ARM: Generalize armv7 as arm.

There are ARM systems which are essentially heterogeneous multicores where
some cores implement a different ARM architecture version than other cores. A
specific example is the tegra124 which boots on an ARMv4 coprocessor while
most code, including most of the firmware, runs on the main ARMv7 core. To
support SOCs like this, the plan is to generalize the ARM architecture so that
all versions are available, and an SOC/CPU can then select what architecture
variant should be used for each component of the firmware; bootblock,
romstage, and ramstage.

Old-Change-Id: I22e048c3bc72bd56371e14200942e436c1e312c2
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://chromium-review.googlesource.com/171338
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit 8423a41529da0ff67fb9873be1e2beb30b09ae2d)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>

ARM: Split out ARMv7 code and make it possible to have other arch versions.

We don't always want to use ARMv7 code when building for ARM, so we should
separate out the ARMv7 code so it can be excluded, and also make it possible
to include code for some other version of the architecture instead, all per
build component for cases where we need more than one architecture version
at a time.

The tegra124 bootblock will ultimately need to be ARMv4, but until we have
some ARMv4 code to switch over to we can leave it set to ARMv7.

Old-Change-Id: Ia982c91057fac9c252397b7c866224f103761cc7
Reviewed-on: https://chromium-review.googlesource.com/171400
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit 799514e6060aa97acdcf081b5c48f965be134483)

Squashed two related patches for splitting ARM support into general
ARM support and ARMv7 specific pieces.

Change-Id: Ic6511507953a2223c87c55f90252c4a4e1dd6010
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6782
Tested-by: build bot (Jenkins)

