armv7: cache maintenance operations for armv7

- Add a framework for layered cache maintenance
	- separate out SOC specific outer cache maintenance from
	  maintenance of caches known to CPU

- Add generic ARMv7 cache maintenance operations that affect all
  caches known to ARMv7 CPUs. For instance in Cortex-A8 these
  opertions will affect both L1 and L2 caches. In Cortex-A9
  these will affect only L1 cache

- D-cache operations supported:
	- Invalidate entire D-cache
	- Invalidate D-cache range
	- Flush(clean & invalidate) entire D-cache
	- Flush D-cache range
- I-cache operations supported:
	- Invalidate entire I-cache

- Add maintenance functions for TLB, branch predictor array etc.

- Enable -march=armv7-a so that armv7 assembly instructions can be
  used

Signed-off-by: Aneesh V <aneesh@ti.com>

4 files changed, 518 insertions, 1 deletions

diff --git a/arch/arm/cpu/armv7/Makefile b/arch/arm/cpu/armv7/Makefile
index 8c0e915..299792a 100644
--- a/arch/arm/cpu/armv7/Makefile
+++ b/arch/arm/cpu/armv7/Makefile
@@ -26,7 +26,7 @@ include $(TOPDIR)/config.mk
 LIB	= $(obj)lib$(CPU).o
 
