Re: [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-06-24 Thread Konrad Rzeszutek Wilk
On Thu, Jun 24, 2021 at 11:58:57PM +0800, Claire Chang wrote:
> On Thu, Jun 24, 2021 at 11:56 PM Konrad Rzeszutek Wilk
>  wrote:
> >
> > On Thu, Jun 24, 2021 at 10:10:51AM -0400, Qian Cai wrote:
> > >
> > >
> > > On 6/24/2021 7:48 AM, Will Deacon wrote:
> > > > Ok, diff below which attempts to tackle the offset issue I mentioned as
> > > > well. Qian Cai -- please can you try with these changes?
> > >
> > > This works fine.
> >
> > Cool. Let me squash this patch in #6 and rebase the rest of them.
> >
> > Claire, could you check the devel/for-linus-5.14 say by end of today to
> > double check that I didn't mess anything up please?
> 
> I just submitted v15 here
> (https://lore.kernel.org/patchwork/cover/1451322/) in case it's
> helpful.

Oh! Nice!
> I'll double check of course. Thanks for the efforts!

I ended up using your patch #6 and #7. Please double-check.



Re: [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-06-24 Thread Claire Chang
On Thu, Jun 24, 2021 at 11:56 PM Konrad Rzeszutek Wilk
 wrote:
>
> On Thu, Jun 24, 2021 at 10:10:51AM -0400, Qian Cai wrote:
> >
> >
> > On 6/24/2021 7:48 AM, Will Deacon wrote:
> > > Ok, diff below which attempts to tackle the offset issue I mentioned as
> > > well. Qian Cai -- please can you try with these changes?
> >
> > This works fine.
>
> Cool. Let me squash this patch in #6 and rebase the rest of them.
>
> Claire, could you check the devel/for-linus-5.14 say by end of today to
> double check that I didn't mess anything up please?

I just submitted v15 here
(https://lore.kernel.org/patchwork/cover/1451322/) in case it's
helpful.
I'll double check of course. Thanks for the efforts!

>
> Will,
>
> Thank you for generating the fix! I am going to run it on x86 and Xen
> to make sure all is good (granted last time I ran devel/for-linus-5.14
> on that setup I didn't see any errors so I need to double check
> I didn't do something silly like run a wrong kernel).
>
>
> >
> > >
> > > Will
> > >
> > > --->8
> > >
> > > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
> > > index 175b6c113ed8..39284ff2a6cd 100644
> > > --- a/include/linux/swiotlb.h
> > > +++ b/include/linux/swiotlb.h
> > > @@ -116,7 +116,9 @@ static inline bool is_swiotlb_buffer(struct device 
> > > *dev, phys_addr_t paddr)
> > >
> > >  static inline bool is_swiotlb_force_bounce(struct device *dev)
> > >  {
> > > -   return dev->dma_io_tlb_mem->force_bounce;
> > > +   struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
> > > +
> > > +   return mem && mem->force_bounce;
> > >  }
> > >
> > >  void __init swiotlb_exit(void);
> > > diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
> > > index 44be8258e27b..0ffbaae9fba2 100644
> > > --- a/kernel/dma/swiotlb.c
> > > +++ b/kernel/dma/swiotlb.c
> > > @@ -449,6 +449,7 @@ static int swiotlb_find_slots(struct device *dev, 
> > > phys_addr_t orig_addr,
> > > dma_get_min_align_mask(dev) & ~(IO_TLB_SIZE - 1);
> > > unsigned int nslots = nr_slots(alloc_size), stride;
> > > unsigned int index, wrap, count = 0, i;
> > > +   unsigned int offset = swiotlb_align_offset(dev, orig_addr);
> > > unsigned long flags;
> > >
> > > BUG_ON(!nslots);
> > > @@ -497,7 +498,7 @@ static int swiotlb_find_slots(struct device *dev, 
> > > phys_addr_t orig_addr,
> > > for (i = index; i < index + nslots; i++) {
> > > mem->slots[i].list = 0;
> > > mem->slots[i].alloc_size =
> > > -   alloc_size - ((i - index) << IO_TLB_SHIFT);
> > > +   alloc_size - (offset + ((i - index) << 
> > > IO_TLB_SHIFT));
> > > }
> > > for (i = index - 1;
> > >  io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 &&
> > >



Re: [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-06-24 Thread Konrad Rzeszutek Wilk
On Thu, Jun 24, 2021 at 10:10:51AM -0400, Qian Cai wrote:
> 
> 
> On 6/24/2021 7:48 AM, Will Deacon wrote:
> > Ok, diff below which attempts to tackle the offset issue I mentioned as
> > well. Qian Cai -- please can you try with these changes?
> 
> This works fine.

