_regs * + @ + adr lr, 1b + b asm_do_IRQ +2: + .endm + +/* + * PRIV mode handlers + */ + .macro priv_entry + sub sp, sp, #(S_FRAME_SIZE - 4) + stm (r1 - r15), [sp]+ + add r5, sp, #S_R15 + stm (r16 - r28), [r5]+ + + ldm (r1 - r3), [r0]+ + add r5, sp, #S_SP - 4 @ here for interlock avoidance + mov r4, #-1 @ "" "" "" "" + add r0, sp, #(S_FRAME_SIZE - 4) + stw.w r1, [sp+], #-4 @ save the "real" r0 copied + @ from the exception stack + + mov r1, lr + + @ + @ We are now ready to fill in the remaining blanks on the stack: + @ + @ r0 - sp_priv + @ r1 - lr_priv + @ r2 - lr_<exception>, already fixed up for correct return/restart + @ r3 - bsr_<exception> + @ r4 - orig_r0 (see pt_regs definition in ptrace.h) + @ + stm (r0 - r4), [r5]+ + .endm + +/* + * User mode handlers + * + */ + .macro user_entry + sub sp, sp, #S_FRAME_SIZE + stm (r1 - r15), [sp+] + add r4, sp, #S_R16 + stm (r16 - r28), [r4]+ + + ldm (r1 - r3), [r0]+ + add r0, sp, #S_PC @ here for interlock avoidance + mov r4, #-1 @ "" "" "" "" + + stw r1, [sp] @ save the "real" r0 copied + @ from the exception stack + + @ + @ We are now ready to fill in the remaining blanks on the stack: + @ + @ r2 - lr_<exception>, already fixed up for correct return/restart + @ r3 - bsr_<exception> + @ r4 - orig_r0 (see pt_regs definition in ptrace.h) + @ + @ Also, separately save sp_user and lr_user + @ + stm (r2 - r4), [r0]+ + stur (sp, lr), [r0-] + + @ + @ Enable the alignment trap while in kernel mode + @ + alignment_trap r0 + + @ + @ Clear FP to mark the first stack frame + @ + zero_fp + .endm + + .text + +@ +@ __invalid - generic code for failed exception +@ (re-entrant version of handlers) +@ +__invalid: + sub sp, sp, #S_FRAME_SIZE + stm (r1 - r15), [sp+] + add r1, sp, #S_R16 + stm (r16 - r28, sp, lr), [r1]+ + + zero_fp + + ldm (r4 - r6), [r0]+ + add r0, sp, #S_PC @ here for interlock avoidance + mov r7, #-1 @ "" "" "" "" + stw r4, [sp] @ save preserved r0 + stm (r5 - r7), [r0]+ @ lr_<exception>, + @ asr_<exception>, "old_r0" + + mov r0, sp + mov r1, asr + b bad_mode +ENDPROC(__invalid) + + .align 5 +__dabt_priv: + priv_entry + + @ + @ get ready to re-enable interrupts if appropriate + @ + mov r17, asr + cand.a r3, #PSR_I_BIT + bne 1f + andn r17, r17, #PSR_I_BIT +1: + + @ + @ Call the processor-specific abort handler: + @ + @ r2 - aborted context pc + @ r3 - aborted context asr + @ + @ The abort handler must return the aborted address in r0, and + @ the fault status register in r1. + @ + movc r1, p0.c3, #0 @ get FSR + movc r0, p0.c4, #0 @ get FAR + + @ + @ set desired INTR state, then call main handler + @ + mov.a asr, r17 + mov r2, sp + b.l do_DataAbort + + @ + @ INTRs off again before pulling preserved data off the stack + @ + disable_irq r0 + + @ + @ restore BSR and restart the instruction + @ + ldw r2, [sp+], #S_PSR + priv_exit r2 @ return from exception +ENDPROC(__dabt_priv) + + .align 5 +__intr_priv: + priv_entry + + intr_handler + + mov r0, #0 @ epip4d + movc p0.c5, r0, #14 + nop; nop; nop; nop; nop; nop; nop; nop + + ldw r4, [sp+], #S_PSR @ irqs are already disabled + + priv_exit r4 @ return from exception +ENDPROC(__intr_priv) + + .ltorg + + .align 5 +__extn_priv: + priv_entry + + mov r0, sp @ struct pt_regs *regs + mov r1, asr + b bad_mode @ not supported +ENDPROC(__extn_priv) + + .align 5 +__pabt_priv: + priv_entry + + @ + @ re-enable interrupts if appropriate + @ + mov r17, asr + cand.a r3, #PSR_I_BIT + bne 1f + andn r17, r17, #PSR_I_BIT +1: + + @ + @ set args, then call main handler + @ + @ r0 - address of faulting instruction + @ r1 - pointer to registers on stack + @ + mov r0, r2 @ pass address of aborted instruction + mov r1, #5 + mov.a asr, r17 + mov r2, sp @ regs + b.l do_PrefetchAbort @ call abort handler + + @ + @ INTRs off again before pulling preserved data off the stack + @ + disable_irq r0 + + @ + @ restore BSR and restart the instruction + @ + ldw r2, [sp+], #S_PSR + priv_exit r2 @ return from exception +ENDPROC(__pabt_priv) + + .align 5 +.LCcralign: + .word cr_alignment + + .align 5 +__dabt_user: + user_entry + +#ifdef CONFIG_UNICORE_FPU_F64 + cff ip, s31 + cand.a ip, #0x08000000 @ FPU execption traps? + beq 209f + + ldw ip, [sp+], #S_PC + add ip, ip, #4 + stw ip, [sp+], #S_PC + @ + @ fall through to the emulation code, which returns using r19 if + @ it has emulated the instruction, or the more conventional lr + @ if we are to treat this as a real extended instruction + @ + @ r0 - instruction + @ +1: ldw.u r0, [r2] + adr r19, ret_from_exception + adr lr, 209f + @ + @ fallthrough to call do_uc_f64 + @ +/* + * Check whether the instruction is a co-processor instruction. + * If yes, we need to call the relevant co-processor handler. + * + * Note that we don't do a full check here for the co-processor + * instructions; all instructions with bit 27 set are well + * defined. The only instructions that should fault are the + * co-processor instructions. + * + * Emulators may wish to make use of the following registers: + * r0 = instruction opcode. + * r2 = PC + * r19 = normal "successful" return address + * r20 = this threads thread_info structure. + * lr = unrecognised instruction return address + */ + get_thread_info r20 @ get current thread + and r8, r0, #0x00003c00 @ mask out CP number + mov r7, #1 + stb r7, [r20+], #TI_USED_CP + 2 @ set appropriate used_cp[] + + @ F64 hardware support entry point. + @ r0 = faulted instruction + @ r19 = return address + @ r20 = fp_state + enable_irq r4 + add r20, r20, #TI_FPSTATE @ r20 = workspace + cff r1, s31 @ get fpu FPSCR + andn r2, r1, #0x08000000 + ctf r2, s31 @ clear 27 bit + mov r2, sp @ nothing stacked - regdump is at TOS + mov lr, r19 @ setup for a return to the user code + + @ Now call the C code to package up the bounce to the support code + @ r0 holds the trigger instruction + @ r1 holds the FPSCR value + @ r2 pointer to register dump + b ucf64_exchandler +209: +#endif + @ + @ Call the processor-specific abort handler: + @ + @ r2 - aborted context pc + @ r3 - aborted context asr + @ + @ The abort handler must return the aborted address in r0, and + @ the fault status register in r1. + @ + movc r1, p0.c3, #0 @ get FSR + movc r0, p0.c4, #0 @ get FAR + + @ + @ INTRs on, then call the main handler + @ + enable_irq r2 + mov r2, sp + adr lr, ret_from_exception + b do_DataAbort +ENDPROC(__dabt_user) + + .align 