These changes are the raw update to linux-4.4.6-rt14. Kernel sources

are taken from kernel.org, and rt patch from the rt wiki download page.

During the rebasing, the following patch collided:

Force tick interrupt and get rid of softirq magic(I70131fb85).

Collisions have been removed because its logic was found on the
source already.

Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>

8 files changed, 240 insertions, 276 deletions

diff --git a/kernel/arch/mips/mti-malta/Makefile b/kernel/arch/mips/mti-malta/Makefile
index 6510ace27..5827af77c 100644
--- a/kernel/arch/mips/mti-malta/Makefile
+++ b/kernel/arch/mips/mti-malta/Makefile
@@ -5,9 +5,18 @@
 # Copyright (C) 2008 Wind River Systems, Inc.
 #   written by Ralf Baechle <ralf@linux-mips.org>
 #
-obj-y				:= malta-display.o malta-init.o \
-				   malta-int.o malta-memory.o malta-platform.o \
-				   malta-reset.o malta-setup.o malta-time.o
+obj-y				+= malta-display.o
+obj-y				+= malta-dt.o
+obj-y				+= malta-dtshim.o
+obj-y				+= malta-init.o
+obj-y				+= malta-int.o
+obj-y				+= malta-memory.o
+obj-y				+= malta-platform.o
+obj-y				+= malta-reset.o
+obj-y				+= malta-setup.o
+obj-y				+= malta-time.o
 
