Messages in this thread Patch in this message | | | Subject | Re: [PATCH 2/2] arm: use swiotlb for bounce buffer on LPAE configs | From | Peter Ujfalusi <> | Date | Wed, 8 Jan 2020 10:28:04 +0200 |
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Hi Christoph,
On 19/12/2019 17.20, Peter Ujfalusi wrote: > 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
Do you have idea on how to fix this in a proper way?
IMHO when drivers are setting the dma_mask and coherent_mask the dma_pfn_offset should not be applied to the mask at all.
If I understand it correctly for EDMA as example:
I set dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32)); since it can only address memory in this range.
It does not matter if dma_pfn_offset is 0 or not 0 (like in k2g, where it is 0x780000) the EDMA still can only address within 32 bits.
The dma_pfn_offset will tell us that the memory location's physical address is seen by the DMA at (phys_pfn - dma_pfn_offset) -> dma_pfn.
The dma_mask should be checked against the dma_pfn.
We can not 'move' the dma_mask with dma_pfn_offset when setting the mask since it is not correct. The DMA can access in 32 bits range and we have the peripherals under 0x8000 0000.
I might be missing something, but it looks to me that the way we set the dma_mask and the coherent_mask is the place where this can be fixed.
Best regards, - Péter
> > - 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 > > _______________________________________________ > 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
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