From nobody Tue Feb 10 04:14:21 2026 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.19]) (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 440A1469D; Thu, 8 Jan 2026 00:03:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.19 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767830586; cv=none; b=rRSBwsPB3wd4uBvmwbWZj03KI6+7LRODAgBv4N/l7DQ4npB9VAin/TsoyVKXbjXDP3V1E4zMI03xhH8mtQWlL0yRPxDI65weXnqgCbNV6RayDbZrQg5S7c3CfVxrgUVri+Rfbgjv5frsgzEvh8adgTPiw/TlM8LBq/nCY/i/omw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767830586; c=relaxed/simple; bh=Bop3zpkorMkLEa3rPejwVhYu9CpvRTGItMYtNXIFDkk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Nf5+ZvmBsJBMrYU5ZMycFiZc4dkijLryGL4g03ZG3TjZWY9T+feln7xoSw73X39gigR8281Jhw5P2uQ5FaeZkZeshd300YgQyKs5PwaZVLWG8IRvb9ughSSCYDA3h1LFn+Poyhj09UVaFi4lg2jbu3oMU9VD+7FhiIXSZHDM0iY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=lzKptKNQ; arc=none smtp.client-ip=192.198.163.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="lzKptKNQ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1767830584; x=1799366584; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=Bop3zpkorMkLEa3rPejwVhYu9CpvRTGItMYtNXIFDkk=; b=lzKptKNQVWHN83H+i5gkCLAwLcf2qWwbfWvyZ9ubt0BWMI31zCUuoMQM 8ZhEcwxQ2r05hyPC7zLsYDp0oarcT145aa+6AmchNzPQ6fgETRZfwNhEn qt+uFrFEYj7i3Wy5zR6o3u/x+2zcmNBU7IU79orxtVPt5V2dSakQbdE8t Zubrwgs/U2TBk7JBFHl7sate8bCEsrs3/atxLGNAyYdQNSZK42Wp8j2SR YLAvTqdiPrp2BxZh/F072ks26bn/M/jvejGkeachMfCOSP4W1665Va93D JfRO1Yng4Ask884JW6tdq9EWAe7oL/KphIxHZ3Zm2ORdQrjMfiEzpBH0S w==; X-CSE-ConnectionGUID: 1X1XDxilSWqQjOXLhBIWRA== X-CSE-MsgGUID: tcxRrTg2TO23fZIfYyF8DA== X-IronPort-AV: E=McAfee;i="6800,10657,11664"; a="68214635" X-IronPort-AV: E=Sophos;i="6.21,209,1763452800"; d="scan'208";a="68214635" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jan 2026 16:03:01 -0800 X-CSE-ConnectionGUID: aQtYZUSmTBe79VgVIpfhCw== X-CSE-MsgGUID: 2ixshudmSjWmot1Qka1FPw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,209,1763452800"; d="scan'208";a="203074580" Received: from vcostago-desk1.jf.intel.com (HELO [10.88.27.144]) ([10.88.27.144]) by orviesa007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jan 2026 16:03:01 -0800 From: Vinicius Costa Gomes Date: Wed, 07 Jan 2026 16:02:22 -0800 Subject: [PATCH RESEND v2 1/2] dmaengine: idxd: Expose DSA3.0 capabilities through sysfs 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: <20260107-idxd-yi-sun-dsa3-sgl-size-v2-1-dbef8f559e48@intel.com> References: <20260107-idxd-yi-sun-dsa3-sgl-size-v2-0-dbef8f559e48@intel.com> In-Reply-To: <20260107-idxd-yi-sun-dsa3-sgl-size-v2-0-dbef8f559e48@intel.com> To: Vinicius Costa Gomes , Dave Jiang , Vinod Koul Cc: linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, Yi Sun , Anil S Keshavamurthy , Yi Lai X-Mailer: b4 0.15-dev-47773 X-Developer-Signature: v=1; a=ed25519-sha256; t=1767830580; l=7284; i=vinicius.gomes@intel.com; s=20230921; h=from:subject:message-id; bh=X3/DM835J8N+Dt8QtaSm7nps284B0jwq7UC0laCdVlo=; b=rj3XGbTMy7oief0sVuGDsPs4YxGbWM3POBdyZuBi+egXnJOWIXN9VGBo/HASZKP4biAmXF1uf 9cQwO4AI5gXDLSG7GXcgtjH0PrQOP/VgKVbptWoax8PwEc+786Juo25 X-Developer-Key: i=vinicius.gomes@intel.com; a=ed25519; pk=aJkrtgqgT6TZ8iIHSG8/rTPsmlYnjMrUjCsMYvCzntk= From: Yi Sun Introduce sysfs interfaces for 3 new Data Streaming