* [PATCH, v2] RISC-V: Add futex support.
@ 2018-10-16 21:42 Jim Wilson
2018-10-16 21:42 ` Jim Wilson
2018-10-17 17:15 ` Christoph Hellwig
0 siblings, 2 replies; 6+ messages in thread
From: Jim Wilson @ 2018-10-16 21:42 UTC (permalink / raw)
To: linux-riscv
Updated as per sugestions from Christoph Hellwig. As before, tested on a
HiFive Unleashed running fedora core 29 with a 4.15 based kernel against the
glibc testsuite and the futex wake_op testcase from
https://lwn.net/Articles/148830/
14 glibc testcase failures are fixed by the patch, and the wake_op testcase
works with the patch.
This is a patch based off of a 4.19 tree. The 4.15 patch is trivially
different as arch/riscv/Kconfig changed. This patch was tested on qemu with
the glibc nptl/tst-cond-except testcase, and the wake_op testcase from above.
Signed-off-by: Jim Wilson <jimw@sifive.com>
---
arch/riscv/Kconfig | 1 +
arch/riscv/include/asm/Kbuild | 1 -
arch/riscv/include/asm/futex.h | 127 +++++++++++++++++++++++++++++++++
3 files changed, 128 insertions(+), 1 deletion(-)
create mode 100644 arch/riscv/include/asm/futex.h
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index a344980287a5..093361e2298c 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -31,6 +31,7 @@ config RISCV
select HAVE_MEMBLOCK
select HAVE_MEMBLOCK_NODE_MAP
select HAVE_DMA_CONTIGUOUS
+ select HAVE_FUTEX_CMPXCHG if FUTEX
select HAVE_GENERIC_DMA_COHERENT
select HAVE_PERF_EVENTS
select IRQ_DOMAIN
diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild
index efdbe311e936..6a646d9ea780 100644
--- a/arch/riscv/include/asm/Kbuild
+++ b/arch/riscv/include/asm/Kbuild
@@ -13,7 +13,6 @@ generic-y += errno.h
generic-y += exec.h
generic-y += fb.h
generic-y += fcntl.h
-generic-y += futex.h
generic-y += hardirq.h
generic-y += hash.h
generic-y += hw_irq.h
diff --git a/arch/riscv/include/asm/futex.h b/arch/riscv/include/asm/futex.h
new file mode 100644
index 000000000000..c594db8fd01c
--- /dev/null
+++ b/arch/riscv/include/asm/futex.h
@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2006 Ralf Baechle (ralf at linux-mips.org)
+ * Copyright (c) 2018 Jim Wilson (jimw at sifive.com)
+ */
+
+#ifndef _ASM_FUTEX_H
+#define _ASM_FUTEX_H
+
+#ifndef CONFIG_RISCV_ISA_A
+/*
+ * Use the generic interrupt disabling versions if the A extension
+ * is not supported.
+ */
+#ifdef CONFIG_SMP
+#error "Can't support generic futex calls without A extension on SMP"
+#endif
+#include <asm-generic/futex.h>
+
+#else /* CONFIG_RISCV_ISA_A */
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <linux/errno.h>
+#include <asm/asm.h>
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+{ \
+ uintptr_t tmp; \
+ __enable_user_access(); \
+ __asm__ __volatile__ ( \
+ "1: " insn " \n" \
+ "2: \n" \
+ " .section .fixup,\"ax\" \n" \
+ " .balign 4 \n" \
+ "3: li %[r],%[e] \n" \
+ " jump 2b,%[t] \n" \
+ " .previous \n" \
+ " .section __ex_table,\"a\" \n" \
+ " .balign " RISCV_SZPTR " \n" \
+ " " RISCV_PTR " 1b, 3b \n" \
+ " .previous \n" \
+ : [r] "+r" (ret), [ov] "=&r" (oldval), \
+ [u] "+m" (*uaddr), [t] "=&r" (tmp) \
+ : [op] "Jr" (oparg), [e] "i" (-EFAULT) \
+ : "memory"); \
+ __disable_user_access(); \
+}
+
+static inline int
+arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
+{
+ int oldval = 0, ret = 0;
+
+ pagefault_disable();
+
+ switch (op) {
+ case FUTEX_OP_SET:
+ __futex_atomic_op("amoswap.w.aqrl %[ov],%z[op],%[u]",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ADD:
+ __futex_atomic_op("amoadd.w.aqrl %[ov],%z[op],%[u]",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_OR:
+ __futex_atomic_op("amoor.w.aqrl %[ov],%z[op],%[u]",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ANDN:
