aboutsummaryrefslogtreecommitdiffstats
path: root/arch/powerpc/platforms
diff options
context:
space:
mode:
authorVasant Hegde <hegdevasant@linux.vnet.ibm.com>2014-01-15 06:02:04 (GMT)
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2014-01-15 06:21:18 (GMT)
commitf7d98d18a01ece2863984d4fb5ae949b18b02715 (patch)
tree062fe89b801c7c017da5fc6403cab2f473492cb4 /arch/powerpc/platforms
parentcb5b242c8c14a4b1dcd358400da28208fde78947 (diff)
powerpc/powernv: Call OPAL sync before kexec'ing
Its possible that OPAL may be writing to host memory during kexec (like dump retrieve scenario). In this situation we might end up corrupting host memory. This patch makes OPAL sync call to make sure OPAL stops writing to host memory before kexec'ing. Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/platforms')
-rw-r--r--arch/powerpc/platforms/powernv/opal-wrappers.S1
-rw-r--r--arch/powerpc/platforms/powernv/opal.c16
-rw-r--r--arch/powerpc/platforms/powernv/setup.c6
3 files changed, 21 insertions, 2 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index 719aa5c..3e8829c 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -128,3 +128,4 @@ OPAL_CALL(opal_manage_flash, OPAL_FLASH_MANAGE);
OPAL_CALL(opal_update_flash, OPAL_FLASH_UPDATE);
OPAL_CALL(opal_get_msg, OPAL_GET_MSG);
OPAL_CALL(opal_check_completion, OPAL_CHECK_ASYNC_COMPLETION);
+OPAL_CALL(opal_sync_host_reboot, OPAL_SYNC_HOST_REBOOT);
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 7a184a0..65499ad 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -20,6 +20,7 @@
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/kobject.h>
+#include <linux/delay.h>
#include <asm/opal.h>
#include <asm/firmware.h>
#include <asm/mce.h>
@@ -482,10 +483,25 @@ subsys_initcall(opal_init);
void opal_shutdown(void)
{
unsigned int i;
+ long rc = OPAL_BUSY;
+ /* First free interrupts, which will also mask them */
for (i = 0; i < opal_irq_count; i++) {
if (opal_irqs[i])
free_irq(opal_irqs[i], NULL);
opal_irqs[i] = 0;
}
+
+ /*
+ * Then sync with OPAL which ensure anything that can
+ * potentially write to our memory has completed such
+ * as an ongoing dump retrieval
+ */
+ while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+ rc = opal_sync_host_reboot();
+ if (rc == OPAL_BUSY)
+ opal_poll_events(NULL);
+ else
+ mdelay(10);
+ }
}
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index 19884b2..a932feb 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -145,8 +145,10 @@ static void pnv_shutdown(void)
/* Let the PCI code clear up IODA tables */
pnv_pci_shutdown();
- /* And unregister all OPAL interrupts so they don't fire
- * up while we kexec
+ /*
+ * Stop OPAL activity: Unregister all OPAL interrupts so they
+ * don't fire up while we kexec and make sure all potentially
+ * DMA'ing ops are complete (such as dump retrieval).
*/
opal_shutdown();
}

Privacy Policy