diff mbox

PCI: designware: fix asynchronous external abort in keystone PCIe h/w

Message ID 1483558350-8169-1-git-send-email-m-karicheri2@ti.com
State Accepted
Headers show

Commit Message

Murali Karicheri Jan. 4, 2017, 7:32 p.m. UTC
Recent fixes for iATU unroll support introduced a bug that causes
asynchronous external abort in Keystone PCIe h/w which doesn't have
ATU port and the corresponding register. So the check should be moved
below where dw_pcie_prog_outbound_atu() is called to avoid that
being called on keystine PCIe h/w.

Here is the backtrace

[    0.771174] OF: PCI:   MEM 0x60000000..0x6fffffff -> 0x60000000
[    0.778118] Unhandled fault: asynchronous external abort (0x1211) at 0x00000000
[    0.785548] pgd = c0003000
[    0.788347] [00000000] *pgd=80000800004003, *pmd=00000000
[    0.793864] Internal error: : 1211 [#1] PREEMPT SMP ARM
[    0.799197] Modules linked in:
[    0.802351] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-00009-g6ff59d2-dirty #7
[    0.810130] Hardware name: Keystone
[    0.813717] task: eb878000 task.stack: eb866000
[    0.818356] PC is at dw_pcie_setup_rc+0x24/0x380
[    0.823083] LR is at ks_pcie_host_init+0x10/0x170

Fixes: 416379f9ebde ("PCI: designware: Check for iATU unroll support after initializing host")
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Tested-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 - Applies to pci/master
 - Bug was introduced in v4.9
 - Tested on K2E EVM with SATA and DRA7-EVM with an intel PCI ethernet card

 drivers/pci/host/pcie-designware.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

Comments

Murali Karicheri Jan. 9, 2017, 4:41 p.m. UTC | #1
On 01/04/2017 02:32 PM, Murali Karicheri wrote:
> Recent fixes for iATU unroll support introduced a bug that causes
> asynchronous external abort in Keystone PCIe h/w which doesn't have
> ATU port and the corresponding register. So the check should be moved
> below where dw_pcie_prog_outbound_atu() is called to avoid that
> being called on keystine PCIe h/w.
> 
> Here is the backtrace
> 
> [    0.771174] OF: PCI:   MEM 0x60000000..0x6fffffff -> 0x60000000
> [    0.778118] Unhandled fault: asynchronous external abort (0x1211) at 0x00000000
> [    0.785548] pgd = c0003000
> [    0.788347] [00000000] *pgd=80000800004003, *pmd=00000000
> [    0.793864] Internal error: : 1211 [#1] PREEMPT SMP ARM
> [    0.799197] Modules linked in:
> [    0.802351] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-00009-g6ff59d2-dirty #7
> [    0.810130] Hardware name: Keystone
> [    0.813717] task: eb878000 task.stack: eb866000
> [    0.818356] PC is at dw_pcie_setup_rc+0x24/0x380
> [    0.823083] LR is at ks_pcie_host_init+0x10/0x170
> 
> Fixes: 416379f9ebde ("PCI: designware: Check for iATU unroll support after initializing host")
> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
> Tested-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
>  - Applies to pci/master
>  - Bug was introduced in v4.9
>  - Tested on K2E EVM with SATA and DRA7-EVM with an intel PCI ethernet card
> 
>  drivers/pci/host/pcie-designware.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
> index bed1999..af8f6e9 100644
> --- a/drivers/pci/host/pcie-designware.c
> +++ b/drivers/pci/host/pcie-designware.c
> @@ -807,11 +807,6 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>  {
>  	u32 val;
>  
> -	/* get iATU unroll support */
> -	pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
> -	dev_dbg(pp->dev, "iATU unroll: %s\n",
> -		pp->iatu_unroll_enabled ? "enabled" : "disabled");
> -
>  	/* set the number of lanes */
>  	val = dw_pcie_readl_rc(pp, PCIE_PORT_LINK_CONTROL);
>  	val &= ~PORT_LINK_MODE_MASK;
> @@ -882,6 +877,11 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>  	 * we should not program the ATU here.
>  	 */
>  	if (!pp->ops->rd_other_conf) {
> +		/* get iATU unroll support */
> +		pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
> +		dev_dbg(pp->dev, "iATU unroll: %s\n",
> +			pp->iatu_unroll_enabled ? "enabled" : "disabled");
> +
>  		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
>  					  PCIE_ATU_TYPE_MEM, pp->mem_base,
>  					  pp->mem_bus_addr, pp->mem_size);
> 
Bjorn,

A Gentle ping to merge this important fix to v4.10-rc kernel for Keystone PCI as
it is broken since v4.9.