+ __futex_atomic_op("amoand.w.aqrl %[ov],%z[op],%[u]",
+ ret, oldval, uaddr, ~oparg);
+ break;
+ case FUTEX_OP_XOR:
+ __futex_atomic_op("amoxor.w.aqrl %[ov],%z[op],%[u]",
+ ret, oldval, uaddr, oparg);
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+
+ pagefault_enable();
+
+ if (!ret)
+ *oval = oldval;
+
+ return ret;
+}
+
+static inline int
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+ u32 oldval, u32 newval)
+{
+ int ret = 0;
+ u32 val;
+ uintptr_t tmp;
+
+ if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+ return -EFAULT;
+
+ __enable_user_access();
+ __asm__ __volatile__ (
+ "1: lr.w.aqrl %[v],%[u] \n"
+ " bne %[v],%z[ov],3f \n"
+ "2: sc.w.aqrl %[t],%z[nv],%[u] \n"
+ " bnez %[t],1b \n"
+ "3: \n"
+ " .section .fixup,\"ax\" \n"
+ " .balign 4 \n"
+ "4: li %[r],%[e] \n"
+ " jump 3b,%[t] \n"
+ " .previous \n"
+ " .section __ex_table,\"a\" \n"
+ " .balign " RISCV_SZPTR " \n"
+ " " RISCV_PTR " 1b, 4b \n"
+ " " RISCV_PTR " 2b, 4b \n"
+ " .previous \n"
+ : [r] "+r" (ret), [v] "=&r" (val), [u] "+m" (*uaddr), [t] "=&r" (tmp)
+ : [ov] "Jr" (oldval), [nv] "Jr" (newval), [e] "i" (-EFAULT)
+ : "memory");
+ __disable_user_access();
+
+ *uval = val;
+ return ret;
+}
+
+#endif /* CONFIG_RISCV_ISA_A */
+#endif /* _ASM_FUTEX_H */
--
2.19.0.rc0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH, v2] RISC-V: Add futex support.
2018-10-16 21:42 [PATCH, v2] RISC-V: Add futex support Jim Wilson
@ 2018-10-16 21:42 ` Jim Wilson
2018-10-17 17:15 ` Christoph Hellwig
1 sibling, 0 replies; 6+ messages in thread
From: Jim Wilson @ 2018-10-16 21:42 UTC (permalink / raw)
To: linux-riscv; +Cc: Jim Wilson
Updated as per sugestions from Christoph Hellwig. As before, tested on a
HiFive Unleashed running fedora core 29 with a 4.15 based kernel against the
glibc testsuite and the futex wake_op testcase from
https://lwn.net/Articles/148830/
14 glibc testcase failures are fixed by the patch, and the wake_op testcase
works with the patch.
This is a patch based off of a 4.19 tree. The 4.15 patch is trivially
different as arch/riscv/Kconfig changed. This patch was tested on qemu with
the glibc nptl/tst-cond-except testcase, and the wake_op testcase from above.
Signed-off-by: Jim Wilson <jimw@sifive.com>
---
arch/riscv/Kconfig | 1 +
arch/riscv/include/asm/Kbuild | 1 -
arch/riscv/include/asm/futex.h | 127 +++++++++++++++++++++++++++++++++
3 files changed, 128 insertions(+), 1 deletion(-)
create mode 100644 arch/riscv/include/asm/futex.h
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index a344980287a5..093361e2298c 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -31,6 +31,7 @@ config RISCV
select HAVE_MEMBLOCK
select HAVE_MEMBLOCK_NODE_MAP
select HAVE_DMA_CONTIGUOUS
+ select HAVE_FUTEX_CMPXCHG if FUTEX
select HAVE_GENERIC_DMA_COHERENT
select HAVE_PERF_EVENTS
select IRQ_DOMAIN
diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild
index efdbe311e936..6a646d9ea780 100644
--- a/arch/riscv/include/asm/Kbuild
+++ b/arch/riscv/include/asm/Kbuild
@@ -13,7 +13,6 @@ generic-y += errno.h
generic-y += exec.h
generic-y += fb.h
generic-y += fcntl.h
-generic-y += futex.h
generic-y += hardirq.h
generic-y += hash.h
generic-y += hw_irq.h
diff --git a/arch/riscv/include/asm/futex.h b/arch/riscv/include/asm/futex.h
new file mode 100644
index 000000000000..c594db8fd01c
--- /dev/null
+++ b/arch/riscv/include/asm/futex.h
@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2006 Ralf Baechle (ralf@linux-mips.org)
+ * Copyright (c) 2018 Jim Wilson (jimw@sifive.com)
+ */
+
+#ifndef _ASM_FUTEX_H
+#define _ASM_FUTEX_H
+
+#ifndef CONFIG_RISCV_ISA_A
+/*
+ * Use the generic interrupt disabling versions if the A extension
+ * is not supported.
