From nobody Tue Feb 10 08:26:40 2026 Received: from out-180.mta0.migadu.com (out-180.mta0.migadu.com [91.218.175.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 505DC25C6FD for ; Mon, 10 Feb 2025 19:40:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.180 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739216427; cv=none; b=CLuk1a869MRp5eDFiXJui18kMqlhx/7+b1ZpsxIE3EtuZ/kaaMt8sI/PeWE23dO8jZz8VxBn2p2hDsU+qltvL6OCuHPUTHn4U7UuOTW3G/moVhQAkQ6N1lMeaZRkz6Ow9oe4oDGdPY0fsrfZnRhv5GeX48Adbv5n7rn1sBL4aK4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739216427; c=relaxed/simple; bh=aaTDpX6ibfDGaC/RfCGv1TxYljIk7EiF/i2ba6hh4K4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=k1ufKZ6V8zKY60ktYH9xO+EmgEEc0lfuMTmgY9ANwZiJ9nvQ+DmV98eICK+MoXmSnYwlt/3RxQWhhBbkJN940ySTvsjM5cQd6Eg+RI7h7Yw82fx6Sz0tUr6deRw0SKKrWvAIPVGOKf4Y2HShU10yrgM/7jO7L8LMWpuiKtFGhKI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=rosenzweig.io; spf=pass smtp.mailfrom=rosenzweig.io; dkim=pass (2048-bit key) header.d=rosenzweig.io header.i=@rosenzweig.io header.b=Yrdlg6Us; arc=none smtp.client-ip=91.218.175.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=rosenzweig.io Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rosenzweig.io Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rosenzweig.io header.i=@rosenzweig.io header.b="Yrdlg6Us" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rosenzweig.io; s=key1; t=1739216423; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Kz0nyJ7WvRmnQlm0RtDzsCt8ytIfHB7c5nD03lfkpQo=; b=Yrdlg6Ustd49sldQRowOZXLEs3setf3ln0voRaH2wpyzcHRMKugrZJJR6cG/nvo7YfRo82 F2SNQJsefmje6IDldZouEfGy/ZFbQcNfmintFJKrfTWdFWeQEkgprAHvIaawXX3R08LX0d myH2eEG2yOT0PdpYfdRP3uMeBRxTdFw7whaQJSTJZw7AisxI/PNMYD/Iv79/Uy3Db7BnHb lSh2GprWdYqrFj/+ib4R2B4TEFkQh8uDGYOIl7pAkdNZ6CDIG8VMAij9UeoIeidRQG+I1M jCcj+EIblzby3we1eq2bs58/ML1A5CKEdIttLYa+t9mwmIrgzXRWPlkujijycw== From: Alyssa Rosenzweig Date: Mon, 10 Feb 2025 14:39:54 -0500 Subject: [PATCH 2/5] iommu/dart: Skip reset for locked DARTs Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250210-locked-dart-v1-2-5d97fe247f35@rosenzweig.io> References: <20250210-locked-dart-v1-0-5d97fe247f35@rosenzweig.io> In-Reply-To: <20250210-locked-dart-v1-0-5d97fe247f35@rosenzweig.io> To: Sven Peter , Janne Grunau , Joerg Roedel , Will Deacon , Robin Murphy Cc: asahi@lists.linux.dev, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Alyssa Rosenzweig , Hector Martin X-Developer-Signature: v=1; a=openpgp-sha256; l=2327; i=alyssa@rosenzweig.io; h=from:subject:message-id; bh=aaTDpX6ibfDGaC/RfCGv1TxYljIk7EiF/i2ba6hh4K4=; b=owEBbQKS/ZANAwAIAf7+UFoK9VgNAcsmYgBnqlYZ4XpVKED3AuP44JWAGY5N9sUenu+SB6n/R MuO7oEpJq6JAjMEAAEIAB0WIQRDXuCbsK8A0B2q9jj+/lBaCvVYDQUCZ6pWGQAKCRD+/lBaCvVY DVZtEACF0ixVnQrS6o/8V7HVns7hmOv7asVpK1AKZstPf+b99/Ojt6HaJkBlZfR5mQXZVpPwF+8 