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>

3 files changed, 446 insertions, 0 deletions

diff --git a/arch/alpha/math-emu/Makefile b/arch/alpha/math-emu/Makefile
new file mode 100644
index 000000000..3206402a8
--- /dev/null
+++ b/arch/alpha/math-emu/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the FPU instruction emulation.
+#
+
+ccflags-y := -w
+
+obj-$(CONFIG_MATHEMU) += math-emu.o
+
+math-emu-objs := math.o
diff --git a/arch/alpha/math-emu/math.c b/arch/alpha/math-emu/math.c
new file mode 100644
index 000000000..68d420bfd
--- /dev/null
+++ b/arch/alpha/math-emu/math.c
@@ -0,0 +1,400 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <asm/ptrace.h>
+#include <asm/fpu.h>
+
+#include <linux/uaccess.h>
+
+#include "sfp-util.h"
+#include <math-emu/soft-fp.h>
+#include <math-emu/single.h>
+#include <math-emu/double.h>
+
+#define	OPC_PAL		0x00
+#define OPC_INTA	0x10
+#define OPC_INTL	0x11
+#define OPC_INTS	0x12
+#define OPC_INTM	0x13
+#define OPC_FLTC	0x14
+#define OPC_FLTV	0x15
+#define OPC_FLTI	0x16
+#define OPC_FLTL	0x17
+#define OPC_MISC	0x18
+#define	OPC_JSR		0x1a
+
+#define FOP_SRC_S	0
+#define FOP_SRC_T	2
+#define FOP_SRC_Q	3
+
+#define FOP_FNC_ADDx	0
+#define FOP_FNC_CVTQL	0
+#define FOP_FNC_SUBx	1
+#define FOP_FNC_MULx	2
+#define FOP_FNC_DIVx	3
+#define FOP_FNC_CMPxUN	4
+#define FOP_FNC_CMPxEQ	5
+#define FOP_FNC_CMPxLT	6
+#define FOP_FNC_CMPxLE	7
+#define FOP_FNC_SQRTx	11
+#define FOP_FNC_CVTxS	12
+#define FOP_FNC_CVTxT	14
+#define FOP_FNC_CVTxQ	15
+
+#define MISC_TRAPB	0x0000
+#define MISC_EXCB	0x0400
+
+#ifdef MODULE
+
+MODULE_DESCRIPTION("FP Software completion module");
+MODULE_LICENSE("GPL v2");
+
+extern long (*alpha_fp_emul_imprecise)(struct pt_regs *, unsigned long);
+extern long (*alpha_fp_emul) (unsigned long pc);
+
+static long (*save_emul_imprecise)(struct pt_regs *, unsigned long);
+static long (*save_emul) (unsigned long pc);
+
+long do_alpha_fp_emul_imprecise(struct pt_regs *, unsigned long);
+long do_alpha_fp_emul(unsigned long);
+
+static int alpha_fp_emul_init_module(void)
+{
+	save_emul_imprecise = alpha_fp_emul_imprecise;
+	save_emul = alpha_fp_emul;
+	alpha_fp_emul_imprecise = do_alpha_fp_emul_imprecise;
+	alpha_fp_emul = do_alpha_fp_emul;
+	return 0;
+}
+module_init(alpha_fp_emul_init_module);
+
+static void alpha_fp_emul_cleanup_module(void)
+{
+	alpha_fp_emul_imprecise = save_emul_imprecise;
+	alpha_fp_emul = save_emul;
+}
+module_exit(alpha_fp_emul_cleanup_module);
+
+#undef  alpha_fp_emul_imprecise
+#define alpha_fp_emul_imprecise		do_alpha_fp_emul_imprecise
+#undef  alpha_fp_emul
+#define alpha_fp_emul			do_alpha_fp_emul
+
+#endif /* MODULE */
+
+
+/*
+ * Emulate the floating point instruction at address PC.  Returns -1 if the
+ * instruction to be emulated is illegal (such as with the opDEC trap), else
+ * the SI_CODE for a SIGFPE signal, else 0 if everything's ok.
+ *
+ * Notice that the kernel does not and cannot use FP regs.  This is good
+ * because it means that instead of saving/restoring all fp regs, we simply
+ * stick the result of the operation into the appropriate register.
