From nobody Tue Oct 7 07:06:27 2025 Received: from layka.disroot.org (layka.disroot.org [178.21.23.139]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0DC5721883C; Sat, 12 Jul 2025 11:49:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.21.23.139 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752321003; cv=none; b=SKN8a9HvxfzrdKMVhuW3FKgWggRBnqc/kC6V7VRM/4t4432/WZwJBKuaRV5SI3scktA21L8K+HM9kNxkoLD3EkDjVp1pMefqgU+zHqkXQSZ87U5XZJ5HZXSXwT/TJp5h2PQ4xsSiDTgxEiSADGnKPhRIUohaPd6m4lfdhokpph8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752321003; c=relaxed/simple; bh=S+tYkmbasYOAVw0o6YkfoWz4FtmHaFsF4csZGWOvnmk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=ZrDiDm25LqY8v0V2fLhQ41qy6OK/ondyUyUfgMKCIvU5levNCfVhkXZtUkWJ3xQxQYVY4lDw23ABdUY3nT6cyX1sgEyC3lobypz6OlWru/QZ24YxuVcgfyWJce1k4waVi/txV3zO/URHgJuupv8YAs+5mWrsynQNsqSGynOzRXI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=disroot.org; spf=pass smtp.mailfrom=disroot.org; dkim=pass (2048-bit key) header.d=disroot.org header.i=@disroot.org header.b=IAslfoZL; arc=none smtp.client-ip=178.21.23.139 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=disroot.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=disroot.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=disroot.org header.i=@disroot.org header.b="IAslfoZL" Received: from mail01.disroot.lan (localhost [127.0.0.1]) by disroot.org (Postfix) with ESMTP id 3C1D825D28; Sat, 12 Jul 2025 13:49:58 +0200 (CEST) X-Virus-Scanned: SPAM Filter at disroot.org Received: from layka.disroot.org ([127.0.0.1]) by localhost (disroot.org [127.0.0.1]) (amavis, port 10024) with ESMTP id UdEQUmxa2Ljx; Sat, 12 Jul 2025 13:49:57 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=disroot.org; s=mail; t=1752320997; bh=S+tYkmbasYOAVw0o6YkfoWz4FtmHaFsF4csZGWOvnmk=; h=From:Date:Subject:To:Cc; b=IAslfoZLT3WCtll3Oqe0CeZ14PDMLkGO+Mkzk+z9CLeJ9LNnX9w8mT+z/85MxOvya F0fBcPK6ZCCyHEZHD+skxRk0J3rrJyWj3NuBbHYp7s7OnT4IGbdq6BC3huxAGyD+Mq piYjNY+QfL6zgFBqY5zMvTBrfLXFMfWLRiSBjmhvzRM+mou1OhgdJ+8zLlDoCspGt3 ZRWCSNaQUAOJuJvR7L8vmPAOJMUFuD4NJVzDamzwMLVHJV/7VINa624PryIQoq2djV 6BVztx3RX2wPI5X/RJjmxaOkjNUMRCg3AEYo+viyXjckO5MMf9VZ18m2e4Nsn653i+ bARP1Jm/ZwsBA== From: Kaustabh Chakraborty Date: Sat, 12 Jul 2025 17:19:30 +0530 Subject: [PATCH] iommu/exynos: add support for reserved regions 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: <20250712-exynos-sysmmu-resv-regions-v1-1-e79681fcab1a@disroot.org> X-B4-Tracking: v=1; b=H4sIAMlLcmgC/x2MMQqAMAwAvyKZDWjAUv2KOIiNNYNVGhRF/LvB5 eCGuweUs7BCVzyQ+RSVLZnUZQHTMqbIKMEcqKKmctQiX3faFPXWdT0ws56GaJWic/VM3reBQgM 22DPPcv3zfnjfDywU1kRsAAAA X-Change-ID: 20250629-exynos-sysmmu-resv-regions-661f2889d2d5 To: Marek Szyprowski , Joerg Roedel , Will Deacon , Robin Murphy , Krzysztof Kozlowski , Alim Akhtar Cc: iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org, Kaustabh Chakraborty X-Developer-Signature: v=1; a=ed25519-sha256; t=1752320988; l=1824; i=kauschluss@disroot.org; s=20250202; h=from:subject:message-id; bh=S+tYkmbasYOAVw0o6YkfoWz4FtmHaFsF4csZGWOvnmk=; b=XrB80dr8a+JpILdcBo5C8ky8eoGj9SFiZjVCtse37Zu1p3PeiZQKE+VHre362XvQFhPjcTFZo rQBP0wI1zv3AWTuPsfcXTXWutuy7l58dImvg6ZriUEHbco9XIsfAiW1 X-Developer-Key: i=kauschluss@disroot.org; a=ed25519; pk=h2xeR+V2I1+GrfDPAhZa3M+NWA0Cnbdkkq1bH3ct1hE= The bootloader configures a reserved memory region for framebuffer, which is protected by the IOMMU. The kernel-side driver is oblivious as of which memory region is set up by the bootloader. In such case, the IOMMU tries to reference the reserved region - which is not reserved in the kernel anymore - and it results in an unrecoverable page fault. More information about it is provided in [1]. Add support for reserved regions using iommu_dma_get_resv_regions(). For OF supported boards, this requires defining the region in the iommu-addresses property of the IOMMU owner's node. Link: https://lore.kernel.org/r/544ad69cba52a9b87447e3ac1c7fa8c3@disroot.or= g [1] Signed-off-by: Kaustabh Chakraborty --- drivers/iommu/exynos-iommu.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c index b62a8f35c3e8516ead6a41f92dc7c8dc057986a8..b6edd178fe25e7c258cc82c47e9= 170fb4db74064 100644 --- a/drivers/iommu/exynos-iommu.c +++ b/drivers/iommu/exynos-iommu.c @@ -22,6 +22,7 @@ #include #include =20 +#include "dma-iommu.h" #include "iommu-pages.h" =20 typedef u32 sysmmu_iova_t; @@ -1479,6 +1480,7 @@ static const struct iommu_ops exynos_iommu_ops =3D { .device_group =3D generic_device_group, .probe_device =3D exynos_iommu_probe_device, .release_device =3D exynos_iommu_release_device, + .get_resv_regions =3D iommu_dma_get_resv_regions, .of_xlate =3D exynos_iommu_of_xlate, .default_domain_ops =3D &(const struct iommu_domain_ops) { .attach_dev =3D exynos_iommu_attach_device, --- base-commit: a62b7a37e6fcf4a675b1548e7c168b96ec836442 change-id: 20250629-exynos-sysmmu-resv-regions-661f2889d2d5 Best regards, --=20 Kaustabh Chakraborty