ARM: bcm281xx: Add L2 cache enable code

- Adds a module to provide calls into secure monitor mode
- Uses this module to make secure monitor calls to enable L2 cache.

Updates from V1:
- Split DT portion into separate patch
- replace #ifdef-ed L2 code with "if".
- move init call to board init
Signed-off-by: Christian Daudt <csd@broadcom.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/mach-bcm/Makefile

@@ -10,4 +10,6 @@
 # of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 
-obj-$(CONFIG_ARCH_BCM) := board_bcm.o
+obj-$(CONFIG_ARCH_BCM)		:= board_bcm.o bcm_kona_smc.o bcm_kona_smc_asm.o
+plus_sec := $(call as-instr,.arch_extension sec,+sec)
+AFLAGS_bcm_kona_smc_asm.o	:=-Wa,-march=armv7-a$(plus_sec)

arch/arm/mach-bcm/bcm_kona_smc.c

+/*
+ * Copyright (C) 2013 Broadcom Corporation
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <stdarg.h>
+#include <linux/smp.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+
+#include <asm/cacheflush.h>
+#include <linux/of_address.h>
+
+#include "bcm_kona_smc.h"
+
+struct secure_bridge_data {
+	void __iomem *bounce;		/* virtual address */
+	u32 __iomem buffer_addr;	/* physical address */
+	int initialized;
+} bridge_data;
+
+struct bcm_kona_smc_data {
+	unsigned service_id;
+	unsigned arg0;
+	unsigned arg1;
+	unsigned arg2;
+	unsigned arg3;
+};
+
+static const struct of_device_id bcm_kona_smc_ids[] __initconst = {
+	{.compatible = "bcm,kona-smc"},
+	{},
+};
+
+/* Map in the bounce area */
+void bcm_kona_smc_init(void)
+{
+	struct device_node *node;
+
+	/* Read buffer addr and size from the device tree node */
+	node = of_find_matching_node(NULL, bcm_kona_smc_ids);
+	BUG_ON(!node);
+
+	/* Don't care about size or flags of the DT node */
+	bridge_data.buffer_addr =
+		be32_to_cpu(*of_get_address(node, 0, NULL, NULL));
+	BUG_ON(!bridge_data.buffer_addr);
+
+	bridge_data.bounce = of_iomap(node, 0);
+	BUG_ON(!bridge_data.bounce);
+
+	bridge_data.initialized = 1;
+
+	pr_info("Secure API initialized!\n");
+}
+
+/* __bcm_kona_smc() should only run on CPU 0, with pre-emption disabled */
+static void __bcm_kona_smc(void *info)
+{
+	struct bcm_kona_smc_data *data = info;
+	u32 *args = bridge_data.bounce;
+	int rc = 0;
+
+	/* Must run on CPU 0 */
+	BUG_ON(smp_processor_id() != 0);
+
+	/* Check map in the bounce area */
+	BUG_ON(!bridge_data.initialized);
+
+	/* Copy one 32 bit word into the bounce area */
+	args[0] = data->arg0;
+	args[1] = data->arg1;
+	args[2] = data->arg2;
+	args[3] = data->arg3;
+
+	/* Flush caches for input data passed to Secure Monitor */
+	if (data->service_id != SSAPI_BRCM_START_VC_CORE)
+		flush_cache_all();
+
+	/* Trap into Secure Monitor */
+	rc = bcm_kona_smc_asm(data->service_id, bridge_data.buffer_addr);
+
+	if (rc != SEC_ROM_RET_OK)
+		pr_err("Secure Monitor call failed (0x%x)!\n", rc);
+}
+
+unsigned bcm_kona_smc(unsigned service_id, unsigned arg0, unsigned arg1,
+		  unsigned arg2, unsigned arg3)
+{
+	struct bcm_kona_smc_data data;
+
+	data.service_id = service_id;
+	data.arg0 = arg0;
+	data.arg1 = arg1;
+	data.arg2 = arg2;
+	data.arg3 = arg3;
+
+	/*
+	 * Due to a limitation of the secure monitor, we must use the SMP
+	 * infrastructure to forward all secure monitor calls to Core 0.
+	 */
+	if (get_cpu() != 0)
+		smp_call_function_single(0, __bcm_kona_smc, (void *)&data, 1);
+	else
+		__bcm_kona_smc(&data);
+
+	put_cpu();
+
+	return 0;
+}

