* [PATCH v2] powerpc/powernv: Add pci_reset_phbs parameter to issue a PHB reset
@ 2017-10-25 15:27 Guilherme G. Piccoli
2017-11-09 21:33 ` Guilherme G. Piccoli
` (2 more replies)
0 siblings, 3 replies; 9+ messages in thread
From: Guilherme G. Piccoli @ 2017-10-25 15:27 UTC (permalink / raw)
To: linuxppc-dev; +Cc: gpiccoli, benh, paulus, mpe
During a kdump kernel boot in PowerPC, we request a reset of the PHBs
to the FW. It makes sense, since if we are booting a kdump kernel it
means we had some trouble before and we cannot rely in the adapters'
health; they could be in a bad state, hence the reset is needed.
But this reset is useful not only in kdump - there are situations,
specially when debugging drivers, that we could break an adapter in
a way it requires such reset. One can tell to just go ahead and
reboot the machine, but happens that many times doing kexec is much
faster, and so preferable than a full power cycle.
This patch adds the pci_reset_phbs parameter to perform such reset
when desired by the user.
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
---
v2: changed name of the parameter [ben/mpe suggestion].
The patch was implemented against powerpc/next.
arch/powerpc/platforms/powernv/pci-ioda.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index fb5cd7511189..6070e0d4a7f3 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -89,6 +89,7 @@ void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level,
}
static bool pnv_iommu_bypass_disabled __read_mostly;
+static bool pci_reset_phbs __read_mostly;
static int __init iommu_setup(char *str)
{
@@ -110,6 +111,14 @@ static int __init iommu_setup(char *str)
}
early_param("iommu", iommu_setup);
+static int __init pci_reset_phbs_setup(char *str)
+{
+ pci_reset_phbs = true;
+ return 0;
+}
+
+early_param("pci_reset_phbs", pci_reset_phbs_setup);
+
static inline bool pnv_pci_is_m64(struct pnv_phb *phb, struct resource *r)
{
/*
@@ -4014,9 +4023,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
* If we're running in kdump kernel, the previous kernel never
* shutdown PCI devices correctly. We already got IODA table
* cleaned out. So we have to issue PHB reset to stop all PCI
- * transactions from previous kernel.
+ * transactions from previous kernel. The pci_reset_phbs
+ * kernel parameter will force this reset too.
*/
- if (is_kdump_kernel()) {
+ if (is_kdump_kernel() || pci_reset_phbs) {
pr_info(" Issue PHB reset ...\n");
pnv_eeh_phb_reset(hose, EEH_RESET_FUNDAMENTAL);
pnv_eeh_phb_reset(hose, EEH_RESET_DEACTIVATE);
--
2.15.0.rc0
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v2] powerpc/powernv: Add pci_reset_phbs parameter to issue a PHB reset
2017-10-25 15:27 [PATCH v2] powerpc/powernv: Add pci_reset_phbs parameter to issue a PHB reset Guilherme G. Piccoli
@ 2017-11-09 21:33 ` Guilherme G. Piccoli
2017-11-13 4:25 ` Michael Ellerman
2017-11-16 3:49 ` Balbir Singh
2 siblings, 0 replies; 9+ messages in thread
From: Guilherme G. Piccoli @ 2017-11-09 21:33 UTC (permalink / raw)
To: Michael Ellerman, Benjamin Herrenschmidt; +Cc: linuxppc-dev
On 10/25/2017 01:27 PM, Guilherme G. Piccoli wrote:
> During a kdump kernel boot in PowerPC, we request a reset of the PHBs
> to the FW. It makes sense, since if we are booting a kdump kernel it
> means we had some trouble before and we cannot rely in the adapters'
> health; they could be in a bad state, hence the reset is needed.
>
> But this reset is useful not only in kdump - there are situations,
> specially when debugging drivers, that we could break an adapter in
> a way it requires such reset. One can tell to just go ahead and
> reboot the machine, but happens that many times doing kexec is much
> faster, and so preferable than a full power cycle.
>
> This patch adds the pci_reset_phbs parameter to perform such reset
> when desired by the user.
>
> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
> ---
> v2: changed name of the parameter [ben/mpe suggestion].
>
> The patch was implemented against powerpc/next.
Hi Michael/Ben...any thoughts about this one?
Thanks in advance!
