1 files changed, 410 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
new file mode 100644
index 000000000000..b4fdf2f2743c
--- /dev/null
+++ b/arch/powerpc/kernel/kgdb.c
@@ -0,0 +1,410 @@
+/*
+ * PowerPC backend to the KGDB stub.
+ *
+ * 1998 (c) Michael AK Tesch (tesch@cs.wisc.edu)
+ * Copyright (C) 2003 Timesys Corporation.
+ * Copyright (C) 2004-2006 MontaVista Software, Inc.
+ * PPC64 Mods (C) 2005 Frank Rowand (frowand@mvista.com)
+ * PPC32 support restored by Vitaly Wool <vwool@ru.mvista.com> and
+ * Sergei Shtylyov <sshtylyov@ru.mvista.com>
+ * Copyright (C) 2007-2008 Wind River Systems, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program as licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/kgdb.h>
+#include <linux/smp.h>
+#include <linux/signal.h>
+#include <linux/ptrace.h>
+#include <asm/current.h>
+#include <asm/processor.h>
+#include <asm/machdep.h>
+
+/*
+ * This table contains the mapping between PowerPC hardware trap types, and
+ * signals, which are primarily what GDB understands.  GDB and the kernel
+ * don't always agree on values, so we use constants taken from gdb-6.2.
+ */
+static struct hard_trap_info
+{
+        unsigned int tt;                /* Trap type code for powerpc */
+        unsigned char signo;            /* Signal that we map this trap into */
+} hard_trap_info[] = {
+        { 0x0100, 0x02 /* SIGINT */  },         /* system reset */
+        { 0x0200, 0x0b /* SIGSEGV */ },         /* machine check */
+        { 0x0300, 0x0b /* SIGSEGV */ },         /* data access */
+        { 0x0400, 0x0b /* SIGSEGV */ },         /* instruction access */
+        { 0x0500, 0x02 /* SIGINT */  },         /* external interrupt */
+        { 0x0600, 0x0a /* SIGBUS */  },         /* alignment */
+        { 0x0700, 0x05 /* SIGTRAP */ },         /* program check */
+        { 0x0800, 0x08 /* SIGFPE */  },         /* fp unavailable */
+        { 0x0900, 0x0e /* SIGALRM */ },         /* decrementer */
+        { 0x0c00, 0x14 /* SIGCHLD */ },         /* system call */
+#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+        { 0x2002, 0x05 /* SIGTRAP */ },         /* debug */
+#if defined(CONFIG_FSL_BOOKE)
+        { 0x2010, 0x08 /* SIGFPE */  },         /* spe unavailable */
+        { 0x2020, 0x08 /* SIGFPE */  },         /* spe unavailable */
+        { 0x2030, 0x08 /* SIGFPE */  },         /* spe fp data */
+        { 0x2040, 0x08 /* SIGFPE */  },         /* spe fp data */
+        { 0x2050, 0x08 /* SIGFPE */  },         /* spe fp round */
+        { 0x2060, 0x0e /* SIGILL */  },         /* performace monitor */
+        { 0x2900, 0x08 /* SIGFPE */  },         /* apu unavailable */
+        { 0x3100, 0x0e /* SIGALRM */ },         /* fixed interval timer */
+        { 0x3200, 0x02 /* SIGINT */  },         /* watchdog */
+#else /* ! CONFIG_FSL_BOOKE */
+        { 0x1000, 0x0e /* SIGALRM */ },         /* prog interval timer */
+        { 0x1010, 0x0e /* SIGALRM */ },         /* fixed interval timer */
+        { 0x1020, 0x02 /* SIGINT */  },         /* watchdog */
+        { 0x2010, 0x08 /* SIGFPE */  },         /* fp unavailable */
