Commit 8139046a authored by Vaibhav Jain's avatar Vaibhav Jain Committed by Michael Ellerman

powerpc/powernv: Make possible for user to force a full ipl cec reboot

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: default avatarVaibhav Jain <vaibhav@linux.ibm.com>
Acked-by: default avatarAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent db6711b7
......@@ -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 */
......
......@@ -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);
}
......
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