extern const struct cpu_operations *cpu_ops[NR_CPUS];
void __init cpu_set_ops(int cpu);
-void cpu_update_secondary_bootdata(unsigned int cpuid,
- struct task_struct *tidle);
#endif /* ifndef __ASM_CPU_OPS_H */
#include <linux/of.h>
#include <linux/string.h>
#include <linux/sched.h>
-#include <linux/sched/task_stack.h>
#include <asm/cpu_ops.h>
#include <asm/sbi.h>
#include <asm/smp.h>
const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;
-void *__cpu_up_stack_pointer[NR_CPUS] __section(".data");
-void *__cpu_up_task_pointer[NR_CPUS] __section(".data");
-
extern const struct cpu_operations cpu_ops_sbi;
extern const struct cpu_operations cpu_ops_spinwait;
-void cpu_update_secondary_bootdata(unsigned int cpuid,
- struct task_struct *tidle)
-{
- int hartid = cpuid_to_hartid_map(cpuid);
-
- /* Make sure tidle is updated */
- smp_mb();
- WRITE_ONCE(__cpu_up_stack_pointer[hartid],
- task_stack_page(tidle) + THREAD_SIZE);
- WRITE_ONCE(__cpu_up_task_pointer[hartid], tidle);
-}
-
void __init cpu_set_ops(int cpuid)
{
#if IS_ENABLED(CONFIG_RISCV_SBI)
#include <linux/errno.h>
#include <linux/of.h>
#include <linux/string.h>
+#include <linux/sched/task_stack.h>
#include <asm/cpu_ops.h>
#include <asm/sbi.h>
#include <asm/smp.h>
const struct cpu_operations cpu_ops_spinwait;
+void *__cpu_spinwait_stack_pointer[NR_CPUS] __section(".data");
+void *__cpu_spinwait_task_pointer[NR_CPUS] __section(".data");
+
+static void cpu_update_secondary_bootdata(unsigned int cpuid,
+ struct task_struct *tidle)
+{
+ int hartid = cpuid_to_hartid_map(cpuid);
+
+ /*
+ * The hartid must be less than NR_CPUS to avoid out-of-bound access
+ * errors for __cpu_spinwait_stack/task_pointer. That is not always possible
+ * for platforms with discontiguous hartid numbering scheme. That's why
+ * spinwait booting is not the recommended approach for any platforms
+ * booting Linux in S-mode and can be disabled in the future.
+ */
+ if (hartid == INVALID_HARTID || hartid >= NR_CPUS)
+ return;
+
+ /* Make sure tidle is updated */
+ smp_mb();
+ WRITE_ONCE(__cpu_spinwait_stack_pointer[hartid],
+ task_stack_page(tidle) + THREAD_SIZE);
+ WRITE_ONCE(__cpu_spinwait_task_pointer[hartid], tidle);
+}
static int spinwait_cpu_prepare(unsigned int cpuid)
{
* selects the first cpu to boot the kernel and causes the remainder
* of the cpus to spin in a loop waiting for their stack pointer to be
* setup by that main cpu. Writing to bootdata
- * (i.e __cpu_up_stack_pointer) signals to the spinning cpus that they
+ * (i.e __cpu_spinwait_stack_pointer) signals to the spinning cpus that they
* can continue the boot process.
*/
cpu_update_secondary_bootdata(cpuid, tidle);
csrw CSR_TVEC, a3
slli a3, a0, LGREG
- la a1, __cpu_up_stack_pointer
+ la a1, __cpu_spinwait_stack_pointer
XIP_FIXUP_OFFSET a1
- la a2, __cpu_up_task_pointer
+ la a2, __cpu_spinwait_task_pointer
XIP_FIXUP_OFFSET a2
add a1, a3, a1
add a2, a3, a2
asmlinkage void __init __copy_data(void);
#endif
-extern void *__cpu_up_stack_pointer[];
-extern void *__cpu_up_task_pointer[];
+extern void *__cpu_spinwait_stack_pointer[];
+extern void *__cpu_spinwait_task_pointer[];
#endif /* __ASM_HEAD_H */