1 files changed, 115 insertions, 118 deletions

diff --git a/arch/powerpc/platforms/pseries/smp.c b/arch/powerpc/platforms/pseries/smp.c
index 306643cc9dbc..db99725e752b 100644
--- a/arch/powerpc/platforms/pseries/smp.c
+++ b/arch/powerpc/platforms/pseries/smp.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * SMP support for pSeries machines.
  *
@@ -5,11 +6,6 @@
  * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
  *
  * Plus various changes from other IBM teams...
- *
- *      This program is free software; you can redistribute it and/or
- *      modify it under the terms of the GNU General Public License
- *      as published by the Free Software Foundation; either version
- *      2 of the License, or (at your option) any later version.
  */
 
 
@@ -24,30 +20,30 @@
 #include <linux/err.h>
 #include <linux/device.h>
 #include <linux/cpu.h>
+#include <linux/pgtable.h>
 
 #include <asm/ptrace.h>
 #include <linux/atomic.h>
 #include <asm/irq.h>
 #include <asm/page.h>
-#include <asm/pgtable.h>
 #include <asm/io.h>
-#include <asm/prom.h>
 #include <asm/smp.h>
 #include <asm/paca.h>
 #include <asm/machdep.h>
 #include <asm/cputable.h>
 #include <asm/firmware.h>
 #include <asm/rtas.h>
-#include <asm/mpic.h>
 #include <asm/vdso_datapage.h>
 #include <asm/cputhreads.h>
 #include <asm/xics.h>
+#include <asm/xive.h>
 #include <asm/dbell.h>
+#include <asm/plpar_wrappers.h>
+#include <asm/text-patching.h>
+#include <asm/svm.h>
+#include <asm/kvm_guest.h>
 
-#include "plpar_wrappers.h"
 #include "pseries.h"
-#include "offline_states.h"
-
 
 /*
  * The Primary thread of each non-boot processor was started from the OF client
@@ -55,16 +51,11 @@
  */
 static cpumask_var_t of_spin_mask;
 
-/*
- * If we multiplex IPI mechanisms, store the appropriate XICS IPI mechanism here
- */
-static void  (*xics_cause_ipi)(int cpu, unsigned long data);
-
 /* Query where a cpu is now.  Return codes #defined in plpar_wrappers.h */
 int smp_query_cpu_stopped(unsigned int pcpu)
 {
 	int cpu_status, status;
-	int qcss_tok = rtas_token("query-cpu-stopped-state");
+	int qcss_tok = rtas_function_token(RTAS_FN_QUERY_CPU_STOPPED_STATE);
 
 	if (qcss_tok == RTAS_UNKNOWN_SERVICE) {
 		printk_once(KERN_INFO
@@ -96,8 +87,8 @@ int smp_query_cpu_stopped(unsigned int pcpu)
 static inline int smp_startup_cpu(unsigned int lcpu)
 {
 	int status;
-	unsigned long start_here = __pa((u32)*((unsigned long *)
-					       generic_secondary_smp_init));
+	unsigned long start_here =
+			__pa(ppc_function_entry(generic_secondary_smp_init));
 	unsigned int pcpu;
 	int start_cpu;
 
@@ -113,17 +104,11 @@ static inline int smp_startup_cpu(unsigned int lcpu)
 		return 1;
 	}
 
-	/* Fixup atomic count: it exited inside IRQ handler. */
-	task_thread_info(paca[lcpu].__current)->preempt_count	= 0;
-#ifdef CONFIG_HOTPLUG_CPU
-	if (get_cpu_current_state(lcpu) == CPU_STATE_INACTIVE)
-		goto out;
-#endif
 	/* 
 	 * If the RTAS start-cpu token does not exist then presume the
 	 * cpu is already spinning.
 	 */
-	start_cpu = rtas_token("start-cpu");
+	start_cpu = rtas_function_token(RTAS_FN_START_CPU);
 	if (start_cpu == RTAS_UNKNOWN_SERVICE)
 		return 1;
 
@@ -133,32 +118,26 @@ static inline int smp_startup_cpu(unsigned int lcpu)
 		return 0;
 	}
 
