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authorGreg Kroah-Hartman <gregkh@google.com>2018-03-06 03:31:47 -0800
committerGreg Kroah-Hartman <gregkh@google.com>2018-03-06 03:31:47 -0800
commitd63fdf61a4dc9ba1ac84bc975f79cdc59296777e (patch)
tree387227930ad3cdeaa9eabcdfa7c18a4e68787079 /arch/mips/lib/multi3.c
parent855ea747806b2e31b844d6fdacd97e0a836be207 (diff)
parent47356cfded444826565f2430bce8ba294372b861 (diff)
Merge 4.4.120 into android-4.4
Changes in 4.4.120 hrtimer: Ensure POSIX compliance (relative CLOCK_REALTIME hrtimers) f2fs: fix a bug caused by NULL extent tree mtd: nand: gpmi: Fix failure when a erased page has a bitflip at BBM ipv6: icmp6: Allow icmp messages to be looped back ARM: 8731/1: Fix csum_partial_copy_from_user() stack mismatch sget(): handle failures of register_shrinker() drm/nouveau/pci: do a msi rearm on init spi: atmel: fixed spin_lock usage inside atmel_spi_remove net: arc_emac: fix arc_emac_rx() error paths scsi: storvsc: Fix scsi_cmd error assignments in storvsc_handle_error ARM: dts: ls1021a: fix incorrect clock references lib/mpi: Fix umul_ppmm() for MIPS64r6 tg3: Add workaround to restrict 5762 MRRS to 2048 tg3: Enable PHY reset in MTU change path for 5720 bnx2x: Improve reliability in case of nested PCI errors led: core: Fix brightness setting when setting delay_off=0 s390/dasd: fix wrongly assigned configuration data IB/mlx4: Fix mlx4_ib_alloc_mr error flow IB/ipoib: Fix race condition in neigh creation xfs: quota: fix missed destroy of qi_tree_lock xfs: quota: check result of register_shrinker() e1000: fix disabling already-disabled warning drm/ttm: check the return value of kzalloc mac80211: mesh: drop frames appearing to be from us can: flex_can: Correct the checking for frame length in flexcan_start_xmit() bnxt_en: Fix the 'Invalid VF' id check in bnxt_vf_ndo_prep routine. xen-netfront: enable device after manual module load mdio-sun4i: Fix a memory leak SolutionEngine771x: fix Ether platform data xen/gntdev: Fix off-by-one error when unmapping with holes xen/gntdev: Fix partial gntdev_mmap() cleanup sctp: make use of pre-calculated len net: gianfar_ptp: move set_fipers() to spinlock protecting area MIPS: Implement __multi3 for GCC7 MIPS64r6 builds Linux 4.4.120 Change-Id: Ie363d2e798f7bbe76e728c995e605af94667dfe5 Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Diffstat (limited to 'arch/mips/lib/multi3.c')
-rw-r--r--arch/mips/lib/multi3.c54
1 files changed, 54 insertions, 0 deletions
diff --git a/arch/mips/lib/multi3.c b/arch/mips/lib/multi3.c
new file mode 100644
index 000000000000..111ad475aa0c
--- /dev/null
+++ b/arch/mips/lib/multi3.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/export.h>
+
+#include "libgcc.h"
+
+/*
+ * GCC 7 suboptimally generates __multi3 calls for mips64r6, so for that
+ * specific case only we'll implement it here.
+ *
+ * See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82981
+ */
+#if defined(CONFIG_64BIT) && defined(CONFIG_CPU_MIPSR6) && (__GNUC__ == 7)
+
+/* multiply 64-bit values, low 64-bits returned */
+static inline long long notrace dmulu(long long a, long long b)
+{
+ long long res;
+
+ asm ("dmulu %0,%1,%2" : "=r" (res) : "r" (a), "r" (b));
+ return res;
+}
+
+/* multiply 64-bit unsigned values, high 64-bits of 128-bit result returned */
+static inline long long notrace dmuhu(long long a, long long b)
+{
+ long long res;
+
+ asm ("dmuhu %0,%1,%2" : "=r" (res) : "r" (a), "r" (b));
+ return res;
+}
+
+/* multiply 128-bit values, low 128-bits returned */
+ti_type notrace __multi3(ti_type a, ti_type b)
+{
+ TWunion res, aa, bb;
+
+ aa.ti = a;
+ bb.ti = b;
+
+ /*
+ * a * b = (a.lo * b.lo)
+ * + 2^64 * (a.hi * b.lo + a.lo * b.hi)
+ * [+ 2^128 * (a.hi * b.hi)]
+ */
+ res.s.low = dmulu(aa.s.low, bb.s.low);
+ res.s.high = dmuhu(aa.s.low, bb.s.low);
+ res.s.high += dmulu(aa.s.high, bb.s.low);
+ res.s.high += dmulu(aa.s.low, bb.s.high);
+
+ return res.ti;
+}
+EXPORT_SYMBOL(__multi3);
+
+#endif /* 64BIT && CPU_MIPSR6 && GCC7 */