 obj-$(CONFIG_MIPS_CMP)		+= malta-amon.o
 obj-$(CONFIG_MIPS_MALTA_PM)	+= malta-pm.o
+
+CFLAGS_malta-dtshim.o = -I$(src)/../../../scripts/dtc/libfdt
diff --git a/kernel/arch/mips/mti-malta/malta-dt.c b/kernel/arch/mips/mti-malta/malta-dt.c
new file mode 100644
index 000000000..47a228892
--- /dev/null
+++ b/kernel/arch/mips/mti-malta/malta-dt.c
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.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.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/init.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
+
+void __init device_tree_init(void)
+{
+	unflatten_and_copy_device_tree();
+}
+
+static const struct of_device_id bus_ids[] __initconst = {
+	{ .compatible = "simple-bus", },
+	{ .compatible = "isa", },
+	{},
+};
+
+static int __init publish_devices(void)
+{
+	if (!of_have_populated_dt())
+		return 0;
+
+	return of_platform_bus_probe(NULL, bus_ids, NULL);
+}
+device_initcall(publish_devices);
diff --git a/kernel/arch/mips/mti-malta/malta-dtshim.c b/kernel/arch/mips/mti-malta/malta-dtshim.c
new file mode 100644
index 000000000..f7133efc5
--- /dev/null
+++ b/kernel/arch/mips/mti-malta/malta-dtshim.c
@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.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.
+ */
+
+#include <linux/bug.h>
+#include <linux/kernel.h>
+#include <linux/libfdt.h>
+#include <linux/of_fdt.h>
+#include <linux/sizes.h>
+#include <asm/bootinfo.h>
+#include <asm/fw/fw.h>
+#include <asm/page.h>
+
+static unsigned char fdt_buf[16 << 10] __initdata;
+
+/* determined physical memory size, not overridden by command line args	 */
+extern unsigned long physical_memsize;
+
+#define MAX_MEM_ARRAY_ENTRIES 1
+
+static unsigned __init gen_fdt_mem_array(__be32 *mem_array, unsigned long size)
+{
+	unsigned long size_preio;
+	unsigned entries;
+
+	entries = 1;
+	mem_array[0] = cpu_to_be32(PHYS_OFFSET);
+	if (config_enabled(CONFIG_EVA)) {
+		/*
+		 * The current Malta EVA configuration is "special" in that it
+		 * always makes use of addresses in the upper half of the 32 bit
+		 * physical address map, which gives it a contiguous region of
+		 * DDR but limits it to 2GB.
+		 */
+		mem_array[1] = cpu_to_be32(size);
+	} else {
+		size_preio = min_t(unsigned long, size, SZ_256M);
+		mem_array[1] = cpu_to_be32(size_preio);
+	}
+
+	BUG_ON(entries > MAX_MEM_ARRAY_ENTRIES);
+	return entries;
+}
+
+static void __init append_memory(void *fdt, int root_off)
+{
+	__be32 mem_array[2 * MAX_MEM_ARRAY_ENTRIES];
+	unsigned long memsize;
+	unsigned mem_entries;
+	int i, err, mem_off;
+	char *var, param_name[10], *var_names[] = {
+		"ememsize", "memsize",
+	};
+
+	/* if a memory node already exists, leave it alone */
+	mem_off = fdt_path_offset(fdt, "/memory");
+	if (mem_off >= 0)
+		return;
+
+	/* find memory size from the bootloader environment */
+	for (i = 0; i < ARRAY_SIZE(var_names); i++) {
+		var = fw_getenv(var_names[i]);
+		if (!var)
+			continue;
+
+		err = kstrtoul(var, 0, &physical_memsize);
+		if (!err)
+			break;
+
+		pr_warn("Failed to read the '%s' env variable '%s'\n",
+			var_names[i], var);
+	}
+
+	if (!physical_memsize) {
+		pr_warn("The bootloader didn't provide memsize: defaulting to 32MB\n");
+		physical_memsize = 32 << 20;
+	}
+
+	if (config_enabled(CONFIG_CPU_BIG_ENDIAN)) {
+		/*
+		 * SOC-it swaps, or perhaps doesn't swap, when DMA'ing
+		 * the last word of physical memory.
+		 */
+		physical_memsize -= PAGE_SIZE;
+	}
+
+	/* default to using all available RAM */
+	memsize = physical_memsize;
+
+	/* allow the user to override the usable memory */
+	for (i = 0; i < ARRAY_SIZE(var_names); i++) {
+		snprintf(param_name, sizeof(param_name), "%s=", var_names[i]);
+		var = strstr(arcs_cmdline, param_name);
+		if (!var)
+			continue;
+
+		memsize = memparse(var + strlen(param_name), NULL);
+	}
+
+	/* if the user says there's more RAM than we thought, believe them */
+	physical_memsize = max_t(unsigned long, physical_memsize, memsize);
+
+	/* append memory to the DT */
+	mem_off = fdt_add_subnode(fdt, root_off, "memory");
+	if (mem_off < 0)
+		panic("Unable to add memory node to DT: %d", mem_off);
+
+	err = fdt_setprop_string(fdt, mem_off, "device_type", "memory");
+	if (err)
+		panic("Unable to set memory node device_type: %d", err);
+
+	mem_entries = gen_fdt_mem_array(mem_array, physical_memsize);
+	err = fdt_setprop(fdt, mem_off, "reg", mem_array,
+			  mem_entries * 2 * sizeof(mem_array[0]));
+	if (err)
+		panic("Unable to set memory regs property: %d", err);
+
+	mem_entries = gen_fdt_mem_array(mem_array, memsize);
+	err = fdt_setprop(fdt, mem_off, "linux,usable-memory", mem_array,
+			  mem_entries * 2 * sizeof(mem_array[0]));
+	if (err)
+		panic("Unable to set linux,usable-memory property: %d", err);
+}
+
+void __init *malta_dt_shim(void *fdt)
+{
+	int root_off, len, err;
+	const char *compat;
+
+	if (fdt_check_header(fdt))
+		panic("Corrupt DT");
+
+	err = fdt_open_into(fdt, fdt_buf, sizeof(fdt_buf));
+	if (err)
+		panic("Unable to open FDT: %d", err);
+
+	root_off = fdt_path_offset(fdt_buf, "/");
+	if (root_off < 0)
+		panic("No / node in DT");
+
+	compat = fdt_getprop(fdt_buf, root_off, "compatible", &len);
+	if (!compat)
+		panic("No root compatible property in DT: %d", len);
+
+	/* if this isn't Malta, leave the DT alone */
+	if (strncmp(compat, "mti,malta", len))
+		return fdt;
+
+	append_memory(fdt_buf, root_off);
+
+	err = fdt_pack(fdt_buf);
+	if (err)
+		panic("Unable to pack FDT: %d\n", err);
+
+	return fdt_buf;
+}
diff --git a/kernel/arch/mips/mti-malta/malta-init.c b/kernel/arch/mips/mti-malta/malta-init.c
index cec3e187c..571148c5f 100644
--- a/kernel/arch/mips/mti-malta/malta-init.c
+++ b/kernel/arch/mips/mti-malta/malta-init.c
@@ -302,4 +302,12 @@ mips_pci_controller:
 		return;
 	if (!register_vsmp_smp_ops())
 		return;
+	register_up_smp_ops();
+}
+
+void platform_early_l2_init(void)
+{
+	/* L2 configuration lives in the CM3 */
+	if (mips_cm_revision() >= CM_REV_CM3)
+		mips_cm_probe();
 }
diff --git a/kernel/arch/mips/mti-malta/malta-int.c b/kernel/arch/mips/mti-malta/malta-int.c
index d1392f8f5..c6a6c7afd 100644
--- a/kernel/arch/mips/mti-malta/malta-int.c
+++ b/kernel/arch/mips/mti-malta/malta-int.c
@@ -222,7 +222,7 @@ static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
 
