From: Catalin Marinas <catalin.marinas@arm•com>
To: Baruch Siach <baruch@tkos•co.il>
Cc: "Rob Herring" <robh@kernel•org>,
linux-s390@vger•kernel.org, "Ramon Fried" <ramon@neureality•ai>,
"Saravana Kannan" <saravanak@google•com>,
devicetree@vger•kernel.org, "Petr Tesařík" <petr@tesarici•cz>,
"Will Deacon" <will@kernel•org>,
linuxppc-dev@lists•ozlabs.org, linux-kernel@vger•kernel.org,
iommu@lists•linux.dev, "Elad Nachman" <enachman@marvell•com>,
"Robin Murphy" <robin.murphy@arm•com>,
"Christoph Hellwig" <hch@lst•de>,
linux-arm-kernel@lists•infradead.org,
"Marek Szyprowski" <m.szyprowski@samsung•com>
Subject: Re: [PATCH RFC v2 4/5] dma-direct: add base offset to zone_dma_bits
Date: Tue, 18 Jun 2024 22:40:39 +0100 [thread overview]
Message-ID: <ZnH-18_lQsdYaxgj@arm.com> (raw)
In-Reply-To: <1d7b0d59590aae631b6f0b894257ab961b907b44.1712642324.git.baruch@tkos.co.il>
On Tue, Apr 09, 2024 at 09:17:57AM +0300, Baruch Siach wrote:
> Current code using zone_dma_bits assume that all addresses range in the
> bits mask are suitable for DMA. For some existing platforms this
> assumption is not correct. DMA range might have non zero lower limit.
[...]
> @@ -59,7 +60,7 @@ static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 *phys_limit)
> * zones.
> */
> *phys_limit = dma_to_phys(dev, dma_limit);
> - if (*phys_limit <= zone_dma_limit)
> + if (*phys_limit <= zone_dma_base + zone_dma_limit)
> return GFP_DMA;
> if (*phys_limit <= DMA_BIT_MASK(32))
> return GFP_DMA32;
As I said previously, we no longer have zone_dma_bits after the first
patch, so adding this limit no longer make sense. In v1, you wanted a
limit like 32G to be added to the 30-bit zone_dma_bits to give you 33G
upper limit for ZONE_DMA. But since the first patch sets zone_dma_limit
to 33G already, this is no longer needed.
--
Catalin
next prev parent reply other threads:[~2024-06-18 21:41 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-09 6:17 [PATCH RFC v2 0/5] arm64: support DMA zone starting above 4GB Baruch Siach
2024-04-09 6:17 ` [PATCH RFC v2 1/5] dma-mapping: replace zone_dma_bits by zone_dma_limit Baruch Siach
2024-06-18 18:26 ` Catalin Marinas
2024-04-09 6:17 ` [PATCH RFC v2 2/5] of: get dma area lower limit Baruch Siach
2024-06-18 21:38 ` Catalin Marinas
2024-07-25 11:49 ` Baruch Siach
2024-07-30 15:52 ` Catalin Marinas
2024-04-09 6:17 ` [PATCH RFC v2 3/5] of: unittest: add test for of_dma_get_cpu_limits() 'min' param Baruch Siach
2024-04-09 6:17 ` [PATCH RFC v2 4/5] dma-direct: add base offset to zone_dma_bits Baruch Siach
2024-06-18 21:40 ` Catalin Marinas [this message]
2024-04-09 6:17 ` [PATCH RFC v2 5/5] arm64: mm: take DMA zone offset into account Baruch Siach
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