Commit d36b4c4f authored by Kumar Gala's avatar Kumar Gala
Browse files

powerpc/fsl-booke64: Add support for Debug Level exception handler


Signed-off-by: default avatarKumar Gala <galak@kernel.crashing.org>
parent 134c428e
......@@ -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 */
......
......@@ -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)
......
......@@ -62,6 +62,7 @@
#include <asm/udbg.h>
#include <asm/kexec.h>
#include <asm/mmu_context.h>
#include <asm/code-patching.h>
#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()
......
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