Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

6 files changed, 1293 insertions, 0 deletions

diff --git a/arch/mips/sibyte/common/Makefile b/arch/mips/sibyte/common/Makefile
new file mode 100644
index 000000000..3ef3fb658
--- /dev/null
+++ b/arch/mips/sibyte/common/Makefile
@@ -0,0 +1,5 @@
+obj-y := cfe.o
+obj-$(CONFIG_SWIOTLB)			+= dma.o
+obj-$(CONFIG_SIBYTE_BUS_WATCHER)	+= bus_watcher.o
+obj-$(CONFIG_SIBYTE_CFE_CONSOLE)	+= cfe_console.o
+obj-$(CONFIG_SIBYTE_TBPROF)		+= sb_tbprof.o
diff --git a/arch/mips/sibyte/common/bus_watcher.c b/arch/mips/sibyte/common/bus_watcher.c
new file mode 100644
index 000000000..4bb85de92
--- /dev/null
+++ b/arch/mips/sibyte/common/bus_watcher.c
@@ -0,0 +1,241 @@
+/*
+ * Copyright (C) 2002,2003 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; 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+/*
+ * The Bus Watcher monitors internal bus transactions and maintains
+ * counts of transactions with error status, logging details and
+ * causing one of several interrupts.  This driver provides a handler
+ * for those interrupts which aggregates the counts (to avoid
+ * saturating the 8-bit counters) and provides a presence in
+ * /proc/bus_watcher if PROC_FS is on.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <asm/io.h>
+
+#include <asm/sibyte/sb1250.h>
+#include <asm/sibyte/sb1250_regs.h>
+#include <asm/sibyte/sb1250_int.h>
+#include <asm/sibyte/sb1250_scd.h>
+#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
+#include <asm/sibyte/bcm1480_regs.h>
+#endif
+
+
+struct bw_stats_struct {
+	uint64_t status;
+	uint32_t l2_err;
+	uint32_t memio_err;
+	int status_printed;
+	unsigned long l2_cor_d;
+	unsigned long l2_bad_d;
+	unsigned long l2_cor_t;
+	unsigned long l2_bad_t;
+	unsigned long mem_cor_d;
+	unsigned long mem_bad_d;
+	unsigned long bus_error;
+} bw_stats;
+
+
+static void print_summary(uint32_t status, uint32_t l2_err,
+			  uint32_t memio_err)
+{
+	printk("Bus watcher error counters: %08x %08x\n", l2_err, memio_err);
+	printk("\nLast recorded signature:\n");
+	printk("Request %02x from %d, answered by %d with Dcode %d\n",
+	       (unsigned int)(G_SCD_BERR_TID(status) & 0x3f),
+	       (int)(G_SCD_BERR_TID(status) >> 6),
+	       (int)G_SCD_BERR_RID(status),
+	       (int)G_SCD_BERR_DCODE(status));
+}
+
+/*
+ * check_bus_watcher is exported for use in situations where we want
+ * to see the most recent status of the bus watcher, which might have
+ * already been destructively read out of the registers.
+ *
+ * notes: this is currently used by the cache error handler
+ *	  should provide locking against the interrupt handler
+ */
+void check_bus_watcher(void)
+{
+	u32 status, l2_err, memio_err;
+
+#if defined(CONFIG_SIBYTE_BCM112X) || defined(CONFIG_SIBYTE_SB1250)
+	/* Use non-destructive register */
+	status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS_DEBUG));
+#elif defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
+	/* Use non-destructive register */
+	/* Same as 1250 except BUS_ERR_STATUS_DEBUG is in a different place. */
+	status = csr_in32(IOADDR(A_BCM1480_BUS_ERR_STATUS_DEBUG));
+#else
+#error bus watcher being built for unknown Sibyte SOC!
+#endif
+	if (!(status & 0x7fffffff)) {
+		printk("Using last values reaped by bus watcher driver\n");
+		status = bw_stats.status;
+		l2_err = bw_stats.l2_err;
+		memio_err = bw_stats.memio_err;
+	} else {
+		l2_err = csr_in32(IOADDR(A_BUS_L2_ERRORS));
+		memio_err = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
+	}
+	if (status & ~(1UL << 31))
+		print_summary(status, l2_err, memio_err);
+	else
+		printk("Bus watcher indicates no error\n");
+}
+
+#ifdef CONFIG_PROC_FS
+
+/* For simplicity, I want to assume a single read is required each
+   time */
+static int bw_proc_show(struct seq_file *m, void *v)
+{
+	struct bw_stats_struct *stats = m->private;
+
+	seq_puts(m, "SiByte Bus Watcher statistics\n");
+	seq_puts(m, "-----------------------------\n");
+	seq_printf(m, "L2-d-cor %8ld\nL2-d-bad %8ld\n",
+		   stats->l2_cor_d, stats->l2_bad_d);
+	seq_printf(m, "L2-t-cor %8ld\nL2-t-bad %8ld\n",
+		   stats->l2_cor_t, stats->l2_bad_t);
+	seq_printf(m, "MC-d-cor %8ld\nMC-d-bad %8ld\n",
+		   stats->mem_cor_d, stats->mem_bad_d);
+	seq_printf(m, "IO-err   %8ld\n", stats->bus_error);
+	seq_puts(m, "\nLast recorded signature:\n");
+	seq_printf(m, "Request %02x from %d, answered by %d with Dcode %d\n",
+		   (unsigned int)(G_SCD_BERR_TID(stats->status) & 0x3f),
+		   (int)(G_SCD_BERR_TID(stats->status) >> 6),
+		   (int)G_SCD_BERR_RID(stats->status),
+		   (int)G_SCD_BERR_DCODE(stats->status));
+	/* XXXKW indicate multiple errors between printings, or stats
+	   collection (or both)? */