+ */
+long
+alpha_fp_emul (unsigned long pc)
+{
+	FP_DECL_EX;
+	FP_DECL_S(SA); FP_DECL_S(SB); FP_DECL_S(SR);
+	FP_DECL_D(DA); FP_DECL_D(DB); FP_DECL_D(DR);
+
+	unsigned long fa, fb, fc, func, mode, src;
+	unsigned long res, va, vb, vc, swcr, fpcr;
+	__u32 insn;
+	long si_code;
+
+	get_user(insn, (__u32 __user *)pc);
+	fc     = (insn >>  0) & 0x1f;	/* destination register */
+	fb     = (insn >> 16) & 0x1f;
+	fa     = (insn >> 21) & 0x1f;
+	func   = (insn >>  5) & 0xf;
+	src    = (insn >>  9) & 0x3;
+	mode   = (insn >> 11) & 0x3;
+	
+	fpcr = rdfpcr();
+	swcr = swcr_update_status(current_thread_info()->ieee_state, fpcr);
+
+	if (mode == 3) {
+		/* Dynamic -- get rounding mode from fpcr.  */
+		mode = (fpcr >> FPCR_DYN_SHIFT) & 3;
+	}
+
+	switch (src) {
+	case FOP_SRC_S:
+		va = alpha_read_fp_reg_s(fa);
+		vb = alpha_read_fp_reg_s(fb);
+		
+		FP_UNPACK_SP(SA, &va);
+		FP_UNPACK_SP(SB, &vb);
+
+		switch (func) {
+		case FOP_FNC_SUBx:
+			FP_SUB_S(SR, SA, SB);
+			goto pack_s;
+
+		case FOP_FNC_ADDx:
+			FP_ADD_S(SR, SA, SB);
+			goto pack_s;
+
+		case FOP_FNC_MULx:
+			FP_MUL_S(SR, SA, SB);
+			goto pack_s;
+
+		case FOP_FNC_DIVx:
+			FP_DIV_S(SR, SA, SB);
+			goto pack_s;
+
+		case FOP_FNC_SQRTx:
+			FP_SQRT_S(SR, SB);
+			goto pack_s;
+		}
+		goto bad_insn;
+
+	case FOP_SRC_T:
+		va = alpha_read_fp_reg(fa);
+		vb = alpha_read_fp_reg(fb);
+
+		if ((func & ~3) == FOP_FNC_CMPxUN) {
+			FP_UNPACK_RAW_DP(DA, &va);
+			FP_UNPACK_RAW_DP(DB, &vb);
+			if (!DA_e && !_FP_FRAC_ZEROP_1(DA)) {
+				FP_SET_EXCEPTION(FP_EX_DENORM);
+				if (FP_DENORM_ZERO)
+					_FP_FRAC_SET_1(DA, _FP_ZEROFRAC_1);
+			}
+			if (!DB_e && !_FP_FRAC_ZEROP_1(DB)) {
+				FP_SET_EXCEPTION(FP_EX_DENORM);
+				if (FP_DENORM_ZERO)
+					_FP_FRAC_SET_1(DB, _FP_ZEROFRAC_1);
+			}
+			FP_CMP_D(res, DA, DB, 3);
+			vc = 0x4000000000000000UL;
+			/* CMPTEQ, CMPTUN don't trap on QNaN,
+			   while CMPTLT and CMPTLE do */
+			if (res == 3
+			    && ((func & 3) >= 2
+				|| FP_ISSIGNAN_D(DA)
+				|| FP_ISSIGNAN_D(DB))) {
+				FP_SET_EXCEPTION(FP_EX_INVALID);
+			}
+			switch (func) {
+			case FOP_FNC_CMPxUN: if (res != 3) vc = 0; break;
+			case FOP_FNC_CMPxEQ: if (res) vc = 0; break;
+			case FOP_FNC_CMPxLT: if (res != -1) vc = 0; break;
+			case FOP_FNC_CMPxLE: if ((long)res > 0) vc = 0; break;
+			}
+			goto done_d;
+		}
+
+		FP_UNPACK_DP(DA, &va);
+		FP_UNPACK_DP(DB, &vb);
+
+		switch (func) {
+		case FOP_FNC_SUBx:
+			FP_SUB_D(DR, DA, DB);