>
> arch/powerpc/platforms/powernv/pci-ioda.c | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> index fb5cd7511189..6070e0d4a7f3 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -89,6 +89,7 @@ void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level,
> }
>
> static bool pnv_iommu_bypass_disabled __read_mostly;
> +static bool pci_reset_phbs __read_mostly;
>
> static int __init iommu_setup(char *str)
> {
> @@ -110,6 +111,14 @@ static int __init iommu_setup(char *str)
> }
> early_param("iommu", iommu_setup);
>
> +static int __init pci_reset_phbs_setup(char *str)
> +{
> + pci_reset_phbs = true;
> + return 0;
> +}
> +
> +early_param("pci_reset_phbs", pci_reset_phbs_setup);
> +
> static inline bool pnv_pci_is_m64(struct pnv_phb *phb, struct resource *r)
> {
> /*
> @@ -4014,9 +4023,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
> * If we're running in kdump kernel, the previous kernel never
> * shutdown PCI devices correctly. We already got IODA table
> * cleaned out. So we have to issue PHB reset to stop all PCI
> - * transactions from previous kernel.
> + * transactions from previous kernel. The pci_reset_phbs
> + * kernel parameter will force this reset too.
> */
> - if (is_kdump_kernel()) {
> + if (is_kdump_kernel() || pci_reset_phbs) {
> pr_info(" Issue PHB reset ...\n");
> pnv_eeh_phb_reset(hose, EEH_RESET_FUNDAMENTAL);
> pnv_eeh_phb_reset(hose, EEH_RESET_DEACTIVATE);
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] powerpc/powernv: Add pci_reset_phbs parameter to issue a PHB reset
2017-10-25 15:27 [PATCH v2] powerpc/powernv: Add pci_reset_phbs parameter to issue a PHB reset Guilherme G. Piccoli
2017-11-09 21:33 ` Guilherme G. Piccoli
@ 2017-11-13 4:25 ` Michael Ellerman
2017-11-16 3:49 ` Balbir Singh
2 siblings, 0 replies; 9+ messages in thread
From: Michael Ellerman @ 2017-11-13 4:25 UTC (permalink / raw)
To: Guilherme G. Piccoli, linuxppc-dev; +Cc: gpiccoli, benh, paulus
"Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> writes:
> During a kdump kernel boot in PowerPC, we request a reset of the PHBs
> to the FW. It makes sense, since if we are booting a kdump kernel it
> means we had some trouble before and we cannot rely in the adapters'
> health; they could be in a bad state, hence the reset is needed.
>
> But this reset is useful not only in kdump - there are situations,
> specially when debugging drivers, that we could break an adapter in
> a way it requires such reset. One can tell to just go ahead and
> reboot the machine, but happens that many times doing kexec is much
> faster, and so preferable than a full power cycle.
>
> This patch adds the pci_reset_phbs parameter to perform such reset
> when desired by the user.
>
> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
> ---
> v2: changed name of the parameter [ben/mpe suggestion].
>
> The patch was implemented against powerpc/next.
>
> arch/powerpc/platforms/powernv/pci-ioda.c | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> index fb5cd7511189..6070e0d4a7f3 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -89,6 +89,7 @@ void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level,
> }
>
> static bool pnv_iommu_bypass_disabled __read_mostly;
> +static bool pci_reset_phbs __read_mostly;
>
> static int __init iommu_setup(char *str)
> {
> @@ -110,6 +111,14 @@ static int __init iommu_setup(char *str)
> }
> early_param("iommu", iommu_setup);
>
> +static int __init pci_reset_phbs_setup(char *str)
> +{
> + pci_reset_phbs = true;
> + return 0;
> +}
> +
> +early_param("pci_reset_phbs", pci_reset_phbs_setup);
Is there a reason you didn't make it a module parameter?
That is preferable IMHO because it is namespaced, which means we don't
need to worry about polluting the top-level parameter namespace.
cheers
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] powerpc/powernv: Add pci_reset_phbs parameter to issue a PHB reset
2017-10-25 15:27 [PATCH v2] powerpc/powernv: Add pci_reset_phbs parameter to issue a PHB reset Guilherme G. Piccoli
2017-11-09 21:33 ` Guilherme G. Piccoli
2017-11-13 4:25 ` Michael Ellerman
@ 2017-11-16 3:49 ` Balbir Singh
2017-11-16 12:14 ` Guilherme G. Piccoli
2 siblings, 1 reply; 9+ messages in thread
From: Balbir Singh @ 2017-11-16 3:49 UTC (permalink / raw)
To: Guilherme G. Piccoli
Cc: open list:LINUX FOR POWERPC (32-BIT AND 64-BIT), Paul Mackerras
On Thu, Oct 26, 2017 at 2:27 AM, Guilherme G. Piccoli
<gpiccoli@linux.vnet.ibm.com> wrote:
> During a kdump kernel boot in PowerPC, we request a reset of the PHBs
> to the FW. It makes sense, since if we are booting a kdump kernel it
> means we had some trouble before and we cannot rely in the adapters'
> health; they could be in a bad state, hence the reset is needed.
