Merge branch 'topic/ppc-kvm' into next

Merge the DAWR series, which touches arch code and KVM code and may need
to be merged into the kvm-ppc tree.

arch/powerpc/kernel/dt_cpu_ftrs.c

@@ -713,6 +713,9 @@ static __init void cpufeatures_cpu_quirks(void)
 	else if ((version & 0xffffefff) == 0x004e0202)
 		cur_cpu_spec->cpu_features |= CPU_FTR_P9_TM_HV_ASSIST |
 			CPU_FTR_P9_TM_XER_SO_BUG;
+
+	if ((version & 0xffff0000) == 0x004e0000)
+		cur_cpu_spec->cpu_features &= ~(CPU_FTR_DAWR);
 }
 
 static void __init cpufeatures_setup_finished(void)

arch/powerpc/kernel/hw_breakpoint.c

@@ -33,6 +33,7 @@
 #include <asm/hw_breakpoint.h>
 #include <asm/processor.h>
 #include <asm/sstep.h>
+#include <asm/debug.h>
 #include <linux/uaccess.h>
 
 /*
@@ -171,6 +172,8 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp)
 	 * HW_BREAKPOINT_ALIGN by rounding off to the lower address, the
 	 * 'symbolsize' should satisfy the check below.
 	 */
+	if (!ppc_breakpoint_available())
+		return -ENODEV;
 	length_max = 8; /* DABR */
 	if (cpu_has_feature(CPU_FTR_DAWR)) {
 		length_max = 512 ; /* 64 doublewords */

arch/powerpc/kernel/process.c

@@ -827,6 +827,18 @@ void set_breakpoint(struct arch_hw_breakpoint *brk)
 	preempt_enable();
 }
 
+/* Check if we have DAWR or DABR hardware */
+bool ppc_breakpoint_available(void)
+{
+	if (cpu_has_feature(CPU_FTR_DAWR))
+		return true; /* POWER8 DAWR */
+	if (cpu_has_feature(CPU_FTR_ARCH_207S))
+		return false; /* POWER9 with DAWR disabled */
+	/* DABR: Everything but POWER8 and POWER9 */
+	return true;
+}
+EXPORT_SYMBOL_GPL(ppc_breakpoint_available);
+
 #ifdef CONFIG_PPC64
 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
 #endif

arch/powerpc/kernel/ptrace.c

@@ -41,6 +41,7 @@
 #include <asm/switch_to.h>
 #include <asm/tm.h>
 #include <asm/asm-prototypes.h>
+#include <asm/debug.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/syscalls.h>
@@ -2378,6 +2379,7 @@ static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
 	struct perf_event_attr attr;
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 #ifndef CONFIG_PPC_ADV_DEBUG_REGS
+	bool set_bp = true;
 	struct arch_hw_breakpoint hw_brk;
 #endif
 
@@ -2411,9 +2413,10 @@ static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
 	hw_brk.address = data & (~HW_BRK_TYPE_DABR);
 	hw_brk.type = (data & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL;
 	hw_brk.len = 8;
+	set_bp = (data) && (hw_brk.type & HW_BRK_TYPE_RDWR);
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	bp = thread->ptrace_bps[0];
-	if ((!data) || !(hw_brk.type & HW_BRK_TYPE_RDWR)) {
+	if (!set_bp) {
 		if (bp) {
 			unregister_hw_breakpoint(bp);
 			thread->ptrace_bps[0] = NULL;
@@ -2450,6 +2453,9 @@ static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
 		return PTR_ERR(bp);
 	}
 
+#else /* !CONFIG_HAVE_HW_BREAKPOINT */
+	if (set_bp && (!ppc_breakpoint_available()))
+		return -ENODEV;
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 	task->thread.hw_brk = hw_brk;
 #else /* CONFIG_PPC_ADV_DEBUG_REGS */
@@ -2904,6 +2910,9 @@ static long ppc_set_hwdebug(struct task_struct *child,
 	if (child->thread.hw_brk.address)
 		return -ENOSPC;
 
+	if (!ppc_breakpoint_available())
+		return -ENODEV;
+
 	child->thread.hw_brk = brk;
 
 	return 1;
@@ -3052,7 +3061,10 @@ long arch_ptrace(struct task_struct *child, long request,
 #endif
 #else /* !CONFIG_PPC_ADV_DEBUG_REGS */
 		dbginfo.num_instruction_bps = 0;
-		dbginfo.num_data_bps = 1;
+		if (ppc_breakpoint_available())
+			dbginfo.num_data_bps = 1;
+		else
+			dbginfo.num_data_bps = 0;
 		dbginfo.num_condition_regs = 0;
 #ifdef CONFIG_PPC64
 		dbginfo.data_bp_alignment = 8;