From patchwork Thu Jun 8 07:58:17 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicholas Piggin X-Patchwork-Id: 13271719 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 23A43C7EE23 for ; Thu, 8 Jun 2023 07:58:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233955AbjFHH6x (ORCPT ); Thu, 8 Jun 2023 03:58:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233894AbjFHH6t (ORCPT ); Thu, 8 Jun 2023 03:58:49 -0400 Received: from mail-qt1-x82b.google.com (mail-qt1-x82b.google.com [IPv6:2607:f8b0:4864:20::82b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A7BE212E for ; Thu, 8 Jun 2023 00:58:48 -0700 (PDT) Received: by mail-qt1-x82b.google.com with SMTP id d75a77b69052e-3f6c6020cfbso2191101cf.2 for ; Thu, 08 Jun 2023 00:58:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1686211127; x=1688803127; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=mmEhHDXqBF9dQ1veYws/GnTEIhu9OPeqy9gy1d4w4DM=; b=FSas9QUg0UpdaLQcAcrgO+WSq/ocmCN8xKJ4KaAPW84Dm1aS8VCARaSFulSe1vWHVS nrK/ONUP3MvBx+ePiWqriKeg3gwanhQv3yghafty8pF3wexJAcWqGSlsqHNN/hYxpbVx iohdAGMELlqbyrR8sZX40mSSF9+OkqzutNEnwViW3tAxDM8+cMxIRyESG1ZQY1Z7ocn8 OZI+QSIJBk912zU93j7b1fGjUwsDG0aMnGmnLHF2+05BG+doiwRs2jNYDntLYaymX6fm 8v1+3JtWuBZQC7NCSDy5QB7RXn/DXmu1VRb2dSD20bZBPHiVMbW3y1esS9kEa82tK/DM k8WA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686211127; x=1688803127; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=mmEhHDXqBF9dQ1veYws/GnTEIhu9OPeqy9gy1d4w4DM=; b=eZqVwbOcXC+9y34lUaRCbMtd1fc3wDMLd7dujIEv9t5DmWsQ+6aeJyhkJNMfkCZUnP F9cbQDK5CdJ1vgj2AhTPzdQuKAC+s9sCrgOxRaouiqnspTl5j49PYodMa0JKDR4bKtE0 u2nOQyI9mB157I6L97TaPeJBI3AC1kTzEJHlChID3HydbS9rDqXapA/UI8uWlXNFDgmD RFGyf6+he1mMlr37BtO4Zqhatqwr9THx1Rdh4M2RXlm8s36me4q76eH9QRjeaDrCGoeh aRdrCrIF92az4sJ82wni7uanMUmY4NdXzxxuO3vVzUlmiMO5UP0xO1SprIcZzcwj2EAf ALKA== X-Gm-Message-State: AC+VfDyeur2c6ySmXLGrT/psoWYBmiBbXHYgo/qS8uXXBOkq/IZ+/oYS hfWO038V+kuKlA7t9VIOFlK9T8CBapw= X-Google-Smtp-Source: ACHHUZ5pZcO+N3Su+GOBU3WMg4D9ivP4jx6OqrrOSe/69gNNpjrbL1hXdwcvJQzjzuzgsPF6UNMhWw== X-Received: by 2002:a05:622a:180a:b0:3f8:6b32:480d with SMTP id t10-20020a05622a180a00b003f86b32480dmr6247042qtc.46.1686211126897; Thu, 08 Jun 2023 00:58:46 -0700 (PDT) Received: from wheely.local0.net ([1.146.34.117]) by smtp.gmail.com with ESMTPSA id 17-20020a630011000000b00542d7720a6fsm673182pga.88.2023.06.08.00.58.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 08 Jun 2023 00:58:46 -0700 (PDT) From: Nicholas Piggin To: kvm@vger.kernel.org Cc: Nicholas Piggin , linuxppc-dev@lists.ozlabs.org, Laurent Vivier , Thomas Huth Subject: [kvm-unit-tests v4 03/12] powerpc: Abstract H_CEDE calls into a sleep functions Date: Thu, 8 Jun 2023 17:58:17 +1000 Message-Id: <20230608075826.86217-4-npiggin@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230608075826.86217-1-npiggin@gmail.com> References: <20230608075826.86217-1-npiggin@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org This consolidates several implementations, and it no longer leaves MSR[EE] enabled after the decrementer interrupt is handled, but rather disables it on return. The handler no longer allows a continuous ticking, but rather dec has to be re-armed and EE re-enabled (e.g., via H_CEDE hcall) each time. Signed-off-by: Nicholas Piggin --- lib/powerpc/asm/handlers.h | 2 +- lib/powerpc/asm/ppc_asm.h | 1 + lib/powerpc/asm/processor.h | 7 ++++++ lib/powerpc/handlers.c | 10 ++++----- lib/powerpc/processor.c | 43 +++++++++++++++++++++++++++++++++++++ powerpc/sprs.c | 6 +----- powerpc/tm.c | 20 +---------------- 7 files changed, 58 insertions(+), 31 deletions(-) diff --git a/lib/powerpc/asm/handlers.h b/lib/powerpc/asm/handlers.h index 64ba727a..e4a0cd45 100644 --- a/lib/powerpc/asm/handlers.h +++ b/lib/powerpc/asm/handlers.h @@ -3,6 +3,6 @@ #include -void dec_except_handler(struct pt_regs *regs, void *data); +void dec_handler_oneshot(struct pt_regs *regs, void *data); #endif /* _ASMPOWERPC_HANDLERS_H_ */ diff --git a/lib/powerpc/asm/ppc_asm.h b/lib/powerpc/asm/ppc_asm.h index 1b85f6bb..6299ff53 100644 --- a/lib/powerpc/asm/ppc_asm.h +++ b/lib/powerpc/asm/ppc_asm.h @@ -36,6 +36,7 @@ #endif /* __BYTE_ORDER__ */ /* Machine State Register definitions: */ +#define MSR_EE_BIT 15 /* External Interrupts Enable */ #define MSR_SF_BIT 63 /* 64-bit mode */ #endif /* _ASMPOWERPC_PPC_ASM_H */ diff --git a/lib/powerpc/asm/processor.h b/lib/powerpc/asm/processor.h index ac001e18..ebfeff2b 100644 --- a/lib/powerpc/asm/processor.h +++ b/lib/powerpc/asm/processor.h @@ -20,6 +20,8 @@ static inline uint64_t get_tb(void) extern void delay(uint64_t cycles); extern void udelay(uint64_t us); +extern void sleep_tb(uint64_t cycles); +extern void usleep(uint64_t us); static inline void mdelay(uint64_t ms) { @@ -27,4 +29,9 @@ static inline void mdelay(uint64_t ms) udelay(1000); } +static inline void msleep(uint64_t ms) +{ + usleep(ms * 1000); +} + #endif /* _ASMPOWERPC_PROCESSOR_H_ */ diff --git a/lib/powerpc/handlers.c b/lib/powerpc/handlers.c index c8721e0a..296f14ff 100644 --- a/lib/powerpc/handlers.c +++ b/lib/powerpc/handlers.c @@ -9,15 +9,13 @@ #include #include #include +#include /* * Generic handler for decrementer exceptions (0x900) - * Just reset the decrementer back to the value specified when registering the - * handler + * Return with MSR[EE] disabled. */ -void dec_except_handler(struct pt_regs *regs __unused, void *data) +void dec_handler_oneshot(struct pt_regs *regs, void *data) { - uint64_t dec = *((uint64_t *) data); - - asm volatile ("mtdec %0" : : "r" (dec)); + regs->msr &= ~(1UL << MSR_EE_BIT); } diff --git a/lib/powerpc/processor.c b/lib/powerpc/processor.c index 0550e4fc..aaf45b68 100644 --- a/lib/powerpc/processor.c +++ b/lib/powerpc/processor.c @@ -10,6 +10,8 @@ #include #include #include +#include +#include static struct { void (*func)(struct pt_regs *, void *data); @@ -58,3 +60,44 @@ void udelay(uint64_t us) { delay((us * tb_hz) / 1000000); } + +void sleep_tb(uint64_t cycles) +{ + uint64_t start, end, now; + + start = now = get_tb(); + end = start + cycles; + + while (end > now) { + uint64_t left = end - now; + + /* TODO: Could support large decrementer */ + if (left > 0x7fffffff) + left = 0x7fffffff; + + /* DEC won't fire until H_CEDE is called because EE=0 */ + asm volatile ("mtdec %0" : : "r" (left)); + handle_exception(0x900, &dec_handler_oneshot, NULL); + /* + * H_CEDE is called with MSR[EE] clear and enables it as part + * of the hcall, returning with EE enabled. The dec interrupt + * is then taken immediately and the handler disables EE. + * + * If H_CEDE returned for any other interrupt than dec + * expiring, that is considered an unhandled interrupt and + * the test case would be stopped. + */ + if (hcall(H_CEDE) != H_SUCCESS) { + printf("H_CEDE failed\n"); + abort(); + } + handle_exception(0x900, NULL, NULL); + + now = get_tb(); + } +} + +void usleep(uint64_t us) +{ + sleep_tb((us * tb_hz) / 1000000); +} diff --git a/powerpc/sprs.c b/powerpc/sprs.c index 5cc1cd16..ba4ddee4 100644 --- a/powerpc/sprs.c +++ b/powerpc/sprs.c @@ -254,7 +254,6 @@ int main(int argc, char **argv) 0x1234567890ABCDEFULL, 0xFEDCBA0987654321ULL, -1ULL, }; - static uint64_t decr = 0x7FFFFFFF; /* Max value */ for (i = 1; i < argc; i++) { if (!strcmp(argv[i], "-w")) { @@ -288,10 +287,7 @@ int main(int argc, char **argv) if (pause) { migrate_once(); } else { - puts("Sleeping...\n"); - handle_exception(0x900, &dec_except_handler, &decr); - asm volatile ("mtdec %0" : : "r" (0x3FFFFFFF)); - hcall(H_CEDE); + msleep(2000); } get_sprs(after); diff --git a/powerpc/tm.c b/powerpc/tm.c index 65cacdf5..7fa91636 100644 --- a/powerpc/tm.c +++ b/powerpc/tm.c @@ -48,17 +48,6 @@ static int count_cpus_with_tm(void) return available; } -static int h_cede(void) -{ - register uint64_t r3 asm("r3") = H_CEDE; - - asm volatile ("sc 1" : "+r"(r3) : - : "r0", "r4", "r5", "r6", "r7", "r8", "r9", - "r10", "r11", "r12", "xer", "ctr", "cc"); - - return r3; -} - /* * Enable transactional memory * Returns: FALSE - Failure @@ -95,14 +84,10 @@ static bool enable_tm(void) static void test_h_cede_tm(int argc, char **argv) { int i; - static uint64_t decr = 0x3FFFFF; /* ~10ms */ if (argc > 2) report_abort("Unsupported argument: '%s'", argv[2]); - handle_exception(0x900, &dec_except_handler, &decr); - asm volatile ("mtdec %0" : : "r" (decr)); - if (!start_all_cpus(halt, 0)) report_abort("Failed to start secondary cpus"); @@ -120,10 +105,7 @@ static void test_h_cede_tm(int argc, char **argv) "bf 2,1b" : : : "cr0"); for (i = 0; i < 500; i++) { - uint64_t rval = h_cede(); - - if (rval != H_SUCCESS) - break; + msleep(10); mdelay(5); }