>
> But this reset is useful not only in kdump - there are situations,
> specially when debugging drivers, that we could break an adapter in
> a way it requires such reset. One can tell to just go ahead and
> reboot the machine, but happens that many times doing kexec is much
> faster, and so preferable than a full power cycle.
>
> This patch adds the pci_reset_phbs parameter to perform such reset
> when desired by the user.
>
Do we care to reset specific phbs or all of them? I guess all based on
your description.
Balbir Singh.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] powerpc/powernv: Add pci_reset_phbs parameter to issue a PHB reset
2017-11-16 3:49 ` Balbir Singh
@ 2017-11-16 12:14 ` Guilherme G. Piccoli
2017-11-21 2:35 ` Balbir Singh
0 siblings, 1 reply; 9+ messages in thread
From: Guilherme G. Piccoli @ 2017-11-16 12:14 UTC (permalink / raw)
To: Balbir Singh
Cc: open list:LINUX FOR POWERPC (32-BIT AND 64-BIT), Paul Mackerras
On 11/16/2017 01:49 AM, Balbir Singh wrote:
> On Thu, Oct 26, 2017 at 2:27 AM, Guilherme G. Piccoli
> <gpiccoli@linux.vnet.ibm.com> wrote:
>> During a kdump kernel boot in PowerPC, we request a reset of the PHBs
>> to the FW. It makes sense, since if we are booting a kdump kernel it
>> means we had some trouble before and we cannot rely in the adapters'
>> health; they could be in a bad state, hence the reset is needed.
>>
>> But this reset is useful not only in kdump - there are situations,
>> specially when debugging drivers, that we could break an adapter in
>> a way it requires such reset. One can tell to just go ahead and
>> reboot the machine, but happens that many times doing kexec is much
>> faster, and so preferable than a full power cycle.
>>
>> This patch adds the pci_reset_phbs parameter to perform such reset
>> when desired by the user.
>>
>
> Do we care to reset specific phbs or all of them? I guess all based on
> your description.
Exactly Balbir, it does reset all of them. We could add such
granularity, but I don't see much usability..
But if somebody feels it's useful, we can change...
Thanks!
>
> Balbir Singh.
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] powerpc/powernv: Add pci_reset_phbs parameter to issue a PHB reset
2017-11-16 12:14 ` Guilherme G. Piccoli
@ 2017-11-21 2:35 ` Balbir Singh
2017-12-06 19:28 ` Guilherme G. Piccoli
0 siblings, 1 reply; 9+ messages in thread
From: Balbir Singh @ 2017-11-21 2:35 UTC (permalink / raw)
To: Guilherme G. Piccoli
Cc: open list:LINUX FOR POWERPC (32-BIT AND 64-BIT), Paul Mackerras
On Thu, Nov 16, 2017 at 11:14 PM, Guilherme G. Piccoli
<gpiccoli@linux.vnet.ibm.com> wrote:
> On 11/16/2017 01:49 AM, Balbir Singh wrote:
>> On Thu, Oct 26, 2017 at 2:27 AM, Guilherme G. Piccoli
>> <gpiccoli@linux.vnet.ibm.com> wrote:
>>> During a kdump kernel boot in PowerPC, we request a reset of the PHBs
>>> to the FW. It makes sense, since if we are booting a kdump kernel it
>>> means we had some trouble before and we cannot rely in the adapters'
>>> health; they could be in a bad state, hence the reset is needed.
>>>
>>> But this reset is useful not only in kdump - there are situations,
>>> specially when debugging drivers, that we could break an adapter in
>>> a way it requires such reset. One can tell to just go ahead and
>>> reboot the machine, but happens that many times doing kexec is much
>>> faster, and so preferable than a full power cycle.
>>>
>>> This patch adds the pci_reset_phbs parameter to perform such reset
>>> when desired by the user.
