From nobody Tue Sep 16 01:25:53 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6820EC54EBD for ; Mon, 9 Jan 2023 09:12:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237052AbjAIJMh (ORCPT ); Mon, 9 Jan 2023 04:12:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236996AbjAIJLu (ORCPT ); Mon, 9 Jan 2023 04:11:50 -0500 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 7399A17E23 for ; Mon, 9 Jan 2023 01:08:14 -0800 (PST) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8AxrvB82btjgHUAAA--.1723S3; Mon, 09 Jan 2023 17:08:12 +0800 (CST) Received: from bogon.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8DxTuRw2btj_6sWAA--.4042S3; Mon, 09 Jan 2023 17:08:11 +0800 (CST) From: Youling Tang To: Huacai Chen , Xi Ruoyao , Jinyang He Cc: Xuerui Wang , loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH 1/4] LoongArch: Use trampoline for exception handlers and kill la.abs Date: Mon, 9 Jan 2023 17:07:51 +0800 Message-Id: <1673255274-18238-2-git-send-email-tangyouling@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1673255274-18238-1-git-send-email-tangyouling@loongson.cn> References: <1673255274-18238-1-git-send-email-tangyouling@loongson.cn> X-CM-TRANSID: AQAAf8DxTuRw2btj_6sWAA--.4042S3 X-CM-SenderInfo: 5wdqw5prxox03j6o00pqjv00gofq/ X-Coremail-Antispam: 1Uk129KBjvJXoW3GF1rXry3tFWfXFW3CrWDtwb_yoW3WF17pw nxAr4DJa10gFn5Za4UKw1UurW5JwnFga1aga17CrWru3W2vF18X34vy397uF9rKay8XF40 9F1rJw4IvFWUJwUanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUj1kv1TuYvTs0mT0YCTnIWj qI5I8CrVACY4xI64kE6c02F40Ex7xfYxn0WfASr-VFAUDa7-sFnT9fnUUIcSsGvfJTRUUU b7AYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s 1l1IIY67AEw4v_Jrv_JF1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVW8JVW5JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwA2z4 x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I8E87Iv6xkF7I0E14v26r4UJVWxJr1l e2I262IYc4CY6c8Ij28IcVAaY2xG8wAqjxCEc2xF0cIa020Ex4CE44I27wAqx4xG64xvF2 IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_JF0_Jw1lYx0Ex4A2jsIE14v26r1j6r4U McvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x0EwIxGrwCFx2 IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v2 6r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67 AKxVWUCVW8JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IY s7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Jr 0_GrUvcSsGvfC2KfnxnUUI43ZEXa7IU82g43UUUUU== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Xi Ruoyao Use a trampoline as an exception handlers, which can kill some use of la.abs in preparation for the subsequent support of the PIE kernel. Signed-off-by: Xi Ruoyao Signed-off-by: Youling Tang --- arch/loongarch/include/asm/stackframe.h | 8 +++---- arch/loongarch/include/asm/uaccess.h | 1 - arch/loongarch/kernel/entry.S | 6 +++--- arch/loongarch/kernel/genex.S | 20 +++++++++--------- arch/loongarch/kernel/head.S | 2 +- arch/loongarch/kernel/traps.c | 4 +++- arch/loongarch/mm/tlbex.S | 28 +++++++------------------ 7 files changed, 29 insertions(+), 40 deletions(-) diff --git a/arch/loongarch/include/asm/stackframe.h b/arch/loongarch/inclu= de/asm/stackframe.h index 4ca953062b5b..96c94035b5d0 100644 --- a/arch/loongarch/include/asm/stackframe.h +++ b/arch/loongarch/include/asm/stackframe.h @@ -76,8 +76,8 @@ * kernelsp array for it. It stores the current sp in t0 and loads the * new value in sp. */ - .macro get_saved_sp docfi=3D0 - la.abs t1, kernelsp + .macro get_saved_sp docfi=3D0 + la.pcrel t1, kernelsp #ifdef CONFIG_SMP csrrd t0, PERCPU_BASE_KS LONG_ADD t1, t1, t0 @@ -89,8 +89,8 @@ LONG_L sp, t1, 0 .endm =20 - .macro set_saved_sp stackp temp temp2 - la.abs \temp, kernelsp + .macro set_saved_sp stackp temp temp2 + la.pcrel \temp, kernelsp #ifdef CONFIG_SMP LONG_ADD \temp, \temp, u0 #endif diff --git a/arch/loongarch/include/asm/uaccess.h b/arch/loongarch/include/= asm/uaccess.h index 255899d4a7c3..0d22991ae430 100644 --- a/arch/loongarch/include/asm/uaccess.h +++ b/arch/loongarch/include/asm/uaccess.h @@ -22,7 +22,6 @@ extern u64 __ua_limit; =20 #define __UA_ADDR ".dword" -#define __UA_LA "la.abs" #define __UA_LIMIT __ua_limit =20 /* diff --git a/arch/loongarch/kernel/entry.S b/arch/loongarch/kernel/entry.S index d53b631c9022..ca01afdbec3f 100644 --- a/arch/loongarch/kernel/entry.S +++ b/arch/loongarch/kernel/entry.S @@ -18,9 +18,9 @@ .text .cfi_sections .debug_frame .align 5 -SYM_FUNC_START(handle_syscall) +SYM_FUNC_START(handle_sys) csrrd t0, PERCPU_BASE_KS - la.abs t1, kernelsp + la.pcrel t1, kernelsp add.d t1, t1, t0 move t2, sp ld.d sp, t1, 0 @@ -66,7 +66,7 @@ SYM_FUNC_START(handle_syscall) bl do_syscall =20 RESTORE_ALL_AND_RET -SYM_FUNC_END(handle_syscall) +SYM_FUNC_END(handle_sys) =20 SYM_CODE_START(ret_from_fork) bl schedule_tail # a0 =3D struct task_struct *prev diff --git a/arch/loongarch/kernel/genex.S b/arch/loongarch/kernel/genex.S index 75e5be807a0d..d3df0fa725a2 100644 --- a/arch/loongarch/kernel/genex.S +++ b/arch/loongarch/kernel/genex.S @@ -32,9 +32,8 @@ SYM_FUNC_START(__arch_cpu_idle) SYM_FUNC_END(__arch_cpu_idle) =20 SYM_FUNC_START(handle_vint) - BACKUP_T0T1 SAVE_ALL - la.abs t1, __arch_cpu_idle + la.pcrel t1, __arch_cpu_idle LONG_L t0, sp, PT_ERA /* 32 byte rollback region */ ori t0, t0, 0x1f @@ -43,8 +42,7 @@ SYM_FUNC_START(handle_vint) LONG_S t0, sp, PT_ERA 1: move a0, sp move a1, sp - la.abs t0, do_vint - jirl ra, t0, 0 + bl do_vint RESTORE_ALL_AND_RET SYM_FUNC_END(handle_vint) =20 @@ -67,12 +65,10 @@ SYM_FUNC_END(except_vec_cex) .macro BUILD_HANDLER exception handler prep .align 5 SYM_FUNC_START(handle_\exception) - BACKUP_T0T1 SAVE_ALL build_prep_\prep move a0, sp - la.abs t0, do_\handler - jirl ra, t0, 0 + bl do_\handler RESTORE_ALL_AND_RET SYM_FUNC_END(handle_\exception) .endm @@ -89,7 +85,11 @@ SYM_FUNC_END(except_vec_cex) BUILD_HANDLER watch watch none BUILD_HANDLER reserved reserved none /* others */ =20 -SYM_FUNC_START(handle_sys) - la.abs t0, handle_syscall +SYM_FUNC_START(handler_trampoline) + csrwr t0, EXCEPTION_KS0 + csrwr t1, EXCEPTION_KS1 + pcaddi t0, 0 + ld.d t0, t0, 16 jr t0 -SYM_FUNC_END(handle_sys) + nop +SYM_FUNC_END(handler_trampoline) diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S index 57bada6b4e93..aa6181714ec3 100644 --- a/arch/loongarch/kernel/head.S +++ b/arch/loongarch/kernel/head.S @@ -117,7 +117,7 @@ SYM_CODE_START(smpboot_entry) li.w t0, 0x00 # FPE=3D0, SXE=3D0, ASXE=3D0, BTE=3D0 csrwr t0, LOONGARCH_CSR_EUEN =20 - la.abs