MIPS: SMP: Update cpu_foreign_map on CPU disable

BugLink: https://bugs.launchpad.net/bugs/1878232

commit 826e99be upstream.

When a CPU is disabled via CPU hotplug, cpu_foreign_map is not updated.
This could result in cache management SMP calls being sent to offline
CPUs instead of online siblings in the same core.

Add a call to calculate_cpu_foreign_map() in the various MIPS cpu
disable callbacks after set_cpu_online(). All cases are updated for
consistency and to keep cpu_foreign_map strictly up to date, not just
those which may support hardware multithreading.

Fixes: cccf34e9 ("MIPS: c-r4k: Fix cache flushing for MT cores")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Hongliang Tao <taohl@lemote.com>
Cc: Hua Yan <yanh@lemote.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13799/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ian May <ian.may@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/mips/cavium-octeon/smp.c

@@ -239,6 +239,7 @@ static int octeon_cpu_disable(void)
 		return -ENOTSUPP;
 
 	set_cpu_online(cpu, false);
+	calculate_cpu_foreign_map();
 	cpumask_clear_cpu(cpu, &cpu_callin_map);
 	octeon_fixup_irqs();
 

arch/mips/include/asm/smp.h

@@ -63,6 +63,8 @@ extern cpumask_t cpu_coherent_mask;
 
 extern void asmlinkage smp_bootstrap(void);
 
+extern void calculate_cpu_foreign_map(void);
+
 /*
  * this function sends a 'reschedule' IPI to another CPU.
  * it goes straight through and wastes no time serializing

arch/mips/kernel/smp-bmips.c

@@ -362,6 +362,7 @@ static int bmips_cpu_disable(void)
 	pr_info("SMP: CPU%d is offline\n", cpu);
 
 	set_cpu_online(cpu, false);
+	calculate_cpu_foreign_map();
 	cpumask_clear_cpu(cpu, &cpu_callin_map);
 	clear_c0_status(IE_IRQ5);
 

arch/mips/kernel/smp-cps.c

@@ -338,6 +338,7 @@ static int cps_cpu_disable(void)
 	atomic_sub(1 << cpu_vpe_id(&current_cpu_data), &core_cfg->vpe_mask);
 	smp_mb__after_atomic();
 	set_cpu_online(cpu, false);
+	calculate_cpu_foreign_map();
 	cpumask_clear_cpu(cpu, &cpu_callin_map);
 
 	return 0;

arch/mips/kernel/smp.c

@@ -118,7 +118,7 @@ static inline void set_cpu_core_map(int cpu)
  * Calculate a new cpu_foreign_map mask whenever a
  * new cpu appears or disappears.
  */
-static inline void calculate_cpu_foreign_map(void)
+void calculate_cpu_foreign_map(void)
 {
 	int i, k, core_present;
 	cpumask_t temp_foreign_map;

arch/mips/loongson64/loongson-3/smp.c

@@ -417,6 +417,7 @@ static int loongson3_cpu_disable(void)
 		return -EBUSY;
 
 	set_cpu_online(cpu, false);
+	calculate_cpu_foreign_map();
 	cpumask_clear_cpu(cpu, &cpu_callin_map);
 	local_irq_save(flags);
 	fixup_irqs();