[PATCH RFC] powerpc/powernv: sysfs entry to force full IPL reboot
From: Andrew Donnellan <hidden>
Date: 2016-11-22 09:23:13
skiboot now supports "fast reboot", a reboot procedure where skiboot reinitialises hardware and loads a new kernel without re-IPLing the machine. At present, fast reboot support is still experimental and is not enabled by default, however it is intended that it will be enabled by default in a near-future release. There may be some circumstances where the user wants to force a full IPL reboot rather than using fast reboot. Add support for the OPAL_REBOOT_FULL_IPL reboot type, enabled by writing 1 to /sys/firmware/opal/force_full_ipl_reboot. On versions of skiboot that implement the OPAL_REBOOT_FULL_IPL reboot type, this will force an IPL. On versions that do not, print an error message on reboot and proceed with a regular reboot (which could be a full IPL or a fast reboot). Cc: Stewart Smith <redacted> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Donnellan <redacted> --- Corresponding skiboot patch: http://patchwork.ozlabs.org/patch/697601/ This seemed like a good idea at the time. A sysfs-based flag was the best option that came to mind; other suggestions are welcome. Is "full IPL" a reasonable term to use or should I try to think of something a bit less IBM-ese? --- arch/powerpc/include/asm/opal-api.h | 1 + arch/powerpc/include/asm/opal.h | 1 + arch/powerpc/platforms/powernv/opal.c | 2 ++ arch/powerpc/platforms/powernv/setup.c | 63 +++++++++++++++++++++++++++++++++- 4 files changed, 66 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
index 0e2e57b..4de1f63 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h@@ -918,6 +918,7 @@ 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/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index e958b70..a5e4065 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h@@ -270,6 +270,7 @@ extern void opal_platform_dump_init(void); extern void opal_sys_param_init(void); extern void opal_msglog_init(void); extern void opal_msglog_sysfs_init(void); +extern void opal_reboot_sysfs_init(void); extern int opal_async_comp_init(void); extern int opal_sensor_init(void); extern int opal_hmi_handler_init(void);
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 6c9a65b..c619d8d 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c@@ -750,6 +750,8 @@ static int __init opal_init(void) opal_sys_param_init(); /* Setup message log sysfs interface. */ opal_msglog_sysfs_init(); + /* Setup reboot sysfs interface. */ + opal_reboot_sysfs_init(); } /* Initialize platform devices: IPMI backend, PRD & flash interface */
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index efe8b6b..d2460fc 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c@@ -28,6 +28,7 @@ #include <linux/bug.h> #include <linux/pci.h> #include <linux/cpufreq.h> +#include <linux/sysfs.h> #include <asm/machdep.h> #include <asm/firmware.h>
@@ -118,6 +119,53 @@ static void pnv_prepare_going_down(void) opal_flash_term_callback(); } +static bool force_full_ipl_reboot = false; + +static ssize_t force_full_ipl_reboot_show(struct kobject *k, + struct kobj_attribute *attr, + char *buf) +{ + return sprintf(buf, "%d\n", (int) force_full_ipl_reboot); +} + +static ssize_t force_full_ipl_reboot_store(struct kobject *k, + struct kobj_attribute *attr, + const char *buf, + size_t count) +{ + if (count != 2) /* including trailing NUL */ + return -EINVAL; + + switch (buf[0]) { + case '0': + force_full_ipl_reboot = false; + return count; + case '1': + force_full_ipl_reboot = true; + return count; + default: + return -EINVAL; + } +} + +static struct kobj_attribute opal_force_full_ipl_reboot_attr = + __ATTR(force_full_ipl_reboot, 0644, force_full_ipl_reboot_show, + force_full_ipl_reboot_store); + +void opal_reboot_sysfs_init(void) { + int rc = 0; + + if (!opal_kobj) { + pr_warn("setup: opal kobject is not available"); + return; + } + + rc = sysfs_create_file(opal_kobj, &opal_force_full_ipl_reboot_attr.attr); + if (rc) + pr_err("setup: unable to create sysfs file " + "force_full_ipl_reboot (%d)", rc); +} + static void __noreturn pnv_restart(char *cmd) { long rc = OPAL_BUSY;
@@ -125,7 +173,20 @@ static void __noreturn pnv_restart(char *cmd) pnv_prepare_going_down(); while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { - rc = opal_cec_reboot(); + if (force_full_ipl_reboot && opal_check_token(OPAL_CEC_REBOOT2)) { + rc = opal_cec_reboot2(OPAL_REBOOT_FULL_IPL, + "Full IPL reboot requested"); + + if (rc == OPAL_UNSUPPORTED) { + pr_err("Firmware doesn't support forcing full " + "IPL reboot"); + force_full_ipl_reboot = false; + rc = opal_cec_reboot(); + } + } else { + rc = opal_cec_reboot(); + } + if (rc == OPAL_BUSY_EVENT) opal_poll_events(NULL); else
--
Andrew Donnellan OzLabs, ADL Canberra
andrew.donnellan@au1.ibm.com IBM Australia Limited