This is a note to let you know that I've just added the patch titled
powerpc/powermac: Use early_* IO variants in via_calibrate_decr()
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-powermac-use-early_-io-variants-in-via_calib.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 86bf187dffeea2ad9201347e69bc9091bec7c21b
Author: Benjamin Gray <bgray@xxxxxxxxxxxxx>
Date: Thu Jul 6 11:08:16 2023 +1000
powerpc/powermac: Use early_* IO variants in via_calibrate_decr()
[ Upstream commit 86582e6189dd8f9f52c25d46c70fe5d111da6345 ]
On a powermac platform, via the call path:
start_kernel()
time_init()
ppc_md.calibrate_decr() (pmac_calibrate_decr)
via_calibrate_decr()
ioremap() and iounmap() are called. The unmap can enable interrupts
unexpectedly (cond_resched() in vunmap_pmd_range()), which causes a
warning 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").
Signed-off-by: Benjamin Gray <bgray@xxxxxxxxxxxxx>
Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://msgid.link/20230706010816.72682-1-bgray@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/powerpc/platforms/powermac/time.c b/arch/powerpc/platforms/powermac/time.c
index 4c5790aff1b54..8633891b7aa58 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;
}