 static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
 {
-	smp_call_function_interrupt();
+	generic_smp_call_function_interrupt();
 
 	return IRQ_HANDLED;
 }
@@ -382,122 +382,12 @@ void malta_be_init(void)
 	/* Could change CM error mask register. */
 }
 
-
-static char *tr[8] = {
-	"mem",	"gcr",	"gic",	"mmio",
-	"0x04", "0x05", "0x06", "0x07"
-};
-
-static char *mcmd[32] = {
-	[0x00] = "0x00",
-	[0x01] = "Legacy Write",
-	[0x02] = "Legacy Read",
-	[0x03] = "0x03",
-	[0x04] = "0x04",
-	[0x05] = "0x05",
-	[0x06] = "0x06",
-	[0x07] = "0x07",
-	[0x08] = "Coherent Read Own",
-	[0x09] = "Coherent Read Share",
-	[0x0a] = "Coherent Read Discard",
-	[0x0b] = "Coherent Ready Share Always",
-	[0x0c] = "Coherent Upgrade",
-	[0x0d] = "Coherent Writeback",
-	[0x0e] = "0x0e",
-	[0x0f] = "0x0f",
-	[0x10] = "Coherent Copyback",
-	[0x11] = "Coherent Copyback Invalidate",
-	[0x12] = "Coherent Invalidate",
-	[0x13] = "Coherent Write Invalidate",
-	[0x14] = "Coherent Completion Sync",
-	[0x15] = "0x15",
-	[0x16] = "0x16",
-	[0x17] = "0x17",
-	[0x18] = "0x18",
-	[0x19] = "0x19",
-	[0x1a] = "0x1a",
-	[0x1b] = "0x1b",
-	[0x1c] = "0x1c",
-	[0x1d] = "0x1d",
-	[0x1e] = "0x1e",
-	[0x1f] = "0x1f"
-};
-
-static char *core[8] = {
-	"Invalid/OK",	"Invalid/Data",
-	"Shared/OK",	"Shared/Data",
-	"Modified/OK",	"Modified/Data",
-	"Exclusive/OK", "Exclusive/Data"
-};
-
-static char *causes[32] = {
-	"None", "GC_WR_ERR", "GC_RD_ERR", "COH_WR_ERR",
-	"COH_RD_ERR", "MMIO_WR_ERR", "MMIO_RD_ERR", "0x07",
-	"0x08", "0x09", "0x0a", "0x0b",
-	"0x0c", "0x0d", "0x0e", "0x0f",
-	"0x10", "0x11", "0x12", "0x13",
-	"0x14", "0x15", "0x16", "INTVN_WR_ERR",
-	"INTVN_RD_ERR", "0x19", "0x1a", "0x1b",
-	"0x1c", "0x1d", "0x1e", "0x1f"
-};
-
 int malta_be_handler(struct pt_regs *regs, int is_fixup)
 {
 	/* This duplicates the handling in do_be which seems wrong */
 	int retval = is_fixup ? MIPS_BE_FIXUP : MIPS_BE_FATAL;
 
