MIPS: add support for SGI Octane (IP30)

This changeset adds support for SGI Octane/Octane2 workstations.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

1 files changed, 138 insertions, 0 deletions

diff --git a/arch/mips/sgi-ip30/ip30-setup.c b/arch/mips/sgi-ip30/ip30-setup.c
new file mode 100644
index 000000000000..44b1607e964d
--- /dev/null
+++ b/arch/mips/sgi-ip30/ip30-setup.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SGI IP30 miscellaneous setup bits.
+ *
+ * Copyright (C) 2004-2007 Stanislaw Skowronek <skylark@unaligned.org>
+ *               2007 Joshua Kinard <kumba@gentoo.org>
+ *               2009 Johannes Dickgreber <tanzy@gmx.de>
+ */
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/percpu.h>
+#include <linux/memblock.h>
+
+#include <asm/smp-ops.h>
+#include <asm/sgialib.h>
+#include <asm/time.h>
+#include <asm/sgi/heart.h>
+
+#include "ip30-common.h"
+
+/* Structure of accessible HEART registers located in XKPHYS space. */
+struct ip30_heart_regs __iomem *heart_regs = HEART_XKPHYS_BASE;
+
+/*
+ * ARCS will report up to the first 1GB of
+ * memory if queried.  Anything beyond that
+ * is marked as reserved.
+ */
+#define IP30_MAX_PROM_MEMORY	_AC(0x40000000, UL)
+
+/*
+ * Memory in the Octane starts at 512MB
+ */
+#define IP30_MEMORY_BASE	_AC(0x20000000, UL)
+
+/*
+ * If using ARCS to probe for memory, then
+ * remaining memory will start at this offset.
+ */
+#define IP30_REAL_MEMORY_START  (IP30_MEMORY_BASE + IP30_MAX_PROM_MEMORY)
+
+#define MEM_SHIFT(x) ((x) >> 20)
+
+static void __init ip30_mem_init(void)
+{
+	unsigned long total_mem;
+	phys_addr_t addr;
+	phys_addr_t size;
+	u32 memcfg;
+	int i;
+
+	total_mem = 0;
+	for (i = 0; i < HEART_MEMORY_BANKS; i++) {
+		memcfg = __raw_readl(&heart_regs->mem_cfg.l[i]);
+		if (!(memcfg & HEART_MEMCFG_VALID))
+			continue;
+
+		addr = memcfg & HEART_MEMCFG_ADDR_MASK;
+		addr <<= HEART_MEMCFG_UNIT_SHIFT;
+		addr += IP30_MEMORY_BASE;
+		size = memcfg & HEART_MEMCFG_SIZE_MASK;
+		size >>= HEART_MEMCFG_SIZE_SHIFT;
+		size += 1;
+		size <<= HEART_MEMCFG_UNIT_SHIFT;
+
+		total_mem += size;
+
+		if (addr >= IP30_REAL_MEMORY_START)
+			memblock_free(addr, size);
+		else if ((addr + size) > IP30_REAL_MEMORY_START)
+			memblock_free(IP30_REAL_MEMORY_START,
+				     size - IP30_MAX_PROM_MEMORY);
+	}
+	pr_info("Detected %luMB of physical memory.\n", MEM_SHIFT(total_mem));
+}
+
+/**
+ * ip30_cpu_time_init - platform time initialization.
+ */
+static void __init ip30_cpu_time_init(void)
+{
+	int cpu = smp_processor_id();
+	u64 heart_compare;
+	unsigned int start, end;
+	int time_diff;
+
+	heart_compare = (heart_read(&heart_regs->count) +
+			 (HEART_CYCLES_PER_SEC / 10));
+	start = read_c0_count();
+	while ((heart_read(&heart_regs->count) - heart_compare) & 0x800000)
+		cpu_relax();
+
+	end = read_c0_count();
+	time_diff = (int)end - (int)start;
+	mips_hpt_frequency = time_diff * 10;
+	pr_info("IP30: CPU%d: %d MHz CPU detected.\n", cpu,
+		(mips_hpt_frequency * 2) / 1000000);
+}
+
+void __init ip30_per_cpu_init(void)
+{
+	/* Disable all interrupts. */
+	clear_c0_status(ST0_IM);
+
+	ip30_cpu_time_init();
+#ifdef CONFIG_SMP
+	ip30_install_ipi();
+#endif
+
+	enable_percpu_irq(IP30_HEART_L0_IRQ, IRQ_TYPE_NONE);
+	enable_percpu_irq(IP30_HEART_L1_IRQ, IRQ_TYPE_NONE);
+	enable_percpu_irq(IP30_HEART_L2_IRQ, IRQ_TYPE_NONE);
+	enable_percpu_irq(IP30_HEART_ERR_IRQ, IRQ_TYPE_NONE);
+}
+
+/**
+ * plat_mem_setup - despite the name, misc setup happens here.
+ */
+void __init plat_mem_setup(void)
+{
+	ip30_mem_init();
+
+	/* XXX: Hard lock on /sbin/init if this flag isn't specified. */
+	prom_flags |= PROM_FLAG_DONT_FREE_TEMP;
+
+#ifdef CONFIG_SMP
+	register_smp_ops(&ip30_smp_ops);
+#else
+	ip30_per_cpu_init();
+#endif
+
+	ioport_resource.start = 0;
+	ioport_resource.end = ~0UL;
+	set_io_port_base(IO_BASE);
+}