From patchwork Thu Jun 22 06:53:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anshuman Khandual X-Patchwork-Id: 13288328 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 B6F8FEB64D8 for ; Thu, 22 Jun 2023 06:55:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=zBrE40QwlQYCq+7g7EItaDMqGUnlSKHckqJjTAZtlLE=; b=F8CIga1XRh1mhe //pLxRCCmTofSYZv2ld9cRQuB2tACckc5tanB2vZA/ochKfCB6EMhDjtR8pqknzqZUqJWaC57Rkjh BbnjsfOfb3jlSxpuL33ffBQfobvEfi9dipR2gAh2taNvgEEnlsPD/9ymAG5d7wMvFJN6XdiGWHijf 88FyyFqJagvk/5am5dmKvuDGECRuS2gaek3FQSnvD+xmcbzlN19PJHQY84gmIM3sqFatzF8BpuTY0 To4tfbbLvP1J4oh+5uPtvqpDK1hLxXgQ9SV6d9WPPt+/FyTwqbd8xwqvvfesUcIthDCr5QfGPEA2a JQlWdZC9XXmAr6FVp0lQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qCEDq-00H7hX-1h; Thu, 22 Jun 2023 06:55:14 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qCEDd-00H7ZX-0g for linux-arm-kernel@bombadil.infradead.org; Thu, 22 Jun 2023 06:55:01 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Transfer-Encoding:MIME-Version :References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=UxMl/HVW9v6UnCW9nydtJDL0yazyeTdhr57JCOn/bfU=; b=Oyddk9AbebCv3RCDFq0IS7cKuz A8fxVjskmABNGPkCN9iN+Y9iMzvQ0GIStKDsYixZEzYfeI1K/bpZWHgByBnqvU2gIwJUV4LCg+EhK kvQcco0zQoZgShND7ysQGSm7Fiq6eW+5isFn/WpVHG0pR4B+d8X0Nk3ElOtQWJMLTyYAKGf2PQOVF jMM9D+0fcTD2WCdMUqrRzUSq3EiNCcXC9BuWCjE5FMB7DMshxLcKrpl1mHAXjKbSDvgQtOvRJRHJr A/XacSPcI0WIeFuefLug5+tZklPsRu/uPZd688MWd1k8IlEBoiANJfZBzY0+L52a8NpiHXmDEmnMR MAmmGhqQ==; Received: from foss.arm.com ([217.140.110.172]) by desiato.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qCEDY-000ysT-0Q for linux-arm-kernel@lists.infradead.org; Thu, 22 Jun 2023 06:54:59 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CD61C113E; Wed, 21 Jun 2023 23:55:34 -0700 (PDT) Received: from a077893.blr.arm.com (unknown [10.162.40.20]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 7FA213F59C; Wed, 21 Jun 2023 23:54:46 -0700 (PDT) From: Anshuman Khandual To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com Cc: Anshuman Khandual , Mark Brown , James Clark , Rob Herring , Marc Zyngier , Suzuki Poulose , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , linux-perf-users@vger.kernel.org Subject: [PATCH V13 08/10] arm64/perf: Add struct brbe_regset helper functions Date: Thu, 22 Jun 2023 12:23:49 +0530 Message-Id: <20230622065351.1092893-9-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230622065351.1092893-1-anshuman.khandual@arm.com> References: <20230622065351.1092893-1-anshuman.khandual@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230622_075457_229258_03447462 X-CRM114-Status: GOOD ( 18.23 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The primary abstraction level for fetching branch records from BRBE HW has been changed as 'struct brbe_regset', which contains storage for all three BRBE registers i.e BRBSRC, BRBTGT, BRBINF. Whether branch record processing happens in the task sched out path, or in the PMU IRQ handling path, these registers need to be extracted from the HW. Afterwards both live and stored sets need to be stitched together to create final branch records set. This adds required helper functions for such operations. Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Tested-by: James Clark Acked-by: Mark Rutland Signed-off-by: Anshuman Khandual --- drivers/perf/arm_brbe.c | 121 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) diff --git a/drivers/perf/arm_brbe.c b/drivers/perf/arm_brbe.c index a74459445813..203cd4f350d5 100644 --- a/drivers/perf/arm_brbe.c +++ b/drivers/perf/arm_brbe.c @@ -44,6 +44,127 @@ static void select_brbe_bank(int bank) isb(); } +static bool __read_brbe_regset(struct brbe_regset *entry, int idx) +{ + entry->brbinf = get_brbinf_reg(idx); + + if (brbe_invalid(entry->brbinf)) + return false; + + entry->brbsrc = get_brbsrc_reg(idx); + entry->brbtgt = get_brbtgt_reg(idx); + return true; +} + +/* + * Read all BRBE entries in HW until the first invalid entry. + * + * The caller must ensure that the BRBE is not concurrently modifying these + * branch entries. + */ +static int capture_brbe_regset(struct brbe_regset *buf, int nr_hw_entries) +{ + int idx = 0; + + select_brbe_bank(BRBE_BANK_IDX_0); + while (idx < nr_hw_entries && idx <= BRBE_BANK0_IDX_MAX) { + if (!__read_brbe_regset(&buf[idx], idx)) + return idx; + idx++; + } + + select_brbe_bank(BRBE_BANK_IDX_1); + while (idx < nr_hw_entries && idx <= BRBE_BANK1_IDX_MAX) { + if (!__read_brbe_regset(&buf[idx], idx)) + return idx; + idx++; + } + return idx; +} + +/* + * This function concatenates branch records from stored and live buffer + * up to maximum nr_max records and the stored buffer holds the resultant + * buffer. The concatenated buffer contains all the branch records from + * the live buffer but might contain some from stored buffer considering + * the maximum combined length does not exceed 'nr_max'. + * + * Stored records Live records + * ------------------------------------------------^ + * | S0 | L0 | Newest | + * --------------------------------- | + * | S1 | L1 | | + * --------------------------------- | + * | S2 | L2 | | + * --------------------------------- | + * | S3 | L3 | | + * --------------------------------- | + * | S4 | L4 | nr_max + * --------------------------------- | + * | | L5 | | + * --------------------------------- | + * | | L6 | | + * --------------------------------- | + * | | L7 | | + * --------------------------------- | + * | | | | + * --------------------------------- | + * | | | Oldest | + * ------------------------------------------------V + * + * + * S0 is the newest in the stored records, where as L7 is the oldest in + * the live records. Unless the live buffer is detected as being full + * thus potentially dropping off some older records, L7 and S0 records + * are contiguous in time for a user task context. The stitched buffer + * here represents maximum possible branch records, contiguous in time. + * + * Stored records Live records + * ------------------------------------------------^ + * | L0 | L0 | Newest | + * --------------------------------- | + * | L0 | L1 | | + * --------------------------------- | + * | L2 | L2 | | + * --------------------------------- | + * | L3 | L3 | | + * --------------------------------- | + * | L4 | L4 | nr_max + * --------------------------------- | + * | L5 | L5 | | + * --------------------------------- | + * | L6 | L6 | | + * --------------------------------- | + * | L7 | L7 | | + * --------------------------------- | + * | S0 | | | + * --------------------------------- | + * | S1 | | Oldest | + * ------------------------------------------------V + * | S2 | <----| + * ----------------- | + * | S3 | <----| Dropped off after nr_max + * ----------------- | + * | S4 | <----| + * ----------------- + */ +static int stitch_stored_live_entries(struct brbe_regset *stored, + struct brbe_regset *live, + int nr_stored, int nr_live, + int nr_max) +{ + int nr_move = min(nr_stored, nr_max - nr_live); + + /* Move the tail of the buffer to make room for the new entries */ + memmove(&stored[nr_live], &stored[0], nr_move * sizeof(*stored)); + + /* Copy the new entries into the head of the buffer */ + memcpy(&stored[0], &live[0], nr_live * sizeof(*stored)); + + /* Return the number of entries in the stitched buffer */ + return min(nr_live + nr_stored, nr_max); +} + /* * Generic perf branch filters supported on BRBE *