unify the dma_capable definition

Hi all,

there is no good reason to have different version of dma_capable.
This series removes the arch overrides and also adds a few cleanups
in the same area.

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@lst.de>
---
 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);

-- 
2.20.1

Move dma_capable down a bit so that we don't need a forward declaration
for phys_to_dma.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/dma-direct.h | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
index 991f8aa2676e..f8959f75e496 100644
--- a/include/linux/dma-direct.h
+++ b/include/linux/dma-direct.h

@@ -6,8 +6,6 @@
 #include <linux/memblock.h> /* for min_low_pfn */
 #include <linux/mem_encrypt.h>
 
-static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
-
 #ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
 #include <asm/dma-direct.h>
 #else

@@ -26,20 +24,6 @@ static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
 }
 #endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
 
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	dma_addr_t end = addr + size - 1;
-
-	if (!dev->dma_mask)
-		return false;
-
-	if (!IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) &&
-	    min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn)))
-		return false;
-
-	return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_mask);
-}
-
 #ifdef CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED
 bool force_dma_unencrypted(struct device *dev);
 #else

@@ -65,6 +49,20 @@ static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
 	return __sme_clr(__dma_to_phys(dev, daddr));
 }
 
+static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
+{
+	dma_addr_t end = addr + size - 1;
+
+	if (!dev->dma_mask)
+		return false;
+
+	if (!IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) &&
+	    min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn)))
+		return false;
+
+	return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_mask);
+}
+
 u64 dma_direct_get_required_mask(struct device *dev);
 void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
 		gfp_t gfp, unsigned long attrs);

-- 
2.20.1

Support for calling the DMA API functions without a valid device pointer
was removed a while ago, so remove the stale support for that from the
powerpc __phys_to_dma / __dma_to_phys helpers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/powerpc/include/asm/dma-direct.h | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/arch/powerpc/include/asm/dma-direct.h b/arch/powerpc/include/asm/dma-direct.h
index e29e8a236b8d..abc154d784b0 100644
--- a/arch/powerpc/include/asm/dma-direct.h
+++ b/arch/powerpc/include/asm/dma-direct.h

@@ -4,15 +4,11 @@
 
 static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 {
-	if (!dev)
-		return paddr + PCI_DRAM_OFFSET;
 	return paddr + dev->archdata.dma_offset;
 }
 
 static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t daddr)
 {
-	if (!dev)
-		return daddr - PCI_DRAM_OFFSET;
 	return daddr - dev->archdata.dma_offset;
 }
 #endif /* ASM_POWERPC_DMA_DIRECT_H */

-- 
2.20.1

On Wed, 2019-11-13 at 08:35 +0100, Christoph Hellwig wrote:

Hi all,

there is no good reason to have different version of dma_capable.
This series removes the arch overrides and also adds a few cleanups
in the same area.

Reviewed-by: Nicolas Saenz Julienne <redacted>

for the whole series,
Thanks!

Christoph Hellwig [off-list ref] writes:

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@lst.de>
---
 arch/arm/include/asm/dma-direct.h     | 19 -------------------
 arch/mips/include/asm/dma-direct.h    |  8 --------
 arch/powerpc/include/asm/dma-direct.h |  9 ---------

Looks OK to me.

Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)

cheers

Christoph Hellwig [off-list ref] writes:

Support for calling the DMA API functions without a valid device pointer
was removed a while ago, so remove the stale support for that from the
powerpc __phys_to_dma / __dma_to_phys helpers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/powerpc/include/asm/dma-direct.h | 4 ----
 1 file changed, 4 deletions(-)

Acked-by: Michael Ellerman <mpe@ellerman.id.au>

cheers

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@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.

