From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
To: <linux-arch@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Cc: <arnd@arndb.de>, <arc-linux-dev@synopsys.com>,
Vineet Gupta <Vineet.Gupta1@synopsys.com>
Subject: [PATCH 10/28] ARCv2: Adhere to Zero Delay loop restriction
Date: Tue, 9 Jun 2015 17:18:10 +0530 [thread overview]
Message-ID: <1433850508-26317-11-git-send-email-vgupta@synopsys.com> (raw)
In-Reply-To: <1433850508-26317-1-git-send-email-vgupta@synopsys.com>
Branch insn can't be scheduled as last insn of Zero Overhead loop
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
arch/arc/include/asm/delay.h | 9 ++++-----
arch/arc/include/asm/uaccess.h | 17 ++++++++---------
arch/arc/lib/memcmp.S | 30 +++++++++++++++++++++++++++++-
3 files changed, 41 insertions(+), 15 deletions(-)
diff --git a/arch/arc/include/asm/delay.h b/arch/arc/include/asm/delay.h
index 43de30256981..08e7e2a16ac1 100644
--- a/arch/arc/include/asm/delay.h
+++ b/arch/arc/include/asm/delay.h
@@ -22,11 +22,10 @@
static inline void __delay(unsigned long loops)
{
__asm__ __volatile__(
- "1: sub.f %0, %0, 1 \n"
- " jpnz 1b \n"
- : "+r"(loops)
- :
- : "cc");
+ " lp 1f \n"
+ " nop \n"
+ "1: \n"
+ : "+l"(loops));
}
extern void __bad_udelay(void);
diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h
index 30c9baffa96f..d1da6032b715 100644
--- a/arch/arc/include/asm/uaccess.h
+++ b/arch/arc/include/asm/uaccess.h
@@ -659,31 +659,30 @@ static inline unsigned long __arc_clear_user(void __user *to, unsigned long n)
static inline long
__arc_strncpy_from_user(char *dst, const char __user *src, long count)
{
- long res = count;
+ long res = 0;
char val;
- unsigned int hw_count;
if (count == 0)
return 0;
__asm__ __volatile__(
- " lp 2f \n"
+ " lp 3f \n"
"1: ldb.ab %3, [%2, 1] \n"
- " breq.d %3, 0, 2f \n"
+ " breq.d %3, 0, 3f \n"
" stb.ab %3, [%1, 1] \n"
- "2: sub %0, %6, %4 \n"
- "3: ;nop \n"
+ " add %0, %0, 1 # Num of NON NULL bytes copied \n"
+ "3: \n"
" .section .fixup, \"ax\" \n"
" .align 4 \n"
- "4: mov %0, %5 \n"
+ "4: mov %0, %4 # sets @res as -EFAULT \n"
" j 3b \n"
" .previous \n"
" .section __ex_table, \"a\" \n"
" .align 4 \n"
" .word 1b, 4b \n"
" .previous \n"
- : "=r"(res), "+r"(dst), "+r"(src), "=&r"(val), "=l"(hw_count)
- : "g"(-EFAULT), "ir"(count), "4"(count) /* this "4" seeds lp_count */
+ : "+r"(res), "+r"(dst), "+r"(src), "=r"(val)
+ : "g"(-EFAULT), "l"(count)
: "memory");
return res;
diff --git a/arch/arc/lib/memcmp.S b/arch/arc/lib/memcmp.S
index 978bf8314dfb..a4015e7d9ab7 100644
--- a/arch/arc/lib/memcmp.S
+++ b/arch/arc/lib/memcmp.S
@@ -24,14 +24,32 @@ ENTRY(memcmp)
ld r4,[r0,0]
ld r5,[r1,0]
lsr.f lp_count,r3,3
+#ifdef CONFIG_ISA_ARCV2
+ /* In ARCv2 a branch can't be the last instruction in a zero overhead
+ * loop.
+ * So we move the branch to the start of the loop, duplicate it
+ * after the end, and set up r12 so that the branch isn't taken
+ * initially.