Cool. Let me squash this patch in #6 and rebase the rest of them.

Claire, could you check the devel/for-linus-5.14 say by end of today to
double check that I didn't mess anything up please?

Will,

Thank you for generating the fix! I am going to run it on x86 and Xen
to make sure all is good (granted last time I ran devel/for-linus-5.14
on that setup I didn't see any errors so I need to double check
I didn't do something silly like run a wrong kernel).


> 
> > 
> > Will
> > 
> > --->8
> > 
> > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
> > index 175b6c113ed8..39284ff2a6cd 100644
> > --- a/include/linux/swiotlb.h
> > +++ b/include/linux/swiotlb.h
> > @@ -116,7 +116,9 @@ static inline bool is_swiotlb_buffer(struct device 
> > *dev, phys_addr_t paddr)
> >  
> >  static inline bool is_swiotlb_force_bounce(struct device *dev)
> >  {
> > -   return dev->dma_io_tlb_mem->force_bounce;
> > +   struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
> > +
> > +   return mem && mem->force_bounce;
> >  }
> >  
> >  void __init swiotlb_exit(void);
> > diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
> > index 44be8258e27b..0ffbaae9fba2 100644
> > --- a/kernel/dma/swiotlb.c
> > +++ b/kernel/dma/swiotlb.c
> > @@ -449,6 +449,7 @@ static int swiotlb_find_slots(struct device *dev, 
> > phys_addr_t orig_addr,
> > dma_get_min_align_mask(dev) & ~(IO_TLB_SIZE - 1);
> > unsigned int nslots = nr_slots(alloc_size), stride;
> > unsigned int index, wrap, count = 0, i;
> > +   unsigned int offset = swiotlb_align_offset(dev, orig_addr);
> > unsigned long flags;
> >  
> > BUG_ON(!nslots);
> > @@ -497,7 +498,7 @@ static int swiotlb_find_slots(struct device *dev, 
> > phys_addr_t orig_addr,
> > for (i = index; i < index + nslots; i++) {
> > mem->slots[i].list = 0;
> > mem->slots[i].alloc_size =
> > -   alloc_size - ((i - index) << IO_TLB_SHIFT);
> > +   alloc_size - (offset + ((i - index) << 
> > IO_TLB_SHIFT));
> > }
> > for (i = index - 1;
> >  io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 &&
> > 



Re: [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-06-24 Thread Qian Cai



On 6/24/2021 7:48 AM, Will Deacon wrote:
> Ok, diff below which attempts to tackle the offset issue I mentioned as
> well. Qian Cai -- please can you try with these changes?

This works fine.

> 
> Will
> 
> --->8
> 
> diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
> index 175b6c113ed8..39284ff2a6cd 100644
> --- a/include/linux/swiotlb.h
> +++ b/include/linux/swiotlb.h
> @@ -116,7 +116,9 @@ static inline bool is_swiotlb_buffer(struct device *dev, 
> phys_addr_t paddr)
>  
>  static inline bool is_swiotlb_force_bounce(struct device *dev)
>  {
> -   return dev->dma_io_tlb_mem->force_bounce;
> +   struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
> +
> +   return mem && mem->force_bounce;
>  }
>  
>  void __init swiotlb_exit(void);
> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
> index 44be8258e27b..0ffbaae9fba2 100644
> --- a/kernel/dma/swiotlb.c
> +++ b/kernel/dma/swiotlb.c
> @@ -449,6 +449,7 @@ static int swiotlb_find_slots(struct device *dev, 
> phys_addr_t orig_addr,
> dma_get_min_align_mask(dev) & ~(IO_TLB_SIZE - 1);
> unsigned int nslots = nr_slots(alloc_size), stride;
> unsigned int index, wrap, count = 0, i;
> +   unsigned int offset = swiotlb_align_offset(dev, orig_addr);
> unsigned long flags;
>  
> BUG_ON(!nslots);
> @@ -497,7 +498,7 @@ static int swiotlb_find_slots(struct device *dev, 
> phys_addr_t orig_addr,
> for (i = index; i < index + nslots; i++) {
> mem->slots[i].list = 0;
> mem->slots[i].alloc_size =
> -   alloc_size - ((i - index) << IO_TLB_SHIFT);
> +   alloc_size - (offset + ((i - index) << IO_TLB_SHIFT));
> }
> for (i = index - 1;
>  io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 &&
> 