+			goto pack_d;
+
+		case FOP_FNC_ADDx:
+			FP_ADD_D(DR, DA, DB);
+			goto pack_d;
+
+		case FOP_FNC_MULx:
+			FP_MUL_D(DR, DA, DB);
+			goto pack_d;
+
+		case FOP_FNC_DIVx:
+			FP_DIV_D(DR, DA, DB);
+			goto pack_d;
+
+		case FOP_FNC_SQRTx:
+			FP_SQRT_D(DR, DB);
+			goto pack_d;
+
+		case FOP_FNC_CVTxS:
+			/* It is irritating that DEC encoded CVTST with
+			   SRC == T_floating.  It is also interesting that
+			   the bit used to tell the two apart is /U... */
+			if (insn & 0x2000) {
+				FP_CONV(S,D,1,1,SR,DB);
+				goto pack_s;
+			} else {
+				vb = alpha_read_fp_reg_s(fb);
+				FP_UNPACK_SP(SB, &vb);
+				DR_c = DB_c;
+				DR_s = DB_s;
+				DR_e = DB_e + (1024 - 128);
+				DR_f = SB_f << (52 - 23);
+				goto pack_d;
+			}
+
+		case FOP_FNC_CVTxQ:
+			if (DB_c == FP_CLS_NAN
+			    && (_FP_FRAC_HIGH_RAW_D(DB) & _FP_QNANBIT_D)) {
+			  /* AAHB Table B-2 says QNaN should not trigger INV */
+				vc = 0;
+			} else
+				FP_TO_INT_ROUND_D(vc, DB, 64, 2);
+			goto done_d;
+		}
+		goto bad_insn;
+
+	case FOP_SRC_Q:
+		vb = alpha_read_fp_reg(fb);
+
+		switch (func) {
+		case FOP_FNC_CVTQL:
+			/* Notice: We can get here only due to an integer
+			   overflow.  Such overflows are reported as invalid
+			   ops.  We return the result the hw would have
+			   computed.  */
+			vc = ((vb & 0xc0000000) << 32 |	/* sign and msb */
+			      (vb & 0x3fffffff) << 29);	/* rest of the int */
+			FP_SET_EXCEPTION (FP_EX_INVALID);
+			goto done_d;
+
+		case FOP_FNC_CVTxS:
+			FP_FROM_INT_S(SR, ((long)vb), 64, long);
+			goto pack_s;
+
+		case FOP_FNC_CVTxT:
+			FP_FROM_INT_D(DR, ((long)vb), 64, long);
+			goto pack_d;
+		}
+		goto bad_insn;
+	}
+	goto bad_insn;
+
+pack_s:
+	FP_PACK_SP(&vc, SR);
+	if ((_fex & FP_EX_UNDERFLOW) && (swcr & IEEE_MAP_UMZ))
+		vc = 0;
+	alpha_write_fp_reg_s(fc, vc);
+	goto done;
+
+pack_d:
+	FP_PACK_DP(&vc, DR);
+	if ((_fex & FP_EX_UNDERFLOW) && (swcr & IEEE_MAP_UMZ))
+		vc = 0;
+done_d:
+	alpha_write_fp_reg(fc, vc);
+	goto done;
+
+	/*
+	 * Take the appropriate action for each possible
+	 * floating-point result:
+	 *
+	 *	- Set the appropriate bits in the FPCR
+	 *	- If the specified exception is enabled in the FPCR,
+	 *	  return.  The caller (entArith) will dispatch
+	 *	  the appropriate signal to the translated program.
+	 *
+	 * In addition, properly track the exception state in software
+	 * as described in the Alpha Architecture Handbook section 4.7.7.3.
