Linux-libre 4.4-gnupck-4.4-gnu

3 files changed, 199 insertions, 31 deletions

diff --git a/arch/arm/mach-uniphier/Makefile b/arch/arm/mach-uniphier/Makefile
index 60bd2265f..1233f9b61 100644
--- a/arch/arm/mach-uniphier/Makefile
+++ b/arch/arm/mach-uniphier/Makefile
@@ -1,2 +1,2 @@
 obj-y			:= uniphier.o
-obj-$(CONFIG_SMP)	+= platsmp.o
+obj-$(CONFIG_SMP)	+= platsmp.o headsmp.o
diff --git a/arch/arm/mach-uniphier/headsmp.S b/arch/arm/mach-uniphier/headsmp.S
new file mode 100644
index 000000000..c819dff84
--- /dev/null
+++ b/arch/arm/mach-uniphier/headsmp.S
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.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.
+ *
+ * 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/linkage.h>
+#include <asm/assembler.h>
+#include <asm/cp15.h>
+
+ENTRY(uniphier_smp_trampoline)
+ARM_BE8(setend	be)			@ ensure we are in BE8 mode
+	mrc	p15, 0, r0, c0, c0, 5	@ MPIDR (Multiprocessor Affinity Reg)
+	and  	r2, r0, #0x3		@ CPU ID
+	ldr	r1, uniphier_smp_trampoline_jump
+	ldr	r3, uniphier_smp_trampoline_poll_addr
+	mrc	p15, 0, r0, c1, c0, 0	@ SCTLR (System Control Register)
+	orr	r0, r0, #CR_I		@ Enable ICache
+	bic	r0, r0, #(CR_C | CR_M)	@ Disable MMU and Dcache
+	mcr	p15, 0, r0, c1, c0, 0
+	b	1f			@ cache the following 5 instructions
+0:	wfe
+1:	ldr	r0, [r3]
+	cmp	r0, r2
+	bxeq	r1			@ branch to secondary_startup
+	b	0b
+	.globl	uniphier_smp_trampoline_jump
+uniphier_smp_trampoline_jump:
+	.word	0			@ set virt_to_phys(secondary_startup)
+	.globl	uniphier_smp_trampoline_poll_addr
+uniphier_smp_trampoline_poll_addr:
+	.word	0			@ set CPU ID to be kicked to this reg
+	.globl	uniphier_smp_trampoline_end
+uniphier_smp_trampoline_end:
+ENDPROC(uniphier_smp_trampoline)
diff --git a/arch/arm/mach-uniphier/platsmp.c b/arch/arm/mach-uniphier/platsmp.c
index 4b784f721..f05776646 100644
--- a/arch/arm/mach-uniphier/platsmp.c
+++ b/arch/arm/mach-uniphier/platsmp.c
@@ -12,73 +12,198 @@
  * GNU General Public License for more details.
  */
 
-#include <linux/sizes.h>
-#include <linux/compiler.h>
+#define pr_fmt(fmt)		"uniphier: " fmt
+
 #include <linux/init.h>
 #include <linux/io.h>
-#include <linux/regmap.h>
-#include <linux/mfd/syscon.h>
+#include <linux/ioport.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/sizes.h>
+#include <asm/cacheflush.h>
+#include <asm/hardware/cache-uniphier.h>
+#include <asm/pgtable.h>
 #include <asm/smp.h>
 #include <asm/smp_scu.h>
 
-static struct regmap *sbcm_regmap;
+/*
+ * The secondary CPUs check this register from the boot ROM for the jump
+ * destination.  After that, it can be reused as a scratch register.
+ */
+#define UNIPHIER_SBC_ROM_BOOT_RSV2	0x1208
 
-static void __init uniphier_smp_prepare_cpus(unsigned int max_cpus)
+static void __iomem *uniphier_smp_rom_boot_rsv2;
+static unsigned int uniphier_smp_max_cpus;
+
+extern char uniphier_smp_trampoline;
+extern char uniphier_smp_trampoline_jump;
+extern char uniphier_smp_trampoline_poll_addr;
+extern char uniphier_smp_trampoline_end;
+
+/*
+ * Copy trampoline code to the tail of the 1st section of the page table used
+ * in the boot ROM.  This area is directly accessible by the secondary CPUs
+ * for all the UniPhier SoCs.
+ */
+static const phys_addr_t uniphier_smp_trampoline_dest_end = SECTION_SIZE;
+static phys_addr_t uniphier_smp_trampoline_dest;
+
+static int __init uniphier_smp_copy_trampoline(phys_addr_t poll_addr)
 {
-	static cpumask_t only_cpu_0 = { CPU_BITS_CPU0 };
-	unsigned long scu_base_phys = 0;
-	void __iomem *scu_base;
+	size_t trmp_size;
+	static void __iomem *trmp_base;
 
-	sbcm_regmap = syscon_regmap_lookup_by_compatible(
-			"socionext,uniphier-system-bus-controller-misc");
-	if (IS_ERR(sbcm_regmap)) {
-		pr_err("failed to regmap system-bus-controller-misc\n");
-		goto err;
+	if (!uniphier_cache_l2_is_enabled()) {
+		pr_warn("outer cache is needed for SMP, but not enabled\n");
+		return -ENODEV;
 	}
 
