Merge tag 'riscv-for-linus-4.20-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

Pull RISC-V updates from Palmer Dabbelt:
 "This patch set contains a lot (at least, for me) of improvements to
  the RISC-V kernel port:

   - The removal of some cacheinfo values that were bogus.

   - On systems with F but without D the kernel will not show the F
     extension to userspace, as it isn't actually supported.

   - Support for futexes.

   - Removal of some unused code.

   - Cleanup of some menuconfig entries.

   - Support for systems without a floating-point unit, and for building
     kernels that will never use the floating-point unit.

   - More fixes to the RV32I port, which regressed again. It's really
     time to get this into a regression test somewhere so I stop
     breaking it. Thanks to Zong for resurrecting it again!

   - Various fixes that resulted from a year old review of our original
     patch set that I finally got around to.

   - Various improvements to SMP support, largely based around having
     switched to logical hart numbering, as well as some interrupt
     improvements. This one is in the same patch set as above, thanks to
     Atish for sheparding everything though as my patch set was a bit of
     a mess.

  I'm pretty sure this is our largest patch set since the original
  kernel contribution, and it's certainly the one with the most
  contributors. While I don't have anything else I know I'm going to
  submit for the merge window, I would be somewhat surprised if I didn't
  screw anything up.

  Thanks for the help, everyone!"

* tag 'riscv-for-linus-4.20-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux: (31 commits)
  RISC-V: Cosmetic menuconfig changes
  riscv: move GCC version check for ARCH_SUPPORTS_INT128 to Kconfig
  RISC-V: remove the unused return_to_handler export
  RISC-V: Add futex support.
  RISC-V: Add FP register ptrace support for gdb.
  RISC-V: Mask out the F extension on systems without D
  RISC-V: Don't set cacheinfo.{physical_line_partition,attributes}
  RISC-V: Show IPI stats
  RISC-V: Show CPU ID and Hart ID separately in /proc/cpuinfo
  RISC-V: Use Linux logical CPU number instead of hartid
  RISC-V: Add logical CPU indexing for RISC-V
  RISC-V: Use WRITE_ONCE instead of direct access
  RISC-V: Use mmgrab()
  RISC-V: Rename im_okay_therefore_i_am to found_boot_cpu
  RISC-V: Rename riscv_of_processor_hart to riscv_of_processor_hartid
  RISC-V: Provide a cleaner raw_smp_processor_id()
  RISC-V: Disable preemption before enabling interrupts
  RISC-V: Comment on the TLB flush in smp_callin()
  RISC-V: Filter ISA and MMU values in cpuinfo
  RISC-V: Don't set cacheinfo.{physical_line_partition,attributes}
  ...

4 files changed, 346 insertions, 0 deletions

diff --git a/lib/Kconfig b/lib/Kconfig
index a3928d4438b5..d82f20609939 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -621,3 +621,6 @@ config GENERIC_LIB_CMPDI2
 
