From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.16]) (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 B1C7D1BD9D3 for ; Thu, 20 Feb 2025 13:18:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740057495; cv=none; b=od0iLELV84M2KvmFBnIfOYVMPRjpt/2GGpHlxBX8GwnuZXYULa9yYj32S7UATOkxkoKkzHMR0mrKd31XJ3o6gNySF8mKJWYrEK/qRarp21z80ZUGZ7vSDdVORHLH/a0Kodb2YB8JR6E8avZUWbnqTvZSJXNIhlri1TST5OjKAJk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740057495; c=relaxed/simple; bh=aYZp/pKrgMtVLLGqplvIN5HaC4fbbgmg5icYacZndDA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=TvBFcc7rO2gFxNocxf7uNMZKvjL1qysoKvd/60qmDWLb7hxC0wyS9Jauv0NMFfsopvjDoV9BulXHJvzpAu2zBEd6iS+oGhBVxh8alnWM4RLiMylXKNSXPxtlDx+BFZOQxzZ5JIVpA1Go5rjihvjeyhatSaZyKt0O2tyAbzgFKm0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=fw3FrgyX; arc=none smtp.client-ip=198.175.65.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="fw3FrgyX" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1740057493; x=1771593493; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=aYZp/pKrgMtVLLGqplvIN5HaC4fbbgmg5icYacZndDA=; b=fw3FrgyXrd0fzalU3ZkzFu4YA3AlC2V3A9zHHv7p02l0FXwfQOp76Gn1 If/6Vg2wWUMUp+CWm8LiUS6qEHjVEtuxpLRAg4CtKNvVXFtyVJedCxPVR MqJJo8rI5fJiSZtALSVtphbxzUjw7xavoalmikc2NtPVQvBY1LAcEd5Xk jMZicy2otisgp6/wedXjjVjSRTwqYDciE/hbI/OmIJDId574HmV64FFUl 50ZGRJEFubPBPOySas+B1TZJvTHPhUIONtdC/6ayG2vemoPKWzkwgaR2H zoR9LpSj6P5nKjABRQquHgb71b990PgfxV/PX1rUqNUgQhQJUWASi6qf5 Q==; X-CSE-ConnectionGUID: BdZBPcTWQTW6sp6Pez+hHQ== X-CSE-MsgGUID: +V83iXe3QuWXzC9sH4lMVQ== X-IronPort-AV: E=McAfee;i="6700,10204,11351"; a="40954501" X-IronPort-AV: E=Sophos;i="6.13,301,1732608000"; d="scan'208";a="40954501" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by orvoesa108.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Feb 2025 05:18:13 -0800 X-CSE-ConnectionGUID: yX01pfR4Ri+65gbuXvkoIw== X-CSE-MsgGUID: C61FJmwvTZGeC9JNxnz9wg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.13,301,1732608000"; d="scan'208";a="120143330" Received: from nneronin-mobl1.ger.corp.intel.com (HELO [10.245.120.28]) ([10.245.120.28]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Feb 2025 05:18:12 -0800 Message-ID: Date: Thu, 20 Feb 2025 15:18:08 +0200 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 5/4 RFC] An alternative dma_in_range() implementation To: =?UTF-8?Q?Micha=C5=82_Pecio?= , mathias.nyman@linux.intel.com Cc: linux-usb@vger.kernel.org References: <20250206103428.1034784-4-niklas.neronin@linux.intel.com> <20250219095637.5bd6e9e4@foxbook> <20250220131451.6f356f31@foxbook> Content-Language: en-US From: "Neronin, Niklas" In-Reply-To: <20250220131451.6f356f31@foxbook> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 20/02/2025 14.14, Michał Pecio wrote: > Here's my attempt at it, the patch goes on top of the whole series. It > compiles and passes basic testing (some URBs completed, some unlinked, > no errors or other malfunction apparent). > > The idea is to translate dma to trb* ASAP and work with that, because > all data structures use trb* so the code gets shorter and less verbose. > This approach is also easy to adapt to changes in handle_tx_event(), > for example it could trivially return trb* instead of seg* or take trb* > (with or without accompanying seg*) and return bool or even seg*. > > I tried to make the common case (start_seg == end_seg) fast, both for > hit and miss. 5 comparisons if the range wraps around, 4 if it doesn't. > Thanks, I have a similar version. If it's alright with you, I'll try to combine your version and mine into one and add it to trb_in_td-v2. Thanks, Niklas > diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c > index 600842425f6d..b18e7fd7d01e 100644 > --- a/drivers/usb/host/xhci-ring.c > +++ b/drivers/usb/host/xhci-ring.c > @@ -300,42 +300,36 @@ static struct xhci_segment *dma_in_range(struct xhci_segment *start_seg, union x > dma_addr_t dma) > { > struct xhci_segment *seg = start_seg; > + union xhci_trb *trb; > > - if (start_seg == end_seg) { > - if (start_trb <= end_trb) { > - if (xhci_trb_virt_to_dma(start_seg, start_trb) <= dma && > - dma <= xhci_trb_virt_to_dma(end_seg, end_trb)) > - return seg; > - return NULL; > + /* check if dma is a TRB in start_seg */ > + if (in_range(dma, seg->dma, TRB_SEGMENT_SIZE)) { > + trb = seg->trbs + (dma - seg->dma) / sizeof(*trb); > + > + if (trb >= start_trb) > + /* check if the range covers it and we are done */ > + return (end_seg != seg || trb <= end_trb) ? seg : NULL; > + > + /* check if the range circles back to the beginning of start_seg */ > + return (end_seg == seg && end_trb < start_trb && trb <= end_trb) ? seg : NULL; > + } > + > + /* stop if the range doesn't pass through any other segment */ > + if (end_seg == seg && (end_trb >= start_trb || seg->next == seg)) > + return NULL; > + > + /* search remaining segments knowing that start_trb isn't there */ > + do { > + seg = seg->next; > + > + if (in_range(dma, seg->dma, TRB_SEGMENT_SIZE)) { > + trb = seg->trbs + (dma - seg->dma) / sizeof(*trb); > + > + return (seg != end_seg || trb <= end_trb) ? seg : NULL; > } > + } while (seg != end_seg && seg != start_seg); > > - /* Edge case, the TD wrapped around to the start segment. */ > - if (xhci_trb_virt_to_dma(end_seg, end_trb) < dma && > - dma < xhci_trb_virt_to_dma(start_seg, start_trb)) > - return NULL; > - if (seg->dma <= dma && dma <= (seg->dma + TRB_SEGMENT_SIZE)) > - return seg; > - seg = seg->next; > - } > - > - /* Loop through segment which don't contain the DMA address. */ > - while (dma < seg->dma || (seg->dma + TRB_SEGMENT_SIZE) <= dma) { > - if (seg == end_seg) > - return NULL; > - > - seg = seg->next; > - if (seg == start_seg) > - return NULL; > - } > - > - if (seg == start_seg) { > - if (dma < xhci_trb_virt_to_dma(start_seg, start_trb)) > - return NULL; > - } else if (seg == end_seg) { > - if (xhci_trb_virt_to_dma(end_seg, end_trb) < dma) > - return NULL; > - } > - return seg; > + return NULL; > } > > static struct xhci_segment *trb_in_td(struct xhci_td *td, dma_addr_t dma)