[RFC PATCH 3/6] powerpc/pseries: Factor out DTL buffer allocation and registration routines

[Naveen N. Rao]

Introduce new helpers for DTL buffer allocation and registration and
have the existing code use those.

Signed-off-by: Naveen N. Rao <naveen.n.rao at linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/plpar_wrappers.h |  2 +
 arch/powerpc/platforms/pseries/lpar.c     | 66 ++++++++++++++++-------
 arch/powerpc/platforms/pseries/setup.c    | 34 +-----------
 3 files changed, 52 insertions(+), 50 deletions(-)

diff --git a/arch/powerpc/include/asm/plpar_wrappers.h b/arch/powerpc/include/asm/plpar_wrappers.h
index cff5a411e595..d08feb1bc2bd 100644
--- a/arch/powerpc/include/asm/plpar_wrappers.h
+++ b/arch/powerpc/include/asm/plpar_wrappers.h
@@ -88,6 +88,8 @@ static inline long register_dtl(unsigned long cpu, unsigned long vpa)
 	return vpa_call(H_VPA_REG_DTL, cpu, vpa);
 }
 
+extern void register_dtl_buffer(int cpu);
+extern void alloc_dtl_buffers(void);
 extern void vpa_init(int cpu);
 
 static inline long plpar_pte_enter(unsigned long flags,
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index 23f2ac6793b7..3375ca8cefb5 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -65,13 +65,58 @@ EXPORT_SYMBOL(plpar_hcall);
 EXPORT_SYMBOL(plpar_hcall9);
 EXPORT_SYMBOL(plpar_hcall_norets);
 
+void alloc_dtl_buffers(void)
+{
+	int cpu;
+	struct paca_struct *pp;
+	struct dtl_entry *dtl;
+
+	for_each_possible_cpu(cpu) {
+		pp = paca_ptrs[cpu];
+		dtl = kmem_cache_alloc(dtl_cache, GFP_KERNEL);
+		if (!dtl) {
+			pr_warn("Failed to allocate dispatch trace log for cpu %d\n",
+				cpu);
+			pr_warn("Stolen time statistics will be unreliable\n");
+			break;
+		}
+
+		pp->dtl_ridx = 0;
+		pp->dispatch_log = dtl;
+		pp->dispatch_log_end = dtl + N_DISPATCH_LOG;
+		pp->dtl_curr = dtl;
+	}
+}
+
+void register_dtl_buffer(int cpu)
+{
+	long ret;
+	struct paca_struct *pp;
+	struct dtl_entry *dtl;
+	int hwcpu = get_hard_smp_processor_id(cpu);
+
+	pp = paca_ptrs[cpu];
+	dtl = pp->dispatch_log;
+	if (dtl) {
+		pp->dtl_ridx = 0;
+		pp->dtl_curr = dtl;
+		lppaca_of(cpu).dtl_idx = 0;
+
+		/* hypervisor reads buffer length from this field */
+		dtl->enqueue_to_dispatch_time = cpu_to_be32(DISPATCH_LOG_BYTES);
+		ret = register_dtl(hwcpu, __pa(dtl));
+		if (ret)
+			pr_err("WARNING: DTL registration of cpu %d (hw %d) "
+			       "failed with %ld\n", cpu, hwcpu, ret);
+		lppaca_of(cpu).dtl_enable_mask = DTL_LOG_PREEMPT;
+	}
+}
+
 void vpa_init(int cpu)
 {
 	int hwcpu = get_hard_smp_processor_id(cpu);
 	unsigned long addr;
 	long ret;
-	struct paca_struct *pp;
-	struct dtl_entry *dtl;
 
 	/*
 	 * The spec says it "may be problematic" if CPU x registers the VPA of
@@ -112,22 +157,7 @@ void vpa_init(int cpu)
 	/*
 	 * Register dispatch trace log, if one has been allocated.
 	 */
-	pp = paca_ptrs[cpu];
-	dtl = pp->dispatch_log;
-	if (dtl) {
-		pp->dtl_ridx = 0;
-		pp->dtl_curr = dtl;
-		lppaca_of(cpu).dtl_idx = 0;
-
-		/* hypervisor reads buffer length from this field */
-		dtl->enqueue_to_dispatch_time = cpu_to_be32(DISPATCH_LOG_BYTES);
-		ret = register_dtl(hwcpu, __pa(dtl));
-		if (ret)
-			pr_err("WARNING: DTL registration of cpu %d (hw %d) "
-			       "failed with %ld\n", smp_processor_id(),
-			       hwcpu, ret);
-		lppaca_of(cpu).dtl_enable_mask = DTL_LOG_PREEMPT;
-	}
+	register_dtl_buffer(cpu);
 }
 
 #ifdef CONFIG_PPC_BOOK3S_64
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index fabaefff8399..b6995e5cc5c9 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -277,46 +277,16 @@ struct kmem_cache *dtl_cache;
  */
 static int alloc_dispatch_logs(void)
 {
-	int cpu, ret;
-	struct paca_struct *pp;
-	struct dtl_entry *dtl;
-
 	if (!firmware_has_feature(FW_FEATURE_SPLPAR))
 		return 0;
 
 	if (!dtl_cache)
 		return 0;
 
-	for_each_possible_cpu(cpu) {
-		pp = paca_ptrs[cpu];
-		dtl = kmem_cache_alloc(dtl_cache, GFP_KERNEL);
-		if (!dtl) {
-			pr_warn("Failed to allocate dispatch trace log for cpu %d\n",
-				cpu);
-			pr_warn("Stolen time statistics will be unreliable\n");
-			break;
-		}
-
-		pp->dtl_ridx = 0;
-		pp->dispatch_log = dtl;
-		pp->dispatch_log_end = dtl + N_DISPATCH_LOG;
-		pp->dtl_curr = dtl;
-	}
+	alloc_dtl_buffers();
 
 	/* Register the DTL for the current (boot) cpu */
-	dtl = get_paca()->dispatch_log;
-	get_paca()->dtl_ridx = 0;
-	get_paca()->dtl_curr = dtl;
-	get_paca()->lppaca_ptr->dtl_idx = 0;
-
-	/* hypervisor reads buffer length from this field */
-	dtl->enqueue_to_dispatch_time = cpu_to_be32(DISPATCH_LOG_BYTES);
-	ret = register_dtl(hard_smp_processor_id(), __pa(dtl));
-	if (ret)
-		pr_err("WARNING: DTL registration of cpu %d (hw %d) failed "
-		       "with %d\n", smp_processor_id(),
-		       hard_smp_processor_id(), ret);
-	get_paca()->lppaca_ptr->dtl_enable_mask = DTL_LOG_PREEMPT;
+	register_dtl_buffer(smp_processor_id());
 
 	return 0;
 }
-- 
2.21.0