 config GENERIC_LIB_UCMPDI2
 	bool
+
+config GENERIC_LIB_UMODDI3
+	bool
diff --git a/lib/Makefile b/lib/Makefile
index 423876446810..56a8d9c23ef3 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -270,3 +270,4 @@ obj-$(CONFIG_GENERIC_LIB_LSHRDI3) += lshrdi3.o
 obj-$(CONFIG_GENERIC_LIB_MULDI3) += muldi3.o
 obj-$(CONFIG_GENERIC_LIB_CMPDI2) += cmpdi2.o
 obj-$(CONFIG_GENERIC_LIB_UCMPDI2) += ucmpdi2.o
+obj-$(CONFIG_GENERIC_LIB_UMODDI3) += umoddi3.o udivmoddi4.o
diff --git a/lib/udivmoddi4.c b/lib/udivmoddi4.c
new file mode 100644
index 000000000000..c08bc8a5f1cf
--- /dev/null
+++ b/lib/udivmoddi4.c
@@ -0,0 +1,310 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.
+ */
+
+#include <linux/libgcc.h>
+
+#define count_leading_zeros(COUNT, X)   ((COUNT) = __builtin_clz(X))
+
+#define W_TYPE_SIZE 32
+
+#define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2))
+#define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1))
+#define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2))
+
+/* If we still don't have umul_ppmm, define it using plain C. */
+#if !defined(umul_ppmm)
+#define umul_ppmm(w1, w0, u, v)						\
+	do {								\
+		unsigned long __x0, __x1, __x2, __x3;			\
+		unsigned short __ul, __vl, __uh, __vh;			\
+									\
+		__ul = __ll_lowpart(u);					\
+		__uh = __ll_highpart(u);				\
+		__vl = __ll_lowpart(v);					\
+		__vh = __ll_highpart(v);				\
+									\
+		__x0 = (unsigned long) __ul * __vl;			\
+		__x1 = (unsigned long) __ul * __vh;			\
+		__x2 = (unsigned long) __uh * __vl;			\
+		__x3 = (unsigned long) __uh * __vh;			\
+									\
+		__x1 += __ll_highpart(__x0);				\
+		__x1 += __x2;						\
+		if (__x1 < __x2)					\
+			__x3 += __ll_B;					\
+									\
+		(w1) = __x3 + __ll_highpart(__x1);			\
+		(w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
+	} while (0)
+#endif
+
+#if !defined(sub_ddmmss)
+#define sub_ddmmss(sh, sl, ah, al, bh, bl)				\
+	do {								\
+		unsigned long __x;					\
+		__x = (al) - (bl);					\
+		(sh) = (ah) - (bh) - (__x > (al));			\
+		(sl) = __x;						\
+	} while (0)
+#endif
+
+/* Define this unconditionally, so it can be used for debugging. */
+#define __udiv_qrnnd_c(q, r, n1, n0, d)					\
+	do {								\
+		unsigned long __d1, __d0, __q1, __q0;			\
+		unsigned long __r1, __r0, __m;				\
+		__d1 = __ll_highpart(d);				\
+		__d0 = __ll_lowpart(d);				\
+									\
+		__r1 = (n1) % __d1;					\
+		__q1 = (n1) / __d1;					\
+		__m = (unsigned long) __q1 * __d0;			\
+		__r1 = __r1 * __ll_B | __ll_highpart(n0);		\
+		if (__r1 < __m) {					\
+			__q1--, __r1 += (d);				\
+			if (__r1 >= (d))				\
+				if (__r1 < __m)				\
+					__q1--, __r1 += (d);		\
+		}							\
+		__r1 -= __m;						\
+									\
+		__r0 = __r1 % __d1;					\
+		__q0 = __r1 / __d1;					\
+		__m = (unsigned long) __q0 * __d0;			\
+		__r0 = __r0 * __ll_B | __ll_lowpart(n0);		\
+		if (__r0 < __m) {					\
+			__q0--, __r0 += (d);				\
+			if (__r0 >= (d))				\
+				if (__r0 < __m)				\
+					__q0--, __r0 += (d);		\
+		}							\
+		__r0 -= __m;						\
+									\
+		(q) = (unsigned long) __q1 * __ll_B | __q0;		\
+		(r) = __r0;						\
+	} while (0)
+
+/* If udiv_qrnnd was not defined for this processor, use __udiv_qrnnd_c. */
+#if !defined(udiv_qrnnd)
+#define UDIV_NEEDS_NORMALIZATION 1
+#define udiv_qrnnd __udiv_qrnnd_c
+#endif
+
+unsigned long long __udivmoddi4(unsigned long long u, unsigned long long v,
+				unsigned long long *rp)
+{
+	const DWunion nn = {.ll = u };
+	const DWunion dd = {.ll = v };
+	DWunion rr, ww;
+	unsigned long d0, d1, n0, n1, n2;
+	unsigned long q0 = 0, q1 = 0;
+	unsigned long b, bm;
+
+	d0 = dd.s.low;
+	d1 = dd.s.high;
+	n0 = nn.s.low;
+	n1 = nn.s.high;
+
+#if !UDIV_NEEDS_NORMALIZATION
+
+	if (d1 == 0) {
+		if (d0 > n1) {
+			/* 0q = nn / 0D */
+
+			udiv_qrnnd(q0, n0, n1, n0, d0);
+			q1 = 0;
+
+			/* Remainder in n0. */
+		} else {