5 +__intr_user: + user_entry + + get_thread_info tsk + + intr_handler + + mov why, #0 + b ret_to_user +ENDPROC(__intr_user) + + .ltorg + + .align 5 +__extn_user: + user_entry + + mov r0, sp + mov r1, asr + b bad_mode +ENDPROC(__extn_user) + + .align 5 +__pabt_user: + user_entry + + mov r0, r2 @ pass address of aborted instruction. + mov r1, #5 + enable_irq r1 @ Enable interrupts + mov r2, sp @ regs + b.l do_PrefetchAbort @ call abort handler + /* fall through */ +/* + * This is the return code to user mode for abort handlers + */ +ENTRY(ret_from_exception) + get_thread_info tsk + mov why, #0 + b ret_to_user +ENDPROC(__pabt_user) +ENDPROC(ret_from_exception) + +/* + * Register switch for UniCore V2 processors + * r0 = previous task_struct, r1 = previous thread_info, r2 = next thread_info + * previous and next are guaranteed not to be the same. + */ +ENTRY(__switch_to) + add ip, r1, #TI_CPU_SAVE + stm.w (r4 - r15), [ip]+ + stm.w (r16 - r27, sp, lr), [ip]+ + +#ifdef CONFIG_UNICORE_FPU_F64 + add ip, r1, #TI_FPSTATE + sfm.w (f0 - f7 ), [ip]+ + sfm.w (f8 - f15), [ip]+ + sfm.w (f16 - f23), [ip]+ + sfm.w (f24 - f31), [ip]+ + cff r4, s31 + stw r4, [ip] + + add ip, r2, #TI_FPSTATE + lfm.w (f0 - f7 ), [ip]+ + lfm.w (f8 - f15), [ip]+ + lfm.w (f16 - f23), [ip]+ + lfm.w (f24 - f31), [ip]+ + ldw r4, [ip] + ctf r4, s31 +#endif + add ip, r2, #TI_CPU_SAVE + ldm.w (r4 - r15), [ip]+ + ldm (r16 - r27, sp, pc), [ip]+ @ Load all regs saved previously +ENDPROC(__switch_to) + + .align 5 +/* + * This is the fast syscall return path. We do as little as + * possible here, and this includes saving r0 back into the PRIV + * stack. + */ +ret_fast_syscall: + disable_irq r1 @ disable interrupts + ldw r1, [tsk+], #TI_FLAGS + cand.a r1, #_TIF_WORK_MASK + bne fast_work_pending + + @ fast_restore_user_regs + restore_user_regs fast = 1, offset = S_OFF + +/* + * Ok, we need to do extra processing, enter the slow path. + */ +fast_work_pending: + stw.w r0, [sp+], #S_R0+S_OFF @ returned r0 +work_pending: + cand.a r1, #_TIF_NEED_RESCHED + bne work_resched + cand.a r1, #_TIF_SIGPENDING|_TIF_NOTIFY_RESUME + beq no_work_pending + mov r0, sp @ 'regs' + mov r2, why @ 'syscall' + cand.a r1, #_TIF_SIGPENDING @ delivering a signal? + cmovne why, #0 @ prevent further restarts + b.l do_notify_resume + b ret_slow_syscall @ Check work again + +work_resched: + b.l schedule +/* + * "slow" syscall return path. "why" tells us if this was a real syscall. + */ +ENTRY(ret_to_user) +ret_slow_syscall: + disable_irq r1 @ disable interrupts + get_thread_info tsk @ epip4d, one path error?! + ldw r1, [tsk+], #TI_FLAGS + cand.a r1, #_TIF_WORK_MASK + bne work_pending +no_work_pending: + @ slow_restore_user_regs + restore_user_regs fast = 0, offset = 0 +ENDPROC(ret_to_user) + +/* + * This is how we return from a fork. + */ +ENTRY(ret_from_fork) + b.l schedule_tail + get_thread_info tsk + ldw r1, [tsk+], #TI_FLAGS @ check for syscall tracing + mov why, #1 + cand.a r1, #_TIF_SYSCALL_TRACE @ are we tracing syscalls? + beq ret_slow_syscall + mov r1, sp + mov r0, #1 @ trace exit [IP = 1] + b.l syscall_trace + b ret_slow_syscall +ENDPROC(ret_from_fork) + +/*============================================================================= + * SWI handler + *----------------------------------------------------------------------------- + */ + .align 5 +ENTRY(vector_swi) + sub sp, sp, #S_FRAME_SIZE + stm (r0 - r15), [sp]+ @ Calling r0 - r15 + add r8, sp, #S_R16 + stm (r16 - r28), [r8]+ @ Calling r16 - r28 + add r8, sp, #S_PC + stur (sp, lr), [r8-] @ Calling sp, lr + mov r8, bsr @ called from non-REAL mode + stw lr, [sp+], #S_PC @ Save calling PC + stw r8, [sp+], #S_PSR @ Save ASR + stw r0, [sp+], #S_OLD_R0 @ Save OLD_R0 + zero_fp + + /* + * Get the system call number. + */ + sub ip, lr, #4 + ldw.u scno, [ip] @ get SWI instruction + +#ifdef CONFIG_ALIGNMENT_TRAP + ldw ip, __cr_alignment + ldw ip, [ip] + movc p0.c1, ip, #0 @ update control register +#endif + enable_irq ip + + get_thread_info tsk + ldw tbl, =sys_call_table @ load syscall table pointer + + andn scno, scno, #0xff000000 @ mask off SWI op-code + andn scno, scno, #0x00ff0000 @ mask off SWI op-code + + stm.w (r4, r5), [sp-] @ push fifth and sixth args + ldw ip, [tsk+], #TI_FLAGS @ check for syscall tracing + cand.a ip, #_TIF_SYSCALL_TRACE @ are we tracing syscalls? + bne __sys_trace + + csub.a scno, #__NR_syscalls @ check upper syscall limit + adr lr, ret_fast_syscall @ return address + bea 1f + ldw pc, [tbl+], scno << #2 @ call sys_* routine +1: + add r1, sp, #S_OFF +2: mov why, #0 @ no longer a real syscall + b sys_ni_syscall @ not private func + + /* + * This is the really slow path. We're going to be doing + * context switches, and waiting for our parent to respond. + */ +__sys_trace: + mov r2, scno + add r1, sp, #S_OFF + mov r0, #0 @ trace entry [IP = 0] + b.l syscall_trace + + adr lr, __sys_trace_return @ return address + mov scno, r0 @ syscall number (possibly new) + add r1, sp, #S_R0 + S_OFF @ pointer to regs + csub.a scno, #__NR_syscalls @ check upper syscall limit + bea 2b + ldm (r0 - r3), [r1]+ @ have to reload r0 - r3 + ldw pc, [tbl+], scno << #2 @ call sys_* routine + +__sys_trace_return: + stw.w r0, [sp+], #S_R0 + S_OFF @ save returned r0 + mov r2, scno + mov r1, sp + mov r0, #1 @ trace exit [IP = 1] + b.l syscall_trace + b ret_slow_syscall + + .align 5 +#ifdef CONFIG_ALIGNMENT_TRAP + .type __cr_alignment, #object +__cr_alignment: + .word cr_alignment +#endif + .ltorg + +ENTRY(sys_execve) + add r3, sp, #S_OFF + b __sys_execve +ENDPROC(sys_execve) + +ENTRY(sys_clone) + add ip, sp, #S_OFF + stw ip, [sp+], #4 + b __sys_clone +ENDPROC(sys_clone) + +ENTRY(sys_rt_sigreturn) + add r0, sp, #S_OFF + mov why, #0 @ prevent syscall restart handling + b __sys_rt_sigreturn +ENDPROC(sys_rt_sigreturn) + +ENTRY(sys_sigaltstack) + ldw r2, [sp+], #S_OFF + S_SP + b do_sigaltstack +ENDPROC(sys_sigaltstack) + + __INIT + +/* + * Vector stubs. + * + * This code is copied to 0xffff0200 so we can use branches in the + * vectors, rather than ldr's. Note that this code must not + * exceed 0x300 bytes. + * + * Common stub entry macro: + * Enter in INTR mode, bsr = PRIV/USER ASR, lr = PRIV/USER PC + * + * SP points to a minimal amount of processor-private memory, the address + * of which is copied into r0 for the mode specific