commit d65283f7 added mod->arch.secstr under
CONFIG_ARC_DW2_UNWIND, but used it unconditionally which broke builds
when the option was disabled. Fix that by adjusting the #ifdef guard.

And while at it add a missing guard (for unwinder) in module.c as well
Reported-by: NWaldemar Brodkorb <wbx@openadk.org>
Cc: stable@vger.kernel.org    #4.9
Fixes: d65283f7 ("ARC: module: elide loop to save reference to .eh_frame")
Tested-by: NAnton Kolesov <akolesov@synopsys.com>
Reviewed-by: NAlexey Brodkin <abrodkin@synopsys.com>
[abrodkin: provided fixlet to Kconfig per failure in allnoconfig build]
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Signed-off-by: NVladimir Kondratiev <vladimir.kondratiev@intel.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

This adds support for

 - CONFIG_ARC_TIMERS : legacy 32-bit TIMER0 and TIMER1 which count UP
   from @CNT to @LIMIT, before optionally triggering an interrupt.
   These are programmed using ARC auxiliary register interface.
   These are present in all ARC cores (ARC700 and ARC HS38)
   TIMER0 serves as clockevent for all ARC linux builds.
   TIMER1 is used for clocksource in arc700 builds.

 - CONFIG_ARC_TIMERS_64BIT: 64-bit counters, RTC and GFRC found in
   ARC HS38 cores. These are independnet IP blocks with different
   programming model respectively.

Link: http://lkml.kernel.org/r/20161111231132.GA4186@maiAcked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

The original distinction was done as they were developed at different
times and primarily because they are specific to UP (RTC) and SMP (GFRC).

But given that driver handles that at runtime, (i.e. not allowing
RTC as clocksource in SMP), we can simplify things a bit.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

... given that we have perf counters abel to do the same thing non
intrusively
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Add support for lzma compressed uImage.

Support for gzip was already available but could not be enabled because
we were missing CONFIG_HAVE_KERNEL_GZIP in arch/arc/Kconfig.
Signed-off-by: NDaniel Mentz <danielmentz@google.com>
Cc: linux-snps-arc@lists.infradead.org
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

The IDU intc is technically part of MCIP (Multi-core IP) hence
historically was only available in a SMP hardware build (and thus only
in a SMP kernel build). Now that hardware restriction has been lifted,
so a UP kernel needs to support it.

This requires breaking mcip.c into parts which are strictly SMP
(inter-core interrupts) and IDU which in reality is just another
intc and thus has no bearing on SMP.

This change allows IDU in UP builds and with a suitable device tree, we
can have the cascaded intc system

    ARCv2 core intc <---> ARCv2 IDU intc <---> periperals
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Seem like values assigned as absolute number and not and
shift value, i.e. should be 0 for one node (2^0) and 1 for
couple of nodes (2^1)
Signed-off-by: NNoam Camus <noamca@mellanox.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

ARCv2 ISA provides 64-bit exclusive load/stores so use them to implement
the 64-bit atomics and elide the spinlock based generic 64-bit atomics

boot tested with atomic64 self-test (and GOD bless the person who wrote
them, I realized my inline assmebly is sloppy as hell)

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

This reverts commit e78fdfef.

The issue was fixed in hardware in HS2.1C release and there are no known
external users of affected RTL so revert the whole delayed retry series !
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

ARC700 support for 2 interrupt priorities historically allowed even slow
perpherals such as emac and uart to setup high priority interrupts
which was wrong from the beginning as they could possibly delay the more
critical timer interrupt.

The hardware support for 2 level interrupts in ARCompact is less than
ideal anyways (judging from the "hacks" in low level entry code and thus
is not used in productions systems I know of.

So reduce the scope of this to timer only, thereby reducing a bunch of
complexity.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

The binary GCD algorithm is based on the following facts:
	1. If a and b are all evens, then gcd(a,b) = 2 * gcd(a/2, b/2)
	2. If a is even and b is odd, then gcd(a,b) = gcd(a/2, b)
	3. If a and b are all odds, then gcd(a,b) = gcd((a-b)/2, b) = gcd((a+b)/2, b)

Even on x86 machines with reasonable division hardware, the binary
algorithm runs about 25% faster (80% the execution time) than the
division-based Euclidian algorithm.

On platforms like Alpha and ARMv6 where division is a function call to
emulation code, it's even more significant.

There are two variants of the code here, depending on whether a fast
__ffs (find least significant set bit) instruction is available.  This
allows the unpredictable branches in the bit-at-a-time shifting loop to
be eliminated.