+	 */
+done:
+	if (_fex) {
+		/* Record exceptions in software control word.  */
+		swcr |= (_fex << IEEE_STATUS_TO_EXCSUM_SHIFT);
+		current_thread_info()->ieee_state
+		  |= (_fex << IEEE_STATUS_TO_EXCSUM_SHIFT);
+
+		/* Update hardware control register.  */
+		fpcr &= (~FPCR_MASK | FPCR_DYN_MASK);
+		fpcr |= ieee_swcr_to_fpcr(swcr);
+		wrfpcr(fpcr);
+
+		/* Do we generate a signal?  */
+		_fex = _fex & swcr & IEEE_TRAP_ENABLE_MASK;
+		si_code = 0;
+		if (_fex) {
+			if (_fex & IEEE_TRAP_ENABLE_DNO) si_code = FPE_FLTUND;
+			if (_fex & IEEE_TRAP_ENABLE_INE) si_code = FPE_FLTRES;
+			if (_fex & IEEE_TRAP_ENABLE_UNF) si_code = FPE_FLTUND;
+			if (_fex & IEEE_TRAP_ENABLE_OVF) si_code = FPE_FLTOVF;
+			if (_fex & IEEE_TRAP_ENABLE_DZE) si_code = FPE_FLTDIV;
+			if (_fex & IEEE_TRAP_ENABLE_INV) si_code = FPE_FLTINV;
+		}
+
+		return si_code;
+	}
+
+	/* We used to write the destination register here, but DEC FORTRAN
+	   requires that the result *always* be written... so we do the write
+	   immediately after the operations above.  */
+
+	return 0;
+
+bad_insn:
+	printk(KERN_ERR "alpha_fp_emul: Invalid FP insn %#x at %#lx\n",
+	       insn, pc);
+	return -1;
+}
+
+long
+alpha_fp_emul_imprecise (struct pt_regs *regs, unsigned long write_mask)
+{
+	unsigned long trigger_pc = regs->pc - 4;
+	unsigned long insn, opcode, rc, si_code = 0;
+
+	/*
+	 * Turn off the bits corresponding to registers that are the
+	 * target of instructions that set bits in the exception
+	 * summary register.  We have some slack doing this because a
+	 * register that is the target of a trapping instruction can
+	 * be written at most once in the trap shadow.
+	 *
+	 * Branches, jumps, TRAPBs, EXCBs and calls to PALcode all
+	 * bound the trap shadow, so we need not look any further than
+	 * up to the first occurrence of such an instruction.
+	 */
+	while (write_mask) {
+		get_user(insn, (__u32 __user *)(trigger_pc));
+		opcode = insn >> 26;
+		rc = insn & 0x1f;
+
+		switch (opcode) {
+		      case OPC_PAL:
+		      case OPC_JSR:
+		      case 0x30 ... 0x3f:	/* branches */
+			goto egress;
+
+		      case OPC_MISC:
+			switch (insn & 0xffff) {
+			      case MISC_TRAPB:
+			      case MISC_EXCB:
+				goto egress;
+
+			      default:
+				break;
+			}
+			break;
+
+		      case OPC_INTA:
+		      case OPC_INTL:
+		      case OPC_INTS:
+		      case OPC_INTM:
+			write_mask &= ~(1UL << rc);
+			break;
+
+		      case OPC_FLTC:
+		      case OPC_FLTV:
+		      case OPC_FLTI:
+		      case OPC_FLTL:
+			write_mask &= ~(1UL << (rc + 32));
+			break;
+		}
+		if (!write_mask) {
+			/* Re-execute insns in the trap-shadow.  */
+			regs->pc = trigger_pc + 4;
+			si_code = alpha_fp_emul(trigger_pc);
+			goto egress;
+		}
+		trigger_pc -= 4;
+	}
+
+egress:
+	return si_code;
+}
diff --git a/arch/alpha/math-emu/sfp-util.h b/arch/alpha/math-emu/sfp-util.h
new file mode 100644
index 000000000..ae30f3417
--- /dev/null
+++ b/arch/alpha/math-emu/sfp-util.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <asm/byteorder.h>
+#include <asm/fpu.h>
+
+#define add_ssaaaa(sh, sl, ah, al, bh, bl) \
+  ((sl) = (al) + (bl), (sh) = (ah) + (bh) + ((sl) < (al)))
+
+#define sub_ddmmss(sh, sl, ah, al, bh, bl) \
+  ((sl) = (al) - (bl), (sh) = (ah) - (bh) - ((al) < (bl)))
+
+#define umul_ppmm(wh, wl, u, v)			\
+  __asm__ ("mulq %2,%3,%1; umulh %2,%3,%0"	\
+	   : "=r" ((UDItype)(wh)),		\
+	     "=&r" ((UDItype)(wl))		\
+	   : "r" ((UDItype)(u)),		\
+	     "r" ((UDItype)(v)))
+
+#define udiv_qrnnd(q, r, n1, n0, d)				\
+  do { unsigned long __r;					\
+    (q) = __udiv_qrnnd (&__r, (n1), (n0), (d));			\
+    (r) = __r;							\
+  } while (0)
+extern unsigned long __udiv_qrnnd (unsigned long *, unsigned long,
+				   unsigned long , unsigned long);
+
+#define UDIV_NEEDS_NORMALIZATION 1  
+
+#define abort()			goto bad_insn
+
+#ifndef __LITTLE_ENDIAN
+#define __LITTLE_ENDIAN -1
+#endif
+#define __BYTE_ORDER __LITTLE_ENDIAN