Thanks
Joao Pinto Jan. 10, 2017, 10:26 a.m. UTC | #2
Hi,

Às 4:41 PM de 1/9/2017, Murali Karicheri escreveu:
> On 01/04/2017 02:32 PM, Murali Karicheri wrote:
>> Recent fixes for iATU unroll support introduced a bug that causes
>> asynchronous external abort in Keystone PCIe h/w which doesn't have
>> ATU port and the corresponding register. So the check should be moved
>> below where dw_pcie_prog_outbound_atu() is called to avoid that
>> being called on keystine PCIe h/w.
>>
>> Here is the backtrace
>>
>> [    0.771174] OF: PCI:   MEM 0x60000000..0x6fffffff -> 0x60000000
>> [    0.778118] Unhandled fault: asynchronous external abort (0x1211) at 0x00000000
>> [    0.785548] pgd = c0003000
>> [    0.788347] [00000000] *pgd=80000800004003, *pmd=00000000
>> [    0.793864] Internal error: : 1211 [#1] PREEMPT SMP ARM
>> [    0.799197] Modules linked in:
>> [    0.802351] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-00009-g6ff59d2-dirty #7
>> [    0.810130] Hardware name: Keystone
>> [    0.813717] task: eb878000 task.stack: eb866000
>> [    0.818356] PC is at dw_pcie_setup_rc+0x24/0x380
>> [    0.823083] LR is at ks_pcie_host_init+0x10/0x170
>>
>> Fixes: 416379f9ebde ("PCI: designware: Check for iATU unroll support after initializing host")
>> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
>> Tested-by: Kishon Vijay Abraham I <kishon@ti.com>
>> ---
>>  - Applies to pci/master
>>  - Bug was introduced in v4.9
>>  - Tested on K2E EVM with SATA and DRA7-EVM with an intel PCI ethernet card
>>
>>  drivers/pci/host/pcie-designware.c | 10 +++++-----
>>  1 file changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
>> index bed1999..af8f6e9 100644
>> --- a/drivers/pci/host/pcie-designware.c
>> +++ b/drivers/pci/host/pcie-designware.c
>> @@ -807,11 +807,6 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>>  {
>>  	u32 val;
>>  
>> -	/* get iATU unroll support */
>> -	pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
>> -	dev_dbg(pp->dev, "iATU unroll: %s\n",
>> -		pp->iatu_unroll_enabled ? "enabled" : "disabled");
>> -
>>  	/* set the number of lanes */
>>  	val = dw_pcie_readl_rc(pp, PCIE_PORT_LINK_CONTROL);
>>  	val &= ~PORT_LINK_MODE_MASK;
>> @@ -882,6 +877,11 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>>  	 * we should not program the ATU here.
>>  	 */
>>  	if (!pp->ops->rd_other_conf) {
>> +		/* get iATU unroll support */
>> +		pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
>> +		dev_dbg(pp->dev, "iATU unroll: %s\n",
>> +			pp->iatu_unroll_enabled ? "enabled" : "disabled");
>> +
>>  		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
>>  					  PCIE_ATU_TYPE_MEM, pp->mem_base,
>>  					  pp->mem_bus_addr, pp->mem_size);
>>
> Bjorn,
> 
> A Gentle ping to merge this important fix to v4.10-rc kernel for Keystone PCI as
> it is broken since v4.9.
> 

In my understanding your proposal will have no impact in platform using ATU, so
for me is fine.

Acked-By: Joao Pinto <jpinto@synopsys.com>

> Thanks
> 

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Bjorn Helgaas Jan. 10, 2017, 3:12 p.m. UTC | #3
Hi Murali,

On Wed, Jan 04, 2017 at 02:32:30PM -0500, Murali Karicheri wrote:
> Recent fixes for iATU unroll support introduced a bug that causes
> asynchronous external abort in Keystone PCIe h/w which doesn't have
> ATU port and the corresponding register. So the check should be moved
> below where dw_pcie_prog_outbound_atu() is called to avoid that
> being called on keystine PCIe h/w.
> 
> Here is the backtrace
> 
> [    0.771174] OF: PCI:   MEM 0x60000000..0x6fffffff -> 0x60000000
> [    0.778118] Unhandled fault: asynchronous external abort (0x1211) at 0x00000000
> [    0.785548] pgd = c0003000
> [    0.788347] [00000000] *pgd=80000800004003, *pmd=00000000
> [    0.793864] Internal error: : 1211 [#1] PREEMPT SMP ARM
> [    0.799197] Modules linked in:
> [    0.802351] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-00009-g6ff59d2-dirty #7
> [    0.810130] Hardware name: Keystone
> [    0.813717] task: eb878000 task.stack: eb866000
> [    0.818356] PC is at dw_pcie_setup_rc+0x24/0x380
> [    0.823083] LR is at ks_pcie_host_init+0x10/0x170
> 
> Fixes: 416379f9ebde ("PCI: designware: Check for iATU unroll support after initializing host")

I tentatively applied this to for-linus for v4.10, with a stable tag
for v4.9+.

