Patchwork [1/2] powerpc: Add smp_generic_cpu_bootable

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Submitter Andy Fleming
Date July 25, 2013, 10:02 p.m.
Message ID <1374789726-10633-1-git-send-email-afleming@freescale.com>
Download mbox | patch
Permalink /patch/261971/
State Superseded
Headers show

Comments

Andy Fleming - July 25, 2013, 10:02 p.m.
Cell and PSeries both implemented their own versions of a
cpu_bootable smp_op which do the same thing (well, the PSeries
one has support for more than 2 threads). Copy the PSeries one
to generic code, and rename it smp_generic_cpu_bootable.

Signed-off-by: Andy Fleming <afleming@freescale.com>
---
 arch/powerpc/include/asm/smp.h |    2 ++
 arch/powerpc/kernel/smp.c      |   23 +++++++++++++++++++++++
 2 files changed, 25 insertions(+)

Patch

diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index ffbaabe..f2b5d41 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -182,6 +182,8 @@  extern int smt_enabled_at_boot;
 extern int smp_mpic_probe(void);
 extern void smp_mpic_setup_cpu(int cpu);
 extern int smp_generic_kick_cpu(int nr);
+extern int smp_generic_cpu_bootable(unsigned int nr);
+
 
 extern void smp_generic_give_timebase(void);
 extern void smp_generic_take_timebase(void);
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 38b0ba6..3cd42aa 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -81,6 +81,29 @@  int smt_enabled_at_boot = 1;
 
 static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
 
+/*
+ * Returns 1 if the specified cpu should be brought up during boot.
+ * Used to inhibit booting threads if they've been disabled or
+ * limited on the command line
+ */
+int smp_generic_cpu_bootable(unsigned int nr)
+{
+	/* 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;
+}
+EXPORT_SYMBOL(smp_generic_cpu_bootable);
+
+
 #ifdef CONFIG_PPC64
 int smp_generic_kick_cpu(int nr)
 {