-	if (mips_cm_present()) {
-		unsigned long cm_error = read_gcr_error_cause();
-		unsigned long cm_addr = read_gcr_error_addr();
-		unsigned long cm_other = read_gcr_error_mult();
-		unsigned long cause, ocause;
-		char buf[256];
-
-		cause = cm_error & CM_GCR_ERROR_CAUSE_ERRTYPE_MSK;
-		if (cause != 0) {
-			cause >>= CM_GCR_ERROR_CAUSE_ERRTYPE_SHF;
-			if (cause < 16) {
-				unsigned long cca_bits = (cm_error >> 15) & 7;
-				unsigned long tr_bits = (cm_error >> 12) & 7;
-				unsigned long cmd_bits = (cm_error >> 7) & 0x1f;
-				unsigned long stag_bits = (cm_error >> 3) & 15;
-				unsigned long sport_bits = (cm_error >> 0) & 7;
-
-				snprintf(buf, sizeof(buf),
-					 "CCA=%lu TR=%s MCmd=%s STag=%lu "
-					 "SPort=%lu\n",
-					 cca_bits, tr[tr_bits], mcmd[cmd_bits],
-					 stag_bits, sport_bits);
-			} else {
-				/* glob state & sresp together */
-				unsigned long c3_bits = (cm_error >> 18) & 7;
-				unsigned long c2_bits = (cm_error >> 15) & 7;
-				unsigned long c1_bits = (cm_error >> 12) & 7;
-				unsigned long c0_bits = (cm_error >> 9) & 7;
-				unsigned long sc_bit = (cm_error >> 8) & 1;
-				unsigned long cmd_bits = (cm_error >> 3) & 0x1f;
-				unsigned long sport_bits = (cm_error >> 0) & 7;
-				snprintf(buf, sizeof(buf),
-					 "C3=%s C2=%s C1=%s C0=%s SC=%s "
-					 "MCmd=%s SPort=%lu\n",
-					 core[c3_bits], core[c2_bits],
-					 core[c1_bits], core[c0_bits],
-					 sc_bit ? "True" : "False",
-					 mcmd[cmd_bits], sport_bits);
-			}
-
-			ocause = (cm_other & CM_GCR_ERROR_MULT_ERR2ND_MSK) >>
-				 CM_GCR_ERROR_MULT_ERR2ND_SHF;
-
-			pr_err("CM_ERROR=%08lx %s <%s>\n", cm_error,
-			       causes[cause], buf);
-			pr_err("CM_ADDR =%08lx\n", cm_addr);
-			pr_err("CM_OTHER=%08lx %s\n", cm_other, causes[ocause]);
-
-			/* reprime cause register */
-			write_gcr_error_cause(0);
-		}
-	}
+	mips_cm_error_report();
 
 	return retval;
 }
diff --git a/kernel/arch/mips/mti-malta/malta-memory.c b/kernel/arch/mips/mti-malta/malta-memory.c
index b769657be..d5f8dae6a 100644
--- a/kernel/arch/mips/mti-malta/malta-memory.c
+++ b/kernel/arch/mips/mti-malta/malta-memory.c
@@ -21,147 +21,20 @@
 #include <asm/sections.h>
 #include <asm/fw/fw.h>
 
-static fw_memblock_t mdesc[FW_MAX_MEMBLOCKS];
-
 /* determined physical memory size, not overridden by command line args	 */
 unsigned long physical_memsize = 0L;
 
