From patchwork Tue Sep 12 18:35:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shawn Anastasio X-Patchwork-Id: 13382033 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 334D1EE3F0E for ; Tue, 12 Sep 2023 18:36:23 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.600735.936494 (Exim 4.92) (envelope-from ) id 1qg8F5-0004O5-GT; Tue, 12 Sep 2023 18:36:07 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 600735.936494; Tue, 12 Sep 2023 18:36:07 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qg8F5-0004Ny-DJ; Tue, 12 Sep 2023 18:36:07 +0000 Received: by outflank-mailman (input) for mailman id 600735; Tue, 12 Sep 2023 18:36:06 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qg8F4-0004Nn-9M for xen-devel@lists.xenproject.org; Tue, 12 Sep 2023 18:36:06 +0000 Received: from raptorengineering.com (mail.raptorengineering.com [23.155.224.40]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 3a25b1da-519b-11ee-9b0d-b553b5be7939; Tue, 12 Sep 2023 20:36:03 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by mail.rptsys.com (Postfix) with ESMTP id BEE5D82869BC; Tue, 12 Sep 2023 13:36:02 -0500 (CDT) Received: from mail.rptsys.com ([127.0.0.1]) by localhost (vali.starlink.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id GDklFJAO7xyW; Tue, 12 Sep 2023 13:36:01 -0500 (CDT) Received: from localhost (localhost [127.0.0.1]) by mail.rptsys.com (Postfix) with ESMTP id 31EF28285806; Tue, 12 Sep 2023 13:36:01 -0500 (CDT) Received: from mail.rptsys.com ([127.0.0.1]) by localhost (vali.starlink.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id c4ciP5Lb7hBL; Tue, 12 Sep 2023 13:36:01 -0500 (CDT) Received: from raptor-ewks-026.rptsys.com (5.edge.rptsys.com [23.155.224.38]) by mail.rptsys.com (Postfix) with ESMTPSA id C6B978285940; Tue, 12 Sep 2023 13:36:00 -0500 (CDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 3a25b1da-519b-11ee-9b0d-b553b5be7939 DKIM-Filter: OpenDKIM Filter v2.10.3 mail.rptsys.com 31EF28285806 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=raptorengineering.com; s=B8E824E6-0BE2-11E6-931D-288C65937AAD; t=1694543761; bh=OMNtHSpQqn89e74CYNhsjMflaiQYP4Sf+eSGFc6n1/U=; h=From:To:Date:Message-Id:MIME-Version; b=YXqsiTDFFOv+trEt+vp8Kdr10QxIxGE9qsC34/undmjI3u/QhGkfcW9AS5LBtSMgI BjAewnbFUKcLb2kFIti1eWtAG5pjAhOPiCLELCQd31D31vHrpJ5pTw1LryxuhyfPuB ZTPM7ENLOt/vCMBtS9PSVehjRDXeXgr7rxEGdNBc= X-Virus-Scanned: amavisd-new at rptsys.com From: Shawn Anastasio To: xen-devel@lists.xenproject.org Cc: Timothy Pearson , Jan Beulich , Shawn Anastasio Subject: [PATCH v5 1/5] xen/ppc: Implement atomic.h Date: Tue, 12 Sep 2023 13:35:50 -0500 Message-Id: X-Mailer: git-send-email 2.30.2 In-Reply-To: References: MIME-Version: 1.0 Implement atomic.h for PPC, based off of the original Xen 3.2 implementation. This implementation depends on some functions that are not yet defined (notably __cmpxchg), so it can't yet be used. Signed-off-by: Shawn Anastasio Acked-by: Jan Beulich --- v5: No changes. v4: - Clarify dependency on __cmpxchg which doesn't get implemented until future patch - Drop !CONFIG_SMP case for PPC_ATOMIC_{ENTRY,EXIT}_BARRIER macro definitions - Add missing newlines to inline asm instructions