+        { 0x2020, 0x08 /* SIGFPE */  },         /* ap unavailable */
+#endif
+#else /* ! (defined(CONFIG_40x) || defined(CONFIG_BOOKE)) */
+        { 0x0d00, 0x05 /* SIGTRAP */ },         /* single-step */
+#if defined(CONFIG_8xx)
+        { 0x1000, 0x04 /* SIGILL */  },         /* software emulation */
+#else /* ! CONFIG_8xx */
+        { 0x0f00, 0x04 /* SIGILL */  },         /* performance monitor */
+        { 0x0f20, 0x08 /* SIGFPE */  },         /* altivec unavailable */
+        { 0x1300, 0x05 /* SIGTRAP */ },         /* instruction address break */
+#if defined(CONFIG_PPC64)
+        { 0x1200, 0x05 /* SIGILL */  },         /* system error */
+        { 0x1500, 0x04 /* SIGILL */  },         /* soft patch */
+        { 0x1600, 0x04 /* SIGILL */  },         /* maintenance */
+        { 0x1700, 0x08 /* SIGFPE */  },         /* altivec assist */
+        { 0x1800, 0x04 /* SIGILL */  },         /* thermal */
+#else /* ! CONFIG_PPC64 */
+        { 0x1400, 0x02 /* SIGINT */  },         /* SMI */
+        { 0x1600, 0x08 /* SIGFPE */  },         /* altivec assist */
+        { 0x1700, 0x04 /* SIGILL */  },         /* TAU */
+        { 0x2000, 0x05 /* SIGTRAP */ },         /* run mode */
+#endif
+#endif
+#endif
+        { 0x0000, 0x00 }                        /* Must be last */
+};
+
+static int computeSignal(unsigned int tt)
+{
+        struct hard_trap_info *ht;
+
+        for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
+                if (ht->tt == tt)
+                        return ht->signo;
+
+        return SIGHUP;          /* default for things we don't know about */
+}
+
+static int kgdb_call_nmi_hook(struct pt_regs *regs)
+{
+        kgdb_nmicallback(raw_smp_processor_id(), regs);
+        return 0;
+}
+
+#ifdef CONFIG_SMP
+void kgdb_roundup_cpus(unsigned long flags)
+{
+        smp_send_debugger_break(MSG_ALL_BUT_SELF);
+}
+#endif
+
+/* KGDB functions to use existing PowerPC64 hooks. */
+static int kgdb_debugger(struct pt_regs *regs)
+{
+        return kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs);
+}
+
+static int kgdb_handle_breakpoint(struct pt_regs *regs)
+{
+        if (user_mode(regs))
+                return 0;
+
+        if (kgdb_handle_exception(0, SIGTRAP, 0, regs) != 0)
+                return 0;
+
+        if (*(u32 *) (regs->nip) == *(u32 *) (&arch_kgdb_ops.gdb_bpt_instr))
+                regs->nip += 4;
+
+        return 1;
+}
+
+static int kgdb_singlestep(struct pt_regs *regs)
+{
+        struct thread_info *thread_info, *exception_thread_info;
+
+        if (user_mode(regs))
+                return 0;
+
+        /*
+         * On Book E and perhaps other processsors, singlestep is handled on
+         * the critical exception stack.  This causes current_thread_info()
+         * to fail, since it it locates the thread_info by masking off
+         * the low bits of the current stack pointer.  We work around
+         * this issue by copying the thread_info from the kernel stack
+         * before calling kgdb_handle_exception, and copying it back
+         * afterwards.  On most processors the copy is avoided since
+         * exception_thread_info == thread_info.