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

On Tue, 19 Nov 2019 at 17:27, Marek Szyprowski [off-list ref] wrote:

Hi Christoph,

On 13.11.2019 08:35, Christoph Hellwig wrote:

quoted

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@lst.de>

This patch breaks DMAengine PL330 driver on Samsung Exynos SoCs:

Thanks Marek for bisecting it. I wonder whether it is also the cause
for boot failures I see on NXP Vybrid VF50 SoC (NXP/Freescale
fsl-edma) since few days:

[ 2.853428] fsl-edma 40018000.dma-controller: overflow 0x40027007+1 of
DMA mask ffffffff bus mask 0
[ 2.862566] ------------[ cut here ]------------
[ 2.867273] WARNING: CPU: 0 PID: 1 at
/home/buildbot/worker/builddir_yocto/build/build/tmp/work-shared/col-vf50-proceq-mainline-next/kernel-source/kernel/dma/direct.c:35
report_addr+0xc0/0xfc
[ 2.884380] Modules linked in:
[ 2.887486] CPU: 0 PID: 1 Comm: swapper Tainted: G W
5.4.0-rc7-next-20191118-g519ead8f6a32 #1
[ 2.897364] Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
[ 2.903892] [<8010ddfc>] (unwind_backtrace) from [<8010b4b8>]
(show_stack+0x10/0x14)
[ 2.911712] [<8010b4b8>] (show_stack) from [<8011b08c>] (__warn+0xd4/0xec)
[ 2.918653] [<8011b08c>] (__warn) from [<8011b154>]
(warn_slowpath_fmt+0xb0/0xb8)
[ 2.926218] [<8011b154>] (warn_slowpath_fmt) from [<80155f7c>]
(report_addr+0xc0/0xfc)
[ 2.934221] [<80155f7c>] (report_addr) from [<801561f0>]
(dma_direct_map_resource+0x98/0xa4)
[ 2.942744] [<801561f0>] (dma_direct_map_resource) from [<8041d5d4>]
(fsl_edma_prep_slave_dma+0x12c/0x150)
[ 2.952475] [<8041d5d4>] (fsl_edma_prep_slave_dma) from [<8041d8cc>]
(fsl_edma_prep_dma_cyclic+0x30/0x21c)
[ 2.962213] [<8041d8cc>] (fsl_edma_prep_dma_cyclic) from [<80452e10>]
(lpuart_rx_dma_startup+0x188/0x36c)
[ 2.971871] [<80452e10>] (lpuart_rx_dma_startup) from [<80453058>]
(lpuart_startup+0x64/0x78)
[ 2.980477] [<80453058>] (lpuart_startup) from [<8044e924>]
(uart_startup.part.7+0x110/0x23c)
[ 2.989080] [<8044e924>] (uart_startup.part.7) from [<8044eaa0>]
(uart_port_activate+0x50/0x7c)
[ 2.997857] [<8044eaa0>] (uart_port_activate) from [<80438dc0>]
(tty_port_open+0x74/0xc0)
[ 3.006111] [<80438dc0>] (tty_port_open) from [<8044be30>] (uart_open+0x18/0x20)
[ 3.013588] [<8044be30>] (uart_open) from [<80431b4c>] (tty_open+0x108/0x428)
[ 3.020794] [<80431b4c>] (tty_open) from [<801edb48>] (chrdev_open+0xac/0x164)
[ 3.028098] [<801edb48>] (chrdev_open) from [<801e55c8>]
(do_dentry_open+0x22c/0x3e4)
[ 3.036010] [<801e55c8>] (do_dentry_open) from [<801f72a8>]
(path_openat+0x4a4/0xf78)
[ 3.043912] [<801f72a8>] (path_openat) from [<801f8d34>]
(do_filp_open+0x70/0xdc)
[ 3.051472] [<801f8d34>] (do_filp_open) from [<801e6998>]
(do_sys_open+0x128/0x1f4)
[ 3.059217] [<801e6998>] (do_sys_open) from [<80a00ee0>]
(kernel_init_freeable+0x150/0x1c4)
[ 3.067658] [<80a00ee0>] (kernel_init_freeable) from [<8068e208>]
(kernel_init+0x8/0x110)
[ 3.075917] [<8068e208>] (kernel_init) from [<801010e8>]
(ret_from_fork+0x14/0x2c)
[ 3.083539] Exception stack(0x86843fb0 to 0x86843ff8)
[ 3.088631] 3fa0: 00000000 00000000 00000000 00000000
[ 3.096866] 3fc0: 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000
[ 3.105103] 3fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[ 3.111752] ---[ end trace 6fb699802256a309 ]---
[    3.116423] fsl-lpuart 40027000.serial: Cannot prepare cyclic DMA
[    3.192968] VFS: Mounted root (nfs4 filesystem) on device 0:13.
[    3.201432] devtmpfs: mounted
[    3.210985] Freeing unused kernel memory: 1024K
[    3.217854] Run /sbin/init as init process
[    4.643355] systemd[1]: System time before build time, advancing clock.
[    4.774106] random: systemd: uninitialized urandom read (16 bytes read)
[    4.838361] systemd[1]: systemd 232 running in system mode. (-PAM
-AUDIT -SELINUX -IMA -APPARMOR -SMACK +SYSVINIT +UTMP -LIBCRYPTSETUP
-GCRYPT -GNUTLS +ACL +XZ -LZ4 -SECCOMP +BLKID -ELFUTILS +KMOD -IDN)
[    4.858997] systemd[1]: Detected architecture arm.
[    4.873438] fsl-lpuart 40027000.serial: Cannot prepare TX slave DMA!
[    4.880138] fsl-lpuart 40027000.serial: Cannot prepare TX slave DMA!
[    4.886585] fsl-lpuart 40027000.serial: Cannot prepare TX slave DMA!
[    4.893124] fsl-lpuart 40027000.serial: Cannot prepare TX slave DMA!
[    4.899679] fsl-lpuart 40027000.serial: Cannot prepare TX slave DMA!
[    4.906110] fsl-lpuart 40027000.serial: Cannot prepare TX slave DMA!
[    4.912616] fsl-lpuart 40027000.serial: Cannot prepare TX slave DMA!

