1 files changed, 109 insertions, 0 deletions

diff --git a/arch/mips/include/asm/maar.h b/arch/mips/include/asm/maar.h
new file mode 100644
index 000000000000..6c62b0f899c0
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+++ b/arch/mips/include/asm/maar.h
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2014 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#ifndef __MIPS_ASM_MIPS_MAAR_H__
+#define __MIPS_ASM_MIPS_MAAR_H__
+
+#include <asm/hazards.h>
+#include <asm/mipsregs.h>
+
+/**
+ * platform_maar_init() - perform platform-level MAAR configuration
+ * @num_pairs:  The number of MAAR pairs present in the system.
+ *
+ * Platforms should implement this function such that it configures as many
+ * MAAR pairs as required, from 0 up to the maximum of num_pairs-1, and returns
+ * the number that were used. Any further MAARs will be configured to be
+ * invalid. The default implementation of this function will simply indicate
+ * that it has configured 0 MAAR pairs.
+ *
+ * Return:      The number of MAAR pairs configured.
+ */
+unsigned __weak platform_maar_init(unsigned num_pairs);
+
+/**
+ * write_maar_pair() - write to a pair of MAARs
+ * @idx:        The index of the pair (ie. use MAARs idx*2 & (idx*2)+1).
+ * @lower:      The lowest address that the MAAR pair will affect. Must be
+ *              aligned to a 2^16 byte boundary.
+ * @upper:      The highest address that the MAAR pair will affect. Must be
+ *              aligned to one byte before a 2^16 byte boundary.
+ * @attrs:      The accessibility attributes to program, eg. MIPS_MAAR_S. The
+ *              MIPS_MAAR_V attribute will automatically be set.
+ *
+ * Program the pair of MAAR registers specified by idx to apply the attributes
+ * specified by attrs to the range of addresses from lower to higher.
+ */
+static inline void write_maar_pair(unsigned idx, phys_addr_t lower,
+                                   phys_addr_t upper, unsigned attrs)
+{
+        /* Addresses begin at bit 16, but are shifted right 4 bits */
+        BUG_ON(lower & (0xffff | ~(MIPS_MAAR_ADDR << 4)));
+        BUG_ON(((upper & 0xffff) != 0xffff)
+                || ((upper & ~0xffffull) & ~(MIPS_MAAR_ADDR << 4)));
+
+        /* Automatically set MIPS_MAAR_V */
+        attrs |= MIPS_MAAR_V;
+
+        /* Write the upper address & attributes (only MIPS_MAAR_V matters) */
+        write_c0_maari(idx << 1);
+        back_to_back_c0_hazard();
+        write_c0_maar(((upper >> 4) & MIPS_MAAR_ADDR) | attrs);
+        back_to_back_c0_hazard();
+
+        /* Write the lower address & attributes */
+        write_c0_maari((idx << 1) | 0x1);
+        back_to_back_c0_hazard();
+        write_c0_maar((lower >> 4) | attrs);
+        back_to_back_c0_hazard();
+}
+
+/**
+ * struct maar_config - MAAR configuration data
+ * @lower:      The lowest address that the MAAR pair will affect. Must be
+ *              aligned to a 2^16 byte boundary.
+ * @upper:      The highest address that the MAAR pair will affect. Must be
+ *              aligned to one byte before a 2^16 byte boundary.
+ * @attrs:      The accessibility attributes to program, eg. MIPS_MAAR_S. The
+ *              MIPS_MAAR_V attribute will automatically be set.
+ *
+ * Describes the configuration of a pair of Memory Accessibility Attribute
+ * Registers - applying attributes from attrs to the range of physical
+ * addresses from lower to upper inclusive.
+ */
+struct maar_config {
+        phys_addr_t lower;
+        phys_addr_t upper;
+        unsigned attrs;
+};
+
+/**
+ * maar_config() - configure MAARs according to provided data
+ * @cfg:        Pointer to an array of struct maar_config.
+ * @num_cfg:    The number of structs in the cfg array.
+ * @num_pairs:  The number of MAAR pairs present in the system.
+ *
+ * Configures as many MAARs as are present and specified in the cfg
+ * array with the values taken from the cfg array.
+ *
+ * Return:      The number of MAAR pairs configured.
+ */
+static inline unsigned maar_config(const struct maar_config *cfg,
+                                   unsigned num_cfg, unsigned num_pairs)
+{
+        unsigned i;
+
+        for (i = 0; i < min(num_cfg, num_pairs); i++)
+                write_maar_pair(i, cfg[i].lower, cfg[i].upper, cfg[i].attrs);
+
+        return i;
+}
+
+#endif /* __MIPS_ASM_MIPS_MAAR_H__ */