+         */
+        thread_info = (struct thread_info *)(regs->gpr[1] & ~(THREAD_SIZE-1));
+        exception_thread_info = current_thread_info();
+
+        if (thread_info != exception_thread_info)
+                memcpy(exception_thread_info, thread_info, sizeof *thread_info);
+
+        kgdb_handle_exception(0, SIGTRAP, 0, regs);
+
+        if (thread_info != exception_thread_info)
+                memcpy(thread_info, exception_thread_info, sizeof *thread_info);
+
+        return 1;
+}
+
+static int kgdb_iabr_match(struct pt_regs *regs)
+{
+        if (user_mode(regs))
+                return 0;
+
+        if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0)
+                return 0;
+        return 1;
+}
+
+static int kgdb_dabr_match(struct pt_regs *regs)
+{
+        if (user_mode(regs))
+                return 0;
+
+        if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0)
+                return 0;
+        return 1;
+}
+
+#define PACK64(ptr, src) do { *(ptr++) = (src); } while (0)
+
+#define PACK32(ptr, src) do {          \
+        u32 *ptr32;                   \
+        ptr32 = (u32 *)ptr;           \
+        *(ptr32++) = (src);           \
+        ptr = (unsigned long *)ptr32; \
+        } while (0)
+
+
+void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+        unsigned long *ptr = gdb_regs;
+        int reg;
+
+        memset(gdb_regs, 0, NUMREGBYTES);
+
+        for (reg = 0; reg < 32; reg++)
+                PACK64(ptr, regs->gpr[reg]);
+
+#ifdef CONFIG_FSL_BOOKE
+#ifdef CONFIG_SPE
+        for (reg = 0; reg < 32; reg++)
+                PACK64(ptr, current->thread.evr[reg]);
+#else
+        ptr += 32;
+#endif
+#else
+        /* fp registers not used by kernel, leave zero */
+        ptr += 32 * 8 / sizeof(long);
+#endif
+
+        PACK64(ptr, regs->nip);
+        PACK64(ptr, regs->msr);
+        PACK32(ptr, regs->ccr);
+        PACK64(ptr, regs->link);
+        PACK64(ptr, regs->ctr);
+        PACK32(ptr, regs->xer);
+
+        BUG_ON((unsigned long)ptr >
+               (unsigned long)(((void *)gdb_regs) + NUMREGBYTES));
+}
+
+void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
+{
+        struct pt_regs *regs = (struct pt_regs *)(p->thread.ksp +
+                                                  STACK_FRAME_OVERHEAD);
+        unsigned long *ptr = gdb_regs;
+        int reg;
+
+        memset(gdb_regs, 0, NUMREGBYTES);
+
+        /* Regs GPR0-2 */
+        for (reg = 0; reg < 3; reg++)
+                PACK64(ptr, regs->gpr[reg]);
+
+        /* Regs GPR3-13 are caller saved, not in regs->gpr[] */
+        ptr += 11;
+
+        /* Regs GPR14-31 */
+        for (reg = 14; reg < 32; reg++)
+                PACK64(ptr, regs->gpr[reg]);
+
+#ifdef CONFIG_FSL_BOOKE
+#ifdef CONFIG_SPE
+        for (reg = 0; reg < 32; reg++)
+                PACK64(ptr, p->thread.evr[reg]);
+#else
+        ptr += 32;
+#endif
+#else
+        /* fp registers not used by kernel, leave zero */
+        ptr += 32 * 8 / sizeof(long);
+#endif
+
+        PACK64(ptr, regs->nip);
+        PACK64(ptr, regs->msr);
+        PACK32(ptr, regs->ccr);
+        PACK64(ptr, regs->link);
+        PACK64(ptr, regs->ctr);
+        PACK32(ptr, regs->xer);
+
+        BUG_ON((unsigned long)ptr >
+               (unsigned long)(((void *)gdb_regs) + NUMREGBYTES));
+}
+
+#define UNPACK64(dest, ptr) do { dest = *(ptr++); } while (0)
+
+#define UNPACK32(dest, ptr) do {       \
+        u32 *ptr32;                   \
+        ptr32 = (u32 *)ptr;           \
+        dest = *(ptr32++);            \
+        ptr = (unsigned long *)ptr32; \
+        } while (0)
+
+void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+        unsigned long *ptr = gdb_regs;
+        int reg;
+#ifdef CONFIG_SPE
+        union {
+                u32 v32[2];
+                u64 v64;
+        } acc;
+#endif
+
+        for (reg = 0; reg < 32; reg++)
+                UNPACK64(regs->gpr[reg], ptr);
+
+#ifdef CONFIG_FSL_BOOKE
+#ifdef CONFIG_SPE
+        for (reg = 0; reg < 32; reg++)
+                UNPACK64(current->thread.evr[reg], ptr);
+#else
+        ptr += 32;
+#endif
+#else
+        /* fp registers not used by kernel, leave zero */
+        ptr += 32 * 8 / sizeof(int);
+#endif
+
+        UNPACK64(regs->nip, ptr);
+        UNPACK64(regs->msr, ptr);
+        UNPACK32(regs->ccr, ptr);
+        UNPACK64(regs->link, ptr);
+        UNPACK64(regs->ctr, ptr);
+        UNPACK32(regs->xer, ptr);
+
+        BUG_ON((unsigned long)ptr >
+               (unsigned long)(((void *)gdb_regs) + NUMREGBYTES));
+}
+
+/*
+ * This function does PowerPC specific procesing for interfacing to gdb.
