From d36b4c4f3cc6caae6d4a12d9f995513e4c3acdd5 Mon Sep 17 00:00:00 2001 From: Kumar Gala Date: Wed, 6 Apr 2011 00:18:48 -0500 Subject: [PATCH] powerpc/fsl-booke64: Add support for Debug Level exception handler Signed-off-by: Kumar Gala --- arch/powerpc/include/asm/cputable.h | 4 +- arch/powerpc/kernel/exceptions-64e.S | 65 ++++++++++++++++++++++++++-- arch/powerpc/kernel/setup_64.c | 8 ++++ 3 files changed, 73 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h index 4efbfb3f3254..c0d842cfd012 100644 --- a/arch/powerpc/include/asm/cputable.h +++ b/arch/powerpc/include/asm/cputable.h @@ -157,6 +157,7 @@ extern const char *powerpc_base_platform; #define CPU_FTR_476_DD2 ASM_CONST(0x0000000000010000) #define CPU_FTR_NEED_COHERENT ASM_CONST(0x0000000000020000) #define CPU_FTR_NO_BTIC ASM_CONST(0x0000000000040000) +#define CPU_FTR_DEBUG_LVL_EXC ASM_CONST(0x0000000000080000) #define CPU_FTR_NODSISRALIGN ASM_CONST(0x0000000000100000) #define CPU_FTR_PPC_LE ASM_CONST(0x0000000000200000) #define CPU_FTR_REAL_LE ASM_CONST(0x0000000000400000) @@ -385,7 +386,8 @@ extern const char *powerpc_base_platform; CPU_FTR_DBELL) #define CPU_FTRS_E5500 (CPU_FTR_USE_TB | CPU_FTR_NODSISRALIGN | \ CPU_FTR_L2CSR | CPU_FTR_LWSYNC | CPU_FTR_NOEXECUTE | \ - CPU_FTR_DBELL | CPU_FTR_POPCNTB | CPU_FTR_POPCNTD) + CPU_FTR_DBELL | CPU_FTR_POPCNTB | CPU_FTR_POPCNTD | \ + CPU_FTR_DEBUG_LVL_EXC) #define CPU_FTRS_GENERIC_32 (CPU_FTR_COMMON | CPU_FTR_NODSISRALIGN) /* 64-bit CPUs */ diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S index 4d0abb4930a1..cf27a8fa0d29 100644 --- a/arch/powerpc/kernel/exceptions-64e.S +++ b/arch/powerpc/kernel/exceptions-64e.S @@ -253,9 +253,6 @@ exception_marker: .balign 0x1000 .globl interrupt_base_book3e interrupt_base_book3e: /* fake trap */ - /* Note: If real debug exceptions are supported by the HW, the vector - * below will have to be patched up to point to an appropriate handler - */ EXCEPTION_STUB(0x000, machine_check) /* 0x0200 */ EXCEPTION_STUB(0x020, critical_input) /* 0x0580 */ EXCEPTION_STUB(0x040, debug_crit) /* 0x0d00 */ @@ -455,6 +452,68 @@ interrupt_end_book3e: kernel_dbg_exc: b . /* NYI */ +/* Debug exception as a debug interrupt*/ + START_EXCEPTION(debug_debug); + DBG_EXCEPTION_PROLOG(0xd00, PROLOG_ADDITION_2REGS) + + /* + * If there is a single step or branch-taken exception in an + * exception entry sequence, it was probably meant to apply to + * the code where the exception occurred (since exception entry + * doesn't turn off DE automatically). We simulate the effect + * of turning off DE on entry to an exception handler by turning + * off DE in the DSRR1 value and clearing the debug status. + */ + + mfspr r14,SPRN_DBSR /* check single-step/branch taken */ + andis. r15,r14,DBSR_IC@h + beq+ 1f + + LOAD_REG_IMMEDIATE(r14,interrupt_base_book3e) + LOAD_REG_IMMEDIATE(r15,interrupt_end_book3e) + cmpld cr0,r10,r14 + cmpld cr1,r10,r15 + blt+ cr0,1f + bge+ cr1,1f + + /* here it looks like we got an inappropriate debug exception. */ + lis r14,DBSR_IC@h /* clear the IC event */ + rlwinm r11,r11,0,~MSR_DE /* clear DE in the DSRR1 value */ + mtspr SPRN_DBSR,r14 + mtspr SPRN_DSRR1,r11 + lwz r10,PACA_EXDBG+EX_CR(r13) /* restore registers */ + ld r1,PACA_EXDBG+EX_R1(r13) + ld r14,PACA_EXDBG+EX_R14(r13) + ld r15,PACA_EXDBG+EX_R15(r13) + mtcr r10 + ld r10,PACA_EXDBG+EX_R10(r13) /* restore registers */ + ld r11,PACA_EXDBG+EX_R11(r13) + mfspr r13,SPRN_SPRG_DBG_SCRATCH + rfdi + + /* Normal debug exception */ + /* XXX We only handle coming from userspace for now since we can't + * quite save properly an interrupted kernel state yet + */ +1: andi. r14,r11,MSR_PR; /* check for userspace again */ + beq kernel_dbg_exc; /* if from kernel mode */ + + /* Now we mash up things to make it look like we are coming on a + * normal exception + */ + mfspr r15,SPRN_SPRG_DBG_SCRATCH + mtspr SPRN_SPRG_GEN_SCRATCH,r15 + mfspr r14,SPRN_DBSR + EXCEPTION_COMMON(0xd00, PACA_EXDBG, INTS_DISABLE_ALL) + std r14,_DSISR(r1) + addi r3,r1,STACK_FRAME_OVERHEAD + mr r4,r14 + ld r14,PACA_EXDBG+EX_R14(r13) + ld r15,PACA_EXDBG+EX_R15(r13) + bl .save_nvgprs + bl .DebugException + b .ret_from_except + /* Doorbell interrupt */ MASKABLE_EXCEPTION(0x2070, doorbell, .doorbell_exception, ACK_NONE) diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index c2ec0a12e14f..a88bf2713d41 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -62,6 +62,7 @@ #include #include #include +#include #include "setup.h" @@ -477,6 +478,9 @@ static void __init irqstack_early_init(void) #ifdef CONFIG_PPC_BOOK3E static void __init exc_lvl_early_init(void) { + extern unsigned int interrupt_base_book3e; + extern unsigned int exc_debug_debug_book3e; + unsigned int i; for_each_possible_cpu(i) { @@ -487,6 +491,10 @@ static void __init exc_lvl_early_init(void) mcheckirq_ctx[i] = (struct thread_info *) __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE)); } + + if (cpu_has_feature(CPU_FTR_DEBUG_LVL_EXC)) + patch_branch(&interrupt_base_book3e + (0x040 / 4) + 1, + (unsigned long)&exc_debug_debug_book3e, 0); } #else #define exc_lvl_early_init() -- 2.20.1