Re: [PATCH 2/2] arm: use swiotlb for bounce buffer on LPAE configs

Peter Ujfalusi via iommu
2019-12-19T15:20:23Z

Hi Christoph,

On 19/12/2019 17.02, Christoph Hellwig wrote:
> Hi Peter,
>
> can you try the patch below (it will need to be split into two):

Thank you!

Unfortunately it does not help:
[ 0.596208] edma: probe of 2700000.edma failed with error -5
[ 0.596626] edma: probe of 2728000.edma failed with error -5
...
[ 2.108602] sdhci-omap 23000000.mmc: Got CD GPIO
[ 2.113899] mmc0: Failed to set 32-bit DMA mask.
[ 2.118592] mmc0: No suitable DMA available - falling back to PIO
[ 2.159038] mmc0: SDHCI controller on 23000000.mmc [23000000.mmc]
using PIO
[ 2.167531] mmc1: Failed to set 32-bit DMA mask.
[ 2.172192] mmc1: No suitable DMA available - falling back to PIO
[ 2.213841] mmc1: SDHCI controller on 23100000.mmc [23100000.mmc]
using PIO

- Péter

> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index e822af0d9219..30b9c6786ce3 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -221,7 +221,8 @@ EXPORT_SYMBOL(arm_coherent_dma_ops);
>
> static int __dma_supported(struct device *dev, u64 mask, bool warn)
> {
> - unsigned long max_dma_pfn = min(max_pfn, arm_dma_pfn_limit);
> + unsigned long max_dma_pfn =
> + min_t(unsigned long, max_pfn, zone_dma_limit >> PAGE_SHIFT);
>
> /*
> * Translate the device's DMA mask to a PFN limit. This
> diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
> index 3ef204137e73..dd0e169a1bb1 100644
> --- a/arch/arm/mm/init.c
> +++ b/arch/arm/mm/init.c
> @@ -19,6 +19,7 @@
> #include <linux/gfp.h>
> #include <linux/memblock.h>
> #include <linux/dma-contiguous.h>
> +#include <linux/dma-direct.h>
> #include <linux/sizes.h>
> #include <linux/stop_machine.h>
> #include <linux/swiotlb.h>
> @@ -84,15 +85,6 @@ static void __init find_limits(unsigned long *min, unsigned long *max_low,
> phys_addr_t arm_dma_zone_size __read_mostly;
> EXPORT_SYMBOL(arm_dma_zone_size);
>
> -/*
> - * The DMA mask corresponding to the maximum bus address allocatable
> - * using GFP_DMA. The default here places no restriction on DMA
> - * allocations. This must be the smallest DMA mask in the system,
> - * so a successful GFP_DMA allocation will always satisfy this.
> - */
> -phys_addr_t arm_dma_limit;
> -unsigned long arm_dma_pfn_limit;
> -
> static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
> unsigned long dma_size)
> {
> @@ -108,14 +100,14 @@ static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
>
> void __init setup_dma_zone(const struct machine_desc *mdesc)
> {
> -#ifdef CONFIG_ZONE_DMA
> - if (mdesc->dma_zone_size) {
> + if (!IS_ENABLED(CONFIG_ZONE_DMA)) {
> + zone_dma_limit = ((phys_addr_t)~0);
> + } else if (mdesc->dma_zone_size) {
> arm_dma_zone_size = mdesc->dma_zone_size;
> - arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
> - } else
> - arm_dma_limit = 0xffffffff;
> - arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT;
> -#endif
> + zone_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
> + } else {
> + zone_dma_limit = 0xffffffff;
> + }
> }
>
> static void __init zone_sizes_init(unsigned long min, unsigned long max_low,
> @@ -279,7 +271,7 @@ void __init arm_memblock_init(const struct machine_desc *mdesc)
> early_init_fdt_scan_reserved_mem();
>
> /* reserve memory for DMA contiguous allocations */
> - dma_contiguous_reserve(arm_dma_limit);
> + dma_contiguous_reserve(zone_dma_limit);
>
> arm_memblock_steal_permitted = false;
> memblock_dump_all();
> diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
> index 88c121ac14b3..7dbd77554273 100644
> --- a/arch/arm/mm/mm.h
> +++ b/arch/arm/mm/mm.h
> @@ -82,14 +82,6 @@ extern __init void add_static_vm_early(struct static_vm *svm);
>
> #endif
>
> -#ifdef CONFIG_ZONE_DMA
> -extern phys_addr_t arm_dma_limit;
> -extern unsigned long arm_dma_pfn_limit;
> -#else
> -#define arm_dma_limit ((phys_addr_t)~0)
> -#define arm_dma_pfn_limit (~0ul >> PAGE_SHIFT)
> -#endif
> -