+ */
+int kgdb_arch_handle_exception(int vector, int signo, int err_code,
+                               char *remcom_in_buffer, char *remcom_out_buffer,
+                               struct pt_regs *linux_regs)
+{
+        char *ptr = &remcom_in_buffer[1];
+        unsigned long addr;
+
+        switch (remcom_in_buffer[0]) {
+                /*
+                 * sAA..AA   Step one instruction from AA..AA
+                 * This will return an error to gdb ..
+                 */
+        case 's':
+        case 'c':
+                /* handle the optional parameter */
+                if (kgdb_hex2long(&ptr, &addr))
+                        linux_regs->nip = addr;
+
+                atomic_set(&kgdb_cpu_doing_single_step, -1);
+                /* set the trace bit if we're stepping */
+                if (remcom_in_buffer[0] == 's') {
+#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+                        mtspr(SPRN_DBCR0,
+                              mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM);
+                        linux_regs->msr |= MSR_DE;
+#else
+                        linux_regs->msr |= MSR_SE;
+#endif
+                        kgdb_single_step = 1;
+                        if (kgdb_contthread)
+                                atomic_set(&kgdb_cpu_doing_single_step,
+                                           raw_smp_processor_id());
+                }
+                return 0;
+        }
+
+        return -1;
+}
+
+/*
+ * Global data
+ */
+struct kgdb_arch arch_kgdb_ops = {
+        .gdb_bpt_instr = {0x7d, 0x82, 0x10, 0x08},
+};
+
+static int kgdb_not_implemented(struct pt_regs *regs)
+{
+        return 0;
+}
+
+static void *old__debugger_ipi;
+static void *old__debugger;
+static void *old__debugger_bpt;
+static void *old__debugger_sstep;
+static void *old__debugger_iabr_match;
+static void *old__debugger_dabr_match;
+static void *old__debugger_fault_handler;
+
+int kgdb_arch_init(void)
+{
+        old__debugger_ipi = __debugger_ipi;
+        old__debugger = __debugger;
+        old__debugger_bpt = __debugger_bpt;
+        old__debugger_sstep = __debugger_sstep;
+        old__debugger_iabr_match = __debugger_iabr_match;
+        old__debugger_dabr_match = __debugger_dabr_match;
+        old__debugger_fault_handler = __debugger_fault_handler;
+
+        __debugger_ipi = kgdb_call_nmi_hook;
+        __debugger = kgdb_debugger;
+        __debugger_bpt = kgdb_handle_breakpoint;
+        __debugger_sstep = kgdb_singlestep;
+        __debugger_iabr_match = kgdb_iabr_match;
+        __debugger_dabr_match = kgdb_dabr_match;
+        __debugger_fault_handler = kgdb_not_implemented;
+
+        return 0;
+}
+
+void kgdb_arch_exit(void)
+{
+        __debugger_ipi = old__debugger_ipi;
+        __debugger = old__debugger;
+        __debugger_bpt = old__debugger_bpt;
+        __debugger_sstep = old__debugger_sstep;
+        __debugger_iabr_match = old__debugger_iabr_match;
+        __debugger_dabr_match = old__debugger_dabr_match;
+        __debugger_fault_handler = old__debugger_fault_handler;
+}