Merge tag 'for-5.18/parisc-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

Pull more parisc architecture updates from Helge Deller:

 - Revert a patch to the invalidate/flush vmap routines which broke
   kernel patching functions on older PA-RISC machines.

 - Fix the kernel patching code wrt locking and flushing. Works now on
   B160L machine as well.

 - Fix CPU IRQ affinity for LASI, WAX and Dino chips

 - Add CPU hotplug support

 - Detect the hppa-suse-linux-gcc compiler when cross-compiling

* tag 'for-5.18/parisc-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix patch code locking and flushing
  parisc: Find a new timesync master if current CPU is removed
  parisc: Move common_stext into .text section when CONFIG_HOTPLUG_CPU=y
  parisc: Rewrite arch_cpu_idle_dead() for CPU hotplugging
  parisc: Implement __cpu_die() and __cpu_disable() for CPU hotplugging
  parisc: Add PDC locking functions for rendezvous code
  parisc: Move disable_sr_hashing_asm() into .text section
  parisc: Move CPU startup-related functions into .text section
  parisc: Move store_cpu_topology() into text section
  parisc: Switch from GENERIC_CPU_DEVICES to GENERIC_ARCH_TOPOLOGY
  parisc: Ensure set_firmware_width() is called only once
  parisc: Add constants for control registers and clean up mfctl()
  parisc: Detect hppa-suse-linux-gcc compiler for cross-building
  parisc: Clean up cpu_check_affinity() and drop cpu_set_affinity_irq()
  parisc: Fix CPU affinity for Lasi, WAX and Dino chips
  Revert "parisc: Fix invalidate/flush vmap routines"

1 files changed, 24 insertions, 3 deletions

diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index 2030c77592d3..28b6a2a5574c 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -38,6 +38,7 @@
 #include <linux/rcupdate.h>
 #include <linux/random.h>
 #include <linux/nmi.h>
+#include <linux/sched/hotplug.h>
 
 #include <asm/io.h>
 #include <asm/asm-offsets.h>
@@ -46,6 +47,7 @@
 #include <asm/pdc_chassis.h>
 #include <asm/unwind.h>
 #include <asm/sections.h>
+#include <asm/cacheflush.h>
 
 #define COMMAND_GLOBAL  F_EXTEND(0xfffe0030)
 #define CMD_RESET       5       /* reset any module */
@@ -158,10 +160,29 @@ void release_thread(struct task_struct *dead_task)
 int running_on_qemu __ro_after_init;
 EXPORT_SYMBOL(running_on_qemu);
 
-void __cpuidle arch_cpu_idle_dead(void)
+/*
+ * Called from the idle thread for the CPU which has been shutdown.
+ */
+void arch_cpu_idle_dead(void)
 {
-	/* nop on real hardware, qemu will offline CPU. */
-	asm volatile("or %%r31,%%r31,%%r31\n":::);
+#ifdef CONFIG_HOTPLUG_CPU
+	idle_task_exit();
+
+	local_irq_disable();
+
+	/* Tell __cpu_die() that this CPU is now safe to dispose of. */
+	(void)cpu_report_death();
+
+	/* Ensure that the cache lines are written out. */
+	flush_cache_all_local();
+	flush_tlb_all_local(NULL);
+
+	/* Let PDC firmware put CPU into firmware idle loop. */
+	__pdc_cpu_rendezvous();
+
+	pr_warn("PDC does not provide rendezvous function.\n");
+#endif
+	while (1);
 }
 
 void __cpuidle arch_cpu_idle(void)