[PATCH v3] powerpc/powernv: Make possible for user to force a full ipl cec reboot
From: Vaibhav Jain <hidden>
Date: 2018-09-07 07:36:04
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 <redacted>
---
Change-log:
v3 -> Re-factored the code to make it more readable [Andrew]
Handle return of OPAL_SUCCESS from cec_reboot variants
[Vasant]
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 | 36 +++++++++++++++++++++-----
2 files changed, 31 insertions(+), 6 deletions(-)
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..79fd839faa2d 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c@@ -219,17 +219,41 @@ static void pnv_prepare_going_down(void) static void __noreturn pnv_restart(char *cmd) { - long rc = OPAL_BUSY; + long rc; pnv_prepare_going_down(); - while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { - rc = opal_cec_reboot(); - if (rc == OPAL_BUSY_EVENT) - opal_poll_events(NULL); + do { + if (!cmd) + rc = opal_cec_reboot(); + else if (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) { + /* Opal is busy wait for some time and retry */ + opal_poll_events(NULL); mdelay(10); - } + + } else if (cmd && rc) { + /* Unknown error while issuing reboot */ + if (rc == OPAL_UNSUPPORTED) + pr_err("Unsupported '%s' reboot.\n", cmd); + else + pr_err("Unable to issue '%s' reboot. Err=%ld\n", + cmd, rc); + pr_info("Forcing a cec-reboot\n"); + cmd = NULL; + rc = OPAL_BUSY; + + } else if (rc != OPAL_SUCCESS) { + /* Unknown error while issuing cec-reboot */ + pr_err("Unable to reboot. Err=%ld\n", rc); + } + + } while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT); + for (;;) opal_poll_events(NULL); }
--
2.17.1