Although maybe that's just the fsl-edma problem?

Best regards,
Krzysztof

On Tue, 2019-11-19 at 10:27 +0100, Marek Szyprowski wrote:

Hi Christoph,

On 13.11.2019 08:35, Christoph Hellwig wrote:

quoted

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@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.

Hi Marek,
is this a on a non LPAE ARM32 device?

Regards,
Nicolas

quoted

---
  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

Hi Krzysztof,

On 19.11.2019 10:44, Krzysztof Kozlowski wrote:

On Tue, 19 Nov 2019 at 17:27, Marek Szyprowski [off-list ref] wrote:

quoted

Hi Christoph,

On 13.11.2019 08:35, Christoph Hellwig wrote:

quoted

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@lst.de>

This patch breaks DMAengine PL330 driver on Samsung Exynos SoCs:

Thanks Marek for bisecting it. I wonder whether it is also the cause
for boot failures I see on NXP Vybrid VF50 SoC (NXP/Freescale
fsl-edma) since few days:

[ 2.853428] fsl-edma 40018000.dma-controller: overflow 0x40027007+1 of
DMA mask ffffffff bus mask 0
[ 2.862566] ------------[ cut here ]------------
[ 2.867273] WARNING: CPU: 0 PID: 1 at
/home/buildbot/worker/builddir_yocto/build/build/tmp/work-shared/col-vf50-proceq-mainline-next/kernel-source/kernel/dma/direct.c:35
report_addr+0xc0/0xfc
[ 2.884380] Modules linked in:
[ 2.887486] CPU: 0 PID: 1 Comm: swapper Tainted: G W
5.4.0-rc7-next-20191118-g519ead8f6a32 #1
[ 2.897364] Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
[ 2.903892] [<8010ddfc>] (unwind_backtrace) from [<8010b4b8>]
(show_stack+0x10/0x14)
[ 2.911712] [<8010b4b8>] (show_stack) from [<8011b08c>] (__warn+0xd4/0xec)
[ 2.918653] [<8011b08c>] (__warn) from [<8011b154>]
(warn_slowpath_fmt+0xb0/0xb8)
[ 2.926218] [<8011b154>] (warn_slowpath_fmt) from [<80155f7c>]
(report_addr+0xc0/0xfc)
[ 2.934221] [<80155f7c>] (report_addr) from [<801561f0>]
(dma_direct_map_resource+0x98/0xa4)
[ 2.942744] [<801561f0>] (dma_direct_map_resource) from [<8041d5d4>]
(fsl_edma_prep_slave_dma+0x12c/0x150)
[ 2.952475] [<8041d5d4>] (fsl_edma_prep_slave_dma) from [<8041d8cc>]
(fsl_edma_prep_dma_cyclic+0x30/0x21c)
[ 2.962213] [<8041d8cc>] (fsl_edma_prep_dma_cyclic) from [<80452e10>]
(lpuart_rx_dma_startup+0x188/0x36c)
[ 2.971871] [<80452e10>] (lpuart_rx_dma_startup) from [<80453058>]
(lpuart_startup+0x64/0x78)
[ 2.980477] [<80453058>] (lpuart_startup) from [<8044e924>]
(uart_startup.part.7+0x110/0x23c)
[ 2.989080] [<8044e924>] (uart_startup.part.7) from [<8044eaa0>]