preceeding PPC_ATOMIC_EXIT_BARRIER. This was only discovered by the change to drop the !CONFIG_SMP definitions of those macros. - Fix line wrapping in atomic_compareandswap - Fix formatting of arch_cmpxchg macro v3: - Drop full copyright text headers - Drop unnecessary spaces after casts - const-ize write_atomic_size - Don't use GNU 0-length array extension in read_atomic - Use "+m" asm constraint instead of separate "=m" and "m" - Fix line-continuing backslash formatting in arch_cmpxchg v2: - Fix style of asm block constraints to include required spaces - Fix macro local variable naming (use trailing underscore instead of leading) - Drop unnecessary parens in __atomic_add_unless xen/arch/ppc/include/asm/atomic.h | 385 ++++++++++++++++++++++++++++++ xen/arch/ppc/include/asm/memory.h | 14 ++ 2 files changed, 399 insertions(+) create mode 100644 xen/arch/ppc/include/asm/atomic.h create mode 100644 xen/arch/ppc/include/asm/memory.h -- 2.30.2 diff --git a/xen/arch/ppc/include/asm/atomic.h b/xen/arch/ppc/include/asm/atomic.h new file mode 100644 index 0000000000..64168aa3f1 --- /dev/null +++ b/xen/arch/ppc/include/asm/atomic.h @@ -0,0 +1,385 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * PowerPC64 atomic operations + * + * Copyright (C) 2001 Paul Mackerras , IBM + * Copyright (C) 2001 Anton Blanchard , IBM + * Copyright Raptor Engineering LLC + */ + +#ifndef _ASM_PPC64_ATOMIC_H_ +#define _ASM_PPC64_ATOMIC_H_ + +#include + +#include + +static inline int atomic_read(const atomic_t *v) +{ + return *(volatile int *)&v->counter; +} + +static inline int _atomic_read(atomic_t v) +{ + return v.counter; +} + +static inline void atomic_set(atomic_t *v, int i) +{ + v->counter = i; +} + +static inline void _atomic_set(atomic_t *v, int i) +{ + v->counter = i; +} + +void __bad_atomic_read(const volatile void *p, void *res); +void __bad_atomic_size(void); + +#define build_atomic_read(name, insn, type) \ + static inline type name(const volatile type *addr) \ + { \ + type ret; \ + asm volatile ( insn "%U1%X1 %0,%1" : "=r" (ret) : "m<>" (*addr) ); \ + return ret; \ + } + +#define build_atomic_write(name, insn, type) \ + static inline void name(volatile type *addr, type val) \ + { \ + asm volatile ( insn "%U0%X0 %1,%0" : "=m<>" (*addr) : "r" (val) ); \ + } + +#define build_add_sized(name, ldinsn, stinsn, type) \ + static inline void name(volatile type *addr, type val) \ + { \ + type t; \ + asm volatile ( "1: " ldinsn " %0,0,%3\n" \ + "add%I2 %0,%0,%2\n" \ + stinsn " %0,0,%3 \n" \ + "bne- 1b\n" \ + : "=&r" (t), "+m" (*addr) \ + : "r" (val), "r" (addr) \ + : "cc" ); \ + } + +build_atomic_read(read_u8_atomic, "lbz", uint8_t) +build_atomic_read(read_u16_atomic, "lhz", uint16_t) +build_atomic_read(read_u32_atomic, "lwz", uint32_t) +build_atomic_read(read_u64_atomic, "ldz", uint64_t) + +build_atomic_write(write_u8_atomic, "stb", uint8_t) +build_atomic_write(write_u16_atomic, "sth", uint16_t) +build_atomic_write(write_u32_atomic, "stw", uint32_t) +build_atomic_write(write_u64_atomic, "std", uint64_t) + +build_add_sized(add_u8_sized, "lbarx", "stbcx.",uint8_t) +build_add_sized(add_u16_sized, "lharx", "sthcx.", uint16_t) +build_add_sized(add_u32_sized, "lwarx", "stwcx.", uint32_t) + +#undef