Re: [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-06-24 Thread Will Deacon
On Thu, Jun 24, 2021 at 12:34:09PM +0100, Robin Murphy wrote:
> On 2021-06-24 12:18, Will Deacon wrote:
> > On Thu, Jun 24, 2021 at 12:14:39PM +0100, Robin Murphy wrote:
> > > On 2021-06-24 07:05, Claire Chang wrote:
> > > > On Thu, Jun 24, 2021 at 1:43 PM Christoph Hellwig  wrote:
> > > > > 
> > > > > On Wed, Jun 23, 2021 at 02:44:34PM -0400, Qian Cai wrote:
> > > > > > is_swiotlb_force_bounce at 
> > > > > > /usr/src/linux-next/./include/linux/swiotlb.h:119
> > > > > > 
> > > > > > is_swiotlb_force_bounce() was the new function introduced in this 
> > > > > > patch here.
> > > > > > 
> > > > > > +static inline bool is_swiotlb_force_bounce(struct device *dev)
> > > > > > +{
> > > > > > + return dev->dma_io_tlb_mem->force_bounce;
> > > > > > +}
> > > > > 
> > > > > To me the crash looks like dev->dma_io_tlb_mem is NULL.  Can you
> > > > > turn this into :
> > > > > 
> > > > >   return dev->dma_io_tlb_mem && 
> > > > > dev->dma_io_tlb_mem->force_bounce;
> > > > > 
> > > > > for a quick debug check?
> > > > 
> > > > I just realized that dma_io_tlb_mem might be NULL like Christoph
> > > > pointed out since swiotlb might not get initialized.
> > > > However,  `Unable to handle kernel paging request at virtual address
> > > > dfff800e` looks more like the address is garbage rather than
> > > > NULL?
> > > > I wonder if that's because dev->dma_io_tlb_mem is not assigned
> > > > properly (which means device_initialize is not called?).
> > > 
> > > What also looks odd is that the base "address" 0xdfff8000 is held 
> > > in
> > > a couple of registers, but the offset 0xe looks too small to match up to 
> > > any
> > > relevant structure member in that dereference chain :/
> > 
> > FWIW, I've managed to trigger a NULL dereference locally when swiotlb hasn't
> > been initialised but we dereference 'dev->dma_io_tlb_mem', so I think
> > Christoph's suggestion is needed regardless.
> 
> Ack to that - for SWIOTLB_NO_FORCE, io_tlb_default_mem will remain NULL. The
> massive jump in KernelCI baseline failures as of yesterday looks like every
> arm64 machine with less than 4GB of RAM blowing up...

Ok, diff below which attempts to tackle the offset issue I mentioned as
well. Qian Cai -- please can you try with these changes?

Will

--->8

diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 175b6c113ed8..39284ff2a6cd 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -116,7 +116,9 @@ static inline bool is_swiotlb_buffer(struct device *dev, 
phys_addr_t paddr)
 
 static inline bool is_swiotlb_force_bounce(struct device *dev)
 {
-   return dev->dma_io_tlb_mem->force_bounce;
+   struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
+
+   return mem && mem->force_bounce;
 }
 
 void __init swiotlb_exit(void);
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 44be8258e27b..0ffbaae9fba2 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -449,6 +449,7 @@ static int swiotlb_find_slots(struct device *dev, 
phys_addr_t orig_addr,
dma_get_min_align_mask(dev) & ~(IO_TLB_SIZE - 1);
unsigned int nslots = nr_slots(alloc_size), stride;
unsigned int index, wrap, count = 0, i;
+   unsigned int offset = swiotlb_align_offset(dev, orig_addr);
unsigned long flags;
 
BUG_ON(!nslots);
@@ -497,7 +498,7 @@ static int swiotlb_find_slots(struct device *dev, 
phys_addr_t orig_addr,
for (i = index; i < index + nslots; i++) {
mem->slots[i].list = 0;
mem->slots[i].alloc_size =
-   alloc_size - ((i - index) << IO_TLB_SHIFT);
+   alloc_size - (offset + ((i - index) << IO_TLB_SHIFT));
}
for (i = index - 1;
 io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 &&



