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c=simple/simple; d=arm.com; s=foss; t=1789995158; bh=K/50ZomrN1bFLTBeeVPhJwuc1yciBmPSu8YX6Qsus9I=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UFZe4bpR5E17t5D1Lm9j6zlnOoMKygimSB1DPY+3+q0C6iJgg+EiBHxg6xnrKV8uS ne9l4ZgvIvWxD6dQ7eM1P+nFVo3S70EXtWpP4Lh2XJhn7wUJFW+NV19QrXwjpC/RJ4 gyNTyjuCs5XZdDcvhmAKMYX8J4AXAbctL+YOlquU= Date: Mon, 21 Sep 2026 13:52:28 +0100 From: Catalin Marinas To: "Aneesh Kumar K.V (Arm)" Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Robin Murphy , Marek Szyprowski , Will Deacon , Marc Zyngier , Steven Price , Suzuki K Poulose , Jiri Pirko , Jason Gunthorpe , Mostafa Saleh , Petr Tesarik , Alexey Kardashevskiy , Dan Williams , Xu Yilun , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , Russell King , Huacai Chen , Thomas Bogendoerfer , Jiaxun Yang , Paul Walmsley , Palmer Dabbelt , Albert Ou , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH v5 3/6] dma: swiotlb: Centralize minimal pool sizing Message-ID: References: <20260921063628.362078-1-aneesh.kumar@kernel.org> <20260921063628.362078-4-aneesh.kumar@kernel.org> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260921063628.362078-4-aneesh.kumar@kernel.org> On Mon, Sep 21, 2026 at 12:06:25PM +0530, Aneesh Kumar K.V (Arm) wrote: > A default SWIOTLB pool used only for unaligned kmalloc bouncing can be > smaller than one required for limited DMA addressing. Arm64 and RISC-V > currently implement this sizing independently, using 1 MiB of SWIOTLB > space per GiB of RAM. > > The SWIOTLB core now identifies this case with SWIOTLB_POOL_MINIMAL. > Size that policy in swiotlb_adjust_pool_size() and remove the > architecture-specific adjustments. > > Explicit swiotlb= sizing remains unchanged because swiotlb_adjust_size() > preserves a user-configured size. > > Signed-off-by: Aneesh Kumar K.V (Arm) Reviewed-by: Catalin Marinas