>>>
>>
>> Do we care to reset specific phbs or all of them? I guess all based on
>> your description.
>
> Exactly Balbir, it does reset all of them. We could add such
> granularity, but I don't see much usability..
> But if somebody feels it's useful, we can change...
>
OK.. makes sense, any reason why this can't be folded into reset_devices?
I guess we want reset_phbs to be independent of reset_devices
Balbir
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] powerpc/powernv: Add pci_reset_phbs parameter to issue a PHB reset
2017-11-21 2:35 ` Balbir Singh
@ 2017-12-06 19:28 ` Guilherme G. Piccoli
2017-12-08 12:03 ` Michael Ellerman
0 siblings, 1 reply; 9+ messages in thread
From: Guilherme G. Piccoli @ 2017-12-06 19:28 UTC (permalink / raw)
To: Balbir Singh
Cc: Paul Mackerras, open list:LINUX FOR POWERPC (32-BIT AND 64-BIT)
On 11/21/2017 12:35 AM, Balbir Singh wrote:
> On Thu, Nov 16, 2017 at 11:14 PM, Guilherme G. Piccoli
> <gpiccoli@linux.vnet.ibm.com> wrote:
>> On 11/16/2017 01:49 AM, Balbir Singh wrote:
>>> On Thu, Oct 26, 2017 at 2:27 AM, Guilherme G. Piccoli
>>> <gpiccoli@linux.vnet.ibm.com> wrote:
>>>> During a kdump kernel boot in PowerPC, we request a reset of the PHBs
>>>> to the FW. It makes sense, since if we are booting a kdump kernel it
>>>> means we had some trouble before and we cannot rely in the adapters'
>>>> health; they could be in a bad state, hence the reset is needed.
>>>>
>>>> But this reset is useful not only in kdump - there are situations,
>>>> specially when debugging drivers, that we could break an adapter in
>>>> a way it requires such reset. One can tell to just go ahead and
>>>> reboot the machine, but happens that many times doing kexec is much
>>>> faster, and so preferable than a full power cycle.
>>>>
>>>> This patch adds the pci_reset_phbs parameter to perform such reset
>>>> when desired by the user.
>>>>
>>>
>>> Do we care to reset specific phbs or all of them? I guess all based on
>>> your description.
>>
>> Exactly Balbir, it does reset all of them. We could add such
>> granularity, but I don't see much usability..
>> But if somebody feels it's useful, we can change...
>>
>
> OK.. makes sense, any reason why this can't be folded into reset_devices?
> I guess we want reset_phbs to be independent of reset_devices
It was, in v1. But mpe asked it to be a powerpc specific parameter heheh
Cheers,
Guilherme
>
> Balbir
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] powerpc/powernv: Add pci_reset_phbs parameter to issue a PHB reset
2017-12-06 19:28 ` Guilherme G. Piccoli
@ 2017-12-08 12:03 ` Michael Ellerman
2017-12-08 18:43 ` Guilherme G. Piccoli
0 siblings, 1 reply; 9+ messages in thread
From: Michael Ellerman @ 2017-12-08 12:03 UTC (permalink / raw)
To: Guilherme G. Piccoli, Balbir Singh
Cc: open list:LINUX FOR POWERPC (32-BIT AND 64-BIT), Paul Mackerras
"Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> writes:
> On 11/21/2017 12:35 AM, Balbir Singh wrote:
>> On Thu, Nov 16, 2017 at 11:14 PM, Guilherme G. Piccoli
>> <gpiccoli@linux.vnet.ibm.com> wrote:
>>> On 11/16/2017 01:49 AM, Balbir Singh wrote:
>>>> On Thu, Oct 26, 2017 at 2:27 AM, Guilherme G. Piccoli
>>>> <gpiccoli@linux.vnet.ibm.com> wrote:
>>>>> During a kdump kernel boot in PowerPC, we request a reset of the PHBs
>>>>> to the FW. It makes sense, since if we are booting a kdump kernel it
>>>>> means we had some trouble before and we cannot rely in the adapters'
>>>>> health; they could be in a bad state, hence the reset is needed.
>>>>>
>>>>> But this reset is useful not only in kdump - there are situations,
>>>>> specially when debugging drivers, that we could break an adapter in
>>>>> a way it requires such reset. One can tell to just go ahead and
>>>>> reboot the machine, but happens that many times doing kexec is much
>>>>> faster, and so preferable than a full power cycle.