+ */
+#ifdef CONFIG_SMP
+#error "Can't support generic futex calls without A extension on SMP"
+#endif
+#include <asm-generic/futex.h>
+
+#else /* CONFIG_RISCV_ISA_A */
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <linux/errno.h>
+#include <asm/asm.h>
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+{ \
+ uintptr_t tmp; \
+ __enable_user_access(); \
+ __asm__ __volatile__ ( \
+ "1: " insn " \n" \
+ "2: \n" \
+ " .section .fixup,\"ax\" \n" \
+ " .balign 4 \n" \
+ "3: li %[r],%[e] \n" \
+ " jump 2b,%[t] \n" \
+ " .previous \n" \
+ " .section __ex_table,\"a\" \n" \
+ " .balign " RISCV_SZPTR " \n" \
+ " " RISCV_PTR " 1b, 3b \n" \
+ " .previous \n" \
+ : [r] "+r" (ret), [ov] "=&r" (oldval), \
+ [u] "+m" (*uaddr), [t] "=&r" (tmp) \
+ : [op] "Jr" (oparg), [e] "i" (-EFAULT) \
+ : "memory"); \
+ __disable_user_access(); \
+}
+
+static inline int
+arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
+{
+ int oldval = 0, ret = 0;
+
+ pagefault_disable();
+
+ switch (op) {
+ case FUTEX_OP_SET:
+ __futex_atomic_op("amoswap.w.aqrl %[ov],%z[op],%[u]",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ADD:
+ __futex_atomic_op("amoadd.w.aqrl %[ov],%z[op],%[u]",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_OR:
+ __futex_atomic_op("amoor.w.aqrl %[ov],%z[op],%[u]",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ANDN:
+ __futex_atomic_op("amoand.w.aqrl %[ov],%z[op],%[u]",
+ ret, oldval, uaddr, ~oparg);
+ break;
+ case FUTEX_OP_XOR:
+ __futex_atomic_op("amoxor.w.aqrl %[ov],%z[op],%[u]",
+ ret, oldval, uaddr, oparg);
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+
+ pagefault_enable();
+
+ if (!ret)
+ *oval = oldval;
+
+ return ret;
+}
+
+static inline int
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+ u32 oldval, u32 newval)
+{
+ int ret = 0;
+ u32 val;
+ uintptr_t tmp;
+
+ if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+ return -EFAULT;
+
+ __enable_user_access();
+ __asm__ __volatile__ (
+ "1: lr.w.aqrl %[v],%[u] \n"
+ " bne %[v],%z[ov],3f \n"
+ "2: sc.w.aqrl %[t],%z[nv],%[u] \n"
+ " bnez %[t],1b \n"
+ "3: \n"
+ " .section .fixup,\"ax\" \n"
+ " .balign 4 \n"
+ "4: li %[r],%[e] \n"
+ " jump 3b,%[t] \n"
+ " .previous \n"
+ " .section __ex_table,\"a\" \n"
+ " .balign " RISCV_SZPTR " \n"
+ " " RISCV_PTR " 1b, 4b \n"
+ " " RISCV_PTR " 2b, 4b \n"
+ " .previous \n"
+ : [r] "+r" (ret), [v] "=&r" (val), [u] "+m" (*uaddr), [t] "=&r" (tmp)
+ : [ov] "Jr" (oldval), [nv] "Jr" (newval), [e] "i" (-EFAULT)
+ : "memory");
+ __disable_user_access();
+
+ *uval = val;
+ return ret;
+}
+
+#endif /* CONFIG_RISCV_ISA_A */
+#endif /* _ASM_FUTEX_H */
--
2.19.0.rc0
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linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH, v2] RISC-V: Add futex support.
