* [PATCH v2] powerpc/powernv: Make possible for user to force a full ipl cec reboot
@ 2018-09-03 10:26 Vaibhav Jain
2018-09-04 1:59 ` Andrew Donnellan
2018-09-05 6:32 ` Vasant Hegde
0 siblings, 2 replies; 4+ messages in thread
From: Vaibhav Jain @ 2018-09-03 10:26 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Michael Ellerman, Stewart Smith
Cc: Vaibhav Jain, linuxppc-dev, Andrew Donnellan, Vasant Hegde,
Michael Neuling, Nicholas Piggin, Oliver O'Halloran
Ever since fast reboot is enabled by default in opal,
opal_cec_reboot() will use fast-reset instead of full IPL to perform
system reboot. This leaves the user with no direct way to force a full
IPL reboot except changing an nvram setting that persistently disables
fast-reset for all subsequent reboots.
This patch provides a more direct way for the user to force a one-shot
full IPL reboot by passing the command line argument 'full' to the
reboot command. So the user will be able to tweak the reboot behavior
via:
$ sudo reboot full # Force a full ipl reboot skipping fast-reset
or
$ sudo reboot # default reboot path (usually fast-reset)
The reboot command passes the un-parsed command argument to the kernel
via the 'Reboot' syscall which is then passed on to the arch function
pnv_restart(). The patch updates pnv_restart() to handle this cmd-arg
and issues opal_cec_reboot2 with OPAL_REBOOT_FULL_IPL to force a full
IPL reset.
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
---
Change-log:
v2 -> Updated the code to handle case when opal_cec_reboot2() is
not supported by opal. [Andrew]
-> Force a call to opal_cec_reboot() is opal_cec_reboot2()
fails or the action verb 'cmd' is not recognized.
---
arch/powerpc/include/asm/opal-api.h | 1 +
arch/powerpc/platforms/powernv/setup.c | 17 ++++++++++++++++-
2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
index 8365353330b4..870fb7b239ea 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h
@@ -1050,6 +1050,7 @@ enum OpalSysCooling {
enum {
OPAL_REBOOT_NORMAL = 0,
OPAL_REBOOT_PLATFORM_ERROR = 1,
+ OPAL_REBOOT_FULL_IPL = 2,
};
/* Argument to OPAL_PCI_TCE_KILL */
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index adddde023622..650484e0940b 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -224,7 +224,22 @@ static void __noreturn pnv_restart(char *cmd)
pnv_prepare_going_down();
while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
- rc = opal_cec_reboot();
+ /* See if we need to do a full IPL reboot */
+ if (cmd && strcmp(cmd, "full") == 0)
+ rc = opal_cec_reboot2(OPAL_REBOOT_FULL_IPL, NULL);
+ else
+ rc = OPAL_UNSUPPORTED;
+
+ if (!(rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT)) {
+ if (cmd) {
+ pr_warn("Couldn't do a '%s' reboot. Err=%ld\n",
+ cmd, rc);
+ /* reset cmd to force a cec_reboot now */
+ cmd = NULL;
+ }
+ rc = opal_cec_reboot();
+ }
+
if (rc == OPAL_BUSY_EVENT)
opal_poll_events(NULL);
else
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] powerpc/powernv: Make possible for user to force a full ipl cec reboot
2018-09-03 10:26 [PATCH v2] powerpc/powernv: Make possible for user to force a full ipl cec reboot Vaibhav Jain
@ 2018-09-04 1:59 ` Andrew Donnellan
2018-09-04 2:42 ` Vaibhav Jain
2018-09-05 6:32 ` Vasant Hegde
1 sibling, 1 reply; 4+ messages in thread
From: Andrew Donnellan @ 2018-09-04 1:59 UTC (permalink / raw)
To: Vaibhav Jain, Benjamin Herrenschmidt, Michael Ellerman, Stewart Smith
Cc: linuxppc-dev, Vasant Hegde, Michael Neuling, Nicholas Piggin,
Oliver O'Halloran
On 03/09/18 20:26, Vaibhav Jain wrote:
> diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
> index adddde023622..650484e0940b 100644
> --- a/arch/powerpc/platforms/powernv/setup.c
> +++ b/arch/powerpc/platforms/powernv/setup.c
> @@ -224,7 +224,22 @@ static void __noreturn pnv_restart(char *cmd)
> pnv_prepare_going_down();
>
> while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
> - rc = opal_cec_reboot();
> + /* See if we need to do a full IPL reboot */
> + if (cmd && strcmp(cmd, "full") == 0)
> + rc = opal_cec_reboot2(OPAL_REBOOT_FULL_IPL, NULL);
> + else
> + rc = OPAL_UNSUPPORTED;
> +
> + if (!(rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT)) {
> + if (cmd) {
> + pr_warn("Couldn't do a '%s' reboot. Err=%ld\n",
> + cmd, rc);
> + /* reset cmd to force a cec_reboot now */
> + cmd = NULL;
> + }
> + rc = opal_cec_reboot();
> + }
> +
The logic here is a bit hard to follow, relying on if (cmd && strcmp...)
failing then setting rc = OPAL_UNSUPPORTED in order to handle the normal
case seems a bit backwards.