Re: [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-06-24 Thread Robin Murphy

On 2021-06-24 12:18, Will Deacon wrote:

On Thu, Jun 24, 2021 at 12:14:39PM +0100, Robin Murphy wrote:

On 2021-06-24 07:05, Claire Chang wrote:

On Thu, Jun 24, 2021 at 1:43 PM Christoph Hellwig  wrote:


On Wed, Jun 23, 2021 at 02:44:34PM -0400, Qian Cai wrote:

is_swiotlb_force_bounce at /usr/src/linux-next/./include/linux/swiotlb.h:119

is_swiotlb_force_bounce() was the new function introduced in this patch here.

+static inline bool is_swiotlb_force_bounce(struct device *dev)
+{
+ return dev->dma_io_tlb_mem->force_bounce;
+}


To me the crash looks like dev->dma_io_tlb_mem is NULL.  Can you
turn this into :

  return dev->dma_io_tlb_mem && dev->dma_io_tlb_mem->force_bounce;

for a quick debug check?


I just realized that dma_io_tlb_mem might be NULL like Christoph
pointed out since swiotlb might not get initialized.
However,  `Unable to handle kernel paging request at virtual address
dfff800e` looks more like the address is garbage rather than
NULL?
I wonder if that's because dev->dma_io_tlb_mem is not assigned
properly (which means device_initialize is not called?).


What also looks odd is that the base "address" 0xdfff8000 is held in
a couple of registers, but the offset 0xe looks too small to match up to any
relevant structure member in that dereference chain :/


FWIW, I've managed to trigger a NULL dereference locally when swiotlb hasn't
been initialised but we dereference 'dev->dma_io_tlb_mem', so I think
Christoph's suggestion is needed regardless.


Ack to that - for SWIOTLB_NO_FORCE, io_tlb_default_mem will remain NULL. 
The massive jump in KernelCI baseline failures as of yesterday looks 
like every arm64 machine with less than 4GB of RAM blowing up...


Robin.


But I agree that it won't help
with the issue reported by Qian Cai.

Qian Cai: please can you share your .config and your command line?

Thanks,

Will





Re: [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-06-24 Thread Will Deacon
On Thu, Jun 24, 2021 at 12:14:39PM +0100, Robin Murphy wrote:
> On 2021-06-24 07:05, Claire Chang wrote:
> > On Thu, Jun 24, 2021 at 1:43 PM Christoph Hellwig  wrote:
> > > 
> > > On Wed, Jun 23, 2021 at 02:44:34PM -0400, Qian Cai wrote:
> > > > is_swiotlb_force_bounce at 
> > > > /usr/src/linux-next/./include/linux/swiotlb.h:119
> > > > 
> > > > is_swiotlb_force_bounce() was the new function introduced in this patch 
> > > > here.
> > > > 
> > > > +static inline bool is_swiotlb_force_bounce(struct device *dev)
> > > > +{
> > > > + return dev->dma_io_tlb_mem->force_bounce;
> > > > +}
> > > 
> > > To me the crash looks like dev->dma_io_tlb_mem is NULL.  Can you
> > > turn this into :
> > > 
> > >  return dev->dma_io_tlb_mem && dev->dma_io_tlb_mem->force_bounce;
> > > 
> > > for a quick debug check?
> > 
> > I just realized that dma_io_tlb_mem might be NULL like Christoph
> > pointed out since swiotlb might not get initialized.
> > However,  `Unable to handle kernel paging request at virtual address
> > dfff800e` looks more like the address is garbage rather than
> > NULL?
> > I wonder if that's because dev->dma_io_tlb_mem is not assigned
> > properly (which means device_initialize is not called?).
> 
> What also looks odd is that the base "address" 0xdfff8000 is held in
> a couple of registers, but the offset 0xe looks too small to match up to any
> relevant structure member in that dereference chain :/

FWIW, I've managed to trigger a NULL dereference locally when swiotlb hasn't
been initialised but we dereference 'dev->dma_io_tlb_mem', so I think
Christoph's suggestion is needed regardless. But I agree that it won't help
with the issue reported by Qian Cai.

Qian Cai: please can you share your .config and your command line?