If fast __ffs is not available, the "even/odd" GCD variant is used.

I use the following code to benchmark:

	#include <stdio.h>
	#include <stdlib.h>
	#include <stdint.h>
	#include <string.h>
	#include <time.h>
	#include <unistd.h>

	#define swap(a, b) \
		do { \
			a ^= b; \
			b ^= a; \
			a ^= b; \
		} while (0)

	unsigned long gcd0(unsigned long a, unsigned long b)
	{
		unsigned long r;

		if (a < b) {
			swap(a, b);
		}

		if (b == 0)
			return a;

		while ((r = a % b) != 0) {
			a = b;
			b = r;
		}

		return b;
	}

	unsigned long gcd1(unsigned long a, unsigned long b)
	{
		unsigned long r = a | b;

		if (!a || !b)
			return r;

		b >>= __builtin_ctzl(b);

		for (;;) {
			a >>= __builtin_ctzl(a);
			if (a == b)
				return a << __builtin_ctzl(r);

			if (a < b)
				swap(a, b);
			a -= b;
		}
	}

	unsigned long gcd2(unsigned long a, unsigned long b)
	{
		unsigned long r = a | b;

		if (!a || !b)
			return r;

		r &= -r;

		while (!(b & r))
			b >>= 1;

		for (;;) {
			while (!(a & r))
				a >>= 1;
			if (a == b)
				return a;

			if (a < b)
				swap(a, b);
			a -= b;
			a >>= 1;
			if (a & r)
				a += b;
			a >>= 1;
		}
	}

	unsigned long gcd3(unsigned long a, unsigned long b)
	{
		unsigned long r = a | b;

		if (!a || !b)
			return r;

		b >>= __builtin_ctzl(b);
		if (b == 1)
			return r & -r;

		for (;;) {
			a >>= __builtin_ctzl(a);
			if (a == 1)
				return r & -r;
			if (a == b)
				return a << __builtin_ctzl(r);

			if (a < b)
				swap(a, b);
			a -= b;
		}
	}

	unsigned long gcd4(unsigned long a, unsigned long b)
	{
		unsigned long r = a | b;

		if (!a || !b)
			return r;

		r &= -r;

		while (!(b & r))
			b >>= 1;
		if (b == r)
			return r;

		for (;;) {
			while (!(a & r))
				a >>= 1;
			if (a == r)
				return r;
			if (a == b)
				return a;

			if (a < b)
				swap(a, b);
			a -= b;
			a >>= 1;
			if (a & r)
				a += b;
			a >>= 1;
		}
	}

	static unsigned long (*gcd_func[])(unsigned long a, unsigned long b) = {
		gcd0, gcd1, gcd2, gcd3, gcd4,
	};

	#define TEST_ENTRIES (sizeof(gcd_func) / sizeof(gcd_func[0]))

	#if defined(__x86_64__)

	#define rdtscll(val) do { \
		unsigned long __a,__d; \
		__asm__ __volatile__("rdtsc" : "=a" (__a), "=d" (__d)); \
		(val) = ((unsigned long long)__a) | (((unsigned long long)__d)<<32); \
	} while(0)

	static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long),
								unsigned long a, unsigned long b, unsigned long *res)
	{
		unsigned long long start, end;
		unsigned long long ret;
		unsigned long gcd_res;

		rdtscll(start);
		gcd_res = gcd(a, b);
		rdtscll(end);

		if (end >= start)
			ret = end - start;
		else
			ret = ~0ULL - start + 1 + end;

		*res = gcd_res;
		return ret;
	}

	#else

	static inline struct timespec read_time(void)
	{
		struct timespec time;
		clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time);
		return time;
	}

	static inline unsigned long long diff_time(struct timespec start, struct timespec end)
	{
		struct timespec temp;

		if ((end.tv_nsec - start.tv_nsec) < 0) {
			temp.tv_sec = end.tv_sec - start.tv_sec - 1;
			temp.tv_nsec = 1000000000ULL + end.tv_nsec - start.tv_nsec;
		} else {
			temp.tv_sec = end.tv_sec - start.tv_sec;
			temp.tv_nsec = end.tv_nsec - start.tv_nsec;
		}

		return temp.tv_sec * 1000000000ULL + temp.tv_nsec;
	}

	static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long),
								unsigned long a, unsigned long b, unsigned long *res)
	{
		struct timespec start, end;
		unsigned long gcd_res;

		start = read_time();
		gcd_res = gcd(a, b);
		end = read_time();

