From: Peter Zijlstra <peterz@infradead.org>
To: torvalds@linux-foundation.org
Cc: corbet@lwn.net, will@kernel.org, peterz@infradead.org,
boqun.feng@gmail.com, mark.rutland@arm.com,
catalin.marinas@arm.com, dennis@kernel.org, tj@kernel.org,
cl@linux.com, hca@linux.ibm.com, gor@linux.ibm.com,
agordeev@linux.ibm.com, borntraeger@linux.ibm.com,
svens@linux.ibm.com, tglx@linutronix.de, mingo@redhat.com,
bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org,
hpa@zytor.com, joro@8bytes.org, suravee.suthikulpanit@amd.com,
robin.murphy@arm.com, dwmw2@infradead.org,
baolu.lu@linux.intel.com, Arnd Bergmann <arnd@arndb.de>,
Herbert Xu <herbert@gondor.apana.org.au>,
davem@davemloft.net, penberg@kernel.org, rientjes@google.com,
iamjoonsoo.kim@lge.com, Andrew Morton <akpm@linux-foundation.org>,
vbabka@suse.cz, roman.gushchin@linux.dev, 42.hyeyoo@gmail.com,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, linux-s390@vger.kernel.org,
iommu@lists.linux.dev, linux-arch@vger.kernel.org,
linux-crypto@vger.kernel.org, sfr@canb.auug.org.au,
mpe@ellerman.id.au, James.Bottomley@hansenpartnership.com,
deller@gmx.de, linux-parisc@vger.kernel.org
Subject: [PATCH 07/12] percpu: #ifndef __SIZEOF_INT128__
Date: Wed, 31 May 2023 15:08:40 +0200 [thread overview]
Message-ID: <20230531132323.722039569@infradead.org> (raw)
In-Reply-To: 20230531130833.635651916@infradead.org
Some 64bit architectures do not advertise __SIZEOF_INT128__ on all
supported compiler versions. Notably the HPPA64 only started doing
with GCC-11.
Since the per-cpu ops are universally availably, and
this_cpu_{,try_}cmpxchg128() is expected to be available on all 64bit
architectures a wee bodge is in order.
Sadly, while C reverts to memcpy() for assignment of POD types, it does
not revert to memcmp() for for equality. Therefore frob that manually.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
include/asm-generic/percpu.h | 56 +++++++++++++++++++++++++++++++++++++++++++
include/linux/types.h | 7 +++++
2 files changed, 63 insertions(+)
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -313,6 +313,35 @@ do { \
#define raw_cpu_xchg_8(pcp, nval) raw_cpu_generic_xchg(pcp, nval)
#endif
+#ifndef __SIZEOF_INT128__
+#define raw_cpu_generic_try_cmpxchg_memcmp(pcp, ovalp, nval) \
+({ \
+ typeof(pcp) *__p = raw_cpu_ptr(&(pcp)); \
+ typeof(pcp) __val = *__p, __old = *(ovalp); \
+ bool __ret; \
+ if (!__builtin_memcmp(&__val, &__old, sizeof(pcp))) { \
+ *__p = nval; \
+ __ret = true; \
+ } else { \
+ *(ovalp) = __val; \
+ __ret = false; \
+ } \
+ __ret; \
+})
+
+#define raw_cpu_generic_cmpxchg_memcmp(pcp, oval, nval) \
+({ \
+ typeof(pcp) __old = (oval); \
+ raw_cpu_generic_try_cmpxchg_memcpy(pcp, &__old, nval); \
+ __old; \
+})
+
+#define raw_cpu_cmpxchg128(pcp, oval, nval) \
+ raw_cpu_generic_cmpxchg_memcmp(pcp, oval, nval)
+#define raw_cpu_try_cmpxchg128(pcp, ovalp, nval) \
+ raw_cpu_generic_try_cmpxchg_memcmp(pcp, ovalp, nval)
+#endif
+
#ifndef raw_cpu_try_cmpxchg_1
#ifdef raw_cpu_cmpxchg_1
#define raw_cpu_try_cmpxchg_1(pcp, ovalp, nval) \
@@ -503,6 +532,33 @@ do { \
#define this_cpu_xchg_8(pcp, nval) this_cpu_generic_xchg(pcp, nval)
#endif
+#ifndef __SIZEOF_INT128__
+#define this_cpu_generic_try_cmpxchg_memcmp(pcp, ovalp, nval) \
