ARM: tegra: rework Tegra secondary CPU core bringup

Prepare the Tegra secondary CPU core bringup code for other Tegra variants.
The reset handler is also generalized to allow for future introduction of
powersaving modes which turn off the CPU cores.

Based on work by:

Scott Williams <scwilliams@nvidia.com>
Chris Johnson <cwj@nvidia.com>
Colin Cross <ccross@android.com>

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

1 files changed, 84 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c
new file mode 100644
index 000000000000..4d6a2ee99c3b
--- /dev/null
+++ b/arch/arm/mach-tegra/reset.c
@@ -0,0 +1,84 @@
+/*
+ * arch/arm/mach-tegra/reset.c
+ *
+ * Copyright (C) 2011,2012 NVIDIA Corporation.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/cpumask.h>
+#include <linux/bitops.h>
+
+#include <asm/cacheflush.h>
+#include <asm/hardware/cache-l2x0.h>
+
+#include <mach/iomap.h>
+#include <mach/irammap.h>
+
+#include "reset.h"
+#include "fuse.h"
+
+#define TEGRA_IRAM_RESET_BASE (TEGRA_IRAM_BASE + \
+                                TEGRA_IRAM_RESET_HANDLER_OFFSET)
+
+static bool is_enabled;
+
+static void tegra_cpu_reset_handler_enable(void)
+{
+        void __iomem *iram_base = IO_ADDRESS(TEGRA_IRAM_RESET_BASE);
+        void __iomem *evp_cpu_reset =
+                IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE + 0x100);
+        void __iomem *sb_ctrl = IO_ADDRESS(TEGRA_SB_BASE);
+        u32 reg;
+
+        BUG_ON(is_enabled);
+        BUG_ON(tegra_cpu_reset_handler_size > TEGRA_IRAM_RESET_HANDLER_SIZE);
+
+        memcpy(iram_base, (void *)__tegra_cpu_reset_handler_start,
+                        tegra_cpu_reset_handler_size);
+
+        /*
+         * NOTE: This must be the one and only write to the EVP CPU reset
+         *       vector in the entire system.
+         */
+        writel(TEGRA_IRAM_RESET_BASE + tegra_cpu_reset_handler_offset,
+                        evp_cpu_reset);
+        wmb();
+        reg = readl(evp_cpu_reset);
+
+        /*
+         * Prevent further modifications to the physical reset vector.
+         *  NOTE: Has no effect on chips prior to Tegra30.
+         */
+        if (tegra_chip_id != TEGRA20) {
+                reg = readl(sb_ctrl);
+                reg |= 2;
+                writel(reg, sb_ctrl);
+                wmb();
+        }
+
+        is_enabled = true;
+}
+
+void __init tegra_cpu_reset_handler_init(void)
+{
+
+#ifdef CONFIG_SMP
+        __tegra_cpu_reset_handler_data[TEGRA_RESET_MASK_PRESENT] =
+                *((u32 *)cpu_present_mask);
+        __tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_SECONDARY] =
+                virt_to_phys((void *)tegra_secondary_startup);
+#endif
+
+        tegra_cpu_reset_handler_enable();
+}