On a powermac platform, under the call path
start_kernel
time_init
ppc_md.calibrate_decr (pmac_calibrate_decr)
via_calibrate_decr
we run ioremap and iounmap. The unmap can enable interrupts
unexpectedly (cond_resched in vunmap_pmd_range), which is warned about
later in the boot sequence in start_kernel.
Use the early_* variants of these IO functions to prevent this.
The issue is pre-existing, but is surfaced by commit 721255b9826b
("genirq: Use a maple tree for interrupt descriptor management").
It's not clear to me why this causes it to surface.
Signed-off-by: Benjamin Gray <bg...@linux.ibm.com>
---
arch/powerpc/platforms/powermac/time.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/platforms/powermac/time.c
b/arch/powerpc/platforms/powermac/time.c
index 4c5790aff1b5..8633891b7aa5 100644
--- a/arch/powerpc/platforms/powermac/time.c
+++ b/arch/powerpc/platforms/powermac/time.c
@@ -26,8 +26,8 @@
#include <linux/rtc.h>
#include <linux/of_address.h>
+#include <asm/early_ioremap.h>
#include <asm/sections.h>
-#include <asm/io.h>
#include <asm/machdep.h>
#include <asm/time.h>
#include <asm/nvram.h>
@@ -182,7 +182,7 @@ static int __init via_calibrate_decr(void)
return 0;
}
of_node_put(vias);
- via = ioremap(rsrc.start, resource_size(&rsrc));
+ via = early_ioremap(rsrc.start, resource_size(&rsrc));
if (via == NULL) {
printk(KERN_ERR "Failed to map VIA for timer calibration !\n");
return 0;
@@ -207,7 +207,7 @@ static int __init via_calibrate_decr(void)
ppc_tb_freq = (dstart - dend) * 100 / 6;
- iounmap(via);
+ early_iounmap((void *)via, resource_size(&rsrc));
return 1;
}
--
2.41.0
