From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 97AE82D97AA; Wed, 27 May 2026 10:02:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779876167; cv=none; b=Fcyuh4nzRUi5FcATe+410buSo2o4S2S0TyuHfV2Ngiajgi7C7cnTCwjBcA9jmPrx+737G1uLK6INY6Zftfzo4OIoi9m5MT/LoJVxlCzBROFqdCy6XI8BQ/kw+4zh7SfcUj+m6N/G2Bf1pxoQY9Wil/zYzJPkp49iQAS2QohtpBU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779876167; c=relaxed/simple; bh=lvD4qR8y4Eoz9VaSEdZuOBmS0pP9QJ0yOVz6rR4IUBM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=cX4TDjdukkUbWY6e4fpqEJWyMzJHybdd1SINLYEvU4+6tUI/y6zpIgkmzE7l7spkpmMnSMOB4NFUwfz3HjT8rMuy5KQ7vRF7BIAwLSc/DNNxX+rThH797wsidHod0NiDI2fTzSJHJ3AIT6SxOkRMBT6OtZ8+iPtvp76xPRsl/6o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SJJuUNH0; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SJJuUNH0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 323581F00A3A; Wed, 27 May 2026 10:02:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779876166; bh=Hu7HoK2hIQnOl4q34hOD8+zjB4sz0oZzSs+uNBXGR34=; h=From:To:Cc:Subject:Date; b=SJJuUNH0kznHm/7NTJUFJDUDcFfxYASzOTl/Bfs0D7HTIRMx5pWuystQL+I2H3rJb dKDWOxMAyGmZRhsR7Wi/v96XGvxjYxN2uV8w6JGXmh8z2lH4bCP6ypQ48HOiFlxSF9 oqqe01KfS9qTThO54vH12vQxak3K8T7+UIHUDv/GlLAvyLWJigzsIFY6/bhUEoJtDQ 1TGNTP27Nqk03jbXkm7oL1Q08NigvNgKc6tLcDe4MeZEF86j6JG7rgr++jZRU8MaqY vMMcrr+bjUEH3IRoYljmskzX0/X1jZGYnzJHIBeBy3el+eORbbp3bFC3n7GbcT1Bgs Trdq5qsVU0V0Q== From: "Aneesh Kumar K.V (Arm)" To: linux-coco@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: "Aneesh Kumar K.V (Arm)" , Catalin Marinas , Greg KH , Jeremy Linton , Jonathan Cameron , Lorenzo Pieralisi , Mark Rutland , Sudeep Holla , Will Deacon , Steven Price , Suzuki K Poulose Subject: [PATCH v6 0/4] Switch Arm SMCCC firmware services to an SMCCC bus Date: Wed, 27 May 2026 15:32:29 +0530 Message-ID: <20260527100233.428018-1-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit As discussed here: https://lore.kernel.org/all/20250728135216.48084-12-aneesh.kumar@kernel.org The earlier CCA guest support used an arm-cca-dev platform device as a pure software anchor for the TSM class device. That platform device did not correspond to a DT/ACPI described device, MMIO range, interrupt, or other platform resource; it existed only to make the CCA guest driver bind and to place the resulting TSM device in the driver model. The same pattern also exists for smccc_trng. Creating separate platform devices for such SMCCC-discovered features is misleading, because those features are not independent platform devices. This series adds an Arm SMCCC bus for services discovered through the SMCCC firmware interface. The bus provides SMCCC device and driver registration helpers, name-based matching, uevent modalias generation, and a sysfs modalias attribute. SMCCC service drivers can use MODULE_DEVICE_TABLE(arm_smccc, ...) to emit arm_smccc: aliases, allowing userspace to autoload service drivers when the SMCCC core registers matching firmware-service devices. The series then moves SMCCC TRNG and the Arm CCA guest RSI service off the platform bus. When the SMCCC core discovers the corresponding firmware service, it registers an arm-smccc device for that service. The hwrng arm_smccc_trng driver and the Arm CCA guest TSM provider are converted to SMCCC drivers that bind to those discovered devices. The old arm-cca-dev platform device has also been used by userspace as a Realm guest indicator. Removing it without a replacement would leave userspace depending on an internal driver-binding device. This series therefore adds /sys/firmware/cca/realm_guest as a stable, architecture-provided ABI for detecting whether the kernel is running as an Arm CCA Realm guest, and then removes the dummy arm-cca-dev platform-device registration. Changes from v5: https://lore.kernel.org/all/20260514094030.42495-1-aneesh.kumar@kernel.org * Replace the arm-smccc platform-device plus auxiliary-child model with a dedicated Arm SMCCC bus. * Add SMCCC module alias support so SMCCC service drivers can use MODULE_DEVICE_TABLE(arm_smccc, ...) and autoload through arm_smccc: aliases. * Convert smccc_trng from a platform driver to an SMCCC driver. * Convert the Arm CCA guest TSM provider from the arm-cca-dev platform device to an SMCCC driver bound to the discovered RSI service. * Add /sys/firmware/cca/realm_guest before removing the old arm-cca-dev dummy platform device. Changes from v4: https://lore.kernel.org/all/20260427061615.905018-1-aneesh.kumar@kernel.org * Add /sys/firmware/cca/realm_guest for detecting realm guest * Convert smccc_trng to auxiliary device from platform device Changes from v3: https://lore.kernel.org/all/20260309100507.2303361-1-aneesh.kumar@kernel.org * Rebased onto the latest kernel * Drop pr_fmt() from drivers/firmware/smccc/rmm.c Cc: Catalin Marinas Cc: Greg KH Cc: Jeremy Linton Cc: Jonathan Cameron Cc: Lorenzo Pieralisi Cc: Mark Rutland Cc: Sudeep Holla Cc: Will Deacon Cc: Steven Price Cc: Suzuki K Poulose Aneesh Kumar K.V (Arm) (4): firmware: smccc: Add an Arm SMCCC bus firmware: hwrng: arm_smccc_trng: Register as an SMCCC device firmware: smccc: arm-cca-guest: Bind the TSM provider to an SMCCC device coco: guest: arm64: Replace dummy CCA device with sysfs ABI Documentation/ABI/testing/sysfs-firmware-cca | 10 + arch/arm64/include/asm/rsi.h | 2 +- arch/arm64/kernel/rsi.c | 39 +++- drivers/char/hw_random/arm_smccc_trng.c | 26 +-- drivers/firmware/smccc/Makefile | 4 + drivers/firmware/smccc/rmm.c | 25 +++ drivers/firmware/smccc/rmm.h | 17 ++ drivers/firmware/smccc/smccc.c | 178 +++++++++++++++++- drivers/virt/coco/arm-cca-guest/Kconfig | 1 + drivers/virt/coco/arm-cca-guest/Makefile | 2 + .../{arm-cca-guest.c => arm-cca.c} | 60 +++--- include/linux/arm-smccc-bus.h | 49 +++++ include/linux/mod_devicetable.h | 13 ++ scripts/mod/devicetable-offsets.c | 3 + scripts/mod/file2alias.c | 8 + 15 files changed, 378 insertions(+), 59 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-firmware-cca create mode 100644 drivers/firmware/smccc/rmm.c create mode 100644 drivers/firmware/smccc/rmm.h rename drivers/virt/coco/arm-cca-guest/{arm-cca-guest.c => arm-cca.c} (85%) create mode 100644 include/linux/arm-smccc-bus.h base-commit: 50897c955902c93ae71c38698abb910525ebdc89 -- 2.43.0