+	if (stats->status & M_SCD_BERR_MULTERRS)
+		seq_puts(m, "Multiple errors observed since last check.\n");
+	if (stats->status_printed) {
+		seq_puts(m, "(no change since last printing)\n");
+	} else {
+		stats->status_printed = 1;
+	}
+
+	return 0;
+}
+
+static void create_proc_decoder(struct bw_stats_struct *stats)
+{
+	struct proc_dir_entry *ent;
+
+	ent = proc_create_single_data("bus_watcher", S_IWUSR | S_IRUGO, NULL,
+			bw_proc_show, stats);
+	if (!ent) {
+		printk(KERN_INFO "Unable to initialize bus_watcher /proc entry\n");
+		return;
+	}
+}
+
+#endif /* CONFIG_PROC_FS */
+
+/*
+ * sibyte_bw_int - handle bus watcher interrupts and accumulate counts
+ *
+ * notes: possible re-entry due to multiple sources
+ *	  should check/indicate saturation
+ */
+static irqreturn_t sibyte_bw_int(int irq, void *data)
+{
+	struct bw_stats_struct *stats = data;
+	unsigned long cntr;
+#ifdef CONFIG_SIBYTE_BW_TRACE
+	int i;
+#endif
+
+#ifdef CONFIG_SIBYTE_BW_TRACE
+	csr_out32(M_SCD_TRACE_CFG_FREEZE, IOADDR(A_SCD_TRACE_CFG));
+	csr_out32(M_SCD_TRACE_CFG_START_READ, IOADDR(A_SCD_TRACE_CFG));
+
+	for (i=0; i<256*6; i++)
+		printk("%016llx\n",
+		       (long long)__raw_readq(IOADDR(A_SCD_TRACE_READ)));
+
+	csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
+	csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
+#endif
+
+	/* Destructive read, clears register and interrupt */
+	stats->status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS));
+	stats->status_printed = 0;
+
+	stats->l2_err = cntr = csr_in32(IOADDR(A_BUS_L2_ERRORS));
+	stats->l2_cor_d += G_SCD_L2ECC_CORR_D(cntr);
+	stats->l2_bad_d += G_SCD_L2ECC_BAD_D(cntr);
+	stats->l2_cor_t += G_SCD_L2ECC_CORR_T(cntr);
+	stats->l2_bad_t += G_SCD_L2ECC_BAD_T(cntr);
+	csr_out32(0, IOADDR(A_BUS_L2_ERRORS));
+
+	stats->memio_err = cntr = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
+	stats->mem_cor_d += G_SCD_MEM_ECC_CORR(cntr);
+	stats->mem_bad_d += G_SCD_MEM_ECC_BAD(cntr);
+	stats->bus_error += G_SCD_MEM_BUSERR(cntr);
+	csr_out32(0, IOADDR(A_BUS_MEM_IO_ERRORS));
+
+	return IRQ_HANDLED;
+}
+
+int __init sibyte_bus_watcher(void)
+{
+	memset(&bw_stats, 0, sizeof(struct bw_stats_struct));
+	bw_stats.status_printed = 1;
+
+	if (request_irq(K_INT_BAD_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
+		printk("Failed to register bus watcher BAD_ECC irq\n");
+		return -1;
+	}
+	if (request_irq(K_INT_COR_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
+		free_irq(K_INT_BAD_ECC, &bw_stats);
+		printk("Failed to register bus watcher COR_ECC irq\n");
+		return -1;
+	}
+	if (request_irq(K_INT_IO_BUS, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
+		free_irq(K_INT_BAD_ECC, &bw_stats);
+		free_irq(K_INT_COR_ECC, &bw_stats);
+		printk("Failed to register bus watcher IO_BUS irq\n");
+		return -1;
+	}
+
+#ifdef CONFIG_PROC_FS
+	create_proc_decoder(&bw_stats);
+#endif
+
+#ifdef CONFIG_SIBYTE_BW_TRACE
+	csr_out32((M_SCD_TRSEQ_ASAMPLE | M_SCD_TRSEQ_DSAMPLE |
+		   K_SCD_TRSEQ_TRIGGER_ALL),
+		  IOADDR(A_SCD_TRACE_SEQUENCE_0));
+	csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
+	csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
+#endif
+
+	return 0;
+}
+
+device_initcall(sibyte_bus_watcher);
diff --git a/arch/mips/sibyte/common/cfe.c b/arch/mips/sibyte/common/cfe.c
new file mode 100644
index 000000000..092fb2a6e
--- /dev/null
+++ b/arch/mips/sibyte/common/cfe.c
@@ -0,0 +1,345 @@
+/*
+ * Copyright (C) 2000, 2001, 2002, 2003 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; 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/linkage.h>
+#include <linux/mm.h>
+#include <linux/blkdev.h>
+#include <linux/bootmem.h>
+#include <linux/pm.h>
+#include <linux/smp.h>
+
+#include <asm/bootinfo.h>
+#include <asm/reboot.h>
+#include <asm/setup.h>
+#include <asm/sibyte/board.h>
+#include <asm/smp-ops.h>
+
+#include <asm/fw/cfe/cfe_api.h>
+#include <asm/fw/cfe/cfe_error.h>
+
+/* Max ram addressable in 32-bit segments */
+#ifdef CONFIG_64BIT
+#define MAX_RAM_SIZE (~0ULL)
+#else
+#ifdef CONFIG_HIGHMEM
+#ifdef CONFIG_PHYS_ADDR_T_64BIT
+#define MAX_RAM_SIZE (~0ULL)
+#else
+#define MAX_RAM_SIZE (0xffffffffULL)
+#endif
+#else
+#define MAX_RAM_SIZE (0x1fffffffULL)
+#endif
+#endif
+
+#define SIBYTE_MAX_MEM_REGIONS 8
+phys_addr_t board_mem_region_addrs[SIBYTE_MAX_MEM_REGIONS];
+phys_addr_t board_mem_region_sizes[SIBYTE_MAX_MEM_REGIONS];
+unsigned int board_mem_region_count;
+
+int cfe_cons_handle;
+
+#ifdef CONFIG_BLK_DEV_INITRD
+extern unsigned long initrd_start, initrd_end;
+#endif
+
+static void __noreturn cfe_linux_exit(void *arg)
+{
+	int warm = *(int *)arg;
+
+	if (smp_processor_id()) {
+		static int reboot_smp;
+
+		/* Don't repeat the process from another CPU */
+		if (!reboot_smp) {