+({ \
+ bool __ret; \
+ unsigned long __flags; \
+ raw_local_irq_save(__flags); \
+ __ret = raw_cpu_generic_try_cmpxchg_memcmp(pcp, ovalp, nval); \
+ raw_local_irq_restore(__flags); \
+ __ret; \
+})
+
+#define this_cpu_generic_cmpxchg_memcmp(pcp, oval, nval) \
+({ \
+ typeof(pcp) __ret; \
+ unsigned long __flags; \
+ raw_local_irq_save(__flags); \
+ __ret = raw_cpu_generic_cmpxchg_memcmp(pcp, oval, nval); \
+ raw_local_irq_restore(__flags); \
+ __ret; \
+})
+
+#define this_cpu_cmpxchg128(pcp, oval, nval) \
+ this_cpu_generic_cmpxchg_memcmp(pcp, oval, nval)
+#define this_cpu_try_cmpxchg128(pcp, ovalp, nval) \
+ this_cpu_generic_try_cmpxchg_memcmp(pcp, ovalp, nval)
+#endif
+
#ifndef this_cpu_try_cmpxchg_1
#ifdef this_cpu_cmpxchg_1
#define this_cpu_try_cmpxchg_1(pcp, ovalp, nval) \
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -13,6 +13,13 @@
#ifdef __SIZEOF_INT128__
typedef __s128 s128;
typedef __u128 u128;
+#else
+#ifdef CONFIG_64BIT
+/* hack for this_cpu_cmpxchg128 */
+typedef struct {
+ u64 a, b;
+} u128 __attribute__((aligned(16)));
+#endif
#endif
typedef u32 __kernel_dev_t;
next prev parent reply other threads:[~2023-05-31 13:28 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-31 13:08 [PATCH 00/12] Introduce cmpxchg128() -- aka. the demise of cmpxchg_double() Peter Zijlstra
2023-05-31 13:08 ` [PATCH 01/12] cyrpto/b128ops: Remove struct u128 Peter Zijlstra
2023-05-31 13:08 ` [PATCH 02/12] types: Introduce [us]128 Peter Zijlstra
2023-05-31 13:08 ` [PATCH 03/12] arch: Introduce arch_{,try_}_cmpxchg128{,_local}() Peter Zijlstra
2023-05-31 13:08 ` [PATCH 04/12] instrumentation: Wire up cmpxchg128() Peter Zijlstra
2023-05-31 13:08 ` [PATCH 05/12] percpu: Add {raw,this}_cpu_try_cmpxchg() Peter Zijlstra
2023-06-09 16:10 ` [PATCH v2 5/12] " Konrad Dybcio
2023-06-09 16:13 ` Nathan Chancellor
2023-06-09 16:20 ` Konrad Dybcio
2023-05-31 13:08 ` [PATCH 06/12] percpu: Wire up cmpxchg128 Peter Zijlstra
2023-05-31 13:08 ` Peter Zijlstra [this message]
2023-05-31 14:21 ` [PATCH 07/12] percpu: #ifndef __SIZEOF_INT128__ Arnd Bergmann
2023-05-31 15:50 ` Peter Zijlstra
2023-06-01 10:14 ` [PATCH v2 07/12] parisc/percpu: Work around the lack of __SIZEOF_INT128__ Peter Zijlstra
2023-06-01 10:32 ` Helge Deller
2023-06-01 10:50 ` Peter Zijlstra
2023-06-01 21:08 ` Sam James
2023-06-01 13:29 ` Linus Torvalds
2023-06-01 17:38 ` Masahiro Yamada
2023-06-02 14:39 ` Peter Zijlstra
2023-06-02 14:50 ` Mark Rutland
2023-06-02 16:09 ` Linus Torvalds
2023-06-02 17:00 ` H. Peter Anvin
2023-06-02 19:10 ` Peter Zijlstra
2023-06-02 19:20 ` H. Peter Anvin
2023-06-02 19:40 ` Peter Zijlstra
2023-06-02 19:57 ` Linus Torvalds
2023-06-02 20:42 ` Helge Deller
2023-05-31 13:08 ` [PATCH 08/12] x86,amd_iommu: Replace cmpxchg_double() Peter Zijlstra
2023-05-31 13:08 ` [PATCH 09/12] x86,intel_iommu: " Peter Zijlstra
2023-05-31 13:08 ` [PATCH 10/12] slub: " Peter Zijlstra
2023-05-31 13:08 ` [PATCH 11/12] arch: Remove cmpxchg_double Peter Zijlstra
2023-05-31 13:08 ` [PATCH 12/12] s390/cpum_sf: Convert to cmpxchg128() Peter Zijlstra
2023-05-31 14:47 ` [PATCH 00/12] Introduce cmpxchg128() -- aka. the demise of cmpxchg_double() Mark Rutland
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