From: Catalin Marinas <catalin.marinas@arm.com>
To: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Cc: robh+dt@kernel.org, hch@lst.de, robin.murphy@arm.com,
devicetree@vger.kernel.org, iommu@lists.linux-foundation.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
will@kernel.org, linux-arm-kernel@lists.infradead.org,
linux-rpi-kernel@lists.infradead.org
Subject: Re: [PATCH 3/4] arm64: Default to 32-bit ZONE_DMA
Date: Thu, 1 Oct 2020 18:19:22 +0100 [thread overview]
Message-ID: <20201001171922.GO21544@gaia> (raw)
In-Reply-To: <20201001161740.29064-4-nsaenzjulienne@suse.de>
On Thu, Oct 01, 2020 at 06:17:39PM +0200, Nicolas Saenz Julienne wrote:
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index e1a69a618832..3c3f462466eb 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -43,8 +43,6 @@
> #include <asm/tlb.h>
> #include <asm/alternative.h>
>
> -#define ARM64_ZONE_DMA_BITS 30
> -
> /*
> * We need to be able to catch inadvertent references to memstart_addr
> * that occur (potentially in generic code) before arm64_memblock_init()
> @@ -388,8 +386,14 @@ void __init arm64_memblock_init(void)
> early_init_fdt_scan_reserved_mem();
>
> if (IS_ENABLED(CONFIG_ZONE_DMA)) {
> - zone_dma_bits = ARM64_ZONE_DMA_BITS;
> - arm64_dma_phys_limit = max_zone_phys(ARM64_ZONE_DMA_BITS);
> + /*
> + * early_init_dt_scan() might alter zone_dma_bits based on the
> + * device's DT. Otherwise, have it cover the 32-bit address
> + * space.
> + */
> + if (zone_dma_bits == ZONE_DMA_BITS_DEFAULT)
> + zone_dma_bits = 32;
> + arm64_dma_phys_limit = max_zone_phys(zone_dma_bits);
So here we assume that if zone_dma_bits is 24, it wasn't initialised. I
think it may be simpler if we just set it in setup_machine_fdt() to 32
or 30 if RPi4. This way we don't have to depend on what the core kernel
sets.
--
Catalin
next prev parent reply other threads:[~2020-10-01 17:19 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-01 16:17 [PATCH 0/4] arm64: Default to 32-bit wide ZONE_DMA Nicolas Saenz Julienne
2020-10-01 16:17 ` [PATCH 1/4] of/fdt: Update zone_dma_bits when running in bcm2711 Nicolas Saenz Julienne
2020-10-01 17:15 ` Catalin Marinas
2020-10-01 17:23 ` Catalin Marinas
2020-10-01 17:31 ` Nicolas Saenz Julienne
2020-10-01 20:02 ` Rob Herring
2020-10-02 11:55 ` Catalin Marinas
2020-10-08 10:05 ` Nicolas Saenz Julienne
2020-10-08 10:13 ` Catalin Marinas
2020-10-08 19:43 ` Ard Biesheuvel
2020-10-09 3:59 ` Jeremy Linton
2020-10-09 8:37 ` Nicolas Saenz Julienne
2020-10-09 7:10 ` Christoph Hellwig
2020-10-09 7:37 ` Ard Biesheuvel
2020-10-09 8:36 ` Nicolas Saenz Julienne
2020-10-09 9:13 ` Ard Biesheuvel
2020-10-09 13:33 ` Nicolas Saenz Julienne
2020-10-09 15:24 ` Lorenzo Pieralisi
2020-10-09 16:23 ` Ard Biesheuvel
2020-10-09 17:10 ` Catalin Marinas
2020-10-10 10:36 ` Ard Biesheuvel
2020-10-10 10:53 ` Nicolas Saenz Julienne
2020-10-10 12:38 ` Catalin Marinas
2020-10-12 6:47 ` Christoph Hellwig
2020-10-12 8:47 ` Catalin Marinas
2020-10-02 9:05 ` kernel test robot
2020-10-01 16:17 ` [PATCH 2/4] dma-direct: Turn zone_dma_bits default value into a define Nicolas Saenz Julienne
2020-10-01 16:17 ` [PATCH 3/4] arm64: Default to 32-bit ZONE_DMA Nicolas Saenz Julienne
2020-10-01 17:19 ` Catalin Marinas [this message]
2020-10-01 16:17 ` [PATCH 4/4] mm: Update DMA zones description Nicolas Saenz Julienne
2020-10-01 17:19 ` Catalin Marinas
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