+			/* Get CPU 0 to do the cfe_exit */
+			reboot_smp = 1;
+			smp_call_function(cfe_linux_exit, arg, 0);
+		}
+	} else {
+		printk("Passing control back to CFE...\n");
+		cfe_exit(warm, 0);
+		printk("cfe_exit returned??\n");
+	}
+	while (1);
+}
+
+static void __noreturn cfe_linux_restart(char *command)
+{
+	static const int zero;
+
+	cfe_linux_exit((void *)&zero);
+}
+
+static void __noreturn cfe_linux_halt(void)
+{
+	static const int one = 1;
+
+	cfe_linux_exit((void *)&one);
+}
+
+static __init void prom_meminit(void)
+{
+	u64 addr, size, type; /* regardless of PHYS_ADDR_T_64BIT */
+	int mem_flags = 0;
+	unsigned int idx;
+	int rd_flag;
+#ifdef CONFIG_BLK_DEV_INITRD
+	unsigned long initrd_pstart;
+	unsigned long initrd_pend;
+
+	initrd_pstart = CPHYSADDR(initrd_start);
+	initrd_pend = CPHYSADDR(initrd_end);
+	if (initrd_start &&
+	    ((initrd_pstart > MAX_RAM_SIZE)
+	     || (initrd_pend > MAX_RAM_SIZE))) {
+		panic("initrd out of addressable memory");
+	}
+
+#endif /* INITRD */
+
+	for (idx = 0; cfe_enummem(idx, mem_flags, &addr, &size, &type) != CFE_ERR_NOMORE;
+	     idx++) {
+		rd_flag = 0;
+		if (type == CFE_MI_AVAILABLE) {
+			/*
+			 * See if this block contains (any portion of) the
+			 * ramdisk
+			 */
+#ifdef CONFIG_BLK_DEV_INITRD
+			if (initrd_start) {
+				if ((initrd_pstart > addr) &&
+				    (initrd_pstart < (addr + size))) {
+					add_memory_region(addr,
+							  initrd_pstart - addr,
+							  BOOT_MEM_RAM);
+					rd_flag = 1;
+				}
+				if ((initrd_pend > addr) &&
+				    (initrd_pend < (addr + size))) {
+					add_memory_region(initrd_pend,
+						(addr + size) - initrd_pend,
+						 BOOT_MEM_RAM);
+					rd_flag = 1;
+				}
+			}
+#endif
+			if (!rd_flag) {
+				if (addr > MAX_RAM_SIZE)
+					continue;
+				if (addr+size > MAX_RAM_SIZE)
+					size = MAX_RAM_SIZE - (addr+size) + 1;
+				/*
+				 * memcpy/__copy_user prefetch, which
+				 * will cause a bus error for
+				 * KSEG/KUSEG addrs not backed by RAM.
+				 * Hence, reserve some padding for the
+				 * prefetch distance.
+				 */
+				if (size > 512)
+					size -= 512;
+				add_memory_region(addr, size, BOOT_MEM_RAM);
+			}
+			board_mem_region_addrs[board_mem_region_count] = addr;
+			board_mem_region_sizes[board_mem_region_count] = size;
+			board_mem_region_count++;
+			if (board_mem_region_count ==
+			    SIBYTE_MAX_MEM_REGIONS) {
+				/*
+				 * Too many regions.  Need to configure more
+				 */
+				while(1);
+			}
+		}
+	}
+#ifdef CONFIG_BLK_DEV_INITRD
+	if (initrd_start) {
+		add_memory_region(initrd_pstart, initrd_pend - initrd_pstart,
+				  BOOT_MEM_RESERVED);
+	}
+#endif
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+static int __init initrd_setup(char *str)
+{
+	char rdarg[64];
+	int idx;
+	char *tmp, *endptr;
+	unsigned long initrd_size;
+
+	/* Make a copy of the initrd argument so we can smash it up here */
+	for (idx = 0; idx < sizeof(rdarg)-1; idx++) {
+		if (!str[idx] || (str[idx] == ' ')) break;
+		rdarg[idx] = str[idx];
+	}
+
+	rdarg[idx] = 0;
+	str = rdarg;
+
+	/*
+	 *Initrd location comes in the form "<hex size of ramdisk in bytes>@<location in memory>"
+	 *  e.g. initrd=3abfd@80010000.	 This is set up by the loader.
+	 */
+	for (tmp = str; *tmp != '@'; tmp++) {
+		if (!*tmp) {
+			goto fail;
+		}
+	}
+	*tmp = 0;
+	tmp++;
+	if (!*tmp) {
+		goto fail;
+	}
+	initrd_size = simple_strtoul(str, &endptr, 16);
+	if (*endptr) {
+		*(tmp-1) = '@';
+		goto fail;
+	}
+	*(tmp-1) = '@';
+	initrd_start = simple_strtoul(tmp, &endptr, 16);
+	if (*endptr) {
+		goto fail;
+	}
+	initrd_end = initrd_start + initrd_size;
+	printk("Found initrd of %lx@%lx\n", initrd_size, initrd_start);
+	return 1;
+ fail:
+	printk("Bad initrd argument.  Disabling initrd\n");
+	initrd_start = 0;
+	initrd_end = 0;
+	return 1;
+}
+
+#endif
+
+extern const struct plat_smp_ops sb_smp_ops;
+extern const struct plat_smp_ops bcm1480_smp_ops;
+
+/*
+ * prom_init is called just after the cpu type is determined, from setup_arch()
+ */
+void __init prom_init(void)
+{
+	uint64_t cfe_ept, cfe_handle;
+	unsigned int cfe_eptseal;
+	int argc = fw_arg0;
+	char **envp = (char **) fw_arg2;
+	int *prom_vec = (int *) fw_arg3;
+
+	_machine_restart   = cfe_linux_restart;
+	_machine_halt	   = cfe_linux_halt;
+	pm_power_off = cfe_linux_halt;
+
+	/*
+	 * Check if a loader was used; if NOT, the 4 arguments are
+	 * what CFE gives us (handle, 0, EPT and EPTSEAL)
+	 */
+	if (argc < 0) {
+		cfe_handle = (uint64_t)(long)argc;
+		cfe_ept = (long)envp;
+		cfe_eptseal = (uint32_t)(unsigned long)prom_vec;
+	} else {
+		if ((int32_t)(long)prom_vec < 0) {
+			/*
+			 * Old loader; all it gives us is the handle,
+			 * so use the "known" entrypoint and assume
+			 * the seal.