		*res = gcd_res;
		return diff_time(start, end);
	}

	#endif

	static inline unsigned long get_rand()
	{
		if (sizeof(long) == 8)
			return (unsigned long)rand() << 32 | rand();
		else
			return rand();
	}

	int main(int argc, char **argv)
	{
		unsigned int seed = time(0);
		int loops = 100;
		int repeats = 1000;
		unsigned long (*res)[TEST_ENTRIES];
		unsigned long long elapsed[TEST_ENTRIES];
		int i, j, k;

		for (;;) {
			int opt = getopt(argc, argv, "n:r:s:");
			/* End condition always first */
			if (opt == -1)
				break;

			switch (opt) {
			case 'n':
				loops = atoi(optarg);
				break;
			case 'r':
				repeats = atoi(optarg);
				break;
			case 's':
				seed = strtoul(optarg, NULL, 10);
				break;
			default:
				/* You won't actually get here. */
				break;
			}
		}

		res = malloc(sizeof(unsigned long) * TEST_ENTRIES * loops);
		memset(elapsed, 0, sizeof(elapsed));

		srand(seed);
		for (j = 0; j < loops; j++) {
			unsigned long a = get_rand();
			/* Do we have args? */
			unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand();
			unsigned long long min_elapsed[TEST_ENTRIES];
			for (k = 0; k < repeats; k++) {
				for (i = 0; i < TEST_ENTRIES; i++) {
					unsigned long long tmp = benchmark_gcd_func(gcd_func[i], a, b, &res[j][i]);
					if (k == 0 || min_elapsed[i] > tmp)
						min_elapsed[i] = tmp;
				}
			}
			for (i = 0; i < TEST_ENTRIES; i++)
				elapsed[i] += min_elapsed[i];
		}

		for (i = 0; i < TEST_ENTRIES; i++)
			printf("gcd%d: elapsed %llu\n", i, elapsed[i]);

		k = 0;
		srand(seed);
		for (j = 0; j < loops; j++) {
			unsigned long a = get_rand();
			unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand();
			for (i = 1; i < TEST_ENTRIES; i++) {
				if (res[j][i] != res[j][0])
					break;
			}
			if (i < TEST_ENTRIES) {
				if (k == 0) {
					k = 1;
					fprintf(stderr, "Error:\n");
				}
				fprintf(stderr, "gcd(%lu, %lu): ", a, b);
				for (i = 0; i < TEST_ENTRIES; i++)
					fprintf(stderr, "%ld%s", res[j][i], i < TEST_ENTRIES - 1 ? ", " : "\n");
			}
		}

		if (k == 0)
			fprintf(stderr, "PASS\n");

		free(res);

		return 0;
	}

Compiled with "-O2", on "VirtualBox 4.4.0-22-generic #38-Ubuntu x86_64" got:

  zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
  gcd0: elapsed 10174
  gcd1: elapsed 2120
  gcd2: elapsed 2902
  gcd3: elapsed 2039
  gcd4: elapsed 2812
  PASS
  zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
  gcd0: elapsed 9309
  gcd1: elapsed 2280
  gcd2: elapsed 2822
  gcd3: elapsed 2217
  gcd4: elapsed 2710
  PASS
  zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
  gcd0: elapsed 9589
  gcd1: elapsed 2098
  gcd2: elapsed 2815
  gcd3: elapsed 2030
  gcd4: elapsed 2718
  PASS
  zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
  gcd0: elapsed 9914
  gcd1: elapsed 2309
  gcd2: elapsed 2779
  gcd3: elapsed 2228
  gcd4: elapsed 2709
  PASS

[akpm@linux-foundation.org: avoid #defining a CONFIG_ variable]
Signed-off-by: NZhaoxiu Zeng <zhaoxiu.zeng@gmail.com>
Signed-off-by: NGeorge Spelvin <linux@horizon.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This commit should be left last since only now eznps platform
is in state which one can actually use.
Signed-off-by: NNoam Camus <noamc@ezchip.com>

On ARC, lower 2G of address space is translated and used for
 - user vaddr space (region 0 to 5)
 - unused kernel-user gutter (region 6)
 - kernel vaddr space (region 7)

where each region simply represents 256MB of address space.

The kernel vaddr space of 256MB is used to implement vmalloc, modules
So far this was enough, but not on EZChip system with 4K CPUs (given
that per cpu mechanism uses vmalloc for allocating chunks)

So allow VMALLOC_SIZE to be configurable by expanding down into the unused
kernel-user gutter region which at default 256M was excessive anyways.