build_atomic_read +#undef build_atomic_write +#undef build_add_sized + +static always_inline void read_atomic_size(const volatile void *p, void *res, + unsigned int size) +{ + ASSERT(IS_ALIGNED((vaddr_t)p, size)); + switch ( size ) + { + case 1: + *(uint8_t *)res = read_u8_atomic(p); + break; + case 2: + *(uint16_t *)res = read_u16_atomic(p); + break; + case 4: + *(uint32_t *)res = read_u32_atomic(p); + break; + case 8: + *(uint64_t *)res = read_u64_atomic(p); + break; + default: + __bad_atomic_read(p, res); + break; + } +} + +static always_inline void write_atomic_size(volatile void *p, const void *val, + unsigned int size) +{ + ASSERT(IS_ALIGNED((vaddr_t)p, size)); + switch ( size ) + { + case 1: + write_u8_atomic(p, *(const uint8_t *)val); + break; + case 2: + write_u16_atomic(p, *(const uint16_t *)val); + break; + case 4: + write_u32_atomic(p, *(const uint32_t *)val); + break; + case 8: + write_u64_atomic(p, *(const uint64_t *)val); + break; + default: + __bad_atomic_size(); + break; + } +} + +#define read_atomic(p) \ + ({ \ + union { \ + typeof(*(p)) val; \ + char c[sizeof(*(p))]; \ + } x_; \ + read_atomic_size(p, x_.c, sizeof(*(p))); \ + x_.val; \ + }) + +#define write_atomic(p, x) \ + do \ + { \ + typeof(*(p)) x_ = (x); \ + write_atomic_size(p, &x_, sizeof(*(p))); \ + } while ( 0 ) + +#define add_sized(p, x) \ + ({ \ + typeof(*(p)) x_ = (x); \ + switch ( sizeof(*(p)) ) \ + { \ + case 1: \ + add_u8_sized((uint8_t *)(p), x_); \ + break; \ + case 2: \ + add_u16_sized((uint16_t *)(p), x_); \ + break; \ + case 4: \ + add_u32_sized((uint32_t *)(p), x_); \ + break; \ + default: \ + __bad_atomic_size(); \ + break; \ + } \ + }) + +static inline void atomic_add(int a, atomic_t *v) +{ + int t; + + asm volatile ( "1: lwarx %0,0,%3\n" + "add %0,%2,%0\n" + "stwcx. %0,0,%3\n" + "bne- 1b" + : "=&r" (t), "+m" (v->counter) + : "r" (a), "r" (&v->counter) + : "cc" ); +} + +static inline int atomic_add_return(int a, atomic_t *v) +{ + int t; + + asm volatile ( PPC_ATOMIC_ENTRY_BARRIER + "1: lwarx %0,0,%2\n" + "add %0,%1,%0\n" + "stwcx. %0,0,%2\n" + "bne- 1b\n" + PPC_ATOMIC_EXIT_BARRIER + : "=&r" (t) + : "r" (a), "r" (&v->counter) + : "cc", "memory" ); + + return t; +} + +static inline void atomic_sub(int a, atomic_t *v) +{ + int t; + + asm volatile ( "1: lwarx %0,0,%3\n" + "subf %0,%2,%0\n" + "stwcx. %0,0,%3\n" + "bne- 1b" + : "=&r" (t), "+m" (v->counter) + : "r" (a), "r" (&v->counter) + : "cc" ); +} + +static inline int atomic_sub_return(int a, atomic_t *v) +{ + int t; + + asm volatile ( PPC_ATOMIC_ENTRY_BARRIER + "1: lwarx %0,0,%2\n" + "subf %0,%1,%0\n" + "stwcx. %0,0,%2\n" + "bne- 1b\n" + PPC_ATOMIC_EXIT_BARRIER + : "=&r" (t) + : "r" (a), "r" (&v->counter) + : "cc", "memory" ); + + return t; +} + +static inline void atomic_inc(atomic_t *v) +{ + int t; + + asm volatile ( "1: lwarx %0,0,%2\n" + "addic %0,%0,1\n" + "stwcx. %0,0,%2\n" + "bne- 1b" + : "=&r" (t), "+m" (v->counter) + : "r" (&v->counter) + : "cc" ); +} + +static inline int atomic_inc_return(atomic_t *v) +{ + int t; + + asm volatile ( PPC_ATOMIC_ENTRY_BARRIER + "1: lwarx %0,0,%1\n" + "addic %0,%0,1\n" + "stwcx. %0,0,%1\n" + "bne- 