+			/* qq = NN / 0d */
+
+			if (d0 == 0)
+				/* Divide intentionally by zero. */
+				d0 = 1 / d0;
+
+			udiv_qrnnd(q1, n1, 0, n1, d0);
+			udiv_qrnnd(q0, n0, n1, n0, d0);
+
+			/* Remainder in n0. */
+		}
+
+		if (rp != 0) {
+			rr.s.low = n0;
+			rr.s.high = 0;
+			*rp = rr.ll;
+		}
+
+#else /* UDIV_NEEDS_NORMALIZATION */
+
+	if (d1 == 0) {
+		if (d0 > n1) {
+			/* 0q = nn / 0D */
+
+			count_leading_zeros(bm, d0);
+
+			if (bm != 0) {
+				/*
+				 * Normalize, i.e. make the most significant bit
+				 * of the denominator set.
+				 */
+
+				d0 = d0 << bm;
+				n1 = (n1 << bm) | (n0 >> (W_TYPE_SIZE - bm));
+				n0 = n0 << bm;
+			}
+
+			udiv_qrnnd(q0, n0, n1, n0, d0);
+			q1 = 0;
+
+			/* Remainder in n0 >> bm. */
+		} else {
+			/* qq = NN / 0d */
+
+			if (d0 == 0)
+				/* Divide intentionally by zero. */
+				d0 = 1 / d0;
+
+			count_leading_zeros(bm, d0);
+
+			if (bm == 0) {
+				/*
+				 * From (n1 >= d0) /\ (the most significant bit
+				 * of d0 is set), conclude (the most significant
+				 * bit of n1 is set) /\ (theleading quotient
+				 * digit q1 = 1).
+				 *
+				 * This special case is necessary, not an
+				 * optimization. (Shifts counts of W_TYPE_SIZE
+				 * are undefined.)
+				 */
+
+				n1 -= d0;
+				q1 = 1;
+			} else {
+				/* Normalize. */
+
+				b = W_TYPE_SIZE - bm;
+
+				d0 = d0 << bm;
+				n2 = n1 >> b;
+				n1 = (n1 << bm) | (n0 >> b);
+				n0 = n0 << bm;
+
+				udiv_qrnnd(q1, n1, n2, n1, d0);
+			}
+
+			/* n1 != d0... */
+
+			udiv_qrnnd(q0, n0, n1, n0, d0);
+
+			/* Remainder in n0 >> bm. */
+		}
+
+		if (rp != 0) {
+			rr.s.low = n0 >> bm;
+			rr.s.high = 0;
+			*rp = rr.ll;
+		}
+
+#endif /* UDIV_NEEDS_NORMALIZATION */
+
+	} else {
+		if (d1 > n1) {
+			/* 00 = nn / DD */
+
+			q0 = 0;
+			q1 = 0;
+
+			/* Remainder in n1n0. */
+			if (rp != 0) {
+				rr.s.low = n0;
+				rr.s.high = n1;
+				*rp = rr.ll;
+			}
+		} else {
+			/* 0q = NN / dd */
+
+			count_leading_zeros(bm, d1);
+			if (bm == 0) {
+				/*
+				 * From (n1 >= d1) /\ (the most significant bit
+				 * of d1 is set), conclude (the most significant
+				 * bit of n1 is set) /\ (the quotient digit q0 =
+				 * 0 or 1).
+				 *
+				 * This special case is necessary, not an
+				 * optimization.
+				 */
+
+				/*
+				 * The condition on the next line takes
+				 * advantage of that n1 >= d1 (true due to
+				 * program flow).
+				 */
+				if (n1 > d1 || n0 >= d0) {
+					q0 = 1;
+					sub_ddmmss(n1, n0, n1, n0, d1, d0);
+				} else {
+					q0 = 0;
+				}
+
+				q1 = 0;
+
+				if (rp != 0) {
+					rr.s.low = n0;
+					rr.s.high = n1;
+					*rp = rr.ll;
+				}
+			} else {
+				unsigned long m1, m0;
+				/* Normalize. */
+
+				b = W_TYPE_SIZE - bm;
+
+				d1 = (d1 << bm) | (d0 >> b);
+				d0 = d0 << bm;
+				n2 = n1 >> b;
+				n1 = (n1 << bm) | (n0 >> b);
+				n0 = n0 << bm;
+
+				udiv_qrnnd(q0, n1, n2, n1, d1);
+				umul_ppmm(m1, m0, q0, d0);
+
+				if (m1 > n1 || (m1 == n1 && m0 > n0)) {
+					q0--;
+					sub_ddmmss(m1, m0, m1, m0, d1, d0);
+				}
+
+				q1 = 0;
+
+				/* Remainder in (n1n0 - m1m0) >> bm. */
+				if (rp != 0) {
+					sub_ddmmss(n1, n0, n1, n0, m1, m0);
+					rr.s.low = (n1 << b) | (n0 >> bm);
+					rr.s.high = n1 >> bm;
+					*rp = rr.ll;
+				}
+			}
+		}
+	}
+
+	ww.s.low = q0;
+	ww.s.high = q1;
+
+	return ww.ll;
+}
diff --git a/lib/umoddi3.c b/lib/umoddi3.c
new file mode 100644
index 000000000000..d7bbf0f85197
--- /dev/null
+++ b/lib/umoddi3.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.
+ */
+
+#include <linux/module.h>
+#include <linux/libgcc.h>
+
+extern unsigned long long __udivmoddi4(unsigned long long u,
+				       unsigned long long v,
+				       unsigned long long *rp);
+
+unsigned long long __umoddi3(unsigned long long u, unsigned long long v)
+{
+	unsigned long long w;
+	(void)__udivmoddi4(u, v, &w);
+	return w;
+}
+EXPORT_SYMBOL(__umoddi3);