(uart_port_activate+0x50/0x7c)
[ 2.997857] [<8044eaa0>] (uart_port_activate) from [<80438dc0>]
(tty_port_open+0x74/0xc0)
[ 3.006111] [<80438dc0>] (tty_port_open) from [<8044be30>] (uart_open+0x18/0x20)
[ 3.013588] [<8044be30>] (uart_open) from [<80431b4c>] (tty_open+0x108/0x428)
[ 3.020794] [<80431b4c>] (tty_open) from [<801edb48>] (chrdev_open+0xac/0x164)
[ 3.028098] [<801edb48>] (chrdev_open) from [<801e55c8>]
(do_dentry_open+0x22c/0x3e4)
[ 3.036010] [<801e55c8>] (do_dentry_open) from [<801f72a8>]
(path_openat+0x4a4/0xf78)
[ 3.043912] [<801f72a8>] (path_openat) from [<801f8d34>]
(do_filp_open+0x70/0xdc)
[ 3.051472] [<801f8d34>] (do_filp_open) from [<801e6998>]
(do_sys_open+0x128/0x1f4)
[ 3.059217] [<801e6998>] (do_sys_open) from [<80a00ee0>]
(kernel_init_freeable+0x150/0x1c4)
[ 3.067658] [<80a00ee0>] (kernel_init_freeable) from [<8068e208>]
(kernel_init+0x8/0x110)
[ 3.075917] [<8068e208>] (kernel_init) from [<801010e8>]
(ret_from_fork+0x14/0x2c)
[ 3.083539] Exception stack(0x86843fb0 to 0x86843ff8)
[ 3.088631] 3fa0: 00000000 00000000 00000000 00000000
[ 3.096866] 3fc0: 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000
[ 3.105103] 3fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[ 3.111752] ---[ end trace 6fb699802256a309 ]---
[    3.116423] fsl-lpuart 40027000.serial: Cannot prepare cyclic DMA
[    3.192968] VFS: Mounted root (nfs4 filesystem) on device 0:13.
[    3.201432] devtmpfs: mounted
[    3.210985] Freeing unused kernel memory: 1024K
[    3.217854] Run /sbin/init as init process
[    4.643355] systemd[1]: System time before build time, advancing clock.
[    4.774106] random: systemd: uninitialized urandom read (16 bytes read)
[    4.838361] systemd[1]: systemd 232 running in system mode. (-PAM
-AUDIT -SELINUX -IMA -APPARMOR -SMACK +SYSVINIT +UTMP -LIBCRYPTSETUP
-GCRYPT -GNUTLS +ACL +XZ -LZ4 -SECCOMP +BLKID -ELFUTILS +KMOD -IDN)
[    4.858997] systemd[1]: Detected architecture arm.
[    4.873438] fsl-lpuart 40027000.serial: Cannot prepare TX slave DMA!
[    4.880138] fsl-lpuart 40027000.serial: Cannot prepare TX slave DMA!
[    4.886585] fsl-lpuart 40027000.serial: Cannot prepare TX slave DMA!
[    4.893124] fsl-lpuart 40027000.serial: Cannot prepare TX slave DMA!
[    4.899679] fsl-lpuart 40027000.serial: Cannot prepare TX slave DMA!
[    4.906110] fsl-lpuart 40027000.serial: Cannot prepare TX slave DMA!
[    4.912616] fsl-lpuart 40027000.serial: Cannot prepare TX slave DMA!