+ */
+ mov_s r12,WORD2
+ lpne .Loop_end
+ brne WORD2,r12,.Lodd
+ ld WORD2,[r0,4]
+#else
lpne .Loop_end
ld_s WORD2,[r0,4]
+#endif
ld_s r12,[r1,4]
brne r4,r5,.Leven
ld.a r4,[r0,8]
ld.a r5,[r1,8]
+#ifdef CONFIG_ISA_ARCV2
+.Loop_end:
+ brne WORD2,r12,.Lodd
+#else
brne WORD2,r12,.Lodd
.Loop_end:
+#endif
asl_s SHIFT,SHIFT,3
bhs_s .Last_cmp
brne r4,r5,.Leven
@@ -89,7 +107,6 @@ ENTRY(memcmp)
bset.cs r0,r0,31
.Lodd:
cmp_s WORD2,r12
-
mov_s r0,1
j_s.d [blink]
bset.cs r0,r0,31
@@ -100,14 +117,25 @@ ENTRY(memcmp)
ldb r4,[r0,0]
ldb r5,[r1,0]
lsr.f lp_count,r3
+#ifdef CONFIG_ISA_ARCV2
+ mov r12,r3
lpne .Lbyte_end
+ brne r3,r12,.Lbyte_odd
+#else
+ lpne .Lbyte_end
+#endif
ldb_s r3,[r0,1]
ldb r12,[r1,1]
brne r4,r5,.Lbyte_even
ldb.a r4,[r0,2]
ldb.a r5,[r1,2]
+#ifdef CONFIG_ISA_ARCV2
+.Lbyte_end:
+ brne r3,r12,.Lbyte_odd
+#else
brne r3,r12,.Lbyte_odd
.Lbyte_end:
+#endif
bcc .Lbyte_even
brne r4,r5,.Lbyte_even
ldb_s r3,[r0,1]
--
1.9.1
WARNING: multiple messages have this Message-ID (diff)
From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
To: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: arnd@arndb.de, arc-linux-dev@synopsys.com,
Vineet Gupta <Vineet.Gupta1@synopsys.com>
Subject: [PATCH 10/28] ARCv2: Adhere to Zero Delay loop restriction
Date: Tue, 9 Jun 2015 17:18:10 +0530 [thread overview]
Message-ID: <1433850508-26317-11-git-send-email-vgupta@synopsys.com> (raw)
In-Reply-To: <1433850508-26317-1-git-send-email-vgupta@synopsys.com>
Branch insn can't be scheduled as last insn of Zero Overhead loop
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
arch/arc/include/asm/delay.h | 9 ++++-----
arch/arc/include/asm/uaccess.h | 17 ++++++++---------
arch/arc/lib/memcmp.S | 30 +++++++++++++++++++++++++++++-
3 files changed, 41 insertions(+), 15 deletions(-)
diff --git a/arch/arc/include/asm/delay.h b/arch/arc/include/asm/delay.h
index 43de30256981..08e7e2a16ac1 100644
--- a/arch/arc/include/asm/delay.h
+++ b/arch/arc/include/asm/delay.h
@@ -22,11 +22,10 @@
static inline void __delay(unsigned long loops)
{
__asm__ __volatile__(
- "1: sub.f %0, %0, 1 \n"
- " jpnz 1b \n"
- : "+r"(loops)
- :
- : "cc");
+ " lp 1f \n"
+ " nop \n"
+ "1: \n"
+ : "+l"(loops));
}
extern void __bad_udelay(void);
diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h
index 30c9baffa96f..d1da6032b715 100644
--- a/arch/arc/include/asm/uaccess.h
+++ b/arch/arc/include/asm/uaccess.h
@@ -659,31 +659,30 @@ static inline unsigned long __arc_clear_user(void __user *to, unsigned long n)
static inline long
__arc_strncpy_from_user(char *dst, const char __user *src, long count)
{
- long res = count;
+ long res = 0;
char val;
- unsigned int hw_count;
if (count == 0)
return 0;
__asm__ __volatile__(
- " lp 2f \n"
+ " lp 3f \n"
"1: ldb.ab %3, [%2, 1] \n"
- " breq.d %3, 0, 2f \n"
+ " breq.d %3, 0, 3f \n"
" stb.ab %3, [%1, 1] \n"
- "2: sub %0, %6, %4 \n"
- "3: ;nop \n"
+ " add %0, %0, 1 # Num of NON NULL bytes copied \n"
+ "3: \n"
" .section .fixup, \"ax\" \n"
" .align 4 \n"
- "4: mov %0, %5 \n"
+ "4: mov %0, %4 # sets @res as -EFAULT \n"
" j 3b \n"
" .previous \n"
" .section __ex_table, \"a\" \n"
" .align 4 \n"
" .word 1b, 4b \n"
" .previous \n"
- : "=r"(res), "+r"(dst), "+r"(src), "=&r"(val), "=l"(hw_count)
- : "g"(-EFAULT), "ir"(count), "4"(count) /* this "4" seeds lp_count */
+ : "+r"(res), "+r"(dst), "+r"(src), "=r"(val)
+ : "g"(-EFAULT), "l"(count)
: "memory");
return res;
diff --git a/arch/arc/lib/memcmp.S b/arch/arc/lib/memcmp.S
index 978bf8314dfb..a4015e7d9ab7 100644
--- a/arch/arc/lib/memcmp.S
+++ b/arch/arc/lib/memcmp.S
@@ -24,14 +24,32 @@ ENTRY(memcmp)
ld r4,[r0,0]
ld r5,[r1,0]
lsr.f lp_count,r3,3
+#ifdef CONFIG_ISA_ARCV2
+ /* In ARCv2 a branch can't be the last instruction in a zero overhead
+ * loop.