+			 */
+			cfe_handle = (uint64_t)(long)prom_vec;
+			cfe_ept = (uint64_t)((int32_t)0x9fc00500);
+			cfe_eptseal = CFE_EPTSEAL;
+		} else {
+			/*
+			 * Newer loaders bundle the handle/ept/eptseal
+			 * Note: prom_vec is in the loader's useg
+			 * which is still alive in the TLB.
+			 */
+			cfe_handle = (uint64_t)((int32_t *)prom_vec)[0];
+			cfe_ept = (uint64_t)((int32_t *)prom_vec)[2];
+			cfe_eptseal = (unsigned int)((uint32_t *)prom_vec)[3];
+		}
+	}
+	if (cfe_eptseal != CFE_EPTSEAL) {
+		/* too early for panic to do any good */
+		printk("CFE's entrypoint seal doesn't match. Spinning.");
+		while (1) ;
+	}
+	cfe_init(cfe_handle, cfe_ept);
+	/*
+	 * Get the handle for (at least) prom_putchar, possibly for
+	 * boot console
+	 */
+	cfe_cons_handle = cfe_getstdhandle(CFE_STDHANDLE_CONSOLE);
+	if (cfe_getenv("LINUX_CMDLINE", arcs_cmdline, COMMAND_LINE_SIZE) < 0) {
+		if (argc >= 0) {
+			/* The loader should have set the command line */
+			/* too early for panic to do any good */
+			printk("LINUX_CMDLINE not defined in cfe.");
+			while (1) ;
+		}
+	}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+	{
+		char *ptr;
+		/* Need to find out early whether we've got an initrd.	So scan
+		   the list looking now */
+		for (ptr = arcs_cmdline; *ptr; ptr++) {
+			while (*ptr == ' ') {
+				ptr++;
+			}
+			if (!strncmp(ptr, "initrd=", 7)) {
+				initrd_setup(ptr+7);
+				break;
+			} else {
+				while (*ptr && (*ptr != ' ')) {
+					ptr++;
+				}
+			}
+		}
+	}
+#endif /* CONFIG_BLK_DEV_INITRD */
+
+	/* Not sure this is needed, but it's the safe way. */
+	arcs_cmdline[COMMAND_LINE_SIZE-1] = 0;
+
+	prom_meminit();
+
+#if defined(CONFIG_SIBYTE_BCM112X) || defined(CONFIG_SIBYTE_SB1250)
+	register_smp_ops(&sb_smp_ops);
+#endif
+#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
+	register_smp_ops(&bcm1480_smp_ops);
+#endif
+}
+
+void __init prom_free_prom_memory(void)
+{
+	/* Not sure what I'm supposed to do here.  Nothing, I think */
+}
+
+void prom_putchar(char c)
+{
+	int ret;
+
+	while ((ret = cfe_write(cfe_cons_handle, &c, 1)) == 0)
+		;
+}
diff --git a/arch/mips/sibyte/common/cfe_console.c b/arch/mips/sibyte/common/cfe_console.c
new file mode 100644
index 000000000..8af7b41f7
--- /dev/null
+++ b/arch/mips/sibyte/common/cfe_console.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/console.h>
+
+#include <asm/sibyte/board.h>
+
+#include <asm/fw/cfe/cfe_api.h>
+#include <asm/fw/cfe/cfe_error.h>
+
+extern int cfe_cons_handle;
+
+static void cfe_console_write(struct console *cons, const char *str,
+		       unsigned int count)
+{
+	int i, last, written;
+
+	for (i=0, last=0; i<count; i++) {
+		if (!str[i])
+			/* XXXKW can/should this ever happen? */
+			return;
+		if (str[i] == '\n') {
+			do {
+				written = cfe_write(cfe_cons_handle, &str[last], i-last);
+				if (written < 0)
+					;
+				last += written;
+			} while (last < i);
+			while (cfe_write(cfe_cons_handle, "\r", 1) <= 0)
+				;
+		}
+	}
+	if (last != count) {
+		do {
+			written = cfe_write(cfe_cons_handle, &str[last], count-last);
+			if (written < 0)
+				;
+			last += written;
+		} while (last < count);
+	}
+
+}
+
+static int cfe_console_setup(struct console *cons, char *str)
+{
+	char consdev[32];
+	/* XXXKW think about interaction with 'console=' cmdline arg */
+	/* If none of the console options are configured, the build will break. */
+	if (cfe_getenv("BOOT_CONSOLE", consdev, 32) >= 0) {
+#ifdef CONFIG_SERIAL_SB1250_DUART
+		if (!strcmp(consdev, "uart0")) {
+			setleds("u0cn");
+		} else if (!strcmp(consdev, "uart1")) {
+			setleds("u1cn");
+		} else
+#endif
+#ifdef CONFIG_VGA_CONSOLE
+		       if (!strcmp(consdev, "pcconsole0")) {
+				setleds("pccn");
+		} else
+#endif
+			return -ENODEV;
+	}
+	return 0;
+}
+
+static struct console sb1250_cfe_cons = {
+	.name		= "cfe",
+	.write		= cfe_console_write,
+	.setup		= cfe_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+};
+
+static int __init sb1250_cfe_console_init(void)
+{
+	register_console(&sb1250_cfe_cons);
+	return 0;
+}
+
+console_initcall(sb1250_cfe_console_init);
diff --git a/arch/mips/sibyte/common/dma.c b/arch/mips/sibyte/common/dma.c
new file mode 100644
index 000000000..eb47a94f3
--- /dev/null
+++ b/arch/mips/sibyte/common/dma.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *	DMA support for Broadcom SiByte platforms.