Thanks,

Will



Re: [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-06-24 Thread Robin Murphy

On 2021-06-24 07:05, Claire Chang wrote:

On Thu, Jun 24, 2021 at 1:43 PM Christoph Hellwig  wrote:


On Wed, Jun 23, 2021 at 02:44:34PM -0400, Qian Cai wrote:

is_swiotlb_force_bounce at /usr/src/linux-next/./include/linux/swiotlb.h:119

is_swiotlb_force_bounce() was the new function introduced in this patch here.

+static inline bool is_swiotlb_force_bounce(struct device *dev)
+{
+ return dev->dma_io_tlb_mem->force_bounce;
+}


To me the crash looks like dev->dma_io_tlb_mem is NULL.  Can you
turn this into :

 return dev->dma_io_tlb_mem && dev->dma_io_tlb_mem->force_bounce;

for a quick debug check?


I just realized that dma_io_tlb_mem might be NULL like Christoph
pointed out since swiotlb might not get initialized.
However,  `Unable to handle kernel paging request at virtual address
dfff800e` looks more like the address is garbage rather than
NULL?
I wonder if that's because dev->dma_io_tlb_mem is not assigned
properly (which means device_initialize is not called?).


What also looks odd is that the base "address" 0xdfff8000 is 
held in a couple of registers, but the offset 0xe looks too small to 
match up to any relevant structure member in that dereference chain :/


Robin.



Re: [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-06-24 Thread Claire Chang
On Thu, Jun 24, 2021 at 1:43 PM Christoph Hellwig  wrote:
>
> On Wed, Jun 23, 2021 at 02:44:34PM -0400, Qian Cai wrote:
> > is_swiotlb_force_bounce at /usr/src/linux-next/./include/linux/swiotlb.h:119
> >
> > is_swiotlb_force_bounce() was the new function introduced in this patch 
> > here.
> >
> > +static inline bool is_swiotlb_force_bounce(struct device *dev)
> > +{
> > + return dev->dma_io_tlb_mem->force_bounce;
> > +}
>
> To me the crash looks like dev->dma_io_tlb_mem is NULL.  Can you
> turn this into :
>
> return dev->dma_io_tlb_mem && dev->dma_io_tlb_mem->force_bounce;
>
> for a quick debug check?

I just realized that dma_io_tlb_mem might be NULL like Christoph
pointed out since swiotlb might not get initialized.
However,  `Unable to handle kernel paging request at virtual address
dfff800e` looks more like the address is garbage rather than
NULL?
I wonder if that's because dev->dma_io_tlb_mem is not assigned
properly (which means device_initialize is not called?).



Re: [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-06-23 Thread Christoph Hellwig
On Wed, Jun 23, 2021 at 02:44:34PM -0400, Qian Cai wrote:
> is_swiotlb_force_bounce at /usr/src/linux-next/./include/linux/swiotlb.h:119
> 
> is_swiotlb_force_bounce() was the new function introduced in this patch here.
> 
> +static inline bool is_swiotlb_force_bounce(struct device *dev)
> +{
> + return dev->dma_io_tlb_mem->force_bounce;
> +}

To me the crash looks like dev->dma_io_tlb_mem is NULL.  Can you
turn this into :

return dev->dma_io_tlb_mem && dev->dma_io_tlb_mem->force_bounce;

for a quick debug check?



Re: [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-06-23 Thread Qian Cai



On 6/18/2021 11:40 PM, Claire Chang wrote:
> Propagate the swiotlb_force into io_tlb_default_mem->force_bounce and
> use it to determine whether to bounce the data or not. This will be
> useful later to allow for different pools.
> 
> Signed-off-by: Claire Chang 
> Reviewed-by: Christoph Hellwig 
> Tested-by: Stefano Stabellini 
> Tested-by: Will Deacon 
> Acked-by: Stefano Stabellini 

Reverting the rest of the series up to this patch fixed a boot crash with NVMe 
on today's linux-next.

