From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 801BD3081D6; Mon, 13 Apr 2026 15:12:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776093135; cv=none; b=FR/rtYTSC7QYGp25M2ADOHASMM23lbrQTwA67yDdC0DUW5SIGmdk81gJG7pakY9suBwcySmU8RpKLTwSSEgXCeZup559A5tyYqKgoAyevvEdATY2Ud4owhnSWYEVg1ukdQRkArc0Qtwt0sJC3RuRvJDEHcYbyKeLykHcm+toP7g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776093135; c=relaxed/simple; bh=Y8Yi/bJJbstcHgVRPIN0sGskUtriLPw0DVHCE6fghxQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=foU2NLMX1221xusy0PlX81wpqC4WFckHQ07vOYctggQbvhvTrAq9k31IKjfjJpeD8MvOUF8vL01es0T3nWtg7rsQEbPA6Bg7rTQL7pLoMq7IXLY6i9360NwNg3F51icA+Dqll/HNtWq8l/7ywEDOY46cyus9rutq1A7bmTs1UsA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oYSebltY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oYSebltY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE8D3C2BCAF; Mon, 13 Apr 2026 15:12:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776093135; bh=Y8Yi/bJJbstcHgVRPIN0sGskUtriLPw0DVHCE6fghxQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=oYSebltYV0b0EJR6dW6OS1C59FdwWEL0aUqpQwzm8jHn5lsb+YABFdEMCOFcq4tSF A6BBaOi5a70XQuE0vh2VSgN67Ws99/tI4izKQOq60CU0LxmibeeHwfDUX3ocow81iX JItqbbJPgGOcVoRDMN2rFfZS1hkdPG1mcylnjKvRMOwdhrfhdmFbHhNwBDvoKDlyAh zNDe766gk3gCO5CqFQvroV7drCSpwxPcBOl99JwWyB3G0iW79yNh16RS7JPfOR9cHL 4kAwDDy/koHfBtThWk8F23shMRn8rk2YOOvPbGjGiKZ17kQ1ksmSy+VOIvPjGzvNtE YyOfny1iDh0Fw== Message-ID: Date: Mon, 13 Apr 2026 17:12:07 +0200 Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/8] mm/memory: add memory_block_align_range() helper To: Gregory Price , linux-mm@kvack.org, vishal.l.verma@intel.com, dave.jiang@intel.com, akpm@linux-foundation.org, osalvador@suse.de Cc: dan.j.williams@intel.com, ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, linux-kernel@vger.kernel.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, kernel-team@meta.com References: <20260321150404.3288786-1-gourry@gourry.net> <20260321150404.3288786-3-gourry@gourry.net> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/21/26 16:03, Gregory Price wrote: > Memory hotplug operations require ranges aligned to memory block > boundaries. This is a generic operation for hotplug. > > Add memory_block_align_range() as a common helper in > that aligns the start address up and end address down to memory block > boundaries. > > Update dax/kmem to use this helper. > > Signed-off-by: Gregory Price > --- > drivers/dax/kmem.c | 4 +--- > include/linux/memory.h | 22 ++++++++++++++++++++++ > 2 files changed, 23 insertions(+), 3 deletions(-) > > diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c > index eb693a581961..798f389df992 100644 > --- a/drivers/dax/kmem.c > +++ b/drivers/dax/kmem.c > @@ -26,9 +26,7 @@ static int dax_kmem_range(struct dev_dax *dev_dax, int i, struct range *r) > struct dev_dax_range *dax_range = &dev_dax->ranges[i]; > struct range *range = &dax_range->range; > > - /* memory-block align the hotplug range */ > - r->start = ALIGN(range->start, memory_block_size_bytes()); > - r->end = ALIGN_DOWN(range->end + 1, memory_block_size_bytes()) - 1; > + *r = memory_block_align_range(range); > if (r->start >= r->end) { > r->start = range->start; > r->end = range->end; > diff --git a/include/linux/memory.h b/include/linux/memory.h > index 5bb5599c6b2b..17cdf6ba3823 100644 > --- a/include/linux/memory.h > +++ b/include/linux/memory.h > @@ -20,6 +20,7 @@ > #include > #include > #include > +#include > > #define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS) > > @@ -100,6 +101,27 @@ int arch_get_memory_phys_device(unsigned long start_pfn); > unsigned long memory_block_size_bytes(void); > int set_memory_block_size_order(unsigned int order); > > +/** > + * memory_block_align_range - align a physical address range to memory blocks > + * @range: the input range to align > + * > + * Aligns the start address up and the end address down to memory block > + * boundaries. This is required for memory hotplug operations which must > + * operate on memory-block aligned ranges. > + * > + * Returns the aligned range. Callers should check that the returned > + * range is valid (aligned.start < aligned.end) before using it. > + */ > +static inline struct range memory_block_align_range(const struct range *range) Reads as if you would be passing in a memory block. Maybe "align_range_to_memory_blocks()" "range_align_to_memory_blocks()" Maybe what also works: "memory_block_aligned_range()" In general, LGTM. -- Cheers, David