ARM: SoC: add per-platform SMP operations
This adds a 'struct smp_operations' to abstract the CPU initialization
and hot plugging functions on SMP systems, which otherwise conflict
in a multiplatform kernel. This also helps shmobile and potentially
others that have more than one method to do these.
To allow the kernel to continue building, the platform hooks are
defined as weak symbols which are overrided by the platform code.
Once all platforms are converted, the "weak" attribute will be
removed and the function made static.
Unlike the original version from Marc, this new version from Arnd
does not use a generalized abstraction for per-soc data structures
but only tries to solve the problem for the SMP operations. This
way, we can collapse the previous four data structures into a
single struct, which is less systematic but also easier to follow
as a causal reader.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/arm/include/asm/mach/arch.h b/arch/arm/include/asm/mach/arch.h
index 0b1c94b..917d4fc 100644
--- a/arch/arm/include/asm/mach/arch.h
+++ b/arch/arm/include/asm/mach/arch.h
@@ -14,6 +14,12 @@
struct meminfo;
struct sys_timer;
struct pt_regs;
+struct smp_operations;
+#ifdef CONFIG_SMP
+#define smp_ops(ops) (&(ops))
+#else
+#define smp_ops(ops) (struct smp_operations *)NULL
+#endif
struct machine_desc {
unsigned int nr; /* architecture number */
@@ -35,6 +41,7 @@
unsigned char reserve_lp1 :1; /* never has lp1 */
unsigned char reserve_lp2 :1; /* never has lp2 */
char restart_mode; /* default restart mode */
+ struct smp_operations *smp; /* SMP operations */
void (*fixup)(struct tag *, char **,
struct meminfo *);
void (*reserve)(void);/* reserve mem blocks */
diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h
index ae29293..f79a9f5 100644
--- a/arch/arm/include/asm/smp.h
+++ b/arch/arm/include/asm/smp.h
@@ -93,4 +93,37 @@
extern void arch_send_call_function_single_ipi(int cpu);
extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
+struct smp_operations {
+#ifdef CONFIG_SMP
+ /*
+ * Setup the set of possible CPUs (via set_cpu_possible)
+ */
+ void (*smp_init_cpus)(void);
+ /*
+ * Initialize cpu_possible map, and enable coherency
+ */
+ void (*smp_prepare_cpus)(unsigned int max_cpus);
+
+ /*
+ * Perform platform specific initialisation of the specified CPU.
+ */
+ void (*smp_secondary_init)(unsigned int cpu);
+ /*
+ * Boot a secondary CPU, and assign it the specified idle task.
+ * This also gives us the initial stack to use for this CPU.
+ */
+ int (*smp_boot_secondary)(unsigned int cpu, struct task_struct *idle);
+#ifdef CONFIG_HOTPLUG_CPU
+ int (*cpu_kill)(unsigned int cpu);
+ void (*cpu_die)(unsigned int cpu);
+ int (*cpu_disable)(unsigned int cpu);
+#endif
+#endif
+};
+
+/*
+ * set platform specific SMP operations
+ */
+extern void smp_set_ops(struct smp_operations *);
+
#endif /* ifndef __ASM_ARM_SMP_H */