Although maybe that's just the fsl-edma problem?

This is the same issue.

A quick looks at the dma-direct code revealed that the 
dma_direct_map_resource() is broken after this unification, because it 
calls dma_direct_possible(), which then calls dma_capable(). The generic 
dma_capable() from include/linux/dma-direct.h checks if the provided 
address is in RAM memory range, what in the case of 
dma_direct_map_resource() is not true.

A quick fix for this issue is to inline dma_direct_possible() with a 
modified dma_capable() directly to the dma_direct_map_resource() 
function (without the min_low_pfn check):

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 077876ae5c74..b6dd6a0b338b 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c

@@ -411,8 +411,10 @@ dma_addr_t dma_direct_map_resource(struct device 

*dev, phys_addr_t paddr,
                 size_t size, enum dma_data_direction dir, unsigned long 
attrs)
  {
         dma_addr_t dma_addr = paddr;
+       dma_addr_t end = dma_addr + size - 1;

-       if (unlikely(!dma_direct_possible(dev, dma_addr, size))) {
+       if (unlikely(swiotlb_force == SWIOTLB_FORCE || !dev->dma_mask ||
+                    end > min_not_zero(*dev->dma_mask, 
dev->bus_dma_mask))) {
                 report_addr(dev, dma_addr, size);
                 return DMA_MAPPING_ERROR;
         }

Christoph: Let me know if this is a proper fix for you, then I will send 
it as a full patch.

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

On 19/11/2019 10:26 am, Marek Szyprowski wrote:

You don't want the swiotlb_force check in there - we can't bounce-buffer 
device-to-device accesses, regardless of the SWIOTLB policy.

Robin.

+                    end > min_not_zero(*dev->dma_mask,
dev->bus_dma_mask))) {
                  report_addr(dev, dma_addr, size);
                  return DMA_MAPPING_ERROR;
          }

Christoph: Let me know if this is a proper fix for you, then I will send
it as a full patch.

Best regards

On Tue, Nov 19, 2019 at 11:26:39AM +0100, Marek Szyprowski wrote:

Christoph: Let me know if this is a proper fix for you, then I will send 
it as a full patch.

Besides the point from Robin, which is really older than you patch
I'm not a fan of duplicating dma_capable here.  Let me know what you
think of the two attached patches.

Hi

On 19.11.2019 17:46, Christoph Hellwig wrote:

On Tue, Nov 19, 2019 at 11:26:39AM +0100, Marek Szyprowski wrote:

quoted

Christoph: Let me know if this is a proper fix for you, then I will send
it as a full patch.

Besides the point from Robin, which is really older than you patch
I'm not a fan of duplicating dma_capable here.  Let me know what you
think of the two attached patches.

I'm fine with both patches.

Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>

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