scftorture: Count single_rpc offline failures in statistics outputgrafted

scf_torture_stats_print() aggregates each invoker thread's counters
into a local scf_statistics structure before printing, but the
n_single_rpc_ofl field is missing from the aggregation loop.  As a
result, the "single_rpc_ofl" value printed in the statistics line is
always zero, even when smp_call_function_single() invocations for the
RPC test have failed due to offline CPUs and been counted by the
invoker threads.

Add the missing accumulation so that the printed value reflects the
actual counts.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

1 files changed, 115 insertions, 0 deletions

diff --git a/include/asm-generic/cmpxchg.h b/include/asm-generic/cmpxchg.h
new file mode 100644
index 000000000..848de25fc
--- /dev/null
+++ b/include/asm-generic/cmpxchg.h
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Generic UP xchg and cmpxchg using interrupt disablement.  Does not
+ * support SMP.
+ */
+
+#ifndef __ASM_GENERIC_CMPXCHG_H
+#define __ASM_GENERIC_CMPXCHG_H
+
+#ifdef CONFIG_SMP
+#error "Cannot use generic cmpxchg on SMP"
+#endif
+
+#include <linux/types.h>
+#include <linux/irqflags.h>
+
+/*
+ * This function doesn't exist, so you'll get a linker error if
+ * something tries to do an invalidly-sized xchg().
+ */
+extern void __generic_xchg_called_with_bad_pointer(void);
+
+static inline
+unsigned long __generic_xchg(unsigned long x, volatile void *ptr, int size)
+{
+	unsigned long ret, flags;
+
+	switch (size) {
+	case 1:
+#ifdef __xchg_u8
+		return __xchg_u8(x, ptr);
+#else
+		local_irq_save(flags);
+		ret = *(volatile u8 *)ptr;
+		*(volatile u8 *)ptr = (x & 0xffu);
+		local_irq_restore(flags);
+		return ret;
+#endif /* __xchg_u8 */
+
+	case 2:
+#ifdef __xchg_u16
+		return __xchg_u16(x, ptr);
+#else
+		local_irq_save(flags);
+		ret = *(volatile u16 *)ptr;
+		*(volatile u16 *)ptr = (x & 0xffffu);
+		local_irq_restore(flags);
+		return ret;
+#endif /* __xchg_u16 */
+
+	case 4:
+#ifdef __xchg_u32
+		return __xchg_u32(x, ptr);
+#else
+		local_irq_save(flags);
+		ret = *(volatile u32 *)ptr;
+		*(volatile u32 *)ptr = (x & 0xffffffffu);
+		local_irq_restore(flags);
+		return ret;
+#endif /* __xchg_u32 */
+
+#ifdef CONFIG_64BIT
+	case 8:
+#ifdef __xchg_u64
+		return __xchg_u64(x, ptr);
+#else
+		local_irq_save(flags);
+		ret = *(volatile u64 *)ptr;
+		*(volatile u64 *)ptr = x;
+		local_irq_restore(flags);
+		return ret;
+#endif /* __xchg_u64 */
+#endif /* CONFIG_64BIT */
+
+	default:
+		__generic_xchg_called_with_bad_pointer();
+		return x;
+	}
+}
+
+#define generic_xchg(ptr, x) ({							\
+	((__typeof__(*(ptr)))							\
+		__generic_xchg((unsigned long)(x), (ptr), sizeof(*(ptr))));	\
+})
+
+/*
+ * Atomic compare and exchange.
+ */
+#include <asm-generic/cmpxchg-local.h>
+
+#define generic_cmpxchg_local(ptr, o, n) ({					\
+	((__typeof__(*(ptr)))__generic_cmpxchg_local((ptr), (unsigned long)(o),	\
+			(unsigned long)(n), sizeof(*(ptr))));			\
+})
+
+#define generic_cmpxchg64_local(ptr, o, n) \
+	__generic_cmpxchg64_local((ptr), (o), (n))
+
+
+#ifndef arch_xchg
+#define arch_xchg		generic_xchg
+#endif
+
+#ifndef arch_cmpxchg_local
+#define arch_cmpxchg_local	generic_cmpxchg_local
+#endif
+
+#ifndef arch_cmpxchg64_local
+#define arch_cmpxchg64_local	generic_cmpxchg64_local
+#endif
+
+#define arch_cmpxchg		arch_cmpxchg_local
+#define arch_cmpxchg64		arch_cmpxchg64_local
+
+#endif /* __ASM_GENERIC_CMPXCHG_H */