-#ifdef CONFIG_HOTPLUG_CPU
-out:
-#endif
 	return 1;
 }
 
-static void smp_xics_setup_cpu(int cpu)
+static void smp_setup_cpu(int cpu)
 {
-	if (cpu != boot_cpuid)
+	if (xive_enabled())
+		xive_smp_setup_cpu();
+	else if (cpu != boot_cpuid)
 		xics_setup_cpu();
-	if (cpu_has_feature(CPU_FTR_DBELL))
-		doorbell_setup_this_cpu();
 
 	if (firmware_has_feature(FW_FEATURE_SPLPAR))
 		vpa_init(cpu);
 
 	cpumask_clear_cpu(cpu, of_spin_mask);
-#ifdef CONFIG_HOTPLUG_CPU
-	set_cpu_current_state(cpu, CPU_STATE_ONLINE);
-	set_default_offline_state(cpu);
-#endif
 }
 
 static int smp_pSeries_kick_cpu(int nr)
 {
-	BUG_ON(nr < 0 || nr >= NR_CPUS);
+	if (nr < 0 || nr >= nr_cpu_ids)
+		return -EINVAL;
 
 	if (!smp_startup_cpu(nr))
 		return -ENOENT;
@@ -168,118 +147,136 @@ static int smp_pSeries_kick_cpu(int nr)
 	 * cpu_start field to become non-zero After we set cpu_start,
 	 * the processor will continue on to secondary_start
 	 */
-	paca[nr].cpu_start = 1;
-#ifdef CONFIG_HOTPLUG_CPU
-	set_preferred_offline_state(nr, CPU_STATE_ONLINE);
-
-	if (get_cpu_current_state(nr) == CPU_STATE_INACTIVE) {
-		long rc;
-		unsigned long hcpuid;
-
-		hcpuid = get_hard_smp_processor_id(nr);
-		rc = plpar_hcall_norets(H_PROD, hcpuid);
-		if (rc != H_SUCCESS)
-			printk(KERN_ERR "Error: Prod to wake up processor %d "
-						"Ret= %ld\n", nr, rc);
-	}
-#endif
+	paca_ptrs[nr]->cpu_start = 1;
 
 	return 0;
 }
 
-static int smp_pSeries_cpu_bootable(unsigned int nr)
+static int pseries_smp_prepare_cpu(int cpu)
 {
-	/* Special case - we inhibit secondary thread startup
-	 * during boot if the user requests it.
-	 */
-	if (system_state == SYSTEM_BOOTING && cpu_has_feature(CPU_FTR_SMT)) {
-		if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
-			return 0;
-		if (smt_enabled_at_boot
-		    && cpu_thread_in_core(nr) >= smt_enabled_at_boot)
-			return 0;
-	}
-
-	return 1;
+	if (xive_enabled())
+		return xive_smp_prepare_cpu(cpu);
+	return 0;
 }
 
-/* Only used on systems that support multiple IPI mechanisms */
-static void pSeries_cause_ipi_mux(int cpu, unsigned long data)
+/* Cause IPI as setup by the interrupt controller (xics or xive) */
+static void (*ic_cause_ipi)(int cpu) __ro_after_init;
+
+/* Use msgsndp doorbells target is a sibling, else use interrupt controller */
+static void dbell_or_ic_cause_ipi(int cpu)
 {
-	if (cpumask_test_cpu(cpu, cpu_sibling_mask(smp_processor_id())))
-		doorbell_cause_ipi(cpu, data);
-	else
-		xics_cause_ipi(cpu, data);
+	if (doorbell_try_core_ipi(cpu))
+		return;
+
+	ic_cause_ipi(cpu);
 }
 
-static __init int pSeries_smp_probe(void)
+static int pseries_cause_nmi_ipi(int cpu)
 {
-	int ret = xics_smp_probe();
+	int hwcpu;
+
+	if (cpu == NMI_IPI_ALL_OTHERS) {
+		hwcpu = H_SIGNAL_SYS_RESET_ALL_OTHERS;
+	} else {
+		if (cpu < 0) {
+			WARN_ONCE(true, "incorrect cpu parameter %d", cpu);
+			return 0;
+		}
 
-	if (cpu_has_feature(CPU_FTR_DBELL)) {
-		xics_cause_ipi = smp_ops->cause_ipi;
-		smp_ops->cause_ipi = pSeries_cause_ipi_mux;
+		hwcpu = get_hard_smp_processor_id(cpu);
 	}
 
-	return ret;
+	if (plpar_signal_sys_reset(hwcpu) == H_SUCCESS)
+		return 1;
+
+	return 0;
 }
 