 START	:= start.o
-COBJS	:= cpu.o
+COBJS	:= cpu.o cache_v7.o
 COBJS  += syslib.o
 
 SRCS	:= $(START:.o=.S) $(COBJS:.o=.c)
diff --git a/arch/arm/cpu/armv7/cache_v7.c b/arch/arm/cpu/armv7/cache_v7.c
new file mode 100644
index 0000000..3e1e1bf
--- /dev/null
+++ b/arch/arm/cpu/armv7/cache_v7.c
@@ -0,0 +1,394 @@
+/*
+ * (C) Copyright 2010
+ * Texas Instruments, <www.ti.com>
+ * Aneesh V <aneesh@ti.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+#include <linux/types.h>
+#include <common.h>
+#include <asm/armv7.h>
+#include <asm/utils.h>
+
+#define ARMV7_DCACHE_INVAL_ALL		1
+#define ARMV7_DCACHE_CLEAN_INVAL_ALL	2
+#define ARMV7_DCACHE_INVAL_RANGE	3
+#define ARMV7_DCACHE_CLEAN_INVAL_RANGE	4
+
+#ifndef CONFIG_SYS_DCACHE_OFF
+/*
+ * Write the level and type you want to Cache Size Selection Register(CSSELR)
+ * to get size details from Current Cache Size ID Register(CCSIDR)
+ */
+static void set_csselr(u32 level, u32 type)
+{	u32 csselr = level << 1 | type;
+
+	/* Write to Cache Size Selection Register(CSSELR) */
+	asm volatile ("mcr p15, 2, %0, c0, c0, 0" : : "r" (csselr));
+}
+
+static u32 get_ccsidr(void)
+{
+	u32 ccsidr;
+
+	/* Read current CP15 Cache Size ID Register */
+	asm volatile ("mrc p15, 1, %0, c0, c0, 0" : "=r" (ccsidr));
+	return ccsidr;
+}
+
+static u32 get_clidr(void)
+{
+	u32 clidr;
+
+	/* Read current CP15 Cache Level ID Register */
+	asm volatile ("mrc p15,1,%0,c0,c0,1" : "=r" (clidr));
+	return clidr;
+}
+
+static void v7_inval_dcache_level_setway(u32 level, u32 num_sets,
+					 u32 num_ways, u32 way_shift,
+					 u32 log2_line_len)
+{
+	int way, set, setway;
+
+	/*
+	 * For optimal assembly code:
+	 *	a. count down
+	 *	b. have bigger loop inside
+	 */
+	for (way = num_ways - 1; way >= 0 ; way--) {
+		for (set = num_sets - 1; set >= 0; set--) {
+			setway = (level << 1) | (set << log2_line_len) |
+				 (way << way_shift);
+			/* Invalidate data/unified cache line by set/way */
+			asm volatile ("	mcr p15, 0, %0, c7, c6, 2"
+					: : "r" (setway));
+		}
+	}
+	/* DMB to make sure the operation is complete */
+	CP15DMB;
+}
+
+static void v7_clean_inval_dcache_level_setway(u32 level, u32 num_sets,
+					       u32 num_ways, u32 way_shift,
+					       u32 log2_line_len)
+{
+	int way, set, setway;
+
+	/*
+	 * For optimal assembly code:
+	 *	a. count down
+	 *	b. have bigger loop inside
+	 */
+	for (way = num_ways - 1; way >= 0 ; way--) {
+		for (set = num_sets - 1; set >= 0; set--) {
+			setway = (level << 1) | (set << log2_line_len) |
+				 (way << way_shift);
+			/*
+			 * Clean & Invalidate data/unified
+			 * cache line by set/way
+			 */
+			asm volatile ("	mcr p15, 0, %0, c7, c14, 2"
+					: : "r" (setway));
+		}
+	}
+	/* DMB to make sure the operation is complete */
+	CP15DMB;
+}
+
+static void v7_maint_dcache_level_setway(u32 level, u32 operation)
+{
+	u32 ccsidr;
+	u32 num_sets, num_ways, log2_line_len, log2_num_ways;
+	u32 way_shift;
+
+	set_csselr(level, ARMV7_CSSELR_IND_DATA_UNIFIED);
+
+	ccsidr = get_ccsidr();
+
+	log2_line_len = ((ccsidr & CCSIDR_LINE_SIZE_MASK) >>
+				CCSIDR_LINE_SIZE_OFFSET) + 2;
+	/* Converting from words to bytes */
+	log2_line_len += 2;
+
+	num_ways  = ((ccsidr & CCSIDR_ASSOCIATIVITY_MASK) >>
+			CCSIDR_ASSOCIATIVITY_OFFSET) + 1;
+	num_sets  = ((ccsidr & CCSIDR_NUM_SETS_MASK) >>
+			CCSIDR_NUM_SETS_OFFSET) + 1;
+	/*
+	 * According to ARMv7 ARM number of sets and number of ways need
+	 * not be a power of 2
+	 */
+	log2_num_ways = log_2_n_round_up(num_ways);
+
+	way_shift = (32 - log2_num_ways);
+	if (operation == ARMV7_DCACHE_INVAL_ALL) {
+		v7_inval_dcache_level_setway(level, num_sets, num_ways,
+				      way_shift, log2_line_len);
+	} else if (operation == ARMV7_DCACHE_CLEAN_INVAL_ALL) {
+		v7_clean_inval_dcache_level_setway(level, num_sets, num_ways,
+						   way_shift, log2_line_len);
+	}
+}
+
+static void v7_maint_dcache_all(u32 operation)
+{
+	u32 level, cache_type, level_start_bit = 0;
+
+	u32 clidr = get_clidr();
+
+	for (level = 0; level < 7; level++) {
+		cache_type = (clidr >> level_start_bit) & 0x7;
+		if ((cache_type == ARMV7_CLIDR_CTYPE_DATA_ONLY) ||
+		    (cache_type == ARMV7_CLIDR_CTYPE_INSTRUCTION_DATA) ||
