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authorLuis Machado <luisgpm@linux.vnet.ibm.com>2008-07-23 12:10:41 -0400
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2008-07-25 01:44:39 -0400
commitd6a61bfc06d6f2248f3e75f208d64e794082013c (patch)
treed46aec6b68e30f9d7d9198bd9102fcf1c054ab7e /arch
parent00bf6e906156b07cd641fe154ad0efe78f989692 (diff)
powerpc: BookE hardware watchpoint support
This patch implements support for HW based watchpoint via the DBSR_DAC (Data Address Compare) facility of the BookE processors. It does so by interfacing with the existing DABR breakpoint code and adding the necessary bits and pieces for the new bits to be properly set or cleared Signed-off-by: Luis Machado <luisgpm@br.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/kernel/entry_32.S6
-rw-r--r--arch/powerpc/kernel/process.c46
-rw-r--r--arch/powerpc/kernel/ptrace.c72
-rw-r--r--arch/powerpc/kernel/signal.c6
-rw-r--r--arch/powerpc/kernel/traps.c16
-rw-r--r--arch/powerpc/mm/fault.c25
6 files changed, 136 insertions, 35 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index da52269aec1e..81c8324a4a3c 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -148,7 +148,7 @@ transfer_to_handler:
148 /* Check to see if the dbcr0 register is set up to debug. Use the 148 /* Check to see if the dbcr0 register is set up to debug. Use the
149 internal debug mode bit to do this. */ 149 internal debug mode bit to do this. */
150 lwz r12,THREAD_DBCR0(r12) 150 lwz r12,THREAD_DBCR0(r12)
151 andis. r12,r12,DBCR0_IDM@h 151 andis. r12,r12,(DBCR0_IDM | DBSR_DAC1R | DBSR_DAC1W)@h
152 beq+ 3f 152 beq+ 3f
153 /* From user and task is ptraced - load up global dbcr0 */ 153 /* From user and task is ptraced - load up global dbcr0 */
154 li r12,-1 /* clear all pending debug events */ 154 li r12,-1 /* clear all pending debug events */
@@ -292,7 +292,7 @@ syscall_exit_cont:
292 /* If the process has its own DBCR0 value, load it up. The internal 292 /* If the process has its own DBCR0 value, load it up. The internal
293 debug mode bit tells us that dbcr0 should be loaded. */ 293 debug mode bit tells us that dbcr0 should be loaded. */
294 lwz r0,THREAD+THREAD_DBCR0(r2) 294 lwz r0,THREAD+THREAD_DBCR0(r2)
295 andis. r10,r0,DBCR0_IDM@h 295 andis. r10,r0,(DBCR0_IDM | DBSR_DAC1R | DBSR_DAC1W)@h
296 bnel- load_dbcr0 296 bnel- load_dbcr0
297#endif 297#endif
298#ifdef CONFIG_44x 298#ifdef CONFIG_44x
@@ -720,7 +720,7 @@ restore_user:
720 /* Check whether this process has its own DBCR0 value. The internal 720 /* Check whether this process has its own DBCR0 value. The internal
721 debug mode bit tells us that dbcr0 should be loaded. */ 721 debug mode bit tells us that dbcr0 should be loaded. */
722 lwz r0,THREAD+THREAD_DBCR0(r2) 722 lwz r0,THREAD+THREAD_DBCR0(r2)
723 andis. r10,r0,DBCR0_IDM@h 723 andis. r10,r0,(DBCR0_IDM | DBSR_DAC1R | DBSR_DAC1W)@h
724 bnel- load_dbcr0 724 bnel- load_dbcr0
725#endif 725#endif
726 726
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 219f3634115e..db2497ccc111 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -47,6 +47,8 @@
47#ifdef CONFIG_PPC64 47#ifdef CONFIG_PPC64
48#include <asm/firmware.h> 48#include <asm/firmware.h>
49#endif 49#endif
50#include <linux/kprobes.h>
51#include <linux/kdebug.h>
50 52
51extern unsigned long _get_SP(void); 53extern unsigned long _get_SP(void);
52 54
@@ -239,6 +241,35 @@ void discard_lazy_cpu_state(void)
239} 241}
240#endif /* CONFIG_SMP */ 242#endif /* CONFIG_SMP */
241 243
244void do_dabr(struct pt_regs *regs, unsigned long address,
245 unsigned long error_code)
246{
247 siginfo_t info;
248
249 if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
250 11, SIGSEGV) == NOTIFY_STOP)
251 return;
252
253 if (debugger_dabr_match(regs))
254 return;
255
256 /* Clear the DAC and struct entries. One shot trigger */
257#if (defined(CONFIG_44x) || defined(CONFIG_BOOKE))
258 mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~(DBSR_DAC1R | DBSR_DAC1W
259 | DBCR0_IDM));
260#endif
261
262 /* Clear the DABR */
263 set_dabr(0);
264
