[PATCH 1/3] dma-direct: unify the dma_capable definitions

Marek Szyprowski m.szyprowski at samsung.com
Tue Nov 19 20:27:13 AEDT 2019


Hi Christoph,

On 13.11.2019 08:35, Christoph Hellwig wrote:
> Currently each architectures that wants to override dma_to_phys and
> phys_to_dma also has to provide dma_capable.  But there isn't really
> any good reason for that.  powerpc and mips just have copies of the
> generic one minus the latests fix, and the arm one was the inspiration
> for said fix, but misses the bus_dma_mask handling.
> Make all architectures use the generic version instead.
>
> Signed-off-by: Christoph Hellwig <hch at lst.de>

This patch breaks DMAengine PL330 driver on Samsung Exynos SoCs:

[    3.602338] dma-pl330 12690000.pdma: overflow 0x13810020+1 of DMA 
mask ffffffff bus mask 0
[    3.605113] ------------[ cut here ]------------
[    3.609719] WARNING: CPU: 2 PID: 1 at kernel/dma/direct.c:36 
report_addr+0xc0/0xfc
[    3.617226] Modules linked in:
[    3.620271] CPU: 2 PID: 1 Comm: init Not tainted 
5.4.0-rc5-00056-gb037b220e71d #6911
[    3.627986] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[    3.634094] [<c01124e8>] (unwind_backtrace) from [<c010dfcc>] 
(show_stack+0x10/0x14)
[    3.641803] [<c010dfcc>] (show_stack) from [<c0ae9af8>] 
(dump_stack+0xa8/0xd4)
[    3.649002] [<c0ae9af8>] (dump_stack) from [<c012746c>] 
(__warn+0xf4/0x10c)
[    3.655940] [<c012746c>] (__warn) from [<c0127534>] 
(warn_slowpath_fmt+0xb0/0xb8)
[    3.663404] [<c0127534>] (warn_slowpath_fmt) from [<c01b4ff4>] 
(report_addr+0xc0/0xfc)
[    3.671303] [<c01b4ff4>] (report_addr) from [<c01b5264>] 
(dma_direct_map_resource+0x98/0xa0)
[    3.679739] [<c01b5264>] (dma_direct_map_resource) from [<c04fbb58>] 
(pl330_prep_slave_fifo+0xe4/0x128)
[    3.689099] [<c04fbb58>] (pl330_prep_slave_fifo) from [<c04fe2b8>] 
(pl330_prep_slave_sg+0x54/0x1cc)
[    3.698129] [<c04fe2b8>] (pl330_prep_slave_sg) from [<c053e5f0>] 
(s3c24xx_serial_start_tx_dma+0x118/0x1e8)
[    3.707764] [<c053e5f0>] (s3c24xx_serial_start_tx_dma) from 
[<c0535f70>] (uart_write+0xe4/0x1e0)
[    3.716532] [<c0535f70>] (uart_write) from [<c05186a0>] 
(n_tty_write+0x1c8/0x474)
[    3.723992] [<c05186a0>] (n_tty_write) from [<c05163c0>] 
(tty_write+0x154/0x314)
[    3.731380] [<c05163c0>] (tty_write) from [<c02a5748>] 
(__vfs_write+0x30/0x1d0)
[    3.738662] [<c02a5748>] (__vfs_write) from [<c02a851c>] 
(vfs_write+0xa4/0x180)
[    3.745949] [<c02a851c>] (vfs_write) from [<c02a8778>] 
(ksys_write+0x60/0xd8)
[    3.753069] [<c02a8778>] (ksys_write) from [<c0101000>] 
(ret_fast_syscall+0x0/0x28)
[    3.760705] Exception stack(0xee8dffa8 to 0xee8dfff0)
[    3.765739] ffa0:                   0000004a beca876c 00000002 
beca876c 0000004a 00000000
[    3.773900] ffc0: 0000004a beca876c b6f02cf0 00000004 beca876c 
0000004a 00000000 b6f99010
[    3.782056] ffe0: 0000006c beca8628 b6e1d000 b6e7a634
[    3.787092] irq event stamp: 289740
[    3.790571] hardirqs last  enabled at (289739): [<c0b0d0c4>] 
_raw_spin_unlock_irqrestore+0x6c/0x74
[    3.799503] hardirqs last disabled at (289740): [<c0b0caf8>] 
_raw_spin_lock_irqsave+0x1c/0x58
[    3.808011] softirqs last  enabled at (289576): [<c01026bc>] 
__do_softirq+0x4fc/0x5fc
[    3.815830] softirqs last disabled at (289567): [<c0130044>] 
irq_exit+0x16c/0x170
[    3.823286] ---[ end trace b1432c658797b861 ]---
[    3.827898] samsung-uart 13810000.serial: Unable to get desc for Tx
[    3.834624] samsung-uart 13810000.serial: Unable to get desc for Tx
[    3.840487] samsung-uart 13810000.serial: Unable to get desc for Tx