Also use _BITUL() to fix a build error since PGDIR_SIZE cannot use "1UL"
as called from assembly code in mm/tlbex.S
Signed-off-by: NNoam Camus <noamc@ezchip.com>
[vgupta: rewrote changelog, debugged bootup crash due to int vs. hex]
Acked-by: NVineet Gupta <vgupta@synopsys.com>

The primary interrupt handler arch_do_IRQ() was passing hwirq as linux
virq to core code. This was fragile and worked so far as we only had legacy/linear
domains.

This came out of a rant by Marc Zyngier.
http://lists.infradead.org/pipermail/linux-snps-arc/2015-December/000298.html

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Noam Camus <noamc@ezchip.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

 - call clocksource_probe()
 - This in turns needs of_clk_init() to be called earlier

Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NNoam Camus <noamc@ezchip.com>
[vgupta: broken off from a bigger patch]
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Initial HIGHMEM support on ARC was introduced for PAE40 where the low
memory (0x8000_0000 based) and high memory (0x1_0000_0000) were
physically contiguous. So CONFIG_FLATMEM sufficed (despite a peipheral
hole in the middle, which wasted a bit of struct page memory, but things
worked).

However w/o PAE, highmem was not possible and we could only reach
~1.75GB of DDR. Now there is a use case to access ~4GB of DDR w/o PAE40
The idea is to have low memory at canonical 0x8000_0000 and highmem
at 0 so enire 4GB address space is available for physical addressing
This needs additional platform/interconnect mapping to convert
the non contiguous physical addresses into linear bus adresses.

From Linux point of view, non contiguous divide means FLATMEM no
longer works and DISCONTIGMEM is needed to track the pfns in the 2
regions.

This scheme would also work for PAE40, only better in that we don't
waste struct page memory for the peripheral hole.

The DT description will be something like

    memory {
        ...
        reg = <0x80000000 0x200000000   /* 512MB: lowmem */
               0x00000000 0x10000000>;  /* 256MB: highmem */
   }
Signed-off-by: NNoam Camus <noamc@ezchip.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Enable reserved memory initialization from device tree.
Signed-off-by: NAlexey Brodkin <abrodkin@synopsys.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Signed-off-by: NAlexey Brodkin <abrodkin@synopsys.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Commit 5f8fc432 ("PCI: Include pci/pcie/Kconfig directly from
pci/Kconfig") in linux-next changed drivers/pci/Kconfig to include
drivers/pci/pcie/Kconfig itself, so that architectures do not need
to source both files themselves. ARC just recently gained PCI support
through commit 6b3fb77998dd ("ARC: Add PCI support"), but this change
was based on the old behaviour of the Kconfig files. This makes
Kconfig now spit out the following warnings:

drivers/pci/pcie/Kconfig:61:warning: choice value used outside its choice group
drivers/pci/pcie/Kconfig:67:warning: choice value used outside its choice group
drivers/pci/pcie/Kconfig:74:warning: choice value used outside its choice group

This change updates the Kconfig file for ARC, dropping the now
unnecessary 'source' statement, which makes the warning disappear.
Signed-off-by: NAndreas Ziegler <andreas.ziegler@fau.de>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

This allows for regression testing in PAE specific code as we lack
a 32+ bit physical memory platform other than nSIM.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Add PCI support to ARC and update drivers/pci Makefile enabling the ARC
arch to use the generic PCI setup functions.

[bhelgaas: fold in Joao's pci-dma-compat.h & pci-bridge.h build fix (I
should have caught this myself, sorry]
Signed-off-by: NJoao Pinto <jpinto@synopsys.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NVineet Gupta <vgupta@synopsys.com>

This was more relevant during SMP bringup.

The warning for bogus msg better be visible always.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Even though DEVTMPFS is required when our pre-built initramfs
is used it is not the case in general. It is perfectly possible
to use initramfs with device nodes already populated or there
could be other usages, see discussion below for more detials:
http://thread.gmane.org/gmane.comp.embedded.openwrt.devel/37819/focus=37821

This change removes mentioned dependency from arch/arc/Kconfig
updating instead those defconfigs that are usually used with this
kind of pre-build initramfs.