265 /* Deliver the signal to userspace */
266 info.si_signo = SIGTRAP;
267 info.si_errno = 0;
268 info.si_code = TRAP_HWBKPT;
269 info.si_addr = (void __user *)address;
270 force_sig_info(SIGTRAP, &info, current);
271}
272
242static DEFINE_PER_CPU(unsigned long, current_dabr); 273static DEFINE_PER_CPU(unsigned long, current_dabr);
243 274
244int set_dabr(unsigned long dabr) 275int set_dabr(unsigned long dabr)
@@ -254,6 +285,11 @@ int set_dabr(unsigned long dabr)
254#if defined(CONFIG_PPC64) || defined(CONFIG_6xx) 285#if defined(CONFIG_PPC64) || defined(CONFIG_6xx)
255 mtspr(SPRN_DABR, dabr); 286 mtspr(SPRN_DABR, dabr);
256#endif 287#endif
288
289#if defined(CONFIG_44x) || defined(CONFIG_BOOKE)
290 mtspr(SPRN_DAC1, dabr);
291#endif
292
257 return 0; 293 return 0;
258} 294}
259 295
@@ -337,6 +373,12 @@ struct task_struct *__switch_to(struct task_struct *prev,
337 if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) 373 if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr))
338 set_dabr(new->thread.dabr); 374 set_dabr(new->thread.dabr);
339 375
376#if defined(CONFIG_44x) || defined(CONFIG_BOOKE)
377 /* If new thread DAC (HW breakpoint) is the same then leave it */
378 if (new->thread.dabr)
379 set_dabr(new->thread.dabr);
380#endif
381
340 new_thread = &new->thread; 382 new_thread = &new->thread;
341 old_thread = &current->thread; 383 old_thread = &current->thread;
342 384
@@ -525,6 +567,10 @@ void flush_thread(void)
525 if (current->thread.dabr) { 567 if (current->thread.dabr) {
526 current->thread.dabr = 0; 568 current->thread.dabr = 0;
527 set_dabr(0); 569 set_dabr(0);
570
571#if defined(CONFIG_44x) || defined(CONFIG_BOOKE)
572 current->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W);
573#endif
528 } 574 }
529} 575}
530 576
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 8feb93e7890c..a5d0e78779c8 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -703,7 +703,7 @@ void user_enable_single_step(struct task_struct *task)
703 703
704 if (regs != NULL) { 704 if (regs != NULL) {
705#if defined(CONFIG_40x) || defined(CONFIG_BOOKE) 705#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
706 task->thread.dbcr0 = DBCR0_IDM | DBCR0_IC; 706 task->thread.dbcr0 |= DBCR0_IDM | DBCR0_IC;
707 regs->msr |= MSR_DE; 707 regs->msr |= MSR_DE;
708#else 708#else
709 regs->msr |= MSR_SE; 709 regs->msr |= MSR_SE;
@@ -716,9 +716,16 @@ void user_disable_single_step(struct task_struct *task)
716{ 716{
717 struct pt_regs *regs = task->thread.regs; 717 struct pt_regs *regs = task->thread.regs;
718 718
719
720#if defined(CONFIG_44x) || defined(CONFIG_BOOKE)
721 /* If DAC then do not single step, skip */
722 if (task->thread.dabr)
723 return;
724#endif
725
719 if (regs != NULL) { 726 if (regs != NULL) {
720#if defined(CONFIG_40x) || defined(CONFIG_BOOKE) 727#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
721 task->thread.dbcr0 = 0; 728 task->thread.dbcr0 &= ~(DBCR0_IC | DBCR0_IDM);
722 regs->msr &= ~MSR_DE; 729 regs->msr &= ~MSR_DE;
723#else 730#else
724 regs->msr &= ~MSR_SE; 731 regs->msr &= ~MSR_SE;
@@ -727,22 +734,75 @@ void user_disable_single_step(struct task_struct *task)
727 clear_tsk_thread_flag(task, TIF_SINGLESTEP); 734 clear_tsk_thread_flag(task, TIF_SINGLESTEP);
728} 735}
729 736
730static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, 737int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
731 unsigned long data) 738 unsigned long data)
732{ 739{
733 /* We only support one DABR and no IABRS at the moment */ 740 /* For ppc64 we support one DABR and no IABR's at the moment (ppc64).
741 * For embedded processors we support one DAC and no IAC's at the
742 * moment.
743 */
734 if (addr > 0) 744 if (addr > 0)
735 return -EINVAL; 745 return -EINVAL;
736 746
737 /* The bottom 3 bits are flags */
738 if ((data & ~0x7UL) >= TASK_SIZE) 747 if ((data & ~0x7UL) >= TASK_SIZE)
739 return -EIO; 748 return -EIO;
740 749
741 /* Ensure translation is on */ 750#ifdef CONFIG_PPC64
751
752 /* For processors using DABR (i.e. 970), the bottom 3 bits are flags.
