From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7B94F2EEE9D; Mon, 3 Aug 2026 12:04:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785758678; cv=none; b=dYdZxAegq/IZwSiVmwPJrVqmNPPmzYh3KXwV+5ZRQz/OAdvBHeQ1EkGXqqoXd5GjD/J/lHdl1twjfYWqc9R2jalnZIkTDymj8MuVWHQfkkEhJELIUNrGG87XziY3kAYxmEsTKei2Oeb+eyz/4WA1MyDsM1SuRzPaC9isyGTG9XE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785758678; c=relaxed/simple; bh=nb6caUVzJDgIDllZO2UI73x8UTtB508wfhnB9z+8GkA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=a4V2gJyXLjE5C57PdsKqOXUFA3aeR/2XvRH9nzpT2/6mUF84WeTLaUC9bE8+qQmgnY1q3Keoi9A7PsbZjBW3AgZulbikdeKiMfs+6tnNvJ10zSKbLfmv9Zy+n7NM6Db3yVkuwg0G4HebHJtGBBF0JO1+Mas6BBTv0ZHP4qBv8JM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=WIuZPVSB; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="WIuZPVSB" 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 C9370143D; Mon, 3 Aug 2026 05:04:31 -0700 (PDT) Received: from [10.2.212.23] (e121345-lin.cambridge.arm.com [10.2.212.23]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D419F3F66F; Mon, 3 Aug 2026 05:04:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1785758675; bh=nb6caUVzJDgIDllZO2UI73x8UTtB508wfhnB9z+8GkA=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=WIuZPVSBjHW1yzZxcyQx5Tkm5xmSb+pKRI+efAiiXAoVWYD+hjUqnUMr0A0k+m3J5 c64HBGNA5geKVv4qwbk+oW5Q9i5+RyQVR+1FYmyBjY99Qai8qlvhfb4LRz1Pp54X+g UkoHYA3EyQHeQXkzna2/hkRVIwtz8jdCpr6C6WUI= Message-ID: Date: Mon, 3 Aug 2026 13:04:33 +0100 Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 4/9] perf/cxl: Split the MSI vector out of info->irq To: Dave Jiang , linux-cxl@vger.kernel.org, linux-perf-users@vger.kernel.org Cc: jic23@kernel.org, will@kernel.org, mark.rutland@arm.com, dave@stgolabs.net References: <20260731232827.401447-1-dave.jiang@intel.com> <20260731232827.401447-5-dave.jiang@intel.com> From: Robin Murphy Content-Language: en-GB In-Reply-To: <20260731232827.401447-5-dave.jiang@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 01/08/2026 12:28 am, Dave Jiang wrote: > info->irq means two different things depending on how far probe has got. > cxl_pmu_parse_caps() sets it to the MSI/MSI-X message number from the CPMU > Capability register. cxl_pmu_probe() passes that to pci_irq_vector() and > then overwrites it with the Linux virq, which is what the hotplug callbacks > hand to irq_set_affinity(). > > Give the message number its own field. No functional change. Thanks, this makes it much less confusing; Reviewed-by: Robin Murphy If the fix itself was just the comparison operator then I'd suggest folding it in so as to avoid extra backporting dependencies/conflicts, but it sounds like we might have a corner case where 0 may still mean "no IRQ", so maybe sort that first then put this refactoring on top? Cheers, Robin. > Assisted-by: Claude:claude-opus-4-8 > Signed-off-by: Dave Jiang > --- > v3: > - New patch > --- > drivers/perf/cxl_pmu.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/perf/cxl_pmu.c b/drivers/perf/cxl_pmu.c > index 3511d049aea4..56e6ae7bebf7 100644 > --- a/drivers/perf/cxl_pmu.c > +++ b/drivers/perf/cxl_pmu.c > @@ -106,6 +106,7 @@ struct cxl_pmu_info { > int on_cpu; > struct hlist_node node; > bool filter_hdm; > + int msi_vec; > int irq; > }; > > @@ -143,9 +144,9 @@ static int cxl_pmu_parse_caps(struct device *dev, struct cxl_pmu_info *info) > > info->filter_hdm = FIELD_GET(CXL_PMU_CAP_FILTERS_SUP_MSK, val) & CXL_PMU_FILTER_HDM; > if (FIELD_GET(CXL_PMU_CAP_INT, val)) > - info->irq = FIELD_GET(CXL_PMU_CAP_MSI_N_MSK, val); > + info->msi_vec = FIELD_GET(CXL_PMU_CAP_MSI_N_MSK, val); > else > - info->irq = -1; > + info->msi_vec = -1; > > /* First handle fixed function counters; note if configurable counters found */ > for (i = 0; i < info->num_counters; i++) { > @@ -874,10 +875,10 @@ static int cxl_pmu_probe(struct device *dev) > .capabilities = PERF_PMU_CAP_NO_EXCLUDE, > }; > > - if (info->irq <= 0) > + if (info->msi_vec <= 0) > return -EINVAL; > > - rc = pci_irq_vector(pdev, info->irq); > + rc = pci_irq_vector(pdev, info->msi_vec); > if (rc < 0) > return rc; > irq = rc;