-fw_memblock_t * __init fw_getmdesc(int eva)
-{
-	char *memsize_str, *ememsize_str = NULL, *ptr;
-	unsigned long memsize = 0, ememsize = 0;
-	static char cmdline[COMMAND_LINE_SIZE] __initdata;
-	int tmp;
-
-	/* otherwise look in the environment */
-
-	memsize_str = fw_getenv("memsize");
-	if (memsize_str) {
-		tmp = kstrtoul(memsize_str, 0, &memsize);
-		if (tmp)
-			pr_warn("Failed to read the 'memsize' env variable.\n");
-	}
-	if (eva) {
-	/* Look for ememsize for EVA */
-		ememsize_str = fw_getenv("ememsize");
-		if (ememsize_str) {
-			tmp = kstrtoul(ememsize_str, 0, &ememsize);
-			if (tmp)
-				pr_warn("Failed to read the 'ememsize' env variable.\n");
-		}
-	}
-	if (!memsize && !ememsize) {
-		pr_warn("memsize not set in YAMON, set to default (32Mb)\n");
-		physical_memsize = 0x02000000;
-	} else {
-		if (memsize > (256 << 20)) { /* memsize should be capped to 256M */
-			pr_warn("Unsupported memsize value (0x%lx) detected! "
-				"Using 0x10000000 (256M) instead\n",
-				memsize);
-			memsize = 256 << 20;
-		}
-		/* If ememsize is set, then set physical_memsize to that */
-		physical_memsize = ememsize ? : memsize;
-	}
-
-#ifdef CONFIG_CPU_BIG_ENDIAN
-	/* SOC-it swaps, or perhaps doesn't swap, when DMA'ing the last
-	   word of physical memory */
-	physical_memsize -= PAGE_SIZE;
-#endif
-
-	/* Check the command line for a memsize directive that overrides
-	   the physical/default amount */
-	strcpy(cmdline, arcs_cmdline);
-	ptr = strstr(cmdline, "memsize=");
-	if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
-		ptr = strstr(ptr, " memsize=");
-	/* And now look for ememsize */
-	if (eva) {
-		ptr = strstr(cmdline, "ememsize=");
-		if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
-			ptr = strstr(ptr, " ememsize=");
-	}
-
-	if (ptr)
-		memsize = memparse(ptr + 8 + (eva ? 1 : 0), &ptr);
-	else
-		memsize = physical_memsize;
-
-	/* Last 64K for HIGHMEM arithmetics */
-	if (memsize > 0x7fff0000)
-		memsize = 0x7fff0000;
-
-	memset(mdesc, 0, sizeof(mdesc));
-
-	mdesc[0].type = fw_dontuse;
-	mdesc[0].base = PHYS_OFFSET;
-	mdesc[0].size = 0x00001000;
-
-	mdesc[1].type = fw_code;
-	mdesc[1].base = mdesc[0].base + 0x00001000UL;
-	mdesc[1].size = 0x000ef000;
-
-	/*
-	 * The area 0x000f0000-0x000fffff is allocated for BIOS memory by the
-	 * south bridge and PCI access always forwarded to the ISA Bus and
-	 * BIOSCS# is always generated.
-	 * This mean that this area can't be used as DMA memory for PCI
-	 * devices.
-	 */
-	mdesc[2].type = fw_dontuse;
-	mdesc[2].base = mdesc[0].base + 0x000f0000UL;
-	mdesc[2].size = 0x00010000;
-
-	mdesc[3].type = fw_dontuse;
-	mdesc[3].base = mdesc[0].base + 0x00100000UL;
-	mdesc[3].size = CPHYSADDR(PFN_ALIGN((unsigned long)&_end)) -
-		0x00100000UL;
-
-	mdesc[4].type = fw_free;
-	mdesc[4].base = mdesc[0].base + CPHYSADDR(PFN_ALIGN(&_end));
-	mdesc[4].size = memsize - CPHYSADDR(mdesc[4].base);
-
-	return &mdesc[0];
-}
-
 static void free_init_pages_eva_malta(void *begin, void *end)
 {
 	free_init_pages("unused kernel", __pa_symbol((unsigned long *)begin),
 			__pa_symbol((unsigned long *)end));
 }
 
-static int __init fw_memtype_classify(unsigned int type)
-{
-	switch (type) {
-	case fw_free:
-		return BOOT_MEM_RAM;
-	case fw_code:
-		return BOOT_MEM_ROM_DATA;
-	default:
-		return BOOT_MEM_RESERVED;
-	}
-}
-
 void __init fw_meminit(void)
 {
-	fw_memblock_t *p;
-
-	p = fw_getmdesc(config_enabled(CONFIG_EVA));
-	free_init_pages_eva = (config_enabled(CONFIG_EVA) ?
-			       free_init_pages_eva_malta : NULL);
-
-	while (p->size) {
-		long type;
-		unsigned long base, size;
-
-		type = fw_memtype_classify(p->type);
-		base = p->base;
-		size = p->size;
+	bool eva = config_enabled(CONFIG_EVA);
 
-		add_memory_region(base, size, type);
-		p++;
-	}
+	free_init_pages_eva = eva ? free_init_pages_eva_malta : NULL;
 }
 
 void __init prom_free_prom_memory(void)
@@ -179,31 +52,6 @@ void __init prom_free_prom_memory(void)
 	}
 }
 