abort handler. + */ + .macro vector_stub, name, mode + .align 5 + +vector_\name: + @ + @ Save r0, lr_<exception> (parent PC) and bsr_<exception> + @ (parent ASR) + @ + stw r0, [sp] + stw lr, [sp+], #4 @ save r0, lr + mov lr, bsr + stw lr, [sp+], #8 @ save bsr + + @ + @ Prepare for PRIV mode. INTRs remain disabled. + @ + mov r0, asr + xor r0, r0, #(\mode ^ PRIV_MODE) + mov.a bsr, r0 + + @ + @ the branch table must immediately follow this code + @ + and lr, lr, #0x03 + add lr, lr, #1 + mov r0, sp + ldw lr, [pc+], lr << #2 + mov.a pc, lr @ branch to handler in PRIV mode +ENDPROC(vector_\name) + .align 2 + @ handler addresses follow this label + .endm + + .globl __stubs_start +__stubs_start: +/* + * Interrupt dispatcher + */ + vector_stub intr, INTR_MODE + + .long __intr_user @ 0 (USER) + .long __invalid @ 1 + .long __invalid @ 2 + .long __intr_priv @ 3 (PRIV) + +/* + * Data abort dispatcher + * Enter in ABT mode, bsr = USER ASR, lr = USER PC + */ + vector_stub dabt, ABRT_MODE + + .long __dabt_user @ 0 (USER) + .long __invalid @ 1 + .long __invalid @ 2 (INTR) + .long __dabt_priv @ 3 (PRIV) + +/* + * Prefetch abort dispatcher + * Enter in ABT mode, bsr = USER ASR, lr = USER PC + */ + vector_stub pabt, ABRT_MODE + + .long __pabt_user @ 0 (USER) + .long __invalid @ 1 + .long __invalid @ 2 (INTR) + .long __pabt_priv @ 3 (PRIV) + +/* + * Undef instr entry dispatcher + * Enter in EXTN mode, bsr = PRIV/USER ASR, lr = PRIV/USER PC + */ + vector_stub extn, EXTN_MODE + + .long __extn_user @ 0 (USER) + .long __invalid @ 1 + .long __invalid @ 2 (INTR) + .long __extn_priv @ 3 (PRIV) + +/* + * We group all the following data together to optimise + * for CPUs with separate I & D caches. + */ + .align 5 + +.LCvswi: + .word vector_swi + + .globl __stubs_end +__stubs_end: + + .equ stubs_offset, __vectors_start + 0x200 - __stubs_start + + .globl __vectors_start +__vectors_start: + jepriv SYS_ERROR0 + b vector_extn + stubs_offset + ldw pc, .LCvswi + stubs_offset + b vector_pabt + stubs_offset + b vector_dabt + stubs_offset + jepriv SYS_ERROR0 + b vector_intr + stubs_offset + jepriv SYS_ERROR0 + + .globl __vectors_end +__vectors_end: + + .data + + .globl cr_alignment + .globl cr_no_alignment +cr_alignment: + .space 4 +cr_no_alignment: + .space 4 diff --git a/arch/unicore32/kernel/head.S b/arch/unicore32/kernel/head.S new file mode 100644 index 000000000000..92255f3ab6a7 --- /dev/null +++ b/arch/unicore32/kernel/head.S @@ -0,0 +1,252 @@ +/* + * linux/arch/unicore32/kernel/head.S + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/linkage.h> +#include <linux/init.h> + +#include <asm/assembler.h> +#include <asm/ptrace.h> +#include <generated/asm-offsets.h> +#include <asm/memory.h> +#include <asm/thread_info.h> +#include <asm/system.h> +#include <asm/pgtable-hwdef.h> + +#if (PHYS_OFFSET & 0x003fffff) +#error "PHYS_OFFSET must be at an even 4MiB boundary!" +#endif + +#define KERNEL_RAM_VADDR (PAGE_OFFSET + KERNEL_IMAGE_START) +#define KERNEL_RAM_PADDR (PHYS_OFFSET + KERNEL_IMAGE_START) + +#define KERNEL_PGD_PADDR (KERNEL_RAM_PADDR - 0x1000) +#define KERNEL_PGD_VADDR (KERNEL_RAM_VADDR - 0x1000) + +#define KERNEL_START KERNEL_RAM_VADDR +#define KERNEL_END _end + +/* + * swapper_pg_dir is the virtual address of the initial page table. + * We place the page tables 4K below KERNEL_RAM_VADDR. Therefore, we must + * make sure that KERNEL_RAM_VADDR is correctly set. Currently, we expect + * the least significant 16 bits to be 0x8000, but we could probably + * relax this restriction to KERNEL_RAM_VADDR >= PAGE_OFFSET + 0x1000. + */ +#if (KERNEL_RAM_VADDR & 0xffff) != 0x8000 +#error KERNEL_RAM_VADDR must start at 0xXXXX8000 +#endif + + .globl swapper_pg_dir + .equ swapper_pg_dir, KERNEL_RAM_VADDR - 0x1000 + +/* + * Kernel startup entry point. + * --------------------------- + * + * This is normally called from the decompressor code. The requirements + * are: MMU = off, D-cache = off, I-cache = dont care + * + * This code is mostly position independent, so if you link the kernel at + * 0xc0008000, you call this at __pa(0xc0008000). + */ + __HEAD +ENTRY(stext) + @ set asr + mov r0, #PRIV_MODE @ ensure priv mode + or r0, #PSR_R_BIT | PSR_I_BIT @ disable irqs + mov.a asr, r0 + + @ process identify + movc r0, p0.c0, #0 @ cpuid + movl r1, 0xff00ffff @ mask + movl r2, 0x4d000863 @ value + and r0, r1, r0 + cxor.a r0, r2 + bne __error_p @ invalid processor id + + /* + * Clear the 4K level 1 swapper page table + */ + movl r0, #KERNEL_PGD_PADDR @ page table address + mov r1, #0 + add r2, r0, #0x1000 +101: stw.w r1, [r0]+, #4 + stw.w r1, [r0]+, #4 + stw.w r1, [r0]+, #4 + stw.w r1, [r0]+, #4 + cxor.a r0, r2 + bne 101b + + movl r4, #KERNEL_PGD_PADDR @ page table address + mov r7, #PMD_TYPE_SECT | PMD_PRESENT @ page size: section + or r7, r7, #PMD_SECT_CACHEABLE @ cacheable + or r7, r7, #PMD_SECT_READ | PMD_SECT_WRITE | PMD_SECT_EXEC + + /* + * Create identity mapping for first 4MB of kernel to + * cater for the MMU enable. This identity mapping + * will be removed by paging_init(). We use our current program + * counter to determine corresponding section base address. + */ + mov r6, pc + mov r6, r6 >> #22 @ start of kernel section + or r1, r7, r6 << #22 @ flags + kernel base + stw r1, [r4+], r6 << #2 @ identity mapping + + /* + * Now setup the pagetables for our kernel direct + * mapped region. + */ + add r0, r4, #(KERNEL_START & 0xff000000) >> 20 + stw.w r1, [r0+], #(KERNEL_START & 0x00c00000) >> 20 + movl r6, #(KERNEL_END - 1) + add r0, r0, #4 + add r6, r4, r6 >> #20 +102: csub.a r0, r6 + add r1, r1, #1 << 22 + bua 103f + stw.w r1, [r0]+, #4 + b 102b +103: + /* + * Then map first 4MB of ram in case it contains our boot params. + */ + add r0, r4, #PAGE_OFFSET >> 20 + or r6, r7, #(PHYS_OFFSET & 0xffc00000) + stw r6, [r0] + + ldw r15, __switch_data @ address to jump to after + + /* + * Initialise TLB, Caches, and MMU state ready to switch the MMU + * on. + */ + mov r0, #0 + movc p0.c5, r0, #28 @ cache invalidate all + nop8 + movc p0.c6, r0, #6 @ TLB invalidate all + nop8 + + /* + * ..V. .... ..TB IDAM + * ..1. .... ..01 1111 + */ + movl r0, #0x201f @ control register setting + + /* + * Setup common bits before finally enabling the MMU. Essentially + * this is just loading the page table pointer and domain access + * registers. + */ + #ifndef