1 files changed, 328 insertions, 0 deletions

diff --git a/src/arch/arm/armv7/cache.c b/src/arch/arm/armv7/cache.c
new file mode 100644
index 0000000000..acd1f9aefa
--- /dev/null
+++ b/src/arch/arm/armv7/cache.c
@@ -0,0 +1,328 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2013 Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * cache.c: Cache maintenance routines for ARMv7-A and ARMv7-R
+ *
+ * Reference: ARM Architecture Reference Manual, ARMv7-A and ARMv7-R edition
+ */
+
+#include <stdint.h>
+
+#include <arch/cache.h>
+
+#define bitmask(high, low) ((1UL << (high)) + \
+			((1UL << (high)) - 1) - ((1UL << (low)) - 1))
+
+/* Basic log2() implementation. Note: log2(0) is 0 for our purposes. */
+/* FIXME: src/include/lib.h is difficult to work with due to romcc */
+static unsigned long log2(unsigned long u)
+{
+	int i = 0;
+
+	while (u >>= 1)
+		i++;
+
+	return i;
+}
+
+void tlb_invalidate_all(void)
+{
+	/*
+	 * FIXME: ARMv7 Architecture Ref. Manual claims that the distinction
+	 * instruction vs. data TLBs is deprecated in ARMv7, however this does
+	 * not seem to be the case as of Cortex-A15.
+	 */
+	tlbiall();
+	dtlbiall();
+	itlbiall();
+	isb();
+	dsb();
+}
+
+void icache_invalidate_all(void)
+{
+	/*
+	 * icache can be entirely invalidated with one operation.
+	 * Note: If branch predictors are architecturally-visible, ICIALLU
+	 * also performs a BPIALL operation (B2-1283 in arch manual)
+	 */
+	iciallu();
+	isb();
+}
+
+enum dcache_op {
+	OP_DCCSW,
+	OP_DCCISW,
+	OP_DCISW,
+	OP_DCCIMVAC,
+	OP_DCCMVAC,
+	OP_DCIMVAC,
+};
+
+/*
+ * Do a dcache operation on entire cache by set/way. This is done for
+ * portability because mapping of memory address to cache location is
+ * implementation defined (See note on "Requirements for operations by
+ * set/way" in arch ref. manual).
+ */
+static void dcache_op_set_way(enum dcache_op op)
+{
+	uint32_t ccsidr;
+	unsigned int associativity, num_sets, linesize_bytes;
+	unsigned int set, way;
+	unsigned int level;
+
+	level = (read_csselr() >> 1) & 0x7;
+
+	/*
+	 * dcache must be invalidated by set/way for portability since virtual
+	 * memory mapping is system-defined. The number of sets and
+	 * associativity is given by CCSIDR. We'll use DCISW to invalidate the
+	 * dcache.
+	 */
+	ccsidr = read_ccsidr();
+
+	/* FIXME: rounding up required here? */
+	num_sets = ((ccsidr & bitmask(27, 13)) >> 13) + 1;
+	associativity = ((ccsidr & bitmask(12, 3)) >> 3) + 1;
+	/* FIXME: do we need to use CTR.DminLine here? */
+	linesize_bytes = (1 << ((ccsidr & 0x7) + 2)) * 4;
+
+	dsb();
+
+	/*
+	 * Set/way operations require an interesting bit packing. See section
+	 * B4-35 in the ARMv7 Architecture Reference Manual:
+	 *
+	 * A: Log2(associativity)
+	 * B: L+S
+	 * L: Log2(linesize)
+	 * S: Log2(num_sets)
+	 *
+	 * The bits are packed as follows:
+	 *  31  31-A        B B-1    L L-1   4 3   1 0
+	 * |---|-------------|--------|-------|-----|-|
+	 * |Way|    zeros    |   Set  | zeros |level|0|
+	 * |---|-------------|--------|-------|-----|-|
+	 */
+	for (way = 0; way < associativity; way++) {
+		for (set = 0; set < num_sets; set++) {
+			uint32_t val = 0;
+			val |= way << (32 - log2(associativity));
+			val |= set << log2(linesize_bytes);
+			val |= level << 1;
+			switch(op) {
+			case OP_DCCISW:
+				dccisw(val);
+				break;
+			case OP_DCISW:
+				dcisw(val);
+				break;
+			case OP_DCCSW:
+				dccsw(val);
+				break;
+			default:
+				break;
+			}
+		}
+	}
+	isb();
+}
+
+static void dcache_foreach(enum dcache_op op)
+{
+	uint32_t clidr;
+	int level;
+
+	clidr = read_clidr();
+	for (level = 0; level < 7; level++) {
+		unsigned int ctype = (clidr >> (level * 3)) & 0x7;
+		uint32_t csselr;
+
+		switch(ctype) {
+		case 0x2:
+		case 0x3:
+		case 0x4:
+			csselr = level << 1;
+			write_csselr(csselr);
+			dcache_op_set_way(op);
+			break;
+		default:
+			/* no cache, icache only, or reserved */
+			break;
+		}
+	}
+}
+
+void dcache_clean_all(void)
+{
+	dcache_foreach(OP_DCCSW);
+}
+
+void dcache_clean_invalidate_all(void)
+{
+	dcache_foreach(OP_DCCISW);
+}
+
+void dcache_invalidate_all(void)
+{
+	dcache_foreach(OP_DCISW);
+}
+
+static unsigned int line_bytes(void)
+{
+	uint32_t ccsidr;
+	unsigned int size;
+
+	ccsidr = read_ccsidr();
+	/* [2:0] - Indicates (Log2(number of words in cache line)) - 2 */
+	size = 1 << ((ccsidr & 0x7) + 2);	/* words per line */
+	size *= sizeof(unsigned int);		/* bytes per line */
+
+	return size;
+}
+
+/*
+ * Do a dcache operation by modified virtual address. This is useful for
+ * maintaining coherency in drivers which do DMA transfers and only need to
+ * perform cache maintenance on a particular memory range rather than the
+ * entire cache.
+ */
+static void dcache_op_mva(void const *addr, size_t len, enum dcache_op op)
+{
+	unsigned long line, linesize;
+
+	linesize = line_bytes();
+	line = (uint32_t)addr & ~(linesize - 1);
+
+	dsb();
+	while ((void *)line < addr + len) {
+		switch(op) {
+		case OP_DCCIMVAC:
+			dccimvac(line);
+			break;
+		case OP_DCCMVAC:
+			dccmvac(line);
+			break;
+		case OP_DCIMVAC:
+			dcimvac(line);
+			break;
+		default:
+			break;
+		}
+		line += linesize;
+	}
+	isb();
+}
+
+void dcache_clean_by_mva(void const *addr, size_t len)
+{
+	dcache_op_mva(addr, len, OP_DCCMVAC);
+}
+
+void dcache_clean_invalidate_by_mva(void const *addr, size_t len)
+{
+	dcache_op_mva(addr, len, OP_DCCIMVAC);
+}
+
+void dcache_invalidate_by_mva(void const *addr, size_t len)
+{
+	dcache_op_mva(addr, len, OP_DCIMVAC);
+}
+
+void dcache_mmu_disable(void)
+{
+	uint32_t sctlr;
+
+	dcache_clean_invalidate_all();
+	sctlr = read_sctlr();
+	sctlr &= ~(SCTLR_C | SCTLR_M);
+	write_sctlr(sctlr);
+}
+
+
+void dcache_mmu_enable(void)
+{
+	uint32_t sctlr;
+
+	sctlr = read_sctlr();
+	dcache_clean_invalidate_all();
+	sctlr |= SCTLR_C | SCTLR_M;
+	write_sctlr(sctlr);
+}
+
+void arm_invalidate_caches(void)
+{
+	uint32_t clidr;
+	int level;
+
+	/* Invalidate branch predictor */
+	bpiall();
+
+	/* Iterate thru each cache identified in CLIDR and invalidate */
+	clidr = read_clidr();
+	for (level = 0; level < 7; level++) {
+		unsigned int ctype = (clidr >> (level * 3)) & 0x7;
+		uint32_t csselr;
+
+		switch(ctype) {
+		case 0x0:
+			/* no cache */
+			break;
+		case 0x1:
+			/* icache only */
+			csselr = (level << 1) | 1;
+			write_csselr(csselr);
+			icache_invalidate_all();
+			break;
+		case 0x2:
+		case 0x4:
+			/* dcache only or unified cache */
+			csselr = level << 1;
+			write_csselr(csselr);
+			dcache_invalidate_all();
+			break;
+		case 0x3:
+			/* separate icache and dcache */
+			csselr = (level << 1) | 1;
+			write_csselr(csselr);
+			icache_invalidate_all();
+
+			csselr = level << 1;
+			write_csselr(csselr);
+			dcache_invalidate_all();
+			break;
+		default:
+			/* reserved */
+			break;
+		}
+	}
+
+	/* Invalidate TLB */
+	tlb_invalidate_all();
+}