2018-10-16 21:42 [PATCH, v2] RISC-V: Add futex support Jim Wilson
2018-10-16 21:42 ` Jim Wilson
@ 2018-10-17 17:15 ` Christoph Hellwig
2018-10-17 17:15 ` Christoph Hellwig
2018-10-17 19:54 ` Palmer Dabbelt
1 sibling, 2 replies; 6+ messages in thread
From: Christoph Hellwig @ 2018-10-17 17:15 UTC (permalink / raw)
To: linux-riscv
On Tue, Oct 16, 2018 at 02:42:59PM -0700, Jim Wilson wrote:
> Updated as per sugestions from Christoph Hellwig.
This tends to go under the ---, but I guess Palmer can just snip it
when applying.
> +/* Copyright (c) 2006 Ralf Baechle (ralf at linux-mips.org)
> + * Copyright (c) 2018 Jim Wilson (jimw at sifive.com)
> + */
Nipick: the /* should be on a line of its own.
Except for that this looks fine to me:
Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH, v2] RISC-V: Add futex support.
2018-10-17 17:15 ` Christoph Hellwig
@ 2018-10-17 17:15 ` Christoph Hellwig
2018-10-17 19:54 ` Palmer Dabbelt
1 sibling, 0 replies; 6+ messages in thread
From: Christoph Hellwig @ 2018-10-17 17:15 UTC (permalink / raw)
To: Jim Wilson; +Cc: linux-riscv
On Tue, Oct 16, 2018 at 02:42:59PM -0700, Jim Wilson wrote:
> Updated as per sugestions from Christoph Hellwig.
This tends to go under the ---, but I guess Palmer can just snip it
when applying.
> +/* Copyright (c) 2006 Ralf Baechle (ralf@linux-mips.org)
> + * Copyright (c) 2018 Jim Wilson (jimw@sifive.com)
> + */
Nipick: the /* should be on a line of its own.
Except for that this looks fine to me:
Reviewed-by: Christoph Hellwig <hch@lst.de>
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linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH, v2] RISC-V: Add futex support.
2018-10-17 17:15 ` Christoph Hellwig
2018-10-17 17:15 ` Christoph Hellwig
@ 2018-10-17 19:54 ` Palmer Dabbelt
2018-10-17 19:54 ` Palmer Dabbelt
1 sibling, 1 reply; 6+ messages in thread
From: Palmer Dabbelt @ 2018-10-17 19:54 UTC (permalink / raw)
To: linux-riscv
On Wed, 17 Oct 2018 10:15:28 PDT (-0700), Christoph Hellwig wrote:
> On Tue, Oct 16, 2018 at 02:42:59PM -0700, Jim Wilson wrote:
>> Updated as per sugestions from Christoph Hellwig.
>
> This tends to go under the ---, but I guess Palmer can just snip it
> when applying.
>
>> +/* Copyright (c) 2006 Ralf Baechle (ralf at linux-mips.org)
>> + * Copyright (c) 2018 Jim Wilson (jimw at sifive.com)
>> + */
>
> Nipick: the /* should be on a line of its own.
>
> Except for that this looks fine to me:
>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
I fixed the comment, cleaned up the commit message a bit, and added this to
for-next.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH, v2] RISC-V: Add futex support.
2018-10-17 19:54 ` Palmer Dabbelt
@ 2018-10-17 19:54 ` Palmer Dabbelt
0 siblings, 0 replies; 6+ messages in thread
From: Palmer Dabbelt @ 2018-10-17 19:54 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: linux-riscv, Jim Wilson
On Wed, 17 Oct 2018 10:15:28 PDT (-0700), Christoph Hellwig wrote:
> On Tue, Oct 16, 2018 at 02:42:59PM -0700, Jim Wilson wrote:
>> Updated as per sugestions from Christoph Hellwig.
>
> This tends to go under the ---, but I guess Palmer can just snip it
> when applying.
>
>> +/* Copyright (c) 2006 Ralf Baechle (ralf@linux-mips.org)
>> + * Copyright (c) 2018 Jim Wilson (jimw@sifive.com)
>> + */
>
> Nipick: the /* should be on a line of its own.
>
> Except for that this looks fine to me:
>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
I fixed the comment, cleaned up the commit message a bit, and added this to
for-next.
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 6+ messages in thread
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2018-10-16 21:42 [PATCH, v2] RISC-V: Add futex support Jim Wilson
2018-10-16 21:42 ` Jim Wilson
2018-10-17 17:15 ` Christoph Hellwig
2018-10-17 17:15 ` Christoph Hellwig
2018-10-17 19:54 ` Palmer Dabbelt
2018-10-17 19:54 ` Palmer Dabbelt
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