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-rw-r--r--arch/parisc/include/asm/prefetch.h45
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diff --git a/arch/parisc/include/asm/prefetch.h b/arch/parisc/include/asm/prefetch.h
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+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * include/asm-parisc/prefetch.h
+ *
+ * PA 2.0 defines data prefetch instructions on page 6-11 of the Kane book.
+ * In addition, many implementations do hardware prefetching of both
+ * instructions and data.
+ *
+ * PA7300LC (page 14-4 of the ERS) also implements prefetching by a load
+ * to gr0 but not in a way that Linux can use. If the load would cause an
+ * interruption (eg due to prefetching 0), it is suppressed on PA2.0
+ * processors, but not on 7300LC.
+ *
+ */
+
+#ifndef __ASM_PARISC_PREFETCH_H
+#define __ASM_PARISC_PREFETCH_H
+
+#ifndef __ASSEMBLY__
+#ifdef CONFIG_PREFETCH
+
+#define ARCH_HAS_PREFETCH
+static inline void prefetch(const void *addr)
+{
+ __asm__(
+#ifndef CONFIG_PA20
+ /* Need to avoid prefetch of NULL on PA7300LC */
+ " extrw,u,= %0,31,32,%%r0\n"
+#endif
+ " ldw 0(%0), %%r0" : : "r" (addr));
+}
+
+/* LDD is a PA2.0 addition. */
+#ifdef CONFIG_PA20
+#define ARCH_HAS_PREFETCHW
+static inline void prefetchw(const void *addr)
+{
+ __asm__("ldd 0(%0), %%r0" : : "r" (addr));
+}
+#endif /* CONFIG_PA20 */
+
+#endif /* CONFIG_PREFETCH */
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_PARISC_PROCESSOR_H */