[   22.286574][T7] Unable to handle kernel paging request at virtual 
address dfff800e
[   22.295225][T7] Mem abort info:
[   22.298743][T7]   ESR = 0x9604
[   22.302496][T7]   EC = 0x25: DABT (current EL), IL = 32 bits
[   22.308525][T7]   SET = 0, FnV = 0
[   22.312274][T7]   EA = 0, S1PTW = 0
[   22.316131][T7]   FSC = 0x04: level 0 translation fault
[   22.321704][T7] Data abort info:
[   22.325278][T7]   ISV = 0, ISS = 0x0004
[   22.329840][T7]   CM = 0, WnR = 0
[   22.333503][T7] [dfff800e] address between user and kernel 
address ranges
[   22.338543][  T256] igb 0006:01:00.0: Intel(R) Gigabit Ethernet Network 
Connection
[   22.341400][T7] Internal error: Oops: 9604 [#1] SMP
[   22.348915][  T256] igb 0006:01:00.0: eth0: (PCIe:2.5Gb/s:Width x1) 
4c:38:d5:09:c8:83
[   22.354458][T7] Modules linked in: igb(+) i2c_algo_bit nvme mlx5_core(+) 
i2c_core nvme_core firmware_class
[   22.362512][  T256] igb 0006:01:00.0: eth0: PBA No: G69016-004
[   22.372287][T7] CPU: 13 PID: 7 Comm: kworker/u64:0 Not tainted 
5.13.0-rc7-next-20210623+ #47
[   22.372293][T7] Hardware name: MiTAC RAPTOR EV-883832-X3-0001/RAPTOR, 
BIOS 1.6 06/28/2020
[   22.372298][T7] Workqueue: nvme-reset-wq nvme_reset_work [nvme]
[   22.378145][  T256] igb 0006:01:00.0: Using MSI-X interrupts. 4 rx queue(s), 
4 tx queue(s)
[   22.386901][T7] 
[   22.386905][T7] pstate: 1005 (nzcV daif -PAN -UAO -TCO BTYPE=--)
[   22.386910][T7] pc : dma_direct_map_sg+0x304/0x8f0

is_swiotlb_force_bounce at /usr/src/linux-next/./include/linux/swiotlb.h:119
(inlined by) dma_direct_map_page at /usr/src/linux-next/kernel/dma/direct.h:90
(inlined by) dma_direct_map_sg at /usr/src/linux-next/kernel/dma/direct.c:428

[   22.386919][T7] lr : dma_map_sg_attrs+0x6c/0x118
[   22.386924][T7] sp : 80001dc8eac0
[   22.386926][T7] x29: 80001dc8eac0 x28: 199e70b0 x27: 

[   22.386935][T7] x26: 000847ee7000 x25: 80001158e570 x24: 
0002
[   22.386943][T7] x23: dfff8000 x22: 0100 x21: 
199e7460
[   22.386951][T7] x20: 199e7488 x19: 0001 x18: 
10062670
[   22.386955][  T253] Unable to handle kernel paging request at virtual 
address dfff800e
[   22.386958][T7] x17: 8000109f6a90 x16: 8000109e1b4c x15: 
89303420
[   22.386965][  T253] Mem abort info:
[   22.386967][T7] x14: 0001 x13: 80001158e000
[   22.386970][  T253]   ESR = 0x9604
[   22.386972][T7]  x12: 1fffe00108fdce01
[   22.386975][  T253]   EC = 0x25: DABT (current EL), IL = 32 bits
[   22.386976][T7] x11: 1fffe00108fdce03 x10: 000847ee700c x9 : 
0004
[   22.386981][  T253]   SET = 0, FnV = 0
[   22.386983][T7] 
[   22.386985][T7] x8 : 73b91d72
[   22.386986][  T253]   EA = 0, S1PTW = 0
[   22.386987][T7]  x7 :  x6 : 000e
[   22.386990][  T253]   FSC = 0x04: level 0 translation fault
[   22.386992][T7] 
[   22.386994][T7] x5 : dfff8000
[   22.386995][  T253] Data abort info:
[   22.386997][T7]  x4 : 0008c7ede000
[   22.386999][  T253]   ISV = 0, ISS = 0x0004
[   22.386999][T7]  x3 : 0008c7ede000
[   22.387003][T7] x2 : 1000
[   22.387003][  T253]   CM = 0, WnR = 0
[   22.387006][T7]  x1 :  x0 : 0071
[   22.387008][  T253] [dfff800e] address between user and kernel 
address ranges
[   22.387011][T7] 
[   22.387013][T7] Call trace:
[   22.387016][T7]  dma_direct_map_sg+0x304/0x8f0
[   22.387022][T7]  dma_map_sg_attrs+0x6c/0x118
[   22.387026][T7]  nvme_map_data+0x2ec/0x21d8 [nvme]
[   22.387040][T7]  nvme_queue_rq+0x274/0x3f0 [nvme]
[   22.387052][T7]  blk_mq_dispatch_rq_list+0x2ec/0x18a0
[   22.387060][T7]  __blk_mq_sched_dispatch_requests+0x2a0/0x3e8
[   22.387065][T7]  blk_mq_sched_dispatch_requests+0xa4/0x100
[   22.387070][T7]  __blk_mq_run_hw_queue+0x148/0x1d8
[   22.387075][T7]  __blk_mq_delay_run_hw_queue+0x3f8/0x730
[   22.414539][  T269] igb 0006:01:00.0 enP6p1s0: renamed from eth0
[   22.418957][T7]  blk_mq_run_hw_queue+0x148/0x248
[   22.418969][T7]  blk_mq_sched_insert_request+0x2a4/0x330
[   22.418975][T7]  blk_execute_rq_nowait+0xc8/0x118
[   22.418981][T7]  blk_execute_rq+0xd4/0x188
[   22.453203][  T255] 

Re: [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-06-23 Thread Qian Cai



On 6/23/2021 2:37 PM, Will Deacon wrote:
> On Wed, Jun 23, 2021 at 12:39:29PM -0400, Qian Cai wrote:
>>
>>
>> On 6/18/2021 11:40 PM, Claire Chang wrote:
>>> Propagate the swiotlb_force into io_tlb_default_mem->force_bounce and
>>> use it to determine whether to bounce the data or not. This will be
>>> useful later to allow for different pools.
>>>
>>> Signed-off-by: Claire Chang 
>>> Reviewed-by: Christoph Hellwig 
>>> Tested-by: Stefano Stabellini 
>>> Tested-by: Will Deacon 
>>> Acked-by: Stefano Stabellini 
>>
>> Reverting the rest of the series up to this patch fixed a boot crash with 
>> NVMe on today's linux-next.
> 
> Hmm, so that makes patch 7 the suspicious one, right?

Will, no. It is rather patch #6 (this patch). Only the patch from #6 to #12 
were reverted to fix the issue. Also, looking at this offset of the crash,

pc : dma_direct_map_sg+0x304/0x8f0
is_swiotlb_force_bounce at /usr/src/linux-next/./include/linux/swiotlb.h:119

is_swiotlb_force_bounce() was the new function introduced in this patch here.

+static inline bool is_swiotlb_force_bounce(struct device *dev)
+{
+   return dev->dma_io_tlb_mem->force_bounce;
+}

> 
> Looking at that one more closely, it looks like swiotlb_find_slots() takes
> 'alloc_size + offset' as its 'alloc_size' parameter from
> swiotlb_tbl_map_single() and initialises 'mem->slots[i].alloc_size' based
> on 'alloc_size + offset', which looks like a change in behaviour from the
> old code, which didn't include the offset there.
> 
> swiotlb_release_slots() then adds the offset back on afaict, so we end up
> accounting for it twice and possibly unmap more than we're supposed to?
> 
> Will
> 



Re: [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-06-23 Thread Will Deacon
On Wed, Jun 23, 2021 at 12:39:29PM -0400, Qian Cai wrote:
> 
> 
> On 6/18/2021 11:40 PM, Claire Chang wrote:
> > Propagate the swiotlb_force into io_tlb_default_mem->force_bounce and
> > use it to determine whether to bounce the data or not. This will be
> > useful later to allow for different pools.
> > 
> > Signed-off-by: Claire Chang 
> > Reviewed-by: Christoph Hellwig 
> > Tested-by: Stefano Stabellini 
> > Tested-by: Will Deacon 
> > Acked-by: Stefano Stabellini 
> 
> Reverting the rest of the series up to this patch fixed a boot crash with 
> NVMe on today's linux-next.

Hmm, so that makes patch 7 the suspicious one, right?

Looking at that one more closely, it looks like swiotlb_find_slots() takes
'alloc_size + offset' as its 'alloc_size' parameter from
swiotlb_tbl_map_single() and initialises 'mem->slots[i].alloc_size' based
on 'alloc_size + offset', which looks like a change in behaviour from the
old code, which didn't include the offset there.

swiotlb_release_slots() then adds the offset back on afaict, so we end up
accounting for it twice and possibly unmap more than we're supposed to?