+ *
+ *	Copyright (c) 2018  Maciej W. Rozycki
+ */
+
+#include <linux/swiotlb.h>
+#include <asm/bootinfo.h>
+
+void __init plat_swiotlb_setup(void)
+{
+	swiotlb_init(1);
+}
diff --git a/arch/mips/sibyte/common/sb_tbprof.c b/arch/mips/sibyte/common/sb_tbprof.c
new file mode 100644
index 000000000..99c720be7
--- /dev/null
+++ b/arch/mips/sibyte/common/sb_tbprof.c
@@ -0,0 +1,607 @@
+/*
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * Copyright (C) 2001, 2002, 2003 Broadcom Corporation
+ * Copyright (C) 2007 Ralf Baechle <ralf@linux-mips.org>
+ * Copyright (C) 2007 MIPS Technologies, Inc.
+ *    written by Ralf Baechle <ralf@linux-mips.org>
+ */
+
+#undef DEBUG
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <asm/io.h>
+#include <asm/sibyte/sb1250.h>
+
+#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
+#include <asm/sibyte/bcm1480_regs.h>
+#include <asm/sibyte/bcm1480_scd.h>
+#include <asm/sibyte/bcm1480_int.h>
+#elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X)
+#include <asm/sibyte/sb1250_regs.h>
+#include <asm/sibyte/sb1250_scd.h>
+#include <asm/sibyte/sb1250_int.h>
+#else
+#error invalid SiByte UART configuration
+#endif
+
+#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
+#undef K_INT_TRACE_FREEZE
+#define K_INT_TRACE_FREEZE K_BCM1480_INT_TRACE_FREEZE
+#undef K_INT_PERF_CNT
+#define K_INT_PERF_CNT K_BCM1480_INT_PERF_CNT
+#endif
+
+#include <linux/uaccess.h>
+
+#define SBPROF_TB_MAJOR 240
+
+typedef u64 tb_sample_t[6*256];
+
+enum open_status {
+	SB_CLOSED,
+	SB_OPENING,
+	SB_OPEN
+};
+
+struct sbprof_tb {
+	wait_queue_head_t	tb_sync;
+	wait_queue_head_t	tb_read;
+	struct mutex		lock;
+	enum open_status	open;
+	tb_sample_t		*sbprof_tbbuf;
+	int			next_tb_sample;
+
+	volatile int		tb_enable;
+	volatile int		tb_armed;
+
+};
+
+static struct sbprof_tb sbp;
+
+#define MAX_SAMPLE_BYTES (24*1024*1024)
+#define MAX_TBSAMPLE_BYTES (12*1024*1024)
+
+#define MAX_SAMPLES (MAX_SAMPLE_BYTES/sizeof(u_int32_t))
+#define TB_SAMPLE_SIZE (sizeof(tb_sample_t))
+#define MAX_TB_SAMPLES (MAX_TBSAMPLE_BYTES/TB_SAMPLE_SIZE)
+
+/* ioctls */
+#define SBPROF_ZBSTART		_IOW('s', 0, int)
+#define SBPROF_ZBSTOP		_IOW('s', 1, int)
+#define SBPROF_ZBWAITFULL	_IOW('s', 2, int)
+
+/*
+ * Routines for using 40-bit SCD cycle counter
+ *
+ * Client responsible for either handling interrupts or making sure
+ * the cycles counter never saturates, e.g., by doing
+ * zclk_timer_init(0) at least every 2^40 - 1 ZCLKs.
+ */
+
+/*
+ * Configures SCD counter 0 to count ZCLKs starting from val;
+ * Configures SCD counters1,2,3 to count nothing.
+ * Must not be called while gathering ZBbus profiles.
+ */
+
+#define zclk_timer_init(val) \
+  __asm__ __volatile__ (".set push;" \
+			".set mips64;" \
+			"la   $8, 0xb00204c0;" /* SCD perf_cnt_cfg */ \
+			"sd   %0, 0x10($8);"   /* write val to counter0 */ \
+			"sd   %1, 0($8);"      /* config counter0 for zclks*/ \
+			".set pop" \
+			: /* no outputs */ \
+						     /* enable, counter0 */ \
+			: /* inputs */ "r"(val), "r" ((1ULL << 33) | 1ULL) \
+			: /* modifies */ "$8" )
+
+
+/* Reads SCD counter 0 and puts result in value
+   unsigned long long val; */
+#define zclk_get(val) \
+  __asm__ __volatile__ (".set push;" \
+			".set mips64;" \
+			"la   $8, 0xb00204c0;" /* SCD perf_cnt_cfg */ \
+			"ld   %0, 0x10($8);"   /* write val to counter0 */ \
+			".set pop" \
+			: /* outputs */ "=r"(val) \
+			: /* inputs */ \
+			: /* modifies */ "$8" )
+
+#define DEVNAME "sb_tbprof"
+
+#define TB_FULL (sbp.next_tb_sample == MAX_TB_SAMPLES)
+
+/*
+ * Support for ZBbus sampling using the trace buffer
+ *
+ * We use the SCD performance counter interrupt, caused by a Zclk counter
+ * overflow, to trigger the start of tracing.
+ *
+ * We set the trace buffer to sample everything and freeze on
+ * overflow.
