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 A2D0422539E for ; Mon, 7 Apr 2025 06:54:32 +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=1744008872; cv=none; b=HU5/2iEIQeiyGg98uYa6+yEGNNQZvmujMEk5t82+zNgvXz0PaObSfeJoQJosN7JqTY51w1jAjGFHzR5J3cKOQU5P0ZaFb254FCmvRaPlY80Y+8jTz3MTbh4Lijyh/CpxY/gu8WPKRMUY27ymwhJBWCIvKSw2JM/+qxODCAtwBYg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744008872; c=relaxed/simple; bh=LS5VAFFXIJwM/MSSY+05QkBo1gZOgTa9umjd9LQcztk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=g+fTDbA81BigrcOD2vnl0PO3GnjVMEEAq68xpWzlZacL/3dnu16u/LCqynRRQtLQ4LMkWACyPXg5kpkGsUMBjpdB0ljFHwzqkmezU1fntcJBRSb0hr6WtryCsHQykPsIjIy0ghYgq9CbKOuPhuuStkWnz/0r2qvt5ZdvVzfGYGk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Xv+M4Mat; 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="Xv+M4Mat" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 309CFC4CEDD; Mon, 7 Apr 2025 06:54:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744008872; bh=LS5VAFFXIJwM/MSSY+05QkBo1gZOgTa9umjd9LQcztk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Xv+M4Mat5kHI/qdqSL1tzNzCIwVTRpJIvLTTz4+vqLSkmxjAYPJTnHqeeemP5FFEO /dZE3YfGdn97xTFXNNgBFNxwviUiSYPYZnlvaEQmGGH7DlrA5GdDfwKyftkELYmjFK RdqQl+fSbVkSlMb7CV/ZNZc8md4SZy7xEV7O5ncMWpfVIwUJPNZy1ybNdEDUWB0yyn tz3/y8runsfEn4FmEgStx5g1Gt+Gl66+pxmnMx/Y1+bsx7VFAoeB+F57ypOQN8jlKq D0KOIRo/zaQSAebLkPOEX1gShEGyMIoaPDF61zp9GF4QIvBzvuKboPdpSFoQK+S+w8 bnG2TkLxajhrw== Date: Mon, 7 Apr 2025 09:54:23 +0300 From: Mike Rapoport To: David Woodhouse Cc: Andrew Morton , "Sauerwein, David" , Anshuman Khandual , Ard Biesheuvel , Catalin Marinas , David Hildenbrand , Marc Zyngier , Mark Rutland , Mike Rapoport , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH v2 2/7] mm: Implement for_each_valid_pfn() for CONFIG_FLATMEM Message-ID: References: <20250404155959.3442111-1-dwmw2@infradead.org> <20250404155959.3442111-2-dwmw2@infradead.org> 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=us-ascii Content-Disposition: inline In-Reply-To: <20250404155959.3442111-2-dwmw2@infradead.org> On Fri, Apr 04, 2025 at 04:59:54PM +0100, David Woodhouse wrote: > From: David Woodhouse > > In the FLATMEM case, the default pfn_valid() just checks that the PFN is > within the range [ ARCH_PFN_OFFSET .. ARCH_PFN_OFFSET + max_mapnr ). > > The for_each_valid_pfn() function can therefore be a simple for() loop > using those as min/max respectively. > > Signed-off-by: David Woodhouse > Reviewed-by: Mike Rapoport (Microsoft) > --- > include/asm-generic/memory_model.h | 26 +++++++++++++++++++++++++- > 1 file changed, 25 insertions(+), 1 deletion(-) > > diff --git a/include/asm-generic/memory_model.h b/include/asm-generic/memory_model.h > index a3b5029aebbd..044536da3390 100644 > --- a/include/asm-generic/memory_model.h > +++ b/include/asm-generic/memory_model.h > @@ -30,7 +30,31 @@ static inline int pfn_valid(unsigned long pfn) > return pfn >= pfn_offset && (pfn - pfn_offset) < max_mapnr; > } > #define pfn_valid pfn_valid > -#endif > + > +static inline bool first_valid_pfn(unsigned long *pfn) This is now different from SPARSEMEM version. Do we need it at all? > +{ > + /* avoid include hell */ > > + extern unsigned long max_mapnr; > + unsigned long pfn_offset = ARCH_PFN_OFFSET; > + > + if (*pfn < pfn_offset) { > + *pfn = pfn_offset; > + return true; > + } > + > + if ((*pfn - pfn_offset) < max_mapnr) > + return true; > + > + return false; > +} > + > +#ifndef for_each_valid_pfn > +#define for_each_valid_pfn(pfn, start_pfn, end_pfn) \ > + for (pfn = max_t(unsigned long, start_pfn, ARCH_PFN_OFFSET); \ > + pfn < min_t(unsigned long, end_pfn, ARCH_PFN_OFFSET + max_mapnr); \ > + pfn++) > +#endif /* for_each_valid_pfn */ > +#endif /* valid_pfn */ > > #elif defined(CONFIG_SPARSEMEM_VMEMMAP) > > -- > 2.49.0 > -- Sincerely yours, Mike.