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authorLinus Torvalds2017-11-15 10:56:56 -0800
committerLinus Torvalds2017-11-15 10:56:56 -0800
commitc9b012e5f4a1d01dfa8abc6318211a67ba7d5db2 (patch)
tree97b2f1c654fc4333e9e3111f76a26ec5503ee5b9 /arch/arm64/lib
parentb293fca43be544483b6488d33ad4b3ed55881064 (diff)
parent6cfa7cc46b1a7a15d81d5389c99cfca633c12b8e (diff)
Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon: "The big highlight is support for the Scalable Vector Extension (SVE) which required extensive ABI work to ensure we don't break existing applications by blowing away their signal stack with the rather large new vector context (<= 2 kbit per vector register). There's further work to be done optimising things like exception return, but the ABI is solid now. Much of the line count comes from some new PMU drivers we have, but they're pretty self-contained and I suspect we'll have more of them in future. Plenty of acronym soup here: - initial support for the Scalable Vector Extension (SVE) - improved handling for SError interrupts (required to handle RAS events) - enable GCC support for 128-bit integer types - remove kernel text addresses from backtraces and register dumps - use of WFE to implement long delay()s - ACPI IORT updates from Lorenzo Pieralisi - perf PMU driver for the Statistical Profiling Extension (SPE) - perf PMU driver for Hisilicon's system PMUs - misc cleanups and non-critical fixes" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (97 commits) arm64: Make ARMV8_DEPRECATED depend on SYSCTL arm64: Implement __lshrti3 library function arm64: support __int128 on gcc 5+ arm64/sve: Add documentation arm64/sve: Detect SVE and activate runtime support arm64/sve: KVM: Hide SVE from CPU features exposed to guests arm64/sve: KVM: Treat guest SVE use as undefined instruction execution arm64/sve: KVM: Prevent guests from using SVE arm64/sve: Add sysctl to set the default vector length for new processes arm64/sve: Add prctl controls for userspace vector length management arm64/sve: ptrace and ELF coredump support arm64/sve: Preserve SVE registers around EFI runtime service calls arm64/sve: Preserve SVE registers around kernel-mode NEON use arm64/sve: Probe SVE capabilities and usable vector lengths arm64: cpufeature: Move sys_caps_initialised declarations arm64/sve: Backend logic for setting the vector length arm64/sve: Signal handling support arm64/sve: Support vector length resetting for new processes arm64/sve: Core task context handling arm64/sve: Low-level CPU setup ...
Diffstat (limited to 'arch/arm64/lib')
-rw-r--r--arch/arm64/lib/Makefile2
-rw-r--r--arch/arm64/lib/delay.c23
-rw-r--r--arch/arm64/lib/tishift.S80
3 files changed, 100 insertions, 5 deletions
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index 9a8cb96555d6..4e696f96451f 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -3,7 +3,7 @@ lib-y := bitops.o clear_user.o delay.o copy_from_user.o \
copy_to_user.o copy_in_user.o copy_page.o \
clear_page.o memchr.o memcpy.o memmove.o memset.o \
memcmp.o strcmp.o strncmp.o strlen.o strnlen.o \
- strchr.o strrchr.o
+ strchr.o strrchr.o tishift.o
# Tell the compiler to treat all general purpose registers (with the
# exception of the IP registers, which are already handled by the caller
diff --git a/arch/arm64/lib/delay.c b/arch/arm64/lib/delay.c
index dad4ec9bbfd1..e48ac402e7be 100644
--- a/arch/arm64/lib/delay.c
+++ b/arch/arm64/lib/delay.c
@@ -24,10 +24,28 @@
#include <linux/module.h>
#include <linux/timex.h>
+#include <clocksource/arm_arch_timer.h>
+
+#define USECS_TO_CYCLES(time_usecs) \
+ xloops_to_cycles((time_usecs) * 0x10C7UL)
+
+static inline unsigned long xloops_to_cycles(unsigned long xloops)
+{
+ return (xloops * loops_per_jiffy * HZ) >> 32;
+}
+
void __delay(unsigned long cycles)
{
cycles_t start = get_cycles();
+ if (arch_timer_evtstrm_available()) {
+ const cycles_t timer_evt_period =
+ USECS_TO_CYCLES(ARCH_TIMER_EVT_STREAM_PERIOD_US);
+
+ while ((get_cycles() - start + timer_evt_period) < cycles)
+ wfe();
+ }
+
while ((get_cycles() - start) < cycles)
cpu_relax();
}
@@ -35,10 +53,7 @@ EXPORT_SYMBOL(__delay);
inline void __const_udelay(unsigned long xloops)
{
- unsigned long loops;
-
- loops = xloops * loops_per_jiffy * HZ;
- __delay(loops >> 32);
+ __delay(xloops_to_cycles(xloops));
}
EXPORT_SYMBOL(__const_udelay);
diff --git a/arch/arm64/lib/tishift.S b/arch/arm64/lib/tishift.S
new file mode 100644
index 000000000000..0179a43cc045
--- /dev/null
+++ b/arch/arm64/lib/tishift.S
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2017 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/linkage.h>
+
+ENTRY(__ashlti3)
+ cbz x2, 1f
+ mov x3, #64
+ sub x3, x3, x2
+ cmp x3, #0
+ b.le 2f
+ lsl x1, x1, x2
+ lsr x3, x0, x3
+ lsl x2, x0, x2
+ orr x1, x1, x3
+ mov x0, x2
+1:
+ ret
+2:
+ neg w1, w3
+ mov x2, #0
+ lsl x1, x0, x1
+ mov x0, x2
+ ret
+ENDPROC(__ashlti3)
+
+ENTRY(__ashrti3)
+ cbz x2, 3f
+ mov x3, #64
+ sub x3, x3, x2
+ cmp x3, #0
+ b.le 4f
+ lsr x0, x0, x2
+ lsl x3, x1, x3
+ asr x2, x1, x2
+ orr x0, x0, x3
+ mov x1, x2
+3:
+ ret
+4:
+ neg w0, w3
+ asr x2, x1, #63
+ asr x0, x1, x0
+ mov x1, x2
+ ret
+ENDPROC(__ashrti3)
+
+ENTRY(__lshrti3)
+ cbz x2, 1f
+ mov x3, #64
+ sub x3, x3, x2
+ cmp x3, #0
+ b.le 2f
+ lsr x0, x0, x2
+ lsl x3, x1, x3
+ lsr x2, x1, x2
+ orr x0, x0, x3
+ mov x1, x2
+1:
+ ret
+2:
+ neg w0, w3
+ mov x2, #0
+ lsr x0, x1, x0
+ mov x1, x2
+ ret
+ENDPROC(__lshrti3)