From patchwork Wed May 25 15:58:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 1635544 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4L7bPJ4mM6z9sG2 for ; Thu, 26 May 2022 02:00:04 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4L7bPJ3y7Pz3dqH for ; Thu, 26 May 2022 02:00:04 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=csgroup.eu (client-ip=93.17.235.10; helo=pegase2.c-s.fr; envelope-from=christophe.leroy@csgroup.eu; receiver=) Received: from pegase2.c-s.fr (pegase2.c-s.fr [93.17.235.10]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4L7bN513cVz3bkW for ; Thu, 26 May 2022 01:59:00 +1000 (AEST) Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4L7bMn2chTz9tFN; Wed, 25 May 2022 17:58:45 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9vEVZE9HpWyB; Wed, 25 May 2022 17:58:45 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4L7bMk5NFmz9tFP; Wed, 25 May 2022 17:58:42 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 9FE958B77A; Wed, 25 May 2022 17:58:42 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id htU6u_JrvheR; Wed, 25 May 2022 17:58:42 +0200 (CEST) Received: from PO20335.IDSI0.si.c-s.fr (unknown [192.168.203.180]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 28D0E8B778; Wed, 25 May 2022 17:58:42 +0200 (CEST) Received: from PO20335.IDSI0.si.c-s.fr (localhost [127.0.0.1]) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.16.1) with ESMTPS id 24PFwR0e419152 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Wed, 25 May 2022 17:58:27 +0200 Received: (from chleroy@localhost) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.17.1/Submit) id 24PFwRZn419151; Wed, 25 May 2022 17:58:27 +0200 X-Authentication-Warning: PO20335.IDSI0.si.c-s.fr: chleroy set sender to christophe.leroy@csgroup.eu using -f From: Christophe Leroy To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , peterz@infradead.org, aik@ozlabs.ru, sv@linux.ibm.com, rostedt@goodmis.org, jpoimboe@redhat.com, naveen.n.rao@linux.vnet.ibm.com, mbenes@suse.cz Subject: [RFC PATCH v1 4/4] powerpc/static_call: Implement inline static calls Date: Wed, 25 May 2022 17:58:17 +0200 Message-Id: <2e74b10072ca594c394dd1c445d827505725f27a.1653494186.git.christophe.leroy@csgroup.eu> X-Mailer: git-send-email 2.35.3 In-Reply-To: References: MIME-Version: 1.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1653494295; l=4004; s=20211009; h=from:subject:message-id; bh=Si7ViaXO/clzpQWdQFEHD12KLid8Hfc27sgBafOTn9A=; b=1u5j19ZyGAUOZn2Be1bpzfdF3Xi2Yq69UCl1H3WI+qNHuP6EbAvpWnSmUmfc2ZpXvf04Wy3rRcpp U79BvpfHCtkQcDPtHARpwiTtn1Wu3Tw0mXJ4Jt1PDGSvb0bEGsTW X-Developer-Key: i=christophe.leroy@csgroup.eu; a=ed25519; pk=HIzTzUj91asvincQGOFx6+ZF5AoUuP9GdOtQChs7Mm0= X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Implement inline static calls: - Put a 'bl' to the destination function - Put a 'nop' when the destination function is NULL - Put a 'li r3,0' when the destination is the RET0 function For the time being it only works if the destination is within 32Mb from the caller. Signed-off-by: Christophe Leroy --- arch/powerpc/Kconfig | 1 + arch/powerpc/include/asm/static_call.h | 2 + arch/powerpc/kernel/static_call.c | 41 ++++++++++++------- tools/objtool/arch/powerpc/include/arch/elf.h | 1 + 4 files changed, 31 insertions(+), 14 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 5ef8bf8eb202..3257a1c258d8 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -246,6 +246,7 @@ config PPC select HAVE_STACKPROTECTOR if PPC32 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r2) select HAVE_STACKPROTECTOR if PPC64 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r13) select HAVE_STATIC_CALL if PPC32 + select HAVE_STATIC_CALL_INLINE if PPC32 select HAVE_SYSCALL_TRACEPOINTS select HAVE_VIRT_CPU_ACCOUNTING select HUGETLB_PAGE_SIZE_VARIABLE if PPC_BOOK3S_64 && HUGETLB_PAGE diff --git a/arch/powerpc/include/asm/static_call.h b/arch/powerpc/include/asm/static_call.h index de1018cc522b..e3d5d3823dac 100644 --- a/arch/powerpc/include/asm/static_call.h +++ b/arch/powerpc/include/asm/static_call.h @@ -26,4 +26,6 @@ #define ARCH_DEFINE_STATIC_CALL_NULL_TRAMP(name) __PPC_SCT(name, "blr") #define ARCH_DEFINE_STATIC_CALL_RET0_TRAMP(name) __PPC_SCT(name, "b .+20") +#define CALL_INSN_SIZE 4 + #endif /* _ASM_POWERPC_STATIC_CALL_H */ diff --git a/arch/powerpc/kernel/static_call.c b/arch/powerpc/kernel/static_call.c index 863a7aa24650..fd25954cfd24 100644 --- a/arch/powerpc/kernel/static_call.c +++ b/arch/powerpc/kernel/static_call.c @@ -9,25 +9,38 @@ void arch_static_call_transform(void *site, void *tramp, void *func, bool tail) int err; bool is_ret0 = (func == __static_call_return0); unsigned long target = (unsigned long)(is_ret0 ? tramp + PPC_SCT_RET0 : func); - bool is_short = is_offset_in_branch_range((long)target - (long)tramp); - - if (!tramp) - return; mutex_lock(&text_mutex); - if (func && !is_short) { - err = patch_instruction(tramp + PPC_SCT_DATA, ppc_inst(target)); - if (err) - goto out; + if (tramp) { + bool is_short = is_offset_in_branch_range((long)target - (long)tramp); + + if (func && !is_short) { + err = patch_instruction(tramp + PPC_SCT_DATA, ppc_inst(target)); + if (err) + goto out; + } + + if (!func) + err = patch_instruction(tramp, ppc_inst(PPC_RAW_BLR())); + else if (is_short) + err = patch_branch(tramp, target, 0); + else + err = patch_instruction(tramp, ppc_inst(PPC_RAW_NOP())); } - if (!func) - err = patch_instruction(tramp, ppc_inst(PPC_RAW_BLR())); - else if (is_short) - err = patch_branch(tramp, target, 0); - else - err = patch_instruction(tramp, ppc_inst(PPC_RAW_NOP())); + if (site) { + bool is_short = is_offset_in_branch_range((long)func - (long)site); + + if (!func) + err = patch_instruction(site, ppc_inst(PPC_RAW_NOP())); + else if (is_ret0) + err = patch_instruction(site, ppc_inst(PPC_RAW_LI(_R3, 0))); + else if (is_short) + err = patch_branch(site, target, BRANCH_SET_LINK); + else + panic("%s: function %pS is out of reach of %pS\n", __func__, func, site); + } out: mutex_unlock(&text_mutex); diff --git a/tools/objtool/arch/powerpc/include/arch/elf.h b/tools/objtool/arch/powerpc/include/arch/elf.h index 3c8ebb7d2a6b..18784c764c14 100644 --- a/tools/objtool/arch/powerpc/include/arch/elf.h +++ b/tools/objtool/arch/powerpc/include/arch/elf.h @@ -4,5 +4,6 @@ #define _OBJTOOL_ARCH_ELF #define R_NONE R_PPC_NONE +#define R_REL32 R_PPC_REL32 #endif /* _OBJTOOL_ARCH_ELF */