From: Heiko Carstens Date: Mon, 17 Aug 2015 05:56:20 +0000 (+0200) Subject: s390/hmcdrv: fix interrupt registration X-Git-Tag: firefly_0821_release~176^2~1215^2~10 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e619cd3d618672bea8602d682ea63b42a1faf1bc;p=firefly-linux-kernel-4.4.55.git s390/hmcdrv: fix interrupt registration The z/VM driver sets bit "63-22" in control register zero to one in order to enable the CP Service interrupt (0x2603). However the irq subclass mask that normally corresponds to the CP Service interrupt is "63-54" (== "63-22-32"). So it looks like the author read the documentation with the 32 bit sized cr0 register bit positions (== 22), but didn't realize that bit numbers change, if applied to a 64 bit register (== 54) due to the numbering scheme. Also use irq_subclass_register() instead if ctl_set_bit() since multiple services depend on the service signal subclass mask, which is the correct bit. This also explains why nobody noticed the bug, since the bit is always enabled anyway (e.g. pfault). Signed-off-by: Heiko Carstens Reviewed-by: Hendrik Brueckner Acked-by: Martin Schwidefsky Signed-off-by: Martin Schwidefsky --- diff --git a/drivers/s390/char/diag_ftp.c b/drivers/s390/char/diag_ftp.c index 93889632fdf9..12db8db04cdd 100644 --- a/drivers/s390/char/diag_ftp.c +++ b/drivers/s390/char/diag_ftp.c @@ -223,7 +223,7 @@ int diag_ftp_startup(void) if (rc) return rc; - ctl_set_bit(0, 63 - 22); + irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); return 0; } @@ -232,6 +232,6 @@ int diag_ftp_startup(void) */ void diag_ftp_shutdown(void) { - ctl_clear_bit(0, 63 - 22); + irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL); unregister_external_irq(EXT_IRQ_CP_SERVICE, diag_ftp_handler); }