spi: Fix per-cpu stats access on 32 bit systems
On 32 bit systems, the following kernel BUG is hit:
BUG: using smp_processor_id() in preemptible [
00000000] code: swapper/0/1
caller is debug_smp_processor_id+0x18/0x24
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc1-00001-g6ae0aec8a366 #181
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Backtrace:
dump_backtrace from show_stack+0x20/0x24
r7:
81024ffd r6:
00000000 r5:
81024ffd r4:
60000013
show_stack from dump_stack_lvl+0x60/0x78
dump_stack_lvl from dump_stack+0x14/0x1c
r7:
81024ffd r6:
80f652de r5:
80bec180 r4:
819a2500
dump_stack from check_preemption_disabled+0xc8/0xf0
check_preemption_disabled from debug_smp_processor_id+0x18/0x24
r8:
8119b7e0 r7:
81205534 r6:
819f5c00 r5:
819f4c00 r4:
c083d724
debug_smp_processor_id from __spi_sync+0x78/0x220
__spi_sync from spi_sync+0x34/0x4c
r10:
bb7bf4e0 r9:
c083d724 r8:
00000007 r7:
81a068c0 r6:
822a83c0 r5:
c083d724
r4:
819f4c00
spi_sync from spi_mem_exec_op+0x338/0x370
r5:
000000b4 r4:
c083d910
spi_mem_exec_op from spi_nor_read_id+0x98/0xdc
r10:
bb7bf4e0 r9:
00000000 r8:
00000000 r7:
00000000 r6:
00000000 r5:
82358040
r4:
819f7c40
spi_nor_read_id from spi_nor_detect+0x38/0x114
r7:
82358040 r6:
00000000 r5:
819f7c40 r4:
819f7c40
spi_nor_detect from spi_nor_scan+0x11c/0xbec
r10:
bb7bf4e0 r9:
00000000 r8:
00000000 r7:
c083da4c r6:
00000000 r5:
00010101
r4:
819f7c40
spi_nor_scan from spi_nor_probe+0x10c/0x2d0
r10:
bb7bf4e0 r9:
bb7bf4d0 r8:
00000000 r7:
819f4c00 r6:
00000000 r5:
00000000
r4:
819f7c40
per-cpu access needs to be guarded against preemption.
Fixes:
6598b91b5ac3 ("spi: spi.c: Convert statistics to per-cpu u64_stats_t")
Reported-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David Jander <david@protonic.nl>
Tested-by: NĂcolas F. R. A. Prado <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20220609121334.2984808-1-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>