1b\n" + PPC_ATOMIC_EXIT_BARRIER + : "=&r" (t) + : "r" (&v->counter) + : "cc", "memory" ); + + return t; +} + +static inline void atomic_dec(atomic_t *v) +{ + int t; + + asm volatile ( "1: lwarx %0,0,%2\n" + "addic %0,%0,-1\n" + "stwcx. %0,0,%2\n" + "bne- 1b" + : "=&r" (t), "+m" (v->counter) + : "r" (&v->counter) + : "cc" ); +} + +static inline int atomic_dec_return(atomic_t *v) +{ + int t; + + asm volatile ( PPC_ATOMIC_ENTRY_BARRIER + "1: lwarx %0,0,%1\n" + "addic %0,%0,-1\n" + "stwcx. %0,0,%1\n" + "bne- 1b\n" + PPC_ATOMIC_EXIT_BARRIER + : "=&r" (t) + : "r" (&v->counter) + : "cc", "memory" ); + + return t; +} + +/* + * Atomically test *v and decrement if it is greater than 0. + * The function returns the old value of *v minus 1. + */ +static inline int atomic_dec_if_positive(atomic_t *v) +{ + int t; + + asm volatile( PPC_ATOMIC_ENTRY_BARRIER + "1: lwarx %0,0,%1 # atomic_dec_if_positive\n" + "addic. %0,%0,-1\n" + "blt- 2f\n" + "stwcx. %0,0,%1\n" + "bne- 1b\n" + PPC_ATOMIC_EXIT_BARRIER + "2:" + : "=&r" (t) + : "r" (&v->counter) + : "cc", "memory" ); + + return t; +} + +static inline atomic_t atomic_compareandswap(atomic_t old, atomic_t new, + atomic_t *v) +{ + atomic_t rc; + rc.counter = __cmpxchg(&v->counter, old.counter, new.counter, + sizeof(v->counter)); + return rc; +} + +#define arch_cmpxchg(ptr, o, n) \ + ({ \ + __typeof__(*(ptr)) o_ = (o); \ + __typeof__(*(ptr)) n_ = (n); \ + (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)o_, \ + (unsigned long)n_, sizeof(*(ptr))); \ + }) + +static inline int atomic_cmpxchg(atomic_t *v, int old, int new) +{ + return arch_cmpxchg(&v->counter, old, new); +} + +#define ATOMIC_OP(op, insn, suffix, sign) \ + static inline void atomic_##op(int a, atomic_t *v) \ + { \ + int t; \ + asm volatile ( "1: lwarx %0,0,%3\n" \ + insn "%I2" suffix " %0,%0,%2\n" \ + "stwcx. %0,0,%3 \n" \ + "bne- 1b\n" \ + : "=&r" (t), "+m" (v->counter) \ + : "r" #sign (a), "r" (&v->counter) \ + : "cc" ); \ + } + +ATOMIC_OP(and, "and", ".", K) + +static inline int atomic_sub_and_test(int i, atomic_t *v) +{ + return atomic_sub_return(i, v) == 0; +} + +static inline int atomic_inc_and_test(atomic_t *v) +{ + return atomic_add_return(1, v) == 0; +} + +static inline int atomic_dec_and_test(atomic_t *v) +{ + return atomic_sub_return(1, v) == 0; +} + +static inline int atomic_add_negative(int i, atomic_t *v) +{ + return atomic_add_return(i, v) < 0; +} + +static inline int __atomic_add_unless(atomic_t *v, int a, int u) +{ + int c, old; + + c = atomic_read(v); + while (c != u && (old = atomic_cmpxchg(v, c, c + a)) != c) + c = old; + return c; +} + +static inline int atomic_add_unless(atomic_t *v, int a, int u) +{ + return __atomic_add_unless(v, a, u); +} + +#endif /* _ASM_PPC64_ATOMIC_H_ */ diff --git a/xen/arch/ppc/include/asm/memory.h b/xen/arch/ppc/include/asm/memory.h new file mode 100644 index 0000000000..57310eb690 --- /dev/null +++ b/xen/arch/ppc/include/asm/memory.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) IBM Corp. 2005 + * + * Authors: Jimi Xenidis + */ + +#ifndef _ASM_MEMORY_H_ +#define _ASM_MEMORY_H_ + +#define PPC_ATOMIC_ENTRY_BARRIER "sync\n" +#define PPC_ATOMIC_EXIT_BARRIER "sync\n" + +#endif