From patchwork Thu Jun 6 11:14:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Ellerman X-Patchwork-Id: 13688297 Received: from mail.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) (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 765991953B5; Thu, 6 Jun 2024 11:15:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=150.107.74.76 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717672505; cv=none; b=AO7sJ2fAhCjkvg6RgMH/VaqopSfKX07wDiqd44rapuUcXAmHYykjVf8g+1ur0niHcstSSiDu73lyhlBtHwTkQJ1PfgUC1qkL2vOkEptAu9yGov9wEF4EAn/ydYQ3NPy+gwyMzlTLTq6cPZ9H8/tWxI14GD7ZXlPFKC+vHUL4xi8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717672505; c=relaxed/simple; bh=P8r1tAkblITJ7kuGQyJFOBAGEE7nFQZlWfQQ9+/eIbM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=kMBSXaP3+HAAusg3KYYJObShm+fQ/lWIGFGJU5ueDgbPSVdbI+ZqKV8rBE0OO0nQDQBrCIVe5mPVSth3UNggw9LNSNC1EOrotHDvF5D/Sg5V1pS69LUgVCwYSKK5/CVKlLKC+HWadOUAekRypfd+9Fy87wX51TT5RV1By2eZUkY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au; spf=pass smtp.mailfrom=ellerman.id.au; dkim=pass (2048-bit key) header.d=ellerman.id.au header.i=@ellerman.id.au header.b=nXEUUmHi; arc=none smtp.client-ip=150.107.74.76 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ellerman.id.au Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ellerman.id.au header.i=@ellerman.id.au header.b="nXEUUmHi" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ellerman.id.au; s=201909; t=1717672496; bh=JkMBHpq5K4ie+dfHpGJjCUD7zTfjKpLevGsS4Gkp3Mo=; h=From:To:Cc:Subject:Date:From; b=nXEUUmHiHHZhMfTLqAfWPU4HerXeYWMJtunn0PvlF4di3y67hn37mGLFF9awnrkD5 qrk328KUcQi/8DamBIXcYuQd6sgdPo4ymjWbEFwQ7jZxB4FUU/pYmDGCpefnb3/b6g 6RA9fwnz+RYxkkAgont6xbe5h1sdAz1jb26tUuYY7TNJjq12YSpSbhDRg3WcbZkwEw Jxkqg+sPV9K9klXKYv2gvf3mJCQwniM/M3LmM3qEjb/zEnwvpEHQmZP+ziCzT9RurX 1hrepvtq0dkhjBwWMt6cfpVQDD2nrcqQ60qkK1391r8vAfoh9SUYwWXA2XIJ5Hikso tR9/WQv+MKAPA== Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4Vw1vM4l74z4wc5; Thu, 6 Jun 2024 21:14:55 +1000 (AEST) From: Michael Ellerman To: martin.petersen@oracle.com, dlemoal@kernel.org, cassel@kernel.org Cc: hch@lst.de, john.g.garry@oracle.com, linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org, , regressions@lists.linux.dev, doru.iorgulescu1@gmail.com Subject: [PATCH] ata: pata_macio: Fix max_segment_size with PAGE_SIZE == 64K Date: Thu, 6 Jun 2024 21:14:45 +1000 Message-ID: <20240606111445.400001-1-mpe@ellerman.id.au> X-Mailer: git-send-email 2.45.1 Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The pata_macio driver advertises a max_segment_size of 0xff00, because the hardware doesn't cope with requests >= 64K. However the SCSI core requires max_segment_size to be at least PAGE_SIZE, which is a problem for pata_macio when the kernel is built with 64K pages. In older kernels the SCSI core would just increase the segment size to be equal to PAGE_SIZE, however since the commit tagged below it causes a warning and the device fails to probe: WARNING: CPU: 0 PID: 26 at block/blk-settings.c:202 .blk_validate_limits+0x2f8/0x35c CPU: 0 PID: 26 Comm: kworker/u4:1 Not tainted 6.10.0-rc1 #1 Hardware name: PowerMac7,2 PPC970 0x390202 PowerMac ... NIP .blk_validate_limits+0x2f8/0x35c LR .blk_alloc_queue+0xc0/0x2f8 Call Trace: .blk_alloc_queue+0xc0/0x2f8 .blk_mq_alloc_queue+0x60/0xf8 .scsi_alloc_sdev+0x208/0x3c0 .scsi_probe_and_add_lun+0x314/0x52c .__scsi_add_device+0x170/0x1a4 .ata_scsi_scan_host+0x2bc/0x3e4 .async_port_probe+0x6c/0xa0 .async_run_entry_fn+0x60/0x1bc .process_one_work+0x228/0x510 .worker_thread+0x360/0x530 .kthread+0x134/0x13c .start_kernel_thread+0x10/0x14 ... scsi_alloc_sdev: Allocation failure during SCSI scanning, some SCSI devices might not be configured Although the hardware can't cope with a 64K segment, the driver already deals with that internally by splitting large requests in pata_macio_qc_prep(). That is how the driver has managed to function until now on 64K kernels. So fix the driver to advertise a max_segment_size of 64K, which avoids the warning and keeps the SCSI core happy. Fixes: afd53a3d8528 ("scsi: core: Initialize scsi midlayer limits before allocating the queue") Reported-by: Guenter Roeck Closes: https://lore.kernel.org/all/ce2bf6af-4382-4fe1-b392-cc6829f5ceb2@roeck-us.net/ Reported-by: Doru Iorgulescu Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218858 Signed-off-by: Michael Ellerman Reviewed-by: Christoph Hellwig Reviewed-by: Damien Le Moal --- drivers/ata/pata_macio.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/ata/pata_macio.c b/drivers/ata/pata_macio.c index 817838e2f70e..3cb455a32d92 100644 --- a/drivers/ata/pata_macio.c +++ b/drivers/ata/pata_macio.c @@ -915,10 +915,13 @@ static const struct scsi_host_template pata_macio_sht = { .sg_tablesize = MAX_DCMDS, /* We may not need that strict one */ .dma_boundary = ATA_DMA_BOUNDARY, - /* Not sure what the real max is but we know it's less than 64K, let's - * use 64K minus 256 + /* + * The SCSI core requires the segment size to cover at least a page, so + * for 64K page size kernels this must be at least 64K. However the + * hardware can't handle 64K, so pata_macio_qc_prep() will split large + * requests. */ - .max_segment_size = MAX_DBDMA_SEG, + .max_segment_size = SZ_64K, .device_configure = pata_macio_device_configure, .sdev_groups = ata_common_sdev_groups, .can_queue = ATA_DEF_QUEUE,