The patch itself mostly makes sense in terms of the code: we only use
iatu_unroll_enabled in dw_pcie_prog_outbound_atu().  We only call that
when "!pp->ops->rd_other_conf" or "!pp->ops->wr_other_conf".

So it makes sense that we only need to initialize iatu_unroll_enabled
in those cases.  But the current patch only initializes it if
"!pp->ops->rd_other_conf".

If we had "pp->ops->rd_other_conf && !pp->ops->wr_other_conf", we
would use iatu_unroll_enabled uninitialized in the
dw_pcie_wr_other_conf() path.  I suppose that's an invalid
configuration, but it'd be better if we didn't have to rely on the
host drivers to avoid that configuration.

It's not obvious how this is connected to 416379f9ebde, though.  It
*looks* like we call dw_pcie_iatu_unroll_enabled() on Keystone both
before and after that commit, so it seems like the external abort
should have happened even before it.

> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
> Tested-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
>  - Applies to pci/master
>  - Bug was introduced in v4.9
>  - Tested on K2E EVM with SATA and DRA7-EVM with an intel PCI ethernet card
> 
>  drivers/pci/host/pcie-designware.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
> index bed1999..af8f6e9 100644
> --- a/drivers/pci/host/pcie-designware.c
> +++ b/drivers/pci/host/pcie-designware.c
> @@ -807,11 +807,6 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>  {
>  	u32 val;
>  
> -	/* get iATU unroll support */
> -	pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
> -	dev_dbg(pp->dev, "iATU unroll: %s\n",
> -		pp->iatu_unroll_enabled ? "enabled" : "disabled");
> -
>  	/* set the number of lanes */
>  	val = dw_pcie_readl_rc(pp, PCIE_PORT_LINK_CONTROL);
>  	val &= ~PORT_LINK_MODE_MASK;
> @@ -882,6 +877,11 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>  	 * we should not program the ATU here.
>  	 */
>  	if (!pp->ops->rd_other_conf) {
> +		/* get iATU unroll support */
> +		pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
> +		dev_dbg(pp->dev, "iATU unroll: %s\n",
> +			pp->iatu_unroll_enabled ? "enabled" : "disabled");
> +
>  		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
>  					  PCIE_ATU_TYPE_MEM, pp->mem_base,
>  					  pp->mem_bus_addr, pp->mem_size);
> -- 
> 1.9.1
> 
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Murali Karicheri Jan. 10, 2017, 5:18 p.m. UTC | #4
On 01/10/2017 10:12 AM, Bjorn Helgaas wrote:
> Hi Murali,
> 
> On Wed, Jan 04, 2017 at 02:32:30PM -0500, Murali Karicheri wrote:
>> Recent fixes for iATU unroll support introduced a bug that causes
>> asynchronous external abort in Keystone PCIe h/w which doesn't have
>> ATU port and the corresponding register. So the check should be moved
>> below where dw_pcie_prog_outbound_atu() is called to avoid that
>> being called on keystine PCIe h/w.
>>
>> Here is the backtrace
>>
>> [    0.771174] OF: PCI:   MEM 0x60000000..0x6fffffff -> 0x60000000
>> [    0.778118] Unhandled fault: asynchronous external abort (0x1211) at 0x00000000
>> [    0.785548] pgd = c0003000
>> [    0.788347] [00000000] *pgd=80000800004003, *pmd=00000000
>> [    0.793864] Internal error: : 1211 [#1] PREEMPT SMP ARM
>> [    0.799197] Modules linked in:
>> [    0.802351] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-00009-g6ff59d2-dirty #7
>> [    0.810130] Hardware name: Keystone
>> [    0.813717] task: eb878000 task.stack: eb866000
>> [    0.818356] PC is at dw_pcie_setup_rc+0x24/0x380
>> [    0.823083] LR is at ks_pcie_host_init+0x10/0x170
>>
>> Fixes: 416379f9ebde ("PCI: designware: Check for iATU unroll support after initializing host")
> 
> I tentatively applied this to for-linus for v4.10, with a stable tag
> for v4.9+.
> 

Ok  Thanks!