+ *
+ * We map the interrupt for trace_buffer_freeze to handle it on CPU 0.
+ *
+ */
+
+static u64 tb_period;
+
+static void arm_tb(void)
+{
+	u64 scdperfcnt;
+	u64 next = (1ULL << 40) - tb_period;
+	u64 tb_options = M_SCD_TRACE_CFG_FREEZE_FULL;
+
+	/*
+	 * Generate an SCD_PERFCNT interrupt in TB_PERIOD Zclks to
+	 * trigger start of trace.  XXX vary sampling period
+	 */
+	__raw_writeq(0, IOADDR(A_SCD_PERF_CNT_1));
+	scdperfcnt = __raw_readq(IOADDR(A_SCD_PERF_CNT_CFG));
+
+	/*
+	 * Unfortunately, in Pass 2 we must clear all counters to knock down
+	 * a previous interrupt request.  This means that bus profiling
+	 * requires ALL of the SCD perf counters.
+	 */
+#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
+	__raw_writeq((scdperfcnt & ~M_SPC_CFG_SRC1) |
+						/* keep counters 0,2,3,4,5,6,7 as is */
+		     V_SPC_CFG_SRC1(1),		/* counter 1 counts cycles */
+		     IOADDR(A_BCM1480_SCD_PERF_CNT_CFG0));
+	__raw_writeq(
+		     M_SPC_CFG_ENABLE |		/* enable counting */
+		     M_SPC_CFG_CLEAR |		/* clear all counters */
+		     V_SPC_CFG_SRC1(1),		/* counter 1 counts cycles */
+		     IOADDR(A_BCM1480_SCD_PERF_CNT_CFG1));
+#else
+	__raw_writeq((scdperfcnt & ~M_SPC_CFG_SRC1) |
+						/* keep counters 0,2,3 as is */
+		     M_SPC_CFG_ENABLE |		/* enable counting */
+		     M_SPC_CFG_CLEAR |		/* clear all counters */
+		     V_SPC_CFG_SRC1(1),		/* counter 1 counts cycles */
+		     IOADDR(A_SCD_PERF_CNT_CFG));
+#endif
+	__raw_writeq(next, IOADDR(A_SCD_PERF_CNT_1));
+	/* Reset the trace buffer */
+	__raw_writeq(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
+#if 0 && defined(M_SCD_TRACE_CFG_FORCECNT)
+	/* XXXKW may want to expose control to the data-collector */
+	tb_options |= M_SCD_TRACE_CFG_FORCECNT;
+#endif
+	__raw_writeq(tb_options, IOADDR(A_SCD_TRACE_CFG));
+	sbp.tb_armed = 1;
+}
+
+static irqreturn_t sbprof_tb_intr(int irq, void *dev_id)
+{
+	int i;
+
+	pr_debug(DEVNAME ": tb_intr\n");
+
+	if (sbp.next_tb_sample < MAX_TB_SAMPLES) {
+		/* XXX should use XKPHYS to make writes bypass L2 */
+		u64 *p = sbp.sbprof_tbbuf[sbp.next_tb_sample++];
+		/* Read out trace */
+		__raw_writeq(M_SCD_TRACE_CFG_START_READ,
+			     IOADDR(A_SCD_TRACE_CFG));
+		__asm__ __volatile__ ("sync" : : : "memory");
+		/* Loop runs backwards because bundles are read out in reverse order */
+		for (i = 256 * 6; i > 0; i -= 6) {
+			/* Subscripts decrease to put bundle in the order */
+			/*   t0 lo, t0 hi, t1 lo, t1 hi, t2 lo, t2 hi */
+			p[i - 1] = __raw_readq(IOADDR(A_SCD_TRACE_READ));
+			/* read t2 hi */
+			p[i - 2] = __raw_readq(IOADDR(A_SCD_TRACE_READ));
+			/* read t2 lo */
+			p[i - 3] = __raw_readq(IOADDR(A_SCD_TRACE_READ));
+			/* read t1 hi */
+			p[i - 4] = __raw_readq(IOADDR(A_SCD_TRACE_READ));
+			/* read t1 lo */
+			p[i - 5] = __raw_readq(IOADDR(A_SCD_TRACE_READ));
+			/* read t0 hi */
+			p[i - 6] = __raw_readq(IOADDR(A_SCD_TRACE_READ));
+			/* read t0 lo */
+		}
+		if (!sbp.tb_enable) {
+			pr_debug(DEVNAME ": tb_intr shutdown\n");
+			__raw_writeq(M_SCD_TRACE_CFG_RESET,
+				     IOADDR(A_SCD_TRACE_CFG));
+			sbp.tb_armed = 0;
+			wake_up_interruptible(&sbp.tb_sync);
+		} else {
+			/* knock down current interrupt and get another one later */
+			arm_tb();
+		}
+	} else {
+		/* No more trace buffer samples */
+		pr_debug(DEVNAME ": tb_intr full\n");
+		__raw_writeq(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
+		sbp.tb_armed = 0;
+		if (!sbp.tb_enable)
+			wake_up_interruptible(&sbp.tb_sync);
+		wake_up_interruptible(&sbp.tb_read);
+	}
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sbprof_pc_intr(int irq, void *dev_id)
+{
+	printk(DEVNAME ": unexpected pc_intr");
+	return IRQ_NONE;
+}
+
+/*
+ * Requires: Already called zclk_timer_init with a value that won't
+ *	     saturate 40 bits.	No subsequent use of SCD performance counters
+ *	     or trace buffer.
