I noticed that spllpt() was defined twice in amd64/include/intr.h, and then upon further inspection that it's not actually used anywhere. The patch below removes the spllpt() definition from the only three architectures that still define it (alpha, amd64, sparc64).
Disclaimer: I don't have any alpha or sparc64 hardware, so I've only tested that it still compiles on amd64. However, grep can't find any other mentions of "spllpt" or "PIL_LPT" in /usr/src/sys, so it seems safe. Index: alpha/include/intr.h =================================================================== RCS file: /cvs/src/sys/arch/alpha/include/intr.h,v retrieving revision 1.35 diff -u -p alpha/include/intr.h --- alpha/include/intr.h 23 Apr 2010 03:50:20 -0000 1.35 +++ alpha/include/intr.h 26 May 2010 23:53:32 -0000 @@ -181,7 +181,6 @@ int _splraise(int); #define splstatclock() _splraise(IPL_CLOCK) #define splhigh() _splraise(IPL_HIGH) -#define spllpt() spltty() #define spllock() splhigh() #define splsched() splhigh() Index: amd64/include/intr.h =================================================================== RCS file: /cvs/src/sys/arch/amd64/include/intr.h,v retrieving revision 1.18 diff -u -p amd64/include/intr.h --- amd64/include/intr.h 22 Aug 2009 02:54:50 -0000 1.18 +++ amd64/include/intr.h 26 May 2010 23:53:32 -0000 @@ -135,10 +135,6 @@ void softintr(int); #define splstatclock() splclock() #define splipi() splraise(IPL_IPI) -#define spllpt() spltty() - -#define spllpt() spltty() - /* * Software interrupt masks */ Index: sparc64/include/psl.h =================================================================== RCS file: /cvs/src/sys/arch/sparc64/include/psl.h,v retrieving revision 1.26 diff -u -p sparc64/include/psl.h --- sparc64/include/psl.h 15 Mar 2009 19:40:40 -0000 1.26 +++ sparc64/include/psl.h 26 May 2010 23:53:32 -0000 @@ -51,7 +51,6 @@ #define PIL_BIO 5 #define PIL_VIDEO 5 #define PIL_TTY 6 -#define PIL_LPT 6 #define PIL_NET 6 #define PIL_VM 7 #define PIL_AUD 8 @@ -418,9 +417,6 @@ SPLHOLD(splnet, PIL_NET) /* tty input runs at software level 6 */ SPLHOLD(spltty, PIL_TTY) -/* parallel port runs at software level 6 */ -SPLHOLD(spllpt, PIL_LPT) - /* * Memory allocation (must be as high as highest network, tty, or disk device) */ @@ -456,7 +452,6 @@ SPLHOLD(splhigh, PIL_HIGH) #define splbio() splbioX(__FILE__, __LINE__) #define splnet() splnetX(__FILE__, __LINE__) #define spltty() splttyX(__FILE__, __LINE__) -#define spllpt() spllptX(__FILE__, __LINE__) #define splvm() splvmX(__FILE__, __LINE__) #define splclock() splclockX(__FILE__, __LINE__) #define splfd() splfdX(__FILE__, __LINE__)