+ * So we move the branch to the start of the loop, duplicate it
+ * after the end, and set up r12 so that the branch isn't taken
+ * initially.
+ */
+ mov_s r12,WORD2
+ lpne .Loop_end
+ brne WORD2,r12,.Lodd
+ ld WORD2,[r0,4]
+#else
lpne .Loop_end
ld_s WORD2,[r0,4]
+#endif
ld_s r12,[r1,4]
brne r4,r5,.Leven
ld.a r4,[r0,8]
ld.a r5,[r1,8]
+#ifdef CONFIG_ISA_ARCV2
+.Loop_end:
+ brne WORD2,r12,.Lodd
+#else
brne WORD2,r12,.Lodd
.Loop_end:
+#endif
asl_s SHIFT,SHIFT,3
bhs_s .Last_cmp
brne r4,r5,.Leven
@@ -89,7 +107,6 @@ ENTRY(memcmp)
bset.cs r0,r0,31
.Lodd:
cmp_s WORD2,r12
-
mov_s r0,1
j_s.d [blink]
bset.cs r0,r0,31
@@ -100,14 +117,25 @@ ENTRY(memcmp)
ldb r4,[r0,0]
ldb r5,[r1,0]
lsr.f lp_count,r3
+#ifdef CONFIG_ISA_ARCV2
+ mov r12,r3
lpne .Lbyte_end
+ brne r3,r12,.Lbyte_odd
+#else
+ lpne .Lbyte_end
+#endif
ldb_s r3,[r0,1]
ldb r12,[r1,1]
brne r4,r5,.Lbyte_even
ldb.a r4,[r0,2]
ldb.a r5,[r1,2]
+#ifdef CONFIG_ISA_ARCV2
+.Lbyte_end:
+ brne r3,r12,.Lbyte_odd
+#else
brne r3,r12,.Lbyte_odd
.Lbyte_end:
+#endif
bcc .Lbyte_even
brne r4,r5,.Lbyte_even
ldb_s r3,[r0,1]
--
1.9.1
next prev parent reply other threads:[~2015-06-09 11:58 UTC|newest]
Thread overview: 109+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-09 11:48 [PATCH 00/28] ARCv2 port to Linux - (B) ISA / Core / platform support Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 01/28] ARCv2: [intc] HS38 core interrupt controller Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 02/28] ARCv2: Support for ARCv2 ISA and HS38x cores Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 03/28] ARCv2: STAR 9000793984: Handle return from intr to Delay Slot Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 04/28] ARCv2: STAR 9000808988: signals involving " Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 05/28] ARCv2: STAR 9000814690: Really Re-enable interrupts to avoid deadlocks Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 06/28] ARCv2: MMUv4: TLB programming Model changes Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 07/28] ARCv2: MMUv4: cache programming model changes Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 08/28] ARCv2: MMUv4: support aliasing icache config Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 09/28] ARCv2: optimised string/mem lib routines Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta [this message]
2015-06-09 11:48 ` [PATCH 10/28] ARCv2: Adhere to Zero Delay loop restriction Vineet Gupta
2015-06-09 11:48 ` [PATCH 11/28] ARCv2: extable: Enable sorting at build time Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-24 5:51 ` Vineet Gupta
2015-06-24 5:51 ` Vineet Gupta
2015-06-29 20:38 ` David Daney
2015-06-30 4:41 ` Vineet Gupta
2015-06-30 4:41 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 12/28] ARCv2: clocksource: Introduce 64bit local RTC counter Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 13/28] ARC: make plat_smp_ops weak to allow over-rides Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 14/28] ARCv2: SMP: ARConnect debug/robustness Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 15/28] ARCv2: SMP: clocksource: Enable Global Real Time counter Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 16/28] ARCv2: SMP: intc: IDU 2nd level intc for dynamic IRQ distribution Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 17/28] ARC: add compiler barrier to LLSC based cmpxchg Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 12:23 ` Peter Zijlstra