753 * It was assumed, on previous implementations, that 3 bits were
754 * passed together with the data address, fitting the design of the
755 * DABR register, as follows:
756 *
757 * bit 0: Read flag
758 * bit 1: Write flag
759 * bit 2: Breakpoint translation
760 *
761 * Thus, we use them here as so.
762 */
763
764 /* Ensure breakpoint translation bit is set */
742 if (data && !(data & DABR_TRANSLATION)) 765 if (data && !(data & DABR_TRANSLATION))
743 return -EIO; 766 return -EIO;
744 767
768 /* Move contents to the DABR register */
745 task->thread.dabr = data; 769 task->thread.dabr = data;
770
771#endif
772#if defined(CONFIG_44x) || defined(CONFIG_BOOKE)
773
774 /* As described above, it was assumed 3 bits were passed with the data
775 * address, but we will assume only the mode bits will be passed
776 * as to not cause alignment restrictions for DAC-based processors.
777 */
778
779 /* DAC's hold the whole address without any mode flags */
780 task->thread.dabr = data & ~0x3UL;
781
782 if (task->thread.dabr == 0) {
783 task->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W | DBCR0_IDM);
784 task->thread.regs->msr &= ~MSR_DE;
785 return 0;
786 }
787
788 /* Read or Write bits must be set */
789
790 if (!(data & 0x3UL))
791 return -EINVAL;
792
793 /* Set the Internal Debugging flag (IDM bit 1) for the DBCR0
794 register */
795 task->thread.dbcr0 = DBCR0_IDM;
796
797 /* Check for write and read flags and set DBCR0
798 accordingly */
799 if (data & 0x1UL)
800 task->thread.dbcr0 |= DBSR_DAC1R;
801 if (data & 0x2UL)
802 task->thread.dbcr0 |= DBSR_DAC1W;
803
804 task->thread.regs->msr |= MSR_DE;
805#endif
746 return 0; 806 return 0;
747} 807}
748 808
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index ad55488939c3..7aada783ec6a 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -145,8 +145,12 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
145 * user space. The DABR will have been cleared if it 145 * user space. The DABR will have been cleared if it
146 * triggered inside the kernel. 146 * triggered inside the kernel.
147 */ 147 */
148 if (current->thread.dabr) 148 if (current->thread.dabr) {
149 set_dabr(current->thread.dabr); 149 set_dabr(current->thread.dabr);
150#if defined(CONFIG_44x) || defined(CONFIG_BOOKE)
151 mtspr(SPRN_DBCR0, current->thread.dbcr0);
152#endif
153 }
150 154
151 if (is32) { 155 if (is32) {
152 if (ka.sa.sa_flags & SA_SIGINFO) 156 if (ka.sa.sa_flags & SA_SIGINFO)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 878fbddb6ae1..81ccb8dd1a54 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1067,6 +1067,22 @@ void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status)
1067 } 1067 }
1068 1068
1069 _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip); 1069 _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
1070 } else if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
1071 regs->msr &= ~MSR_DE;
1072
1073 if (user_mode(regs)) {
1074 current->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W |
1075 DBCR0_IDM);
1076 } else {
1077 /* Disable DAC interupts */
1078 mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~(DBSR_DAC1R |
1079 DBSR_DAC1W | DBCR0_IDM));
1080
1081 /* Clear the DAC event */
1082 mtspr(SPRN_DBSR, (DBSR_DAC1R | DBSR_DAC1W));
1083 }
1084 /* Setup and send the trap to the handler */
1085 do_dabr(regs, mfspr(SPRN_DAC1), debug_status);
1070 } 1086 }
1071} 1087}
1072#endif /* CONFIG_4xx || CONFIG_BOOKE */ 1088#endif /* CONFIG_4xx || CONFIG_BOOKE */
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 1707d00331fc..565b7a237c84 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -100,31 +100,6 @@ static int store_updates_sp(struct pt_regs *regs)
100 return 0; 100 return 0;
101} 101}
102 102
103#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
104static void do_dabr(struct pt_regs *regs, unsigned long address,
105 unsigned long error_code)
106{
107 siginfo_t info;
108
109 if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
110 11, SIGSEGV) == NOTIFY_STOP)
111 return;
112
113 if (debugger_dabr_match(regs))
114 return;
115
116 /* Clear the DABR */
117 set_dabr(0);
118
119 /* Deliver the signal to userspace */
120 info.si_signo = SIGTRAP;
121 info.si_errno = 0;
122 info.si_code = TRAP_HWBKPT;
123 info.si_addr = (void __user *)address;
124 force_sig_info(SIGTRAP, &info, current);
125}
126#endif /* !(CONFIG_4xx || CONFIG_BOOKE)*/
127
128/* 103/*
129 * For 600- and 800-family processors, the error_code parameter is DSISR 104 * For 600- and 800-family processors, the error_code parameter is DSISR
130 * for a data fault, SRR1 for an instruction fault. For 400-family processors 105 * for a data fault, SRR1 for an instruction fault. For 400-family processors