powerpc/pseries: Fix CONFIG_DTL=n build

The recently moved dtl code must be compiled-in if
CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y even if CONFIG_DTL=n.

Fixes: 6ba5aa541a ("powerpc/pseries: Move dtl scanning and steal time accounting to pseries platform")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221013073131.1485742-1-npiggin@gmail.com

arch/powerpc/platforms/pseries/Makefile

@@ -7,7 +7,7 @@ obj-y			:= lpar.o hvCall.o nvram.o reconfig.o \
 			   setup.o iommu.o event_sources.o ras.o \
 			   firmware.o power.o dlpar.o mobility.o rng.o \
 			   pci.o pci_dlpar.o eeh_pseries.o msi.o \
-			   papr_platform_attributes.o
+			   papr_platform_attributes.o dtl.o
 obj-$(CONFIG_SMP)	+= smp.o
 obj-$(CONFIG_KEXEC_CORE)	+= kexec.o
 obj-$(CONFIG_PSERIES_ENERGY)	+= pseries_energy.o
@@ -19,7 +19,6 @@ obj-$(CONFIG_HVC_CONSOLE)	+= hvconsole.o
 obj-$(CONFIG_HVCS)		+= hvcserver.o
 obj-$(CONFIG_HCALL_STATS)	+= hvCall_inst.o
 obj-$(CONFIG_CMM)		+= cmm.o
-obj-$(CONFIG_DTL)		+= dtl.o
 obj-$(CONFIG_IO_EVENT_IRQ)	+= io_event_irq.o
 obj-$(CONFIG_LPARCFG)		+= lparcfg.o
 obj-$(CONFIG_IBMVIO)		+= vio.o

arch/powerpc/platforms/pseries/dtl.c

@@ -18,6 +18,7 @@
 #include <asm/plpar_wrappers.h>
 #include <asm/machdep.h>
 
+#ifdef CONFIG_DTL
 struct dtl {
 	struct dtl_entry	*buf;
 	int			cpu;
@@ -57,78 +58,6 @@ static DEFINE_PER_CPU(struct dtl_ring, dtl_rings);
 
 static atomic_t dtl_count;
 
-/*
- * Scan the dispatch trace log and count up the stolen time.
- * Should be called with interrupts disabled.
- */
-static notrace u64 scan_dispatch_log(u64 stop_tb)
-{
-	u64 i = local_paca->dtl_ridx;
-	struct dtl_entry *dtl = local_paca->dtl_curr;
-	struct dtl_entry *dtl_end = local_paca->dispatch_log_end;
-	struct lppaca *vpa = local_paca->lppaca_ptr;
-	u64 tb_delta;
-	u64 stolen = 0;
-	u64 dtb;
-
-	if (!dtl)
-		return 0;
-
-	if (i == be64_to_cpu(vpa->dtl_idx))
-		return 0;
-	while (i < be64_to_cpu(vpa->dtl_idx)) {
-		dtb = be64_to_cpu(dtl->timebase);
-		tb_delta = be32_to_cpu(dtl->enqueue_to_dispatch_time) +
-			be32_to_cpu(dtl->ready_to_enqueue_time);
-		barrier();
-		if (i + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx)) {
-			/* buffer has overflowed */
-			i = be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG;
-			dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
-			continue;
-		}
-		if (dtb > stop_tb)
-			break;
-		if (dtl_consumer)
-			dtl_consumer(dtl, i);
-		stolen += tb_delta;
-		++i;
-		++dtl;
-		if (dtl == dtl_end)
-			dtl = local_paca->dispatch_log;
-	}
-	local_paca->dtl_ridx = i;
-	local_paca->dtl_curr = dtl;
-	return stolen;
-}
-
-/*
- * Accumulate stolen time by scanning the dispatch trace log.
- * Called on entry from user mode.
- */
-void notrace pseries_accumulate_stolen_time(void)
-{
-	u64 sst, ust;
-	struct cpu_accounting_data *acct = &local_paca->accounting;
-
-	sst = scan_dispatch_log(acct->starttime_user);
-	ust = scan_dispatch_log(acct->starttime);
-	acct->stime -= sst;
-	acct->utime -= ust;
-	acct->steal_time += ust + sst;
-}
-
-u64 pseries_calculate_stolen_time(u64 stop_tb)
-{
-	if (!firmware_has_feature(FW_FEATURE_SPLPAR))
-		return 0;
-
-	if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx))
-		return scan_dispatch_log(stop_tb);
-
-	return 0;
-}
-
 /*
  * The cpu accounting code controls the DTL ring buffer, and we get
  * given entries as they are processed.
@@ -436,3 +365,81 @@ static int dtl_init(void)
 	return 0;
 }
 machine_arch_initcall(pseries, dtl_init);
+#endif /* CONFIG_DTL */
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+/*
+ * Scan the dispatch trace log and count up the stolen time.
+ * Should be called with interrupts disabled.
+ */
+static notrace u64 scan_dispatch_log(u64 stop_tb)
+{
+	u64 i = local_paca->dtl_ridx;
+	struct dtl_entry *dtl = local_paca->dtl_curr;
+	struct dtl_entry *dtl_end = local_paca->dispatch_log_end;
+	struct lppaca *vpa = local_paca->lppaca_ptr;
+	u64 tb_delta;
+	u64 stolen = 0;
+	u64 dtb;
+
+	if (!dtl)
+		return 0;
+
+	if (i == be64_to_cpu(vpa->dtl_idx))
+		return 0;
+	while (i < be64_to_cpu(vpa->dtl_idx)) {
+		dtb = be64_to_cpu(dtl->timebase);
+		tb_delta = be32_to_cpu(dtl->enqueue_to_dispatch_time) +
+			be32_to_cpu(dtl->ready_to_enqueue_time);
+		barrier();
+		if (i + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx)) {
+			/* buffer has overflowed */
+			i = be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG;
+			dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
+			continue;
+		}
+		if (dtb > stop_tb)
+			break;
+#ifdef CONFIG_DTL
+		if (dtl_consumer)
+			dtl_consumer(dtl, i);
+#endif
+		stolen += tb_delta;
+		++i;
+		++dtl;
+		if (dtl == dtl_end)
+			dtl = local_paca->dispatch_log;
+	}
+	local_paca->dtl_ridx = i;
+	local_paca->dtl_curr = dtl;
+	return stolen;
+}
+
+/*
+ * Accumulate stolen time by scanning the dispatch trace log.
+ * Called on entry from user mode.
+ */
+void notrace pseries_accumulate_stolen_time(void)
+{
+	u64 sst, ust;
+	struct cpu_accounting_data *acct = &local_paca->accounting;
+
+	sst = scan_dispatch_log(acct->starttime_user);
+	ust = scan_dispatch_log(acct->starttime);
+	acct->stime -= sst;
+	acct->utime -= ust;
+	acct->steal_time += ust + sst;
+}
+
+u64 pseries_calculate_stolen_time(u64 stop_tb)
+{
+	if (!firmware_has_feature(FW_FEATURE_SPLPAR))
+		return 0;
+
+	if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx))
+		return scan_dispatch_log(stop_tb);
+
+	return 0;
+}
+
+#endif