I think I would slightly prefer it if the !cmd case were handled first
to make it clear that opal_cec_reboot() is the normal case.
But either way:
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
--
Andrew Donnellan OzLabs, ADL Canberra
andrew.donnellan@au1.ibm.com IBM Australia Limited
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] powerpc/powernv: Make possible for user to force a full ipl cec reboot
2018-09-04 1:59 ` Andrew Donnellan
@ 2018-09-04 2:42 ` Vaibhav Jain
0 siblings, 0 replies; 4+ messages in thread
From: Vaibhav Jain @ 2018-09-04 2:42 UTC (permalink / raw)
To: Andrew Donnellan, Benjamin Herrenschmidt, Michael Ellerman,
Stewart Smith
Cc: linuxppc-dev, Vasant Hegde, Michael Neuling, Nicholas Piggin,
Oliver O'Halloran
Thanks for reviewing this patch Andrew,
Andrew Donnellan <andrew.donnellan@au1.ibm.com> writes:
> The logic here is a bit hard to follow, relying on if (cmd && strcmp...)
> failing then setting rc = OPAL_UNSUPPORTED in order to handle the normal
> case seems a bit backwards.
Agree. With this change I am trying to make adding new reboot types in
future simpler, without resorting to major refactoring of the
function. opal_cec_reboot() should be a fallback for any failures in
doing a typed reboot. So adding a new foobar reboot type just needs
adding a new branch in the if-else ladder.
if (cmd && strcmp(cmd, "full") == 0)
rc = opal_cec_reboot2(OPAL_REBOOT_FULL_IPL, NULL);
else if(cmd && strcmd(cmd, "foobar") == 0)
rc = /* new code here */
else
rc = OPAL_UNSUPPORTED;
> I think I would slightly prefer it if the !cmd case were handled first
> to make it clear that opal_cec_reboot() is the normal case.
Fair suggestion. But then I will still have to handle the errors just
after the if-else ladder is finished to determine if I need to fallback.
> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Thanks
--
Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Linux Technology Center, IBM India Pvt. Ltd.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] powerpc/powernv: Make possible for user to force a full ipl cec reboot
2018-09-03 10:26 [PATCH v2] powerpc/powernv: Make possible for user to force a full ipl cec reboot Vaibhav Jain
2018-09-04 1:59 ` Andrew Donnellan
@ 2018-09-05 6:32 ` Vasant Hegde
1 sibling, 0 replies; 4+ messages in thread
From: Vasant Hegde @ 2018-09-05 6:32 UTC (permalink / raw)
To: Vaibhav Jain, Benjamin Herrenschmidt, Michael Ellerman, Stewart Smith
Cc: Michael Neuling, Nicholas Piggin, Oliver O'Halloran,
Andrew Donnellan, linuxppc-dev
On 09/03/2018 03:56 PM, Vaibhav Jain wrote:
> Ever since fast reboot is enabled by default in opal,
> opal_cec_reboot() will use fast-reset instead of full IPL to perform
> system reboot. This leaves the user with no direct way to force a full
> IPL reboot except changing an nvram setting that persistently disables
> fast-reset for all subsequent reboots.
>
> This patch provides a more direct way for the user to force a one-shot
> full IPL reboot by passing the command line argument 'full' to the
> reboot command. So the user will be able to tweak the reboot behavior
> via:
>
.../...
>
> /* Argument to OPAL_PCI_TCE_KILL */
> diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
> index adddde023622..650484e0940b 100644
> --- a/arch/powerpc/platforms/powernv/setup.c
> +++ b/arch/powerpc/platforms/powernv/setup.c
> @@ -224,7 +224,22 @@ static void __noreturn pnv_restart(char *cmd)
> pnv_prepare_going_down();
>
> while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
> - rc = opal_cec_reboot();
> + /* See if we need to do a full IPL reboot */
> + if (cmd && strcmp(cmd, "full") == 0)
> + rc = opal_cec_reboot2(OPAL_REBOOT_FULL_IPL, NULL);
> + else
> + rc = OPAL_UNSUPPORTED;
As discussed offline, please handle OPAL_SUCCESS case well.
-Vasant
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-09-05 6:32 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-09-03 10:26 [PATCH v2] powerpc/powernv: Make possible for user to force a full ipl cec reboot Vaibhav Jain
2018-09-04 1:59 ` Andrew Donnellan
2018-09-04 2:42 ` Vaibhav Jain
2018-09-05 6:32 ` Vasant Hegde
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.