Cq9lJpfykH/tBMISpG2Uhr6qkBDcDe8AQALK/179b3VCOydowJ2njiRYTUqe7jTaUFs6GrEuI4M 3/kee6DR+rA7s0SqTE9huwjyAo/tIFQKuQUf2ha1o5LeBQ7Hmkjt0OjW9qCiaTdrk/xawtzCjtp K9Ee2y4/Ev90qmvm/0cpj4QcuCvSKehKn930a7biQu83n0mDSdWBXqeigbHDzRxPwhsee+fw8aa /LxMi5bw/CmyUf1orROoFQG3NfPQT+5lnO7hu/gPfDXRvbNGlR+tNY3qWosjT10wssd+2sq9lp/ qCIP2+XYnOA0M5bFNwDKkcTvjm2Uy+AV1MheCb+LXXX35BCKlMPHc7BeeMNhtIBUW0u1UeWpbo7 6opowGblNJW0OdQY8TidlegtFq5uSyDlXuWYYWYdBElBvpte0CqinXEVwgiGvHDTHXf61aYrXm6 pTdSCj3YS8/IcDNVRqsEZYUqKhMaBmcrLLBWSKK7RX01BeMdT3rTD7AzkErkiv5pxM1CSyRLcLQ qar7Wl3CUPorSW2uVQMzGfSqGKQGjtcHRMkjYIgJaz8vk3jb7oy6Sku6S/awoFpvhLYU4xV+UBt 2eAYA9IwaIuqDBQ== X-Developer-Key: i=alyssa@rosenzweig.io; a=openpgp; fpr=435EE09BB0AF00D01DAAF638FEFE505A0AF5580D X-Migadu-Flow: FLOW_OUT Locked DARTs cannot be reconfigured, therefore the reset/restore procedure can't work and should not be needed. Skip it, allowing locked DARTs to probe. Co-developed-by: Hector Martin Signed-off-by: Hector Martin Signed-off-by: Alyssa Rosenzweig --- drivers/iommu/apple-dart.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c index 460cf96bc8001e051916f356d5d175b35e36c608..9c74a95eb7e819e94ab2fb47ed0= d411a1eba8bf7 100644 --- a/drivers/iommu/apple-dart.c +++ b/drivers/iommu/apple-dart.c @@ -452,17 +452,9 @@ apple_dart_t8110_hw_invalidate_tlb(struct apple_dart_s= tream_map *stream_map) =20 static int apple_dart_hw_reset(struct apple_dart *dart) { - u32 config; struct apple_dart_stream_map stream_map; int i; =20 - config =3D readl(dart->regs + dart->hw->lock); - if (config & dart->hw->lock_bit) { - dev_err(dart->dev, "DART is locked down until reboot: %08x\n", - config); - return -EINVAL; - } - stream_map.dart =3D dart; bitmap_zero(stream_map.sidmap, DART_MAX_STREAMS); bitmap_set(stream_map.sidmap, 0, dart->num_streams); @@ -1151,9 +1143,11 @@ static int apple_dart_probe(struct platform_device *= pdev) } =20 dart->locked =3D apple_dart_is_locked(dart); - ret =3D apple_dart_hw_reset(dart); - if (ret) - goto err_clk_disable; + if (!dart->locked) { + ret =3D apple_dart_hw_reset(dart); + if (ret) + goto err_clk_disable; + } =20 ret =3D request_irq(dart->irq, dart->hw->irq_handler, IRQF_SHARED, "apple-dart fault handler", dart); @@ -1192,7 +1186,9 @@ static void apple_dart_remove(struct platform_device = *pdev) { struct apple_dart *dart =3D platform_get_drvdata(pdev); =20 - apple_dart_hw_reset(dart); + if (!dart->locked) + apple_dart_hw_reset(dart); + free_irq(dart->irq, dart); =20 iommu_device_unregister(&dart->iommu); @@ -1325,6 +1321,10 @@ static __maybe_unused int apple_dart_resume(struct d= evice *dev) unsigned int sid, idx; int ret; =20 + /* Locked DARTs can't be restored, and they should not need it */ + if (dart->locked) + return 0; + ret =3D apple_dart_hw_reset(dart); if (ret) { dev_err(dev, "Failed to reset DART on resume\n"); --=20 2.48.1