+ */
+
+static int sbprof_zbprof_start(struct file *filp)
+{
+	u64 scdperfcnt;
+	int err;
+
+	if (xchg(&sbp.tb_enable, 1))
+		return -EBUSY;
+
+	pr_debug(DEVNAME ": starting\n");
+
+	sbp.next_tb_sample = 0;
+	filp->f_pos = 0;
+
+	err = request_irq(K_INT_TRACE_FREEZE, sbprof_tb_intr, 0,
+			  DEVNAME " trace freeze", &sbp);
+	if (err)
+		return -EBUSY;
+
+	/* Make sure there isn't a perf-cnt interrupt waiting */
+	scdperfcnt = __raw_readq(IOADDR(A_SCD_PERF_CNT_CFG));
+	/* Disable and clear counters, override SRC_1 */
+	__raw_writeq((scdperfcnt & ~(M_SPC_CFG_SRC1 | M_SPC_CFG_ENABLE)) |
+		     M_SPC_CFG_ENABLE | M_SPC_CFG_CLEAR | V_SPC_CFG_SRC1(1),
+		     IOADDR(A_SCD_PERF_CNT_CFG));
+
+	/*
+	 * We grab this interrupt to prevent others from trying to use
+	 * it, even though we don't want to service the interrupts
+	 * (they only feed into the trace-on-interrupt mechanism)
+	 */
+	if (request_irq(K_INT_PERF_CNT, sbprof_pc_intr, 0, DEVNAME " scd perfcnt", &sbp)) {
+		free_irq(K_INT_TRACE_FREEZE, &sbp);
+		return -EBUSY;
+	}
+
+	/*
+	 * I need the core to mask these, but the interrupt mapper to
+	 *  pass them through.	I am exploiting my knowledge that
+	 *  cp0_status masks out IP[5]. krw
+	 */
+#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
+	__raw_writeq(K_BCM1480_INT_MAP_I3,
+		     IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_INTERRUPT_MAP_BASE_L) +
+			    ((K_BCM1480_INT_PERF_CNT & 0x3f) << 3)));
+#else
+	__raw_writeq(K_INT_MAP_I3,
+		     IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) +
+			    (K_INT_PERF_CNT << 3)));
+#endif
+
+	/* Initialize address traps */
+	__raw_writeq(0, IOADDR(A_ADDR_TRAP_UP_0));
+	__raw_writeq(0, IOADDR(A_ADDR_TRAP_UP_1));
+	__raw_writeq(0, IOADDR(A_ADDR_TRAP_UP_2));
+	__raw_writeq(0, IOADDR(A_ADDR_TRAP_UP_3));
+
+	__raw_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_0));
+	__raw_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_1));
+	__raw_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_2));
+	__raw_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_3));
+
+	__raw_writeq(0, IOADDR(A_ADDR_TRAP_CFG_0));
+	__raw_writeq(0, IOADDR(A_ADDR_TRAP_CFG_1));
+	__raw_writeq(0, IOADDR(A_ADDR_TRAP_CFG_2));
+	__raw_writeq(0, IOADDR(A_ADDR_TRAP_CFG_3));
+
+	/* Initialize Trace Event 0-7 */
+	/*				when interrupt	*/
+	__raw_writeq(M_SCD_TREVT_INTERRUPT, IOADDR(A_SCD_TRACE_EVENT_0));
+	__raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_1));
+	__raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_2));
+	__raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_3));
+	__raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_4));
+	__raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_5));
+	__raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_6));
+	__raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_7));
+
+	/* Initialize Trace Sequence 0-7 */
+	/*				     Start on event 0 (interrupt) */
+	__raw_writeq(V_SCD_TRSEQ_FUNC_START | 0x0fff,
+		     IOADDR(A_SCD_TRACE_SEQUENCE_0));
+	/*			  dsamp when d used | asamp when a used */
+	__raw_writeq(M_SCD_TRSEQ_ASAMPLE | M_SCD_TRSEQ_DSAMPLE |
+		     K_SCD_TRSEQ_TRIGGER_ALL,
+		     IOADDR(A_SCD_TRACE_SEQUENCE_1));
+	__raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_2));
+	__raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_3));
+	__raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_4));
+	__raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_5));
+	__raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_6));
+	__raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_7));
+
+	/* Now indicate the PERF_CNT interrupt as a trace-relevant interrupt */
+#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
+	__raw_writeq(1ULL << (K_BCM1480_INT_PERF_CNT & 0x3f),
+		     IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_INTERRUPT_TRACE_L)));
+#else
+	__raw_writeq(1ULL << K_INT_PERF_CNT,
+		     IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_TRACE)));
+#endif
+	arm_tb();
+
+	pr_debug(DEVNAME ": done starting\n");
+
+	return 0;
+}
+
+static int sbprof_zbprof_stop(void)
+{
+	int err = 0;
+
+	pr_debug(DEVNAME ": stopping\n");
+
+	if (sbp.tb_enable) {
+		/*
+		 * XXXKW there is a window here where the intr handler may run,
+		 * see the disable, and do the wake_up before this sleep
+		 * happens.