+		    (cache_type == ARMV7_CLIDR_CTYPE_UNIFIED))
+			v7_maint_dcache_level_setway(level, operation);
+		level_start_bit += 3;
+	}
+}
+
+static void v7_dcache_clean_inval_range(u32 start,
+					u32 stop, u32 line_len)
+{
+	u32 mva;
+
+	/* Align start to cache line boundary */
+	start &= ~(line_len - 1);
+	for (mva = start; mva < stop; mva = mva + line_len) {
+		/* DCCIMVAC - Clean & Invalidate data cache by MVA to PoC */
+		asm volatile ("mcr p15, 0, %0, c7, c14, 1" : : "r" (mva));
+	}
+}
+
+static void v7_dcache_inval_range(u32 start, u32 stop, u32 line_len)
+{
+	u32 mva;
+
+	/*
+	 * If start address is not aligned to cache-line flush the first
+	 * line to prevent affecting somebody else's buffer
+	 */
+	if (start & (line_len - 1)) {
+		v7_dcache_clean_inval_range(start, start + 1, line_len);
+		/* move to next cache line */
+		start = (start + line_len - 1) & ~(line_len - 1);
+	}
+
+	/*
+	 * If stop address is not aligned to cache-line flush the last
+	 * line to prevent affecting somebody else's buffer
+	 */
+	if (stop & (line_len - 1)) {
+		v7_dcache_clean_inval_range(stop, stop + 1, line_len);
+		/* align to the beginning of this cache line */
+		stop &= ~(line_len - 1);
+	}
+
+	for (mva = start; mva < stop; mva = mva + line_len) {
+		/* DCIMVAC - Invalidate data cache by MVA to PoC */
+		asm volatile ("mcr p15, 0, %0, c7, c6, 1" : : "r" (mva));
+	}
+}
+
+static void v7_dcache_maint_range(u32 start, u32 stop, u32 range_op)
+{
+	u32 line_len, ccsidr;
+
+	ccsidr = get_ccsidr();
+	line_len = ((ccsidr & CCSIDR_LINE_SIZE_MASK) >>
+			CCSIDR_LINE_SIZE_OFFSET) + 2;
+	/* Converting from words to bytes */
+	line_len += 2;
+	/* converting from log2(linelen) to linelen */
+	line_len = 1 << line_len;
+
+	switch (range_op) {
+	case ARMV7_DCACHE_CLEAN_INVAL_RANGE:
+		v7_dcache_clean_inval_range(start, stop, line_len);
+		break;
+	case ARMV7_DCACHE_INVAL_RANGE:
+		v7_dcache_inval_range(start, stop, line_len);
+		break;
+	}
+
+	/* DMB to make sure the operation is complete */
+	CP15DMB;
+}
+
+/* Invalidate TLB */
+static void v7_inval_tlb(void)
+{
+	/* Invalidate entire unified TLB */
+	asm volatile ("mcr p15, 0, %0, c8, c7, 0" : : "r" (0));
+	/* Invalidate entire data TLB */
+	asm volatile ("mcr p15, 0, %0, c8, c6, 0" : : "r" (0));
+	/* Invalidate entire instruction TLB */
+	asm volatile ("mcr p15, 0, %0, c8, c5, 0" : : "r" (0));
+	/* Full system DSB - make sure that the invalidation is complete */
+	CP15DSB;
+	/* Full system ISB - make sure the instruction stream sees it */
+	CP15ISB;
+}
+
+void invalidate_dcache_all(void)
+{
+	v7_maint_dcache_all(ARMV7_DCACHE_INVAL_ALL);
+
+	v7_outer_cache_inval_all();
+}
+
+/*
+ * Performs a clean & invalidation of the entire data cache
+ * at all levels
+ */
+void flush_dcache_all(void)
+{
+	v7_maint_dcache_all(ARMV7_DCACHE_CLEAN_INVAL_ALL);
+
+	v7_outer_cache_flush_all();
+}
+
+/*
+ * Invalidates range in all levels of D-cache/unified cache used:
+ * Affects the range [start, stop - 1]
+ */
+void invalidate_dcache_range(unsigned long start, unsigned long stop)
+{
+
+	v7_dcache_maint_range(start, stop, ARMV7_DCACHE_INVAL_RANGE);
+
+	v7_outer_cache_inval_range(start, stop);
+}
+
+/*
+ * Flush range(clean & invalidate) from all levels of D-cache/unified
+ * cache used:
+ * Affects the range [start, stop - 1]
+ */
+void flush_dcache_range(unsigned long start, unsigned long stop)
+{
+	v7_dcache_maint_range(start, stop, ARMV7_DCACHE_CLEAN_INVAL_RANGE);
+
+	v7_outer_cache_flush_range(start, stop);
+}
+
+void arm_init_before_mmu(void)
+{
+	v7_outer_cache_enable();
+	invalidate_dcache_all();
+	v7_inval_tlb();
+}
+
+/*
+ * Flush range from all levels of d-cache/unified-cache used:
+ * Affects the range [start, start + size - 1]
+ */
+void  flush_cache(unsigned long start, unsigned long size)
+{
+	flush_dcache_range(start, start + size);
+}
+#else /* #ifndef CONFIG_SYS_DCACHE_OFF */
+void invalidate_dcache_all(void)
+{
+}
+
+void flush_dcache_all(void)
+{
+}
+
+void invalidate_dcache_range(unsigned long start, unsigned long stop)
+{
+}
+
+void flush_dcache_range(unsigned long start, unsigned long stop)
+{
+}
+
+void arm_init_before_mmu(void)
+{
+}
+
+void  flush_cache(unsigned long start, unsigned long size)