2015-06-09 11:48 ` [PATCH 18/28] ARC: add smp barriers around atomics per memory-barrriers.txt Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 12:30 ` Peter Zijlstra
2015-06-10 9:17 ` Vineet Gupta
2015-06-10 10:53 ` Peter Zijlstra
2015-06-11 13:03 ` Vineet Gupta
2015-06-12 12:15 ` [PATCH v2] ARC: add smp barriers around atomics per Documentation/atomic_ops.txt Vineet Gupta
2015-06-12 12:15 ` Vineet Gupta
2015-06-12 13:04 ` Peter Zijlstra
2015-06-12 13:16 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 19/28] arch: conditionally define smp_{mb,rmb,wmb} Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 12:32 ` Peter Zijlstra
2015-06-09 11:48 ` [PATCH 20/28] ARCv2: barriers Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 12:40 ` Peter Zijlstra
2015-06-10 9:34 ` Vineet Gupta
2015-06-10 10:58 ` Peter Zijlstra
2015-06-10 13:01 ` Will Deacon
2015-06-11 12:13 ` Vineet Gupta
2015-06-11 13:39 ` Will Deacon
2015-06-19 13:13 ` Vineet Gupta
2015-06-19 13:13 ` Vineet Gupta
2015-06-19 13:13 ` Vineet Gupta
2015-06-22 13:36 ` Will Deacon
2015-06-22 13:36 ` Will Deacon
2015-06-22 13:36 ` Will Deacon
2015-06-23 7:58 ` [PATCH v2 " Vineet Gupta
2015-06-23 7:58 ` Vineet Gupta
2015-06-23 8:49 ` Will Deacon
2015-06-23 9:03 ` Vineet Gupta
2015-06-23 9:26 ` Will Deacon
2015-06-23 9:52 ` [PATCH v3 22/28] " Vineet Gupta
2015-06-23 9:52 ` Vineet Gupta
2015-06-23 16:28 ` Will Deacon
2015-06-23 9:25 ` [PATCH v2 20/28] " Peter Zijlstra
2015-06-23 8:02 ` [PATCH " Vineet Gupta
2015-06-09 11:48 ` [PATCH 21/28] ARC: Reduce bitops lines of code using macros Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-12 12:20 ` [PATCH v2] " Vineet Gupta
2015-06-12 12:20 ` Vineet Gupta
2015-06-12 13:05 ` Peter Zijlstra
2015-06-09 11:48 ` [PATCH 22/28] ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelock Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 12:35 ` Peter Zijlstra
2015-06-10 10:01 ` Vineet Gupta
2015-06-10 11:02 ` Peter Zijlstra
2015-06-19 9:55 ` [PATCH v2 " Vineet Gupta
2015-06-19 9:55 ` Vineet Gupta
2015-06-19 9:59 ` Will Deacon
2015-06-19 10:09 ` Vineet Gupta
2015-06-23 7:59 ` Vineet Gupta
2015-06-23 7:59 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 23/28] ARCv2: SLC: Handle explcit flush for DMA ops (w/o IO-coherency) Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 24/28] ARCv2: All bits in place, allow ARCv2 builds Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 25/28] ARCv2: [nsim*hs*] Support simulation platforms for HS38x cores Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 26/28] ARC: [axs101] Prepare for AXS103 Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 27/28] ARCv2: [axs103] Support ARC SDP FPGA platform for HS38x cores Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 28/28] ARCv2: [vdk] dts files and defconfig for HS38 VDK Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
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