> The patch itself mostly makes sense in terms of the code: we only use
> iatu_unroll_enabled in dw_pcie_prog_outbound_atu().  We only call that
> when "!pp->ops->rd_other_conf" or "!pp->ops->wr_other_conf".
> 
> So it makes sense that we only need to initialize iatu_unroll_enabled
> in those cases.  But the current patch only initializes it if
> "!pp->ops->rd_other_conf".
> 

I think the code before also should have checked for both 
if ((!pp->ops->rd_other_conf) && (!pp->ops->wr_other_conf))

The assumption was if rd_other_conf is Null, the platform provides 
both rd_other_conf and wr_other_conf. I see I have added this API 
to support Keystone and the above assumption is true so far. 
It make sense to fix it if you agree.

> If we had "pp->ops->rd_other_conf && !pp->ops->wr_other_conf", we
> would use iatu_unroll_enabled uninitialized in the
> dw_pcie_wr_other_conf() path.  I suppose that's an invalid

Yes. So we need to fix the above to make the code correct instead
of leaving it exposed.

> configuration, but it'd be better if we didn't have to rely on the
> host drivers to avoid that configuration.

You mean to introduce the check in the designware core code above 
right?

Murali
> 
> It's not obvious how this is connected to 416379f9ebde, though.  It
> *looks* like we call dw_pcie_iatu_unroll_enabled() on Keystone both
> before and after that commit, so it seems like the external abort
> should have happened even before it.
> 

You are right. The problem was introduced by 

commit a0601a47053714eecec726aea5ebcd829f817497
Author: Joao Pinto <Joao.Pinto@synopsys.com>
Date:   Wed Aug 10 11:02:39 2016 +0100

    PCI: designware: Add iATU Unroll feature

which is fixed by commit 416379f9ebde and is again fixed by my 
commit. So probably I should have added both commits in
my description. 

Murali

>> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
>> Tested-by: Kishon Vijay Abraham I <kishon@ti.com>
>> ---
>>  - Applies to pci/master
>>  - Bug was introduced in v4.9
>>  - Tested on K2E EVM with SATA and DRA7-EVM with an intel PCI ethernet card
>>
>>  drivers/pci/host/pcie-designware.c | 10 +++++-----
>>  1 file changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
>> index bed1999..af8f6e9 100644
>> --- a/drivers/pci/host/pcie-designware.c
>> +++ b/drivers/pci/host/pcie-designware.c
>> @@ -807,11 +807,6 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>>  {
>>  	u32 val;
>>  
>> -	/* get iATU unroll support */
>> -	pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
>> -	dev_dbg(pp->dev, "iATU unroll: %s\n",
>> -		pp->iatu_unroll_enabled ? "enabled" : "disabled");
>> -
>>  	/* set the number of lanes */
>>  	val = dw_pcie_readl_rc(pp, PCIE_PORT_LINK_CONTROL);
>>  	val &= ~PORT_LINK_MODE_MASK;
>> @@ -882,6 +877,11 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>>  	 * we should not program the ATU here.
>>  	 */
>>  	if (!pp->ops->rd_other_conf) {
>> +		/* get iATU unroll support */
>> +		pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
>> +		dev_dbg(pp->dev, "iATU unroll: %s\n",
>> +			pp->iatu_unroll_enabled ? "enabled" : "disabled");
>> +
>>  		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
>>  					  PCIE_ATU_TYPE_MEM, pp->mem_base,
>>  					  pp->mem_bus_addr, pp->mem_size);
>> -- 
>> 1.9.1
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
>> the body of a message to majordomo@vger.kernel.org
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diff mbox

Patch

diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index bed1999..af8f6e9 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -807,11 +807,6 @@  void dw_pcie_setup_rc(struct pcie_port *pp)
 {
 	u32 val;
 
-	/* get iATU unroll support */
-	pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
-	dev_dbg(pp->dev, "iATU unroll: %s\n",
-		pp->iatu_unroll_enabled ? "enabled" : "disabled");
-
 	/* set the number of lanes */
 	val = dw_pcie_readl_rc(pp, PCIE_PORT_LINK_CONTROL);
 	val &= ~PORT_LINK_MODE_MASK;
@@ -882,6 +877,11 @@  void dw_pcie_setup_rc(struct pcie_port *pp)
 	 * we should not program the ATU here.
 	 */
 	if (!pp->ops->rd_other_conf) {
+		/* get iATU unroll support */
+		pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
+		dev_dbg(pp->dev, "iATU unroll: %s\n",
+			pp->iatu_unroll_enabled ? "enabled" : "disabled");
+
 		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
 					  PCIE_ATU_TYPE_MEM, pp->mem_base,
 					  pp->mem_bus_addr, pp->mem_size);