+{
+}
+#endif /* #ifndef CONFIG_SYS_DCACHE_OFF */
+
+#ifndef CONFIG_SYS_ICACHE_OFF
+/* Invalidate entire I-cache and branch predictor array */
+void invalidate_icache_all(void)
+{
+	/*
+	 * Invalidate all instruction caches to PoU.
+	 * Also flushes branch target cache.
+	 */
+	asm volatile ("mcr p15, 0, %0, c7, c5, 0" : : "r" (0));
+
+	/* Invalidate entire branch predictor array */
+	asm volatile ("mcr p15, 0, %0, c7, c5, 6" : : "r" (0));
+
+	/* Full system DSB - make sure that the invalidation is complete */
+	CP15DSB;
+
+	/* ISB - make sure the instruction stream sees it */
+	CP15ISB;
+}
+#else
+void invalidate_icache_all(void)
+{
+}
+#endif
+
+/*
+ * Stub implementations for outer cache operations
+ */
+void __v7_outer_cache_enable(void)
+{
+}
+void v7_outer_cache_enable(void)
+	__attribute__((weak, alias("__v7_outer_cache_enable")));
+
+void __v7_outer_cache_disable(void)
+{
+}
+void v7_outer_cache_disable(void)
+	__attribute__((weak, alias("__v7_outer_cache_disable")));
+
+void __v7_outer_cache_flush_all(void)
+{
+}
+void v7_outer_cache_flush_all(void)
+	__attribute__((weak, alias("__v7_outer_cache_flush_all")));
+
+void __v7_outer_cache_inval_all(void)
+{
+}
+void v7_outer_cache_inval_all(void)
+	__attribute__((weak, alias("__v7_outer_cache_inval_all")));
+
+void __v7_outer_cache_flush_range(u32 start, u32 end)
+{
+}
+void v7_outer_cache_flush_range(u32 start, u32 end)
+	__attribute__((weak, alias("__v7_outer_cache_flush_range")));
+
+void __v7_outer_cache_inval_range(u32 start, u32 end)
+{
+}
+void v7_outer_cache_inval_range(u32 start, u32 end)
+	__attribute__((weak, alias("__v7_outer_cache_inval_range")));
diff --git a/arch/arm/include/asm/armv7.h b/arch/arm/include/asm/armv7.h
new file mode 100644
index 0000000..88b9c62
--- /dev/null
+++ b/arch/arm/include/asm/armv7.h
@@ -0,0 +1,67 @@
+/*
+ * (C) Copyright 2010
+ * Texas Instruments, <www.ti.com>
+ * Aneesh V <aneesh@ti.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+#ifndef ARMV7_H
+#define ARMV7_H
+#include <linux/types.h>
+
+/* CCSIDR */
+#define CCSIDR_LINE_SIZE_OFFSET		0
+#define CCSIDR_LINE_SIZE_MASK		0x7
+#define CCSIDR_ASSOCIATIVITY_OFFSET	3
+#define CCSIDR_ASSOCIATIVITY_MASK	(0x3FF << 3)
+#define CCSIDR_NUM_SETS_OFFSET		13
+#define CCSIDR_NUM_SETS_MASK		(0x7FFF << 13)
+
+/*
+ * Values for InD field in CSSELR
+ * Selects the type of cache
+ */
+#define ARMV7_CSSELR_IND_DATA_UNIFIED	0
+#define ARMV7_CSSELR_IND_INSTRUCTION	1
+
+/* Values for Ctype fields in CLIDR */
+#define ARMV7_CLIDR_CTYPE_NO_CACHE		0
+#define ARMV7_CLIDR_CTYPE_INSTRUCTION_ONLY	1
+#define ARMV7_CLIDR_CTYPE_DATA_ONLY		2
+#define ARMV7_CLIDR_CTYPE_INSTRUCTION_DATA	3
+#define ARMV7_CLIDR_CTYPE_UNIFIED		4
+
+/*
+ * CP15 Barrier instructions
+ * Please note that we have separate barrier instructions in ARMv7
+ * However, we use the CP15 based instructtions because we use
+ * -march=armv5 in U-Boot
+ */
+#define CP15ISB	asm volatile ("mcr     p15, 0, %0, c7, c5, 4" : : "r" (0))
+#define CP15DSB	asm volatile ("mcr     p15, 0, %0, c7, c10, 4" : : "r" (0))
+#define CP15DMB	asm volatile ("mcr     p15, 0, %0, c7, c10, 5" : : "r" (0))
+
+void v7_outer_cache_enable(void);
+void v7_outer_cache_disable(void);
+void v7_outer_cache_flush_all(void);
+void v7_outer_cache_inval_all(void);
+void v7_outer_cache_flush_range(u32 start, u32 end);
+void v7_outer_cache_inval_range(u32 start, u32 end);
+
+#endif
diff --git a/arch/arm/include/asm/utils.h b/arch/arm/include/asm/utils.h
new file mode 100644
index 0000000..828b86c
--- /dev/null
+++ b/arch/arm/include/asm/utils.h
@@ -0,0 +1,56 @@
+/*
+ * (C) Copyright 2010
+ * Texas Instruments, <www.ti.com>
+ * Aneesh V <aneesh@ti.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+#ifndef _UTILS_H_
+#define _UTILS_H_
+
+static inline s32 log_2_n_round_up(u32 n)
+{
+	s32 log2n = -1;
+	u32 temp = n;
+
+	while (temp) {
+		log2n++;
+		temp >>= 1;
+	}
+
+	if (n & (n - 1))
+		return log2n + 1; /* not power of 2 - round up */
+	else
+		return log2n; /* power of 2 */
+}
+
+static inline s32 log_2_n_round_down(u32 n)
+{
+	s32 log2n = -1;
+	u32 temp = n;
+
+	while (temp) {
+		log2n++;
+		temp >>= 1;
+	}
+
+	return log2n;
+}
+
+#endif