>>>>>
>>>>> This patch adds the pci_reset_phbs parameter to perform such reset
>>>>> when desired by the user.
>>>>>
>>>>
>>>> Do we care to reset specific phbs or all of them? I guess all based on
>>>> your description.
>>>
>>> Exactly Balbir, it does reset all of them. We could add such
>>> granularity, but I don't see much usability..
>>> But if somebody feels it's useful, we can change...
>>>
>>
>> OK.. makes sense, any reason why this can't be folded into reset_devices?
>> I guess we want reset_phbs to be independent of reset_devices
>
> It was, in v1. But mpe asked it to be a powerpc specific parameter heheh
LOL. Turtles.
I still feel like we shouldn't be creating a generically named parameter
like this, though we have done it many times in the past.
Can we call it "ppc_reset_phbs". And then I'll merge it without further
quibbling, honest.
cheers
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] powerpc/powernv: Add pci_reset_phbs parameter to issue a PHB reset
2017-12-08 12:03 ` Michael Ellerman
@ 2017-12-08 18:43 ` Guilherme G. Piccoli
0 siblings, 0 replies; 9+ messages in thread
From: Guilherme G. Piccoli @ 2017-12-08 18:43 UTC (permalink / raw)
To: Michael Ellerman, Balbir Singh
Cc: open list:LINUX FOR POWERPC (32-BIT AND 64-BIT), Paul Mackerras
On 12/08/2017 10:03 AM, Michael Ellerman wrote:
> "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> writes:
>
>> On 11/21/2017 12:35 AM, Balbir Singh wrote:
>>> On Thu, Nov 16, 2017 at 11:14 PM, Guilherme G. Piccoli
>>> <gpiccoli@linux.vnet.ibm.com> wrote:
>>>> On 11/16/2017 01:49 AM, Balbir Singh wrote:
>>>>> On Thu, Oct 26, 2017 at 2:27 AM, Guilherme G. Piccoli
>>>>> <gpiccoli@linux.vnet.ibm.com> wrote:
>>>>>> During a kdump kernel boot in PowerPC, we request a reset of the PHBs
>>>>>> to the FW. It makes sense, since if we are booting a kdump kernel it
>>>>>> means we had some trouble before and we cannot rely in the adapters'
>>>>>> health; they could be in a bad state, hence the reset is needed.
>>>>>>
>>>>>> But this reset is useful not only in kdump - there are situations,
>>>>>> specially when debugging drivers, that we could break an adapter in
>>>>>> a way it requires such reset. One can tell to just go ahead and
>>>>>> reboot the machine, but happens that many times doing kexec is much
>>>>>> faster, and so preferable than a full power cycle.
>>>>>>
>>>>>> This patch adds the pci_reset_phbs parameter to perform such reset
>>>>>> when desired by the user.
>>>>>>
>>>>>
>>>>> Do we care to reset specific phbs or all of them? I guess all based on
>>>>> your description.
>>>>
>>>> Exactly Balbir, it does reset all of them. We could add such
>>>> granularity, but I don't see much usability..
>>>> But if somebody feels it's useful, we can change...
>>>>
>>>
>>> OK.. makes sense, any reason why this can't be folded into reset_devices?
>>> I guess we want reset_phbs to be independent of reset_devices
>>
>> It was, in v1. But mpe asked it to be a powerpc specific parameter heheh
>
> LOL. Turtles.
>
> I still feel like we shouldn't be creating a generically named parameter
> like this, though we have done it many times in the past.
>
> Can we call it "ppc_reset_phbs". And then I'll merge it without further
> quibbling, honest.
hahah sure! How about this one: https://patchwork.ozlabs.org/patch/839123
Let me know your thoughts!
Cheers,
Guilherme
>
> cheers
>
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2017-12-08 18:43 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
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2017-10-25 15:27 [PATCH v2] powerpc/powernv: Add pci_reset_phbs parameter to issue a PHB reset Guilherme G. Piccoli
2017-11-09 21:33 ` Guilherme G. Piccoli
2017-11-13 4:25 ` Michael Ellerman
2017-11-16 3:49 ` Balbir Singh
2017-11-16 12:14 ` Guilherme G. Piccoli
2017-11-21 2:35 ` Balbir Singh
2017-12-06 19:28 ` Guilherme G. Piccoli
2017-12-08 12:03 ` Michael Ellerman
2017-12-08 18:43 ` Guilherme G. Piccoli
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