From 527dcdccd60759ee38e6224c93f87a6194d970ad Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 28 Mar 2012 18:30:02 +0100 Subject: Disintegrate asm/system.h for PA-RISC Disintegrate asm/system.h for PA-RISC. Signed-off-by: David Howells cc: linux-parisc@vger.kernel.org --- arch/parisc/include/asm/ldcw.h | 48 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 arch/parisc/include/asm/ldcw.h (limited to 'arch/parisc/include/asm/ldcw.h') diff --git a/arch/parisc/include/asm/ldcw.h b/arch/parisc/include/asm/ldcw.h new file mode 100644 index 000000000000..d2d11b7055ba --- /dev/null +++ b/arch/parisc/include/asm/ldcw.h @@ -0,0 +1,48 @@ +#ifndef __PARISC_LDCW_H +#define __PARISC_LDCW_H + +#ifndef CONFIG_PA20 +/* Because kmalloc only guarantees 8-byte alignment for kmalloc'd data, + and GCC only guarantees 8-byte alignment for stack locals, we can't + be assured of 16-byte alignment for atomic lock data even if we + specify "__attribute ((aligned(16)))" in the type declaration. So, + we use a struct containing an array of four ints for the atomic lock + type and dynamically select the 16-byte aligned int from the array + for the semaphore. */ + +#define __PA_LDCW_ALIGNMENT 16 +#define __ldcw_align(a) ({ \ + unsigned long __ret = (unsigned long) &(a)->lock[0]; \ + __ret = (__ret + __PA_LDCW_ALIGNMENT - 1) \ + & ~(__PA_LDCW_ALIGNMENT - 1); \ + (volatile unsigned int *) __ret; \ +}) +#define __LDCW "ldcw" + +#else /*CONFIG_PA20*/ +/* From: "Jim Hull" + I've attached a summary of the change, but basically, for PA 2.0, as + long as the ",CO" (coherent operation) completer is specified, then the + 16-byte alignment requirement for ldcw and ldcd is relaxed, and instead + they only require "natural" alignment (4-byte for ldcw, 8-byte for + ldcd). */ + +#define __PA_LDCW_ALIGNMENT 4 +#define __ldcw_align(a) (&(a)->slock) +#define __LDCW "ldcw,co" + +#endif /*!CONFIG_PA20*/ + +/* LDCW, the only atomic read-write operation PA-RISC has. *sigh*. */ +#define __ldcw(a) ({ \ + unsigned __ret; \ + __asm__ __volatile__(__LDCW " 0(%2),%0" \ + : "=r" (__ret), "+m" (*(a)) : "r" (a)); \ + __ret; \ +}) + +#ifdef CONFIG_SMP +# define __lock_aligned __attribute__((__section__(".data..lock_aligned"))) +#endif + +#endif /* __PARISC_LDCW_H */ -- cgit v1.2.1