arch/arm/mach-bcm/bcm_kona_smc.h

+/*
+ * Copyright (C) 2013 Broadcom Corporation
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef BCM_KONA_SMC_H
+#define BCM_KONA_SMC_H
+
+#include <linux/types.h>
+#define FLAGS	(SEC_ROM_ICACHE_ENABLE_MASK | SEC_ROM_DCACHE_ENABLE_MASK | \
+			SEC_ROM_IRQ_ENABLE_MASK | SEC_ROM_FIQ_ENABLE_MASK)
+
+/*!
+ * Definitions for IRQ & FIQ Mask for ARM
+ */
+
+#define FIQ_IRQ_MASK						0xC0
+#define FIQ_MASK						0x40
+#define IRQ_MASK						0x80
+
+/*!
+ * Secure Mode FLAGs
+ */
+
+/* When set, enables ICache within the secure mode */
+#define SEC_ROM_ICACHE_ENABLE_MASK                        0x00000001
+
+/* When set, enables DCache within the secure mode */
+#define SEC_ROM_DCACHE_ENABLE_MASK                        0x00000002
+
+/* When set, enables IRQ within the secure mode */
+#define SEC_ROM_IRQ_ENABLE_MASK                           0x00000004
+
+/* When set, enables FIQ within the secure mode */
+#define SEC_ROM_FIQ_ENABLE_MASK                           0x00000008
+
+/* When set, enables Unified L2 cache within the secure mode */
+#define SEC_ROM_UL2_CACHE_ENABLE_MASK                     0x00000010
+
+/* Broadcom Secure Service API Service IDs */
+#define SSAPI_DORMANT_ENTRY_SERV                          0x01000000
+#define SSAPI_PUBLIC_OTP_SERV                             0x01000001
+#define SSAPI_ENABLE_L2_CACHE                             0x01000002
+#define SSAPI_DISABLE_L2_CACHE                            0x01000003
+#define SSAPI_WRITE_SCU_STATUS                            0x01000004
+#define SSAPI_WRITE_PWR_GATE                              0x01000005
+
+/* Broadcom Secure Service API Return Codes */
+#define SEC_ROM_RET_OK			0x00000001
+#define SEC_ROM_RET_FAIL		0x00000009
+
+#define SSAPI_RET_FROM_INT_SERV		0x4
+#define SEC_EXIT_NORMAL			0x1
+
+#define SSAPI_ROW_AES			0x0E000006
+#define SSAPI_BRCM_START_VC_CORE	0x0E000008
+
+#ifndef	__ASSEMBLY__
+extern void bcm_kona_smc_init(void);
+
+extern unsigned bcm_kona_smc(unsigned service_id,
+			     unsigned arg0,
+			     unsigned arg1,
+			     unsigned arg2,
+			     unsigned arg3);
+
+extern int bcm_kona_smc_asm(u32 service_id,
+			    u32 buffer_addr);
+
+#endif	/* __ASSEMBLY__ */
+
+#endif /* BCM_KONA_SMC_H */

arch/arm/mach-bcm/bcm_kona_smc_asm.S

+/*
+ * Copyright (C) 2013 Broadcom Corporation
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/linkage.h>
+#include "bcm_kona_smc.h"
+
+/*
+ * int bcm_kona_smc_asm(u32 service_id, u32 buffer_addr)
+ */
+
+ENTRY(bcm_kona_smc_asm)
+	stmfd	sp!, {r4-r12, lr}
+	mov	r4, r0		@ service_id
+	mov	r5, #3		@ Keep IRQ and FIQ off in SM
+	/*
+	 * Since interrupts are disabled in the open mode, we must keep
+	 * interrupts disabled in secure mode by setting R5=0x3. If interrupts
+	 * are enabled in open mode, we can set R5=0x0 to allow interrupts in
+	 * secure mode.  If we did this, the secure monitor would return back
+	 * control to the open mode to handle the interrupt prior to completing
+	 * the secure service. If this happened, R12 would not be
+	 * SEC_EXIT_NORMAL and we would need to call SMC again after resetting
+	 * R5 (it gets clobbered by the secure monitor) and setting R4 to
+	 * SSAPI_RET_FROM_INT_SERV to indicate that we want the secure monitor
+	 * to finish up the previous uncompleted secure service.
+	 */
+	mov	r6, r1		@ buffer_addr
+	smc	#0
+	/* Check r12 for SEC_EXIT_NORMAL here if interrupts are enabled */
+	ldmfd	sp!, {r4-r12, pc}
+ENDPROC(bcm_kona_smc_asm)

arch/arm/mach-bcm/board_bcm.c

@@ -19,16 +19,39 @@
 
 #include <asm/mach/arch.h>
 #include <asm/mach/time.h>
+#include <asm/hardware/cache-l2x0.h>
 
 static void timer_init(void)
 {
 }
 
 
+#include "bcm_kona_smc.h"
+
+static int __init kona_l2_cache_init(void)
+{
+	if (!IS_ENABLED(CONFIG_CACHE_L2X0))
+		return 0;
+
+	bcm_kona_smc(SSAPI_ENABLE_L2_CACHE, 0, 0, 0, 0);
+
+	/*
+	 * The aux_val and aux_mask have no effect since L2 cache is already
+	 * enabled.  Pass 0s for aux_val and 1s for aux_mask for default value.
+	 */
+	l2x0_of_init(0, ~0);
+
+	return 0;
+}
+
 static void __init board_init(void)
 {
 	of_platform_populate(NULL, of_default_bus_match_table, NULL,
 		&platform_bus);
+
+	bcm_kona_smc_init();
+
+	kona_l2_cache_init();
 }
 
 static const char * const bcm11351_dt_compat[] = { "bcm,bcm11351", NULL, };