Accelerator (DSA) capability registers (dsacap0-2) to enable userspace awareness of hardware features in DSA version 3 and later devices. Userspace components (e.g. configure libraries, workload Apps) require this information to: 1. Select optimal data transfer strategies based on SGL capabilities 2. Enable hardware-specific optimizations for floating-point operations 3. Configure memory operations with proper numerical handling 4. Verify compute operation compatibility before submitting jobs The output format is ,,, where each DSA capability value is a 64-bit hexadecimal number, separated by commas. The ordering follows the DSA 3.0 specification layout: Offset: 0x190 0x188 0x180 Reg: dsacap2 dsacap1 dsacap0 Example: cat /sys/bus/dsa/devices/dsa0/dsacaps 000000000000f18d,0014000e000007aa,00fa01ff01ff03ff According to the DSA 3.0 specification, there are 15 fields defined for the three dsacap registers. However, there's no need to define all register structures unless a use case requires them. At this point, support for the Scatter-Gather List (SGL) located in dsacap0 is necessary, so only dsacap0 is defined accordingly. For reference, the DSA 3.0 specification is available at: Link: https://software.intel.com/content/www/us/en/develop/articles/intel-d= ata-streaming-accelerator-architecture-specification.html Signed-off-by: Yi Sun Co-developed-by: Anil S Keshavamurthy Signed-off-by: Anil S Keshavamurthy Reviewed-by: Dave Jiang Tested-by: Yi Lai Acked-by: Vinicius Costa Gomes --- Documentation/ABI/stable/sysfs-driver-dma-idxd | 15 +++++++++++++++ drivers/dma/idxd/idxd.h | 3 +++ drivers/dma/idxd/init.c | 6 ++++++ drivers/dma/idxd/registers.h | 25 ++++++++++++++++++++++= +++ drivers/dma/idxd/sysfs.c | 24 ++++++++++++++++++++++= ++ 5 files changed, 73 insertions(+) diff --git a/Documentation/ABI/stable/sysfs-driver-dma-idxd b/Documentation= /ABI/stable/sysfs-driver-dma-idxd index 4a355e6747ae..08d030159f09 100644 --- a/Documentation/ABI/stable/sysfs-driver-dma-idxd +++ b/Documentation/ABI/stable/sysfs-driver-dma-idxd @@ -136,6 +136,21 @@ Description: The last executed device administrative c= ommand's status/error. Also last configuration error overloaded. Writing to it will clear the status. =20 +What: /sys/bus/dsa/devices/dsa/dsacaps +Date: April 5, 2026 +KernelVersion: 6.20.0 +Contact: dmaengine@vger.kernel.org +Description: The DSA3 specification introduces three new capability + registers: dsacap[0-2]. User components (e.g., configuration + libraries and workload applications) require this information + to properly utilize the DSA3 features. + This includes SGL capability support, Enabling hardware-specific + optimizations, Configuring memory, etc. + The output format is ',,' where each + DSA cap value is a 64 bit hex value. + This attribute should only be visible on DSA devices of version + 3 or later. + What: /sys/bus/dsa/devices/dsa/iaa_cap Date: Sept 14, 2022 KernelVersion: 6.0.0 diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h index 74e6695881e6..cc0a3fe1c957 100644 --- a/drivers/dma/idxd/idxd.h +++ b/drivers/dma/idxd/idxd.h @@ -252,6 +252,9 @@ struct idxd_hw { struct opcap opcap; u32 cmd_cap; union iaa_cap_reg iaa_cap; + union dsacap0_reg dsacap0; + union dsacap1_reg dsacap1; + union dsacap2_reg dsacap2; }; =20 enum