-unsigned platform_maar_init(unsigned num_pairs)
-{
-	phys_addr_t mem_end = (physical_memsize & ~0xffffull) - 1;
-	struct maar_config cfg[] = {
-		/* DRAM preceding I/O */
-		{ 0x00000000, 0x0fffffff, MIPS_MAAR_S },
-
-		/* DRAM following I/O */
-		{ 0x20000000, mem_end, MIPS_MAAR_S },
-
-		/* DRAM alias in upper half of physical */
-		{ 0x80000000, 0x80000000 + mem_end, MIPS_MAAR_S },
-	};
-	unsigned i, num_cfg = ARRAY_SIZE(cfg);
-
-	/* If DRAM fits before I/O, drop the region following it */
-	if (physical_memsize <= 0x10000000) {
-		num_cfg--;
-		for (i = 1; i < num_cfg; i++)
-			cfg[i] = cfg[i + 1];
-	}
-
-	return maar_config(cfg, num_cfg, num_pairs);
-}
-
 phys_addr_t mips_cdmm_phys_base(void)
 {
 	/* This address is "typically unused" */
diff --git a/kernel/arch/mips/mti-malta/malta-setup.c b/kernel/arch/mips/mti-malta/malta-setup.c
index db7c9e582..4740c82fb 100644
--- a/kernel/arch/mips/mti-malta/malta-setup.c
+++ b/kernel/arch/mips/mti-malta/malta-setup.c
@@ -21,16 +21,19 @@
 #include <linux/sched.h>
 #include <linux/ioport.h>
 #include <linux/irq.h>
+#include <linux/of_fdt.h>
 #include <linux/pci.h>
 #include <linux/screen_info.h>
 #include <linux/time.h>
 
 #include <asm/fw/fw.h>
+#include <asm/mach-malta/malta-dtshim.h>
 #include <asm/mips-cm.h>
 #include <asm/mips-boards/generic.h>
 #include <asm/mips-boards/malta.h>
 #include <asm/mips-boards/maltaint.h>
 #include <asm/dma.h>
+#include <asm/prom.h>
 #include <asm/traps.h>
 #ifdef CONFIG_VT
 #include <linux/console.h>
@@ -248,6 +251,10 @@ static void __init bonito_quirks_setup(void)
 void __init plat_mem_setup(void)
 {
 	unsigned int i;
+	void *fdt = __dtb_start;
+
+	fdt = malta_dt_shim(fdt);
+	__dt_setup_arch(fdt);
 
 	if (config_enabled(CONFIG_EVA))
 		/* EVA has already been configured in mach-malta/kernel-init.h */
diff --git a/kernel/arch/mips/mti-malta/malta-time.c b/kernel/arch/mips/mti-malta/malta-time.c
index a7f7d9ffb..b7bf721ea 100644
--- a/kernel/arch/mips/mti-malta/malta-time.c
+++ b/kernel/arch/mips/mti-malta/malta-time.c
@@ -119,18 +119,24 @@ void read_persistent_clock(struct timespec *ts)
 
 int get_c0_fdc_int(void)
 {
-	int mips_cpu_fdc_irq;
+	/*
+	 * Some cores claim the FDC is routable through the GIC, but it doesn't
+	 * actually seem to be connected for those Malta bitstreams.
+	 */
+	switch (current_cpu_type()) {
+	case CPU_INTERAPTIV:
+	case CPU_PROAPTIV:
+		return -1;
+	};
 
 	if (cpu_has_veic)
-		mips_cpu_fdc_irq = -1;
+		return -1;
 	else if (gic_present)
-		mips_cpu_fdc_irq = gic_get_c0_fdc_int();
+		return gic_get_c0_fdc_int();
 	else if (cp0_fdc_irq >= 0)
-		mips_cpu_fdc_irq = MIPS_CPU_IRQ_BASE + cp0_fdc_irq;
+		return MIPS_CPU_IRQ_BASE + cp0_fdc_irq;
 	else
-		mips_cpu_fdc_irq = -1;
-
-	return mips_cpu_fdc_irq;
+		return -1;
 }
 
 int get_c0_perfcount_int(void)