+	uniphier_cache_l2_set_locked_ways(1);
+
+	outer_flush_all();
+
+	trmp_size = &uniphier_smp_trampoline_end - &uniphier_smp_trampoline;
+	uniphier_smp_trampoline_dest = uniphier_smp_trampoline_dest_end -
+								trmp_size;
+
+	uniphier_cache_l2_touch_range(uniphier_smp_trampoline_dest,
+				      uniphier_smp_trampoline_dest_end);
+
+	trmp_base = ioremap_cache(uniphier_smp_trampoline_dest, trmp_size);
+	if (!trmp_base) {
+		pr_err("failed to map trampoline destination area\n");
+		return -ENOMEM;
+	}
+
+	memcpy(trmp_base, &uniphier_smp_trampoline, trmp_size);
+
+	writel(virt_to_phys(secondary_startup),
+	       trmp_base + (&uniphier_smp_trampoline_jump -
+			    &uniphier_smp_trampoline));
+
+	writel(poll_addr, trmp_base + (&uniphier_smp_trampoline_poll_addr -
+				       &uniphier_smp_trampoline));
+
+	flush_cache_all();	/* flush out trampoline code to outer cache */
+
+	iounmap(trmp_base);
+
+	return 0;
+}
+
+static int __init uniphier_smp_prepare_trampoline(unsigned int max_cpus)
+{
+	struct device_node *np;
+	struct resource res;
+	phys_addr_t rom_rsv2_phys;
+	int ret;
+
+	np = of_find_compatible_node(NULL, NULL,
+				"socionext,uniphier-system-bus-controller");
+	ret = of_address_to_resource(np, 1, &res);
+	if (ret) {
+		pr_err("failed to get resource of system-bus-controller\n");
+		return ret;
+	}
+
+	rom_rsv2_phys = res.start + UNIPHIER_SBC_ROM_BOOT_RSV2;
+
+	ret = uniphier_smp_copy_trampoline(rom_rsv2_phys);
+	if (ret)
+		return ret;
+
+	uniphier_smp_rom_boot_rsv2 = ioremap(rom_rsv2_phys, sizeof(SZ_4));
+	if (!uniphier_smp_rom_boot_rsv2) {
+		pr_err("failed to map ROM_BOOT_RSV2 register\n");
+		return -ENOMEM;
+	}
+
+	writel(uniphier_smp_trampoline_dest, uniphier_smp_rom_boot_rsv2);
+	asm("sev"); /* Bring up all secondary CPUs to the trampoline code */
+
+	uniphier_smp_max_cpus = max_cpus;	/* save for later use */
+
+	return 0;
+}
+
+static void __init uniphier_smp_unprepare_trampoline(void)
+{
+	iounmap(uniphier_smp_rom_boot_rsv2);
+
+	if (uniphier_smp_trampoline_dest)
+		outer_inv_range(uniphier_smp_trampoline_dest,
+				uniphier_smp_trampoline_dest_end);
+
+	uniphier_cache_l2_set_locked_ways(0);
+}
+
+static int __init uniphier_smp_enable_scu(void)
+{
+	unsigned long scu_base_phys = 0;
+	void __iomem *scu_base;
+
 	if (scu_a9_has_base())
 		scu_base_phys = scu_a9_get_base();
 
 	if (!scu_base_phys) {
 		pr_err("failed to get scu base\n");
-		goto err;
+		return -ENODEV;
 	}
 
 	scu_base = ioremap(scu_base_phys, SZ_128);
 	if (!scu_base) {
-		pr_err("failed to remap scu base (0x%08lx)\n", scu_base_phys);
-		goto err;
+		pr_err("failed to map scu base\n");
+		return -ENOMEM;
 	}
 
 	scu_enable(scu_base);
 	iounmap(scu_base);
 
+	return 0;
+}
+
+static void __init uniphier_smp_prepare_cpus(unsigned int max_cpus)
+{
+	static cpumask_t only_cpu_0 = { CPU_BITS_CPU0 };
+	int ret;
+
+	ret = uniphier_smp_prepare_trampoline(max_cpus);
+	if (ret)
+		goto err;
+
+	ret = uniphier_smp_enable_scu();
+	if (ret)
+		goto err;
+
 	return;
 err:
 	pr_warn("disabling SMP\n");
 	init_cpu_present(&only_cpu_0);
-	sbcm_regmap = NULL;
+	uniphier_smp_unprepare_trampoline();
 }
 
-static int uniphier_boot_secondary(unsigned int cpu,
-				   struct task_struct *idle)
+static int __init uniphier_smp_boot_secondary(unsigned int cpu,
+					      struct task_struct *idle)
 {
-	int ret;
+	if (WARN_ON_ONCE(!uniphier_smp_rom_boot_rsv2))
+		return -EFAULT;
 
-	if (!sbcm_regmap)
-		return -ENODEV;
+	writel(cpu, uniphier_smp_rom_boot_rsv2);
+	readl(uniphier_smp_rom_boot_rsv2); /* relax */
 
-	ret = regmap_write(sbcm_regmap, 0x1208,
-			   virt_to_phys(secondary_startup));
-	if (!ret)
-		asm("sev"); /* wake up secondary CPU */
+	asm("sev"); /* wake up secondary CPUs sleeping in the trampoline */
+
+	if (cpu == uniphier_smp_max_cpus - 1) {
+		/* clean up resources if this is the last CPU */
+		uniphier_smp_unprepare_trampoline();
+	}
 
-	return ret;
+	return 0;
 }
 
-struct smp_operations uniphier_smp_ops __initdata = {
+static struct smp_operations uniphier_smp_ops __initdata = {
 	.smp_prepare_cpus	= uniphier_smp_prepare_cpus,
-	.smp_boot_secondary	= uniphier_boot_secondary,
+	.smp_boot_secondary	= uniphier_smp_boot_secondary,
 };
 CPU_METHOD_OF_DECLARE(uniphier_smp, "socionext,uniphier-smp",
 		      &uniphier_smp_ops);