I'm checking now which part of it causes the issue.


> ---
>   arch/arm/include/asm/dma-direct.h     | 19 -------------------
>   arch/mips/include/asm/dma-direct.h    |  8 --------
>   arch/powerpc/include/asm/dma-direct.h |  9 ---------
>   include/linux/dma-direct.h            |  2 +-
>   4 files changed, 1 insertion(+), 37 deletions(-)
>
> diff --git a/arch/arm/include/asm/dma-direct.h b/arch/arm/include/asm/dma-direct.h
> index b67e5fc1fe43..7c3001a6a775 100644
> --- a/arch/arm/include/asm/dma-direct.h
> +++ b/arch/arm/include/asm/dma-direct.h
> @@ -14,23 +14,4 @@ static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
>   	return __pfn_to_phys(dma_to_pfn(dev, dev_addr)) + offset;
>   }
>   
> -static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
> -{
> -	u64 limit, mask;
> -
> -	if (!dev->dma_mask)
> -		return 0;
> -
> -	mask = *dev->dma_mask;
> -
> -	limit = (mask + 1) & ~mask;
> -	if (limit && size > limit)
> -		return 0;
> -
> -	if ((addr | (addr + size - 1)) & ~mask)
> -		return 0;
> -
> -	return 1;
> -}
> -
>   #endif /* ASM_ARM_DMA_DIRECT_H */
> diff --git a/arch/mips/include/asm/dma-direct.h b/arch/mips/include/asm/dma-direct.h
> index b5c240806e1b..14e352651ce9 100644
> --- a/arch/mips/include/asm/dma-direct.h
> +++ b/arch/mips/include/asm/dma-direct.h
> @@ -2,14 +2,6 @@
>   #ifndef _MIPS_DMA_DIRECT_H
>   #define _MIPS_DMA_DIRECT_H 1
>   
> -static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
> -{
> -	if (!dev->dma_mask)
> -		return false;
> -
> -	return addr + size - 1 <= *dev->dma_mask;
> -}
> -
>   dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr);
>   phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t daddr);
>   
> diff --git a/arch/powerpc/include/asm/dma-direct.h b/arch/powerpc/include/asm/dma-direct.h
> index a2912b47102c..e29e8a236b8d 100644
> --- a/arch/powerpc/include/asm/dma-direct.h
> +++ b/arch/powerpc/include/asm/dma-direct.h
> @@ -2,15 +2,6 @@
>   #ifndef ASM_POWERPC_DMA_DIRECT_H
>   #define ASM_POWERPC_DMA_DIRECT_H 1
>   
> -static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
> -{
> -	if (!dev->dma_mask)
> -		return false;
> -
> -	return addr + size - 1 <=
> -		min_not_zero(*dev->dma_mask, dev->bus_dma_mask);
> -}
> -
>   static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
>   {
>   	if (!dev)
> diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
> index 6db863c3eb93..991f8aa2676e 100644
> --- a/include/linux/dma-direct.h
> +++ b/include/linux/dma-direct.h
> @@ -24,6 +24,7 @@ static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
>   
>   	return paddr + ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
>   }
> +#endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
>   
>   static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
>   {
> @@ -38,7 +39,6 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
>   
>   	return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_mask);
>   }
> -#endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
>   
>   #ifdef CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED
>   bool force_dma_unencrypted(struct device *dev);

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland



More information about the Linuxppc-dev mailing list