CONFIG_ALIGNMENT_TRAP + andn r0, r0, #CR_A + #endif + #ifdef CONFIG_CPU_DCACHE_DISABLE + andn r0, r0, #CR_D + #endif + #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH + andn r0, r0, #CR_B + #endif + #ifdef CONFIG_CPU_ICACHE_DISABLE + andn r0, r0, #CR_I + #endif + + movc p0.c2, r4, #0 @ set pgd + b __turn_mmu_on +ENDPROC(stext) + +/* + * Enable the MMU. This completely changes the stucture of the visible + * memory space. You will not be able to trace execution through this. + * + * r0 = cp#0 control register + * r15 = *virtual* address to jump to upon completion + */ + .align 5 +__turn_mmu_on: + mov r0, r0 + movc p0.c1, r0, #0 @ write control reg + nop @ fetch inst by phys addr + mov pc, r15 + nop8 @ fetch inst by phys addr +ENDPROC(__turn_mmu_on) + +/* + * Setup the initial page tables. We only setup the barest + * amount which are required to get the kernel running, which + * generally means mapping in the kernel code. + * + * r9 = cpuid + * r10 = procinfo + * + * Returns: + * r0, r3, r6, r7 corrupted + * r4 = physical page table address + */ + .ltorg + + .align 2 + .type __switch_data, %object +__switch_data: + .long __mmap_switched + .long __bss_start @ r6 + .long _end @ r7 + .long cr_alignment @ r8 + .long init_thread_union + THREAD_START_SP @ sp + +/* + * The following fragment of code is executed with the MMU on in MMU mode, + * and uses absolute addresses; this is not position independent. + * + * r0 = cp#0 control register + */ +__mmap_switched: + adr r3, __switch_data + 4 + + ldm.w (r6, r7, r8), [r3]+ + ldw sp, [r3] + + mov fp, #0 @ Clear BSS (and zero fp) +203: csub.a r6, r7 + bea 204f + stw.w fp, [r6]+,#4 + b 203b +204: + andn r1, r0, #CR_A @ Clear 'A' bit + stm (r0, r1), [r8]+ @ Save control register values + b start_kernel +ENDPROC(__mmap_switched) + +/* + * Exception handling. Something went wrong and we can't proceed. We + * ought to tell the user, but since we don't have any guarantee that + * we're even running on the right architecture, we do virtually nothing. + * + * If CONFIG_DEBUG_LL is set we try to print out something about the error + * and hope for the best (useful if bootloader fails to pass a proper + * machine ID for example). + */ +__error_p: +#ifdef CONFIG_DEBUG_LL + adr r0, str_p1 + b.l printascii + mov r0, r9 + b.l printhex8 + adr r0, str_p2 + b.l printascii +901: nop8 + b 901b +str_p1: .asciz "\nError: unrecognized processor variant (0x" +str_p2: .asciz ").\n" + .align +#endif +ENDPROC(__error_p) + diff --git a/arch/unicore32/kernel/setup.c b/arch/unicore32/kernel/setup.c new file mode 100644 index 000000000000..1e175a82844d --- /dev/null +++ b/arch/unicore32/kernel/setup.c @@ -0,0 +1,360 @@ +/* + * linux/arch/unicore32/kernel/setup.c + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/stddef.h> +#include <linux/ioport.h> +#include <linux/delay.h> +#include <linux/utsname.h> +#include <linux/initrd.h> +#include <linux/console.h> +#include <linux/bootmem.h> +#include <linux/seq_file.h> +#include <linux/screen_info.h> +#include <linux/init.h> +#include <linux/root_dev.h> +#include <linux/cpu.h> +#include <linux/interrupt.h> +#include <linux/smp.h> +#include <linux/fs.h> +#include <linux/proc_fs.h> +#include <linux/memblock.h> +#include <linux/elf.h> +#include <linux/io.h> + +#include <asm/cputype.h> +#include <asm/sections.h> +#include <asm/setup.h> +#include <asm/cacheflush.h> +#include <asm/tlbflush.h> +#include <asm/traps.h> + +#include "setup.h" + +#ifndef MEM_SIZE +#define MEM_SIZE (16*1024*1024) +#endif + +struct stack { + u32 irq[3]; + u32 abt[3]; + u32 und[3]; +} ____cacheline_aligned; + +static struct stack stacks[NR_CPUS]; + +char elf_platform[ELF_PLATFORM_SIZE]; +EXPORT_SYMBOL(elf_platform); + +static char __initdata cmd_line[COMMAND_LINE_SIZE]; + +static char default_command_line[COMMAND_LINE_SIZE] __initdata = CONFIG_CMDLINE; + +/* + * Standard memory resources + */ +static struct resource mem_res[] = { + { + .name = "Video RAM", + .start = 0, + .end = 0, + .flags = IORESOURCE_MEM + }, + { + .name = "Kernel text", + .start = 0, + .end = 0, + .flags = IORESOURCE_MEM + }, + { + .name = "Kernel data", + .start = 0, + .end = 0, + .flags = IORESOURCE_MEM + } +}; + +#define video_ram mem_res[0] +#define kernel_code mem_res[1] +#define kernel_data mem_res[2] + +/* + * These functions re-use the assembly code in head.S, which + * already provide the required functionality. + */ +static void __init setup_processor(void) +{ + printk(KERN_DEFAULT "CPU: UniCore-II [%08x] revision %d, cr=%08lx\n", + uc32_cpuid, (int)(uc32_cpuid >> 16) & 15, cr_alignment); + + sprintf(init_utsname()->machine, "puv3"); + sprintf(elf_platform, "ucv2"); +} + +/* + * cpu_init - initialise one CPU. + * + * cpu_init sets up the per-CPU stacks. + */ +void cpu_init(void) +{ + unsigned int cpu = smp_processor_id(); + struct stack *stk = &stacks[cpu]; + + /* + * setup stacks for re-entrant exception handlers + */ + __asm__ ( + "mov.a asr, %1\n\t" + "add sp, %0, %2\n\t" + "mov.a asr, %3\n\t" + "add sp, %0, %4\n\t" + "mov.a asr, %5\n\t" + "add sp, %0, %6\n\t" + "mov.a asr, %7" + : + : "r" (stk), + "r" (PSR_R_BIT | PSR_I_BIT | INTR_MODE), + "I" (offsetof(struct stack, irq[0])), + "r" (PSR_R_BIT | PSR_I_BIT | ABRT_MODE), + "I" (offsetof(struct stack, abt[0])), + "r" (PSR_R_BIT | PSR_I_BIT | EXTN_MODE), + "I" (offsetof(struct stack, und[0])), + "r" (PSR_R_BIT | PSR_I_BIT | PRIV_MODE) + : "r30", "cc"); +} + +static int __init uc32_add_memory(unsigned long start, unsigned long size) +{ + struct membank *bank = &meminfo.bank[meminfo.nr_banks]; + + if (meminfo.nr_banks >= NR_BANKS) { + printk(KERN_CRIT "NR_BANKS too low, " + "ignoring memory at %#lx\n", start); + return -EINVAL; + } + + /* + * Ensure that start/size are aligned to a page boundary. + * Size is appropriately rounded down, start is rounded up. + */ + size -= start & ~PAGE_MASK; + + bank->start = PAGE_ALIGN(start); + bank->size = size & PAGE_MASK; + + /* + * Check whether this memory region has non-zero size or + * invalid node number. + */ + if (bank->size == 0) + return -EINVAL; + + meminfo.nr_banks++; + return 0; +} + +/* + * Pick out the memory size. We look for mem=size@start, + * where start and size are "size[KkMm]" + */ +static int __init early_mem(char *p) +{ + static int usermem __initdata = 1; + unsigned long size, start; |