+		 */
+		pr_debug(DEVNAME ": wait for disarm\n");
+		err = wait_event_interruptible(sbp.tb_sync, !sbp.tb_armed);
+		pr_debug(DEVNAME ": disarm complete, stat %d\n", err);
+
+		if (err)
+			return err;
+
+		sbp.tb_enable = 0;
+		free_irq(K_INT_TRACE_FREEZE, &sbp);
+		free_irq(K_INT_PERF_CNT, &sbp);
+	}
+
+	pr_debug(DEVNAME ": done stopping\n");
+
+	return err;
+}
+
+static int sbprof_tb_open(struct inode *inode, struct file *filp)
+{
+	int minor;
+
+	minor = iminor(inode);
+	if (minor != 0)
+		return -ENODEV;
+
+	if (xchg(&sbp.open, SB_OPENING) != SB_CLOSED)
+		return -EBUSY;
+
+	memset(&sbp, 0, sizeof(struct sbprof_tb));
+	sbp.sbprof_tbbuf = vzalloc(MAX_TBSAMPLE_BYTES);
+	if (!sbp.sbprof_tbbuf) {
+		sbp.open = SB_CLOSED;
+		wmb();
+		return -ENOMEM;
+	}
+
+	init_waitqueue_head(&sbp.tb_sync);
+	init_waitqueue_head(&sbp.tb_read);
+	mutex_init(&sbp.lock);
+
+	sbp.open = SB_OPEN;
+	wmb();
+
+	return 0;
+}
+
+static int sbprof_tb_release(struct inode *inode, struct file *filp)
+{
+	int minor;
+
+	minor = iminor(inode);
+	if (minor != 0 || sbp.open != SB_CLOSED)
+		return -ENODEV;
+
+	mutex_lock(&sbp.lock);
+
+	if (sbp.tb_armed || sbp.tb_enable)
+		sbprof_zbprof_stop();
+
+	vfree(sbp.sbprof_tbbuf);
+	sbp.open = SB_CLOSED;
+	wmb();
+
+	mutex_unlock(&sbp.lock);
+
+	return 0;
+}
+
+static ssize_t sbprof_tb_read(struct file *filp, char *buf,
+			      size_t size, loff_t *offp)
+{
+	int cur_sample, sample_off, cur_count, sample_left;
+	char *src;
+	int   count   =	 0;
+	char *dest    =	 buf;
+	long  cur_off = *offp;
+
+	if (!access_ok(VERIFY_WRITE, buf, size))
+		return -EFAULT;
+
+	mutex_lock(&sbp.lock);
+
+	count = 0;
+	cur_sample = cur_off / TB_SAMPLE_SIZE;
+	sample_off = cur_off % TB_SAMPLE_SIZE;
+	sample_left = TB_SAMPLE_SIZE - sample_off;
+
+	while (size && (cur_sample < sbp.next_tb_sample)) {
+		int err;
+
+		cur_count = size < sample_left ? size : sample_left;
+		src = (char *)(((long)sbp.sbprof_tbbuf[cur_sample])+sample_off);
+		err = __copy_to_user(dest, src, cur_count);
+		if (err) {
+			*offp = cur_off + cur_count - err;
+			mutex_unlock(&sbp.lock);
+			return err;
+		}
+		pr_debug(DEVNAME ": read from sample %d, %d bytes\n",
+			 cur_sample, cur_count);
+		size -= cur_count;
+		sample_left -= cur_count;
+		if (!sample_left) {
+			cur_sample++;
+			sample_off = 0;
+			sample_left = TB_SAMPLE_SIZE;
+		} else {
+			sample_off += cur_count;
+		}
+		cur_off += cur_count;
+		dest += cur_count;
+		count += cur_count;
+	}
+	*offp = cur_off;
+	mutex_unlock(&sbp.lock);
+
+	return count;
+}
+
+static long sbprof_tb_ioctl(struct file *filp,
+			    unsigned int command,
+			    unsigned long arg)
+{
+	int err = 0;
+
+	switch (command) {
+	case SBPROF_ZBSTART:
+		mutex_lock(&sbp.lock);
+		err = sbprof_zbprof_start(filp);
+		mutex_unlock(&sbp.lock);
+		break;
+
+	case SBPROF_ZBSTOP:
+		mutex_lock(&sbp.lock);
+		err = sbprof_zbprof_stop();
+		mutex_unlock(&sbp.lock);
+		break;
+
+	case SBPROF_ZBWAITFULL: {
+		err = wait_event_interruptible(sbp.tb_read, TB_FULL);
+		if (err)
+			break;
+
+		err = put_user(TB_FULL, (int *) arg);
+		break;
+	}
+
+	default:
+		err = -EINVAL;
+		break;
+	}
+
+	return err;
+}
+
+static const struct file_operations sbprof_tb_fops = {
+	.owner		= THIS_MODULE,
+	.open		= sbprof_tb_open,
+	.release	= sbprof_tb_release,
+	.read		= sbprof_tb_read,
+	.unlocked_ioctl = sbprof_tb_ioctl,
+	.compat_ioctl	= sbprof_tb_ioctl,
+	.mmap		= NULL,
+	.llseek		= default_llseek,
+};
+
+static struct class *tb_class;
+static struct device *tb_dev;
+
+static int __init sbprof_tb_init(void)
+{
+	struct device *dev;
+	struct class *tbc;
+	int err;
+
+	if (register_chrdev(SBPROF_TB_MAJOR, DEVNAME, &sbprof_tb_fops)) {
+		printk(KERN_WARNING DEVNAME ": initialization failed (dev %d)\n",
+		       SBPROF_TB_MAJOR);
+		return -EIO;
+	}
+
+	tbc = class_create(THIS_MODULE, "sb_tracebuffer");
+	if (IS_ERR(tbc)) {
+		err = PTR_ERR(tbc);
+		goto out_chrdev;
+	}
+
+	tb_class = tbc;
+
+	dev = device_create(tbc, NULL, MKDEV(SBPROF_TB_MAJOR, 0), NULL, "tb");
+	if (IS_ERR(dev)) {
+		err = PTR_ERR(dev);
+		goto out_class;
+	}
+	tb_dev = dev;
+
+	sbp.open = SB_CLOSED;
+	wmb();
+	tb_period = zbbus_mhz * 10000LL;
+	pr_info(DEVNAME ": initialized - tb_period = %lld\n",
+		(long long) tb_period);
+	return 0;
+
+out_class:
+	class_destroy(tb_class);
+out_chrdev:
+	unregister_chrdev(SBPROF_TB_MAJOR, DEVNAME);
+
+	return err;
+}
+
+static void __exit sbprof_tb_cleanup(void)
+{
+	device_destroy(tb_class, MKDEV(SBPROF_TB_MAJOR, 0));
+	unregister_chrdev(SBPROF_TB_MAJOR, DEVNAME);
+	class_destroy(tb_class);
+}
+
+module_init(sbprof_tb_init);
+module_exit(sbprof_tb_cleanup);
+
+MODULE_ALIAS_CHARDEV_MAJOR(SBPROF_TB_MAJOR);
+MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
+MODULE_LICENSE("GPL");