From 464b96bb8094a359f7b27027319eda64a961c5af Mon Sep 17 00:00:00 2001
From: Gregory CLEMENT <gregory.clement@bootlin.com>
Date: Fri, 14 Dec 2018 16:16:46 +0100
Subject: [PATCH] MIPS: Allow to prefetch and lock instructions into cache
This path add a new helper allowing to prefetch and lock instructions
into cache. This is useful very early in the boot when no RAM is
available yet.
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
---
arch/mips/include/asm/cacheops.h | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/arch/mips/include/asm/cacheops.h b/arch/mips/include/asm/cacheops.h
index 3161875441..98b67ccc8e 100644
--- a/arch/mips/include/asm/cacheops.h
+++ b/arch/mips/include/asm/cacheops.h
@@ -19,6 +19,25 @@ static inline void mips_cache(int op, const volatile void *addr)
#endif
}
+#define MIPS32_WHICH_ICACHE 0x0
+#define MIPS32_FETCH_AND_LOCK 0x7
+
+#define ICACHE_LOAD_LOCK (MIPS32_WHICH_ICACHE | (MIPS32_FETCH_AND_LOCK << 2))
+
+/* Prefetch and lock instructions into cache */
+static inline void icache_lock(void *func, size_t len)
+{
+ int i, lines = ((len - 1) / ARCH_DMA_MINALIGN) + 1;
+
+ for (i = 0; i < lines; i++) {
+ asm volatile (" cache %0, %1(%2)"
+ : /* No Output */
+ : "I" ICACHE_LOAD_LOCK,
+ "n" (i * ARCH_DMA_MINALIGN),
+ "r" (func)
+ : /* No Clobbers */);
+ }
+}
#endif /* !__ASSEMBLY__ */
/*
--
2.39.5