Will



[PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

2021-06-18 Thread Claire Chang
Propagate the swiotlb_force into io_tlb_default_mem->force_bounce and
use it to determine whether to bounce the data or not. This will be
useful later to allow for different pools.

Signed-off-by: Claire Chang 
Reviewed-by: Christoph Hellwig 
Tested-by: Stefano Stabellini 
Tested-by: Will Deacon 
Acked-by: Stefano Stabellini 
---
 drivers/xen/swiotlb-xen.c |  2 +-
 include/linux/swiotlb.h   | 11 +++
 kernel/dma/direct.c   |  2 +-
 kernel/dma/direct.h   |  2 +-
 kernel/dma/swiotlb.c  |  4 
 5 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 0c6ed09f8513..4730a146fa35 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -369,7 +369,7 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, 
struct page *page,
if (dma_capable(dev, dev_addr, size, true) &&
!range_straddles_page_boundary(phys, size) &&
!xen_arch_need_swiotlb(dev, phys, dev_addr) &&
-   swiotlb_force != SWIOTLB_FORCE)
+   !is_swiotlb_force_bounce(dev))
goto done;
 
/*
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index dd1c30a83058..8d8855c77d9a 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -84,6 +84,7 @@ extern enum swiotlb_force swiotlb_force;
  * unmap calls.
  * @debugfs:   The dentry to debugfs.
  * @late_alloc:%true if allocated using the page allocator
+ * @force_bounce: %true if swiotlb bouncing is forced
  */
 struct io_tlb_mem {
phys_addr_t start;
@@ -94,6 +95,7 @@ struct io_tlb_mem {
spinlock_t lock;
struct dentry *debugfs;
bool late_alloc;
+   bool force_bounce;
struct io_tlb_slot {
phys_addr_t orig_addr;
size_t alloc_size;
@@ -109,6 +111,11 @@ static inline bool is_swiotlb_buffer(struct device *dev, 
phys_addr_t paddr)
return mem && paddr >= mem->start && paddr < mem->end;
 }
 
+static inline bool is_swiotlb_force_bounce(struct device *dev)
+{
+   return dev->dma_io_tlb_mem->force_bounce;
+}
+
 void __init swiotlb_exit(void);
 unsigned int swiotlb_max_segment(void);
 size_t swiotlb_max_mapping_size(struct device *dev);
@@ -120,6 +127,10 @@ static inline bool is_swiotlb_buffer(struct device *dev, 
phys_addr_t paddr)
 {
return false;
 }
+static inline bool is_swiotlb_force_bounce(struct device *dev)
+{
+   return false;
+}
 static inline void swiotlb_exit(void)
 {
 }
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 7a88c34d0867..a92465b4eb12 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -496,7 +496,7 @@ size_t dma_direct_max_mapping_size(struct device *dev)
 {
/* If SWIOTLB is active, use its maximum mapping size */
if (is_swiotlb_active(dev) &&
-   (dma_addressing_limited(dev) || swiotlb_force == SWIOTLB_FORCE))
+   (dma_addressing_limited(dev) || is_swiotlb_force_bounce(dev)))
return swiotlb_max_mapping_size(dev);
return SIZE_MAX;
 }
diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h
index 13e9e7158d94..4632b0f4f72e 100644
--- a/kernel/dma/direct.h
+++ b/kernel/dma/direct.h
@@ -87,7 +87,7 @@ static inline dma_addr_t dma_direct_map_page(struct device 
*dev,
phys_addr_t phys = page_to_phys(page) + offset;
dma_addr_t dma_addr = phys_to_dma(dev, phys);
 
-   if (unlikely(swiotlb_force == SWIOTLB_FORCE))
+   if (is_swiotlb_force_bounce(dev))
return swiotlb_map(dev, phys, size, dir, attrs);
 
if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 8a120f42340b..0d294bbf274c 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -179,6 +179,10 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem 
*mem, phys_addr_t start,
mem->end = mem->start + bytes;
mem->index = 0;
mem->late_alloc = late_alloc;
+
+   if (swiotlb_force == SWIOTLB_FORCE)
+   mem->force_bounce = true;
+
spin_lock_init(>lock);
for (i = 0; i < mem->nslabs; i++) {
mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
-- 
2.32.0.288.g62a8d224e6-goog