Disintegrate asm/system.h for PA-RISC
Disintegrate asm/system.h for PA-RISC.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-parisc@vger.kernel.org
diff --git a/arch/parisc/include/asm/ldcw.h b/arch/parisc/include/asm/ldcw.h
new file mode 100644
index 0000000..d2d11b7
--- /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" <jim.hull of hp.com>
+ 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 */