idxd_device_state { diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c index 2acc34b3daff..2bdd1b34d50a 100644 --- a/drivers/dma/idxd/init.c +++ b/drivers/dma/idxd/init.c @@ -585,6 +585,12 @@ static void idxd_read_caps(struct idxd_device *idxd) } multi_u64_to_bmap(idxd->opcap_bmap, &idxd->hw.opcap.bits[0], 4); =20 + if (idxd->hw.version >=3D DEVICE_VERSION_3) { + idxd->hw.dsacap0.bits =3D ioread64(idxd->reg_base + IDXD_DSACAP0_OFFSET); + idxd->hw.dsacap1.bits =3D ioread64(idxd->reg_base + IDXD_DSACAP1_OFFSET); + idxd->hw.dsacap2.bits =3D ioread64(idxd->reg_base + IDXD_DSACAP2_OFFSET); + } + /* read iaa cap */ if (idxd->data->type =3D=3D IDXD_TYPE_IAX && idxd->hw.version >=3D DEVICE= _VERSION_2) idxd->hw.iaa_cap.bits =3D ioread64(idxd->reg_base + IDXD_IAACAP_OFFSET); diff --git a/drivers/dma/idxd/registers.h b/drivers/dma/idxd/registers.h index 8dc2e8bca779..85e83a61a50b 100644 --- a/drivers/dma/idxd/registers.h +++ b/drivers/dma/idxd/registers.h @@ -18,6 +18,7 @@ =20 #define DEVICE_VERSION_1 0x100 #define DEVICE_VERSION_2 0x200 +#define DEVICE_VERSION_3 0x300 =20 #define IDXD_MMIO_BAR 0 #define IDXD_WQ_BAR 2 @@ -587,6 +588,30 @@ union evl_status_reg { u64 bits; }; =20 +#define IDXD_DSACAP0_OFFSET 0x180 +union dsacap0_reg { + u64 bits; + struct { + u64 max_sgl_shift:4; + u64 max_gr_block_shift:4; + u64 ops_inter_domain:7; + u64 rsvd1:17; + u64 sgl_formats:16; + u64 max_sg_process:8; + u64 rsvd2:8; + }; +}; + +#define IDXD_DSACAP1_OFFSET 0x188 +union dsacap1_reg { + u64 bits; +}; + +#define IDXD_DSACAP2_OFFSET 0x190 +union dsacap2_reg { + u64 bits; +}; + #define IDXD_MAX_BATCH_IDENT 256 =20 struct __evl_entry { diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c index 9f0701021af0..cc2c83d7f710 100644 --- a/drivers/dma/idxd/sysfs.c +++ b/drivers/dma/idxd/sysfs.c @@ -1713,6 +1713,18 @@ static ssize_t event_log_size_store(struct device *d= ev, } static DEVICE_ATTR_RW(event_log_size); =20 +static ssize_t dsacaps_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct idxd_device *idxd =3D confdev_to_idxd(dev); + + return sysfs_emit(buf, "%016llx,%016llx,%016llx\n", + (u64)idxd->hw.dsacap2.bits, + (u64)idxd->hw.dsacap1.bits, + (u64)idxd->hw.dsacap0.bits); +} +static DEVICE_ATTR_RO(dsacaps); + static bool idxd_device_attr_max_batch_size_invisible(struct attribute *at= tr, struct idxd_device *idxd) { @@ -1750,6 +1762,14 @@ static bool idxd_device_attr_event_log_size_invisibl= e(struct attribute *attr, !idxd->hw.gen_cap.evl_support); } =20 +static bool idxd_device_attr_dsacaps_invisible(struct attribute *attr, + struct idxd_device *idxd) +{ + return attr =3D=3D &dev_attr_dsacaps.attr && + (idxd->data->type !=3D IDXD_TYPE_DSA || + idxd->hw.version < DEVICE_VERSION_3); +} + static umode_t idxd_device_attr_visible(struct kobject *kobj, struct attribute *attr, int n) { @@ -1768,6 +1788,9 @@ static umode_t idxd_device_attr_visible(struct kobjec= t *kobj, if (idxd_device_attr_event_log_size_invisible(attr, idxd)) return 0; =20 + if (idxd_device_attr_dsacaps_invisible(attr, idxd)) + return 0; + return attr->mode; } =20 @@ -1795,6 +1818,7 @@ static struct attribute *idxd_device_attributes[] =3D= { &dev_attr_cmd_status.attr, &dev_attr_iaa_cap.attr, &dev_attr_event_log_size.attr, + &dev_attr_dsacaps.attr, NULL, }; =20 --=20 2.52.0