-static struct smp_ops_t pSeries_mpic_smp_ops = {
-	.message_pass	= smp_mpic_message_pass,
-	.probe		= smp_mpic_probe,
-	.kick_cpu	= smp_pSeries_kick_cpu,
-	.setup_cpu	= smp_mpic_setup_cpu,
-};
+static __init void pSeries_smp_probe(void)
+{
+	if (xive_enabled())
+		xive_smp_probe();
+	else
+		xics_smp_probe();
+
+	/* No doorbell facility, must use the interrupt controller for IPIs */
+	if (!cpu_has_feature(CPU_FTR_DBELL))
+		return;
+
+	/* Doorbells can only be used for IPIs between SMT siblings */
+	if (!cpu_has_feature(CPU_FTR_SMT))
+		return;
+
+	check_kvm_guest();
+
+	if (is_kvm_guest()) {
+		/*
+		 * KVM emulates doorbells by disabling FSCR[MSGP] so msgsndp
+		 * faults to the hypervisor which then reads the instruction
+		 * from guest memory, which tends to be slower than using XIVE.
+		 */
+		if (xive_enabled())
+			return;
+
+		/*
+		 * XICS hcalls aren't as fast, so we can use msgsndp (which
+		 * also helps exercise KVM emulation), however KVM can't
+		 * emulate secure guests because it can't read the instruction
+		 * out of their memory.
+		 */
+		if (is_secure_guest())
+			return;
+	}
+
+	/*
+	 * Under PowerVM, FSCR[MSGP] is enabled as guest vCPU siblings are
+	 * gang scheduled on the same physical core, so doorbells are always
+	 * faster than the interrupt controller, and they can be used by
+	 * secure guests.
+	 */
+
+	ic_cause_ipi = smp_ops->cause_ipi;
+	smp_ops->cause_ipi = dbell_or_ic_cause_ipi;
+}
 
-static struct smp_ops_t pSeries_xics_smp_ops = {
+static struct smp_ops_t pseries_smp_ops = {
 	.message_pass	= NULL,	/* Use smp_muxed_ipi_message_pass */
 	.cause_ipi	= NULL,	/* Filled at runtime by pSeries_smp_probe() */
+	.cause_nmi_ipi	= pseries_cause_nmi_ipi,
 	.probe		= pSeries_smp_probe,
+	.prepare_cpu	= pseries_smp_prepare_cpu,
 	.kick_cpu	= smp_pSeries_kick_cpu,
-	.setup_cpu	= smp_xics_setup_cpu,
-	.cpu_bootable	= smp_pSeries_cpu_bootable,
+	.setup_cpu	= smp_setup_cpu,
+	.cpu_bootable	= smp_generic_cpu_bootable,
 };
 
 /* This is called very early */
-static void __init smp_init_pseries(void)
+void __init smp_init_pseries(void)
 {
 	int i;
 
 	pr_debug(" -> smp_init_pSeries()\n");
+	smp_ops = &pseries_smp_ops;
 
 	alloc_bootmem_cpumask_var(&of_spin_mask);
 
-	/* Mark threads which are still spinning in hold loops. */
-	if (cpu_has_feature(CPU_FTR_SMT)) {
-		for_each_present_cpu(i) { 
-			if (cpu_thread_in_core(i) == 0)
-				cpumask_set_cpu(i, of_spin_mask);
-		}
-	} else {
-		cpumask_copy(of_spin_mask, cpu_present_mask);
-	}
-
-	cpumask_clear_cpu(boot_cpuid, of_spin_mask);
-
-	/* Non-lpar has additional take/give timebase */
-	if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) {
-		smp_ops->give_timebase = rtas_give_timebase;
-		smp_ops->take_timebase = rtas_take_timebase;
+	/*
+	 * Mark threads which are still spinning in hold loops
+	 *
+	 * We know prom_init will not have started them if RTAS supports
+	 * query-cpu-stopped-state.
+	 */
+	if (rtas_function_token(RTAS_FN_QUERY_CPU_STOPPED_STATE) == RTAS_UNKNOWN_SERVICE) {
+		if (cpu_has_feature(CPU_FTR_SMT)) {
+			for_each_present_cpu(i) {
+				if (cpu_thread_in_core(i) == 0)
+					cpumask_set_cpu(i, of_spin_mask);
+			}
+		} else
+			cpumask_copy(of_spin_mask, cpu_present_mask);
+
+		cpumask_clear_cpu(boot_cpuid, of_spin_mask);
 	}
 
 	pr_debug(" <- smp_init_pSeries()\n");
 }
-
-void __init smp_init_pseries_mpic(void)
-{
-	smp_ops = &pSeries_mpic_smp_ops;
-
-	smp_init_pseries();
-}
-
-void __init smp_init_pseries_xics(void)
-{
-	smp_ops = &pSeries_xics_smp_ops;
-
-	smp_init_pseries();
-}