> extern phys_addr_t arm_lowmem_limit;
>
> void __init bootmem_init(void);
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index b65dffdfb201..7a7501acd763 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -441,7 +441,7 @@ 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;
> + zone_dma_limit = DMA_BIT_MASK(ARM64_ZONE_DMA_BITS);
> arm64_dma_phys_limit = max_zone_phys(ARM64_ZONE_DMA_BITS);
> }
>
> diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
> index 9488b63dfc87..337ace03d3f0 100644
> --- a/arch/powerpc/mm/mem.c
> +++ b/arch/powerpc/mm/mem.c
> @@ -223,7 +223,7 @@ static int __init mark_nonram_nosave(void)
> * everything else. GFP_DMA32 page allocations automatically fall back to
> * ZONE_DMA.
> *
> - * By using 31-bit unconditionally, we can exploit zone_dma_bits to inform the
> + * By using 31-bit unconditionally, we can exploit zone_dma_limit to inform the
> * generic DMA mapping code. 32-bit only devices (if not handled by an IOMMU
> * anyway) will take a first dip into ZONE_NORMAL and get otherwise served by
> * ZONE_DMA.
> @@ -257,18 +257,20 @@ void __init paging_init(void)
> printk(KERN_DEBUG "Memory hole size: %ldMB\n",
> (long int)((top_of_ram - total_ram) >> 20));
>
> +#ifdef CONFIG_ZONE_DMA
> /*
> * Allow 30-bit DMA for very limited Broadcom wifi chips on many
> * powerbooks.
> */
> - if (IS_ENABLED(CONFIG_PPC32))
> - zone_dma_bits = 30;
> - else
> - zone_dma_bits = 31;
> -
> -#ifdef CONFIG_ZONE_DMA
> - max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
> - 1UL << (zone_dma_bits - PAGE_SHIFT));
> + if (IS_ENABLED(CONFIG_PPC32)) {
> + zone_dma_limit = DMA_BIT_MASK(30);
> + max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
> + 1UL << (30 - PAGE_SHIFT));
> + } else {
> + zone_dma_limit = DMA_BIT_MASK(31);
> + max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
> + 1UL << (31 - PAGE_SHIFT));
> + }
> #endif
> max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
> #ifdef CONFIG_HIGHMEM
> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
> index f0ce22220565..c403f61cb56b 100644
> --- a/arch/s390/mm/init.c
> +++ b/arch/s390/mm/init.c
> @@ -118,7 +118,7 @@ void __init paging_init(void)
>
> sparse_memory_present_with_active_regions(MAX_NUMNODES);
> sparse_init();
> - zone_dma_bits = 31;
> + zone_dma_limit = DMA_BIT_MASK(31);
> memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
> max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
> max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
> diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
> index 24b8684aa21d..20d56d597506 100644
> --- a/include/linux/dma-direct.h
> +++ b/include/linux/dma-direct.h
> @@ -6,7 +6,7 @@
> #include <linux/memblock.h> /* for min_low_pfn */
> #include <linux/mem_encrypt.h>
>
> -extern unsigned int zone_dma_bits;
> +extern phys_addr_t zone_dma_limit;
>
> #ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
> #include <asm/dma-direct.h>
> diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
> index 6af7ae83c4ad..5ea1bed2ba6f 100644
> --- a/kernel/dma/direct.c
> +++ b/kernel/dma/direct.c
> @@ -21,7 +21,7 @@
> * 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;
> +phys_addr_t zone_dma_limit __ro_after_init = DMA_BIT_MASK(24);
>
> static void report_addr(struct device *dev, dma_addr_t dma_addr, size_t size)
> {
> @@ -74,7 +74,7 @@ static gfp_t __dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
> * Note that GFP_DMA32 and GFP_DMA are no ops without the corresponding
> * zones.
> */
> - if (*phys_limit <= DMA_BIT_MASK(zone_dma_bits))
> + if (*phys_limit <= zone_dma_limit)
> return GFP_DMA;
> if (*phys_limit <= DMA_BIT_MASK(32))
> return GFP_DMA32;
> @@ -483,7 +483,7 @@ int dma_direct_supported(struct device *dev, u64 mask)
> u64 min_mask;
>
> if (IS_ENABLED(CONFIG_ZONE_DMA))
> - min_mask = DMA_BIT_MASK(zone_dma_bits);
> + min_mask = zone_dma_limit;
> else
> min_mask = DMA_BIT_MASK(32);
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki