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 220871C2312; Fri, 2 Aug 2024 09:37:43 +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=1722591464; cv=none; b=nj9I3+3L/Zdu6IU3Z84wBJ2V1F5sQCRFzc116qQdVOkjM3IId3Gb9jFcUMuINuivi6s11RY0ceutLch21KNH9Cgc4ruWdIWhskAJb9I3cPEWM2W+lNsR1yNfzSy0Lk3lIIui5W3KB0/GdUEI3BLdHfpI3SBjBWP4nZa1oj4X3rc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722591464; c=relaxed/simple; bh=ltOSUPsZibGklzCT+726uDqpI/gR+HZvRJVWnku4cnU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=i21sYO1AR40qpQegvDZvNHpFajyzKDN18buW2hdIp0wJoG7GPjsgnTefQOZ0ISjQIIq8ND5EG5PgH+SpxvQs46stF3Qq+5qOiW/20r/swPlBkYpHIfVUXPKZQPahw107ziv24YznRQNlb5PNAKPq9XvMRkgwOsEjd/ydPsuOWiQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C709C32782; Fri, 2 Aug 2024 09:37:41 +0000 (UTC) Date: Fri, 2 Aug 2024 10:37:38 +0100 From: Catalin Marinas To: Baruch Siach Cc: Christoph Hellwig , Marek Szyprowski , Will Deacon , Robin Murphy , iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, Petr =?utf-8?B?VGVzYcWZw61r?= , Ramon Fried , Elad Nachman Subject: Re: [PATCH v5 2/3] dma: replace zone_dma_bits by zone_dma_limit Message-ID: References: <5821a1b2eb82847ccbac0945da040518d6f6f16b.1722578375.git.baruch@tkos.co.il> 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: <5821a1b2eb82847ccbac0945da040518d6f6f16b.1722578375.git.baruch@tkos.co.il> On Fri, Aug 02, 2024 at 09:03:47AM +0300, Baruch Siach wrote: > diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c > index 3b4be4ca3b08..62b36fda44c9 100644 > --- a/kernel/dma/direct.c > +++ b/kernel/dma/direct.c > @@ -20,7 +20,7 @@ > * it for entirely different regions. In that case the arch code needs to > * override the variable below for dma-direct to work properly. > */ > -unsigned int zone_dma_bits __ro_after_init = 24; > +u64 zone_dma_limit __ro_after_init = DMA_BIT_MASK(24); u64 here makes sense even if it may be larger than phys_addr_t. It matches the phys_limit type in the swiotlb code. The compilers should no longer complain. > diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c > index d10613eb0f63..7b04f7575796 100644 > --- a/kernel/dma/pool.c > +++ b/kernel/dma/pool.c > @@ -70,9 +70,9 @@ static bool cma_in_zone(gfp_t gfp) > /* CMA can't cross zone boundaries, see cma_activate_area() */ > end = cma_get_base(cma) + size - 1; > if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA)) > - return end <= DMA_BIT_MASK(zone_dma_bits); > + return end <= zone_dma_limit; > if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32)) > - return end <= DMA_BIT_MASK(32); > + return end <= max(DMA_BIT_MASK(32), zone_dma_limit); > return true; > } > > diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c > index 043b0ecd3e8d..bb51bd5335ad 100644 > --- a/kernel/dma/swiotlb.c > +++ b/kernel/dma/swiotlb.c > @@ -450,9 +450,9 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask, > if (!remap) > io_tlb_default_mem.can_grow = true; > if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp_mask & __GFP_DMA)) > - io_tlb_default_mem.phys_limit = DMA_BIT_MASK(zone_dma_bits); > + io_tlb_default_mem.phys_limit = zone_dma_limit; > else if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp_mask & __GFP_DMA32)) > - io_tlb_default_mem.phys_limit = DMA_BIT_MASK(32); > + io_tlb_default_mem.phys_limit = max(DMA_BIT_MASK(32), zone_dma_limit); > else > io_tlb_default_mem.phys_limit = virt_to_phys(high_memory - 1); > #endif These two look correct to me now and it's the least intrusive (the alternative would have been a zone_dma32_limit). The arch code, however, needs to ensure that zone_dma_limit can always support 32-bit devices even if it is above 4GB (with the relevant dma offsets in place for such devices). -- Catalin