t0, cpuboot_data + la.pcrel t0, cpuboot_data ld.d sp, t0, CPU_BOOT_STACK ld.d tp, t0, CPU_BOOT_TINFO =20 diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c index 7ea62faeeadb..0e8faaca3679 100644 --- a/arch/loongarch/kernel/traps.c +++ b/arch/loongarch/kernel/traps.c @@ -61,6 +61,7 @@ extern asmlinkage void handle_lasx(void); extern asmlinkage void handle_reserved(void); extern asmlinkage void handle_watch(void); extern asmlinkage void handle_vint(void); +extern asmlinkage void handler_trampoline(void); =20 static void show_backtrace(struct task_struct *task, const struct pt_regs = *regs, const char *loglvl, bool user) @@ -716,7 +717,8 @@ void per_cpu_trap_init(int cpu) /* Install CPU exception handler */ void set_handler(unsigned long offset, void *addr, unsigned long size) { - memcpy((void *)(eentry + offset), addr, size); + memcpy((void *)(eentry + offset), &handler_trampoline, 24); + memcpy((void *)(eentry + offset + 24), &addr, 8); local_flush_icache_range(eentry + offset, eentry + offset + size); } =20 diff --git a/arch/loongarch/mm/tlbex.S b/arch/loongarch/mm/tlbex.S index 58781c6e4191..cfaacdac518c 100644 --- a/arch/loongarch/mm/tlbex.S +++ b/arch/loongarch/mm/tlbex.S @@ -24,8 +24,7 @@ move a0, sp REG_S a2, sp, PT_BVADDR li.w a1, \write - la.abs t0, do_page_fault - jirl ra, t0, 0 + bl do_page_fault RESTORE_ALL_AND_RET SYM_FUNC_END(tlb_do_page_fault_\write) .endm @@ -34,20 +33,16 @@ tlb_do_page_fault 1 =20 SYM_FUNC_START(handle_tlb_protect) - BACKUP_T0T1 SAVE_ALL move a0, sp move a1, zero csrrd a2, LOONGARCH_CSR_BADV REG_S a2, sp, PT_BVADDR - la.abs t0, do_page_fault - jirl ra, t0, 0 + bl do_page_fault RESTORE_ALL_AND_RET SYM_FUNC_END(handle_tlb_protect) =20 SYM_FUNC_START(handle_tlb_load) - csrwr t0, EXCEPTION_KS0 - csrwr t1, EXCEPTION_KS1 csrwr ra, EXCEPTION_KS2 =20 /* @@ -116,7 +111,7 @@ smp_pgtable_change_load: =20 #ifdef CONFIG_64BIT vmalloc_load: - la.abs t1, swapper_pg_dir + la.pcrel t1, swapper_pg_dir b vmalloc_done_load #endif =20 @@ -187,13 +182,10 @@ tlb_huge_update_load: nopage_tlb_load: dbar 0 csrrd ra, EXCEPTION_KS2 - la.abs t0, tlb_do_page_fault_0 - jr t0 + b tlb_do_page_fault_0 SYM_FUNC_END(handle_tlb_load) =20 SYM_FUNC_START(handle_tlb_store) - csrwr t0, EXCEPTION_KS0 - csrwr t1, EXCEPTION_KS1 csrwr ra, EXCEPTION_KS2 =20 /* @@ -263,7 +255,7 @@ smp_pgtable_change_store: =20 #ifdef CONFIG_64BIT vmalloc_store: - la.abs t1, swapper_pg_dir + la.pcrel t1, swapper_pg_dir b vmalloc_done_store #endif =20 @@ -336,13 +328,10 @@ tlb_huge_update_store: nopage_tlb_store: dbar 0 csrrd ra, EXCEPTION_KS2 - la.abs t0, tlb_do_page_fault_1 - jr t0 + b tlb_do_page_fault_1 SYM_FUNC_END(handle_tlb_store) =20 SYM_FUNC_START(handle_tlb_modify) - csrwr t0, EXCEPTION_KS0 - csrwr t1, EXCEPTION_KS1 csrwr ra, EXCEPTION_KS2 =20 /* @@ -411,7 +400,7 @@ smp_pgtable_change_modify: =20 #ifdef CONFIG_64BIT vmalloc_modify: - la.abs t1, swapper_pg_dir + la.pcrel t1, swapper_pg_dir b vmalloc_done_modify #endif =20 @@ -483,8 +472,7 @@ tlb_huge_update_modify: nopage_tlb_modify: dbar 0 csrrd ra, EXCEPTION_KS2 - la.abs t0, tlb_do_page_fault_1 - jr t0 + b tlb_do_page_fault_1 SYM_FUNC_END(handle_tlb_modify) =20 SYM_FUNC_START(handle_tlb_refill) --=20 2.37.1