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powerpc/powermac: Use early_* IO variants in via_calibrate_decr()

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[ Upstream commit 86582e6189 ]

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 721255b982
("genirq: Use a maple tree for interrupt descriptor management").

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230706010816.72682-1-bgray@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Benjamin Gray 2023-07-06 11:08:16 +10:00 committed by Greg Kroah-Hartman
parent ab3c602d15
commit ee66ee99ee
1 changed files with 3 additions and 3 deletions
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6
arch/powerpc/platforms/powermac/time.c
View file

@ -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;
}