And while at it all touched defconfigs were regenerated via
savedefconfig and some options were removed:
 * USB is selected by other options implicitly
 * VGA_CONSOLE is disableb for ARC since
   031e29b5
 * EXT3_FS automatically selects EXT4_FS
 * MTDxxx and JFFS2_FS make no sense for AXS because
   AXS NAND controller is not upstreamed
 * NET_OSCI_LAN is not in upstream as well
 * ARCPGU_xxx options make no sense because ARC PGU is not yet
   in upstream and when it gets there all config options would
   be taken from devicetree
Signed-off-by: NAlexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

It is unlikely that designs running Linux will not have multiplier.
Further the current support is not complete as tool don't generate a
multilib w/o multiplier.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

MMUv4 supports 2 concurrent page sizes: Normal and Super [4K to 16M]

So far Linux supported a single super page size for a given Normal page,
depending on the software page walking address split.
e.g. we had 11:8:13 address split for 8K page, which meant super page
was 2 ^(8+13) = 2M (given that THP size has to be PMD_SHIFT)

Now we turn this around, by allowing multiple Super Pages in Kconfig
(currently 2M and 16M only) and forcing page walker address split to
PGDIR_SHIFT and PAGE_SHIFT

For configs without Super page, things are same as before and
PGDIR_SHIFT can be hacked to get non default address split

The motivation for this change is a customer who needs 16M super page
and a 8K Normal page combo.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

... it is now called Global Free Running Counter
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Move the generic implementation to <linux/dma-mapping.h> now that all
architectures support it and remove the HAVE_DMA_ATTR Kconfig symbol now
that everyone supports them.

[valentinrothberg@gmail.com: remove leftovers in Kconfig]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Helge Deller <deller@gmx.de>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NValentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

[vgupta@synopsys.com: ARC: dma mapping fixes #2]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Carlos Palminha <CARLOS.PALMINHA@synopsys.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As illustrated by commit a3afe70b ("[S390] latencytop s390
support."), HAVE_LATENCYTOP_SUPPORT is defined by an architecture to
advertise an implementation of save_stack_trace_tsk.

However, as of 9212ddb5 ("stacktrace: provide save_stack_trace_tsk()
weak alias") a dummy implementation is provided if STACKTRACE=y.  Given
that LATENCYTOP already depends on STACKTRACE_SUPPORT and selects
STACKTRACE, we can remove HAVE_LATENCYTOP_SUPPORT altogether.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Helge Deller <deller@gmx.de>
Acked-by: NMichael Ellerman <mpe@ellerman.id.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

HIGHMEM support bumped the default memory size for nsim platform to 1G.
Thus total memory ended at the very edge of start of peripherals address
space. With linux link base shifted, memory started bleeding into
peripheral space which caused early boot bad_page spew !

Fixes: 29e33226 ("ARC: mm: HIGHMEM: populate high memory from DT")
Reported-by: NAnton Kolesov <akolesov@synopsys.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

This is the first working implementation of 40-bit physical address
extension on ARCv2.
Signed-off-by: NAlexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Implement kmap* API for ARC.

This enables
 - permanent kernel maps (pkmaps): :kmap() API
 - fixmap : kmap_atomic()

We use a very simple/uniform approach for both (unlike some of the other
arches). So fixmap doesn't use the customary compile time address stuff.
The important semantic is sleep'ability (pkmap) vs. not (fixmap) which
the API guarantees.

Note that this patch only enables highmem for subsequent PAE40 support
as there is no real highmem for ARC in pure 32-bit paradigm as explained
below.

ARC has 2:2 address split of the 32-bit address space with lower half
being translated (virtual) while upper half unstranslated
(0x8000_0000 to 0xFFFF_FFFF). kernel itself is linked at base of
unstranslated space (i.e. 0x8000_0000 onwards), which is mapped to say
DDR 0x0 by external Bus Glue logic (outside the core). So kernel can
potentially access 1.75G worth of memory directly w/o need for highmem.
(the top 256M is taken by uncached peripheral space from 0xF000_0000 to
0xFFFF_FFFF)

In PAE40, hardware can address memory beyond 4G (0x1_0000_0000) while
the logical/virtual addresses remain 32-bits. Thus highmem is required
for kernel proper to be able to access these pages for it's own purposes
(user space is agnostic to this anyways).
Signed-off-by: NAlexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

For Run-on-reset, non masters need to spin wait. For Halt-on-reset they
can jump to entry point directly.

Also while at it, made reset vector handler as "the" entry point for
kernel including host debugger based boot (which uses the ELF header
entry point)
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

MMUv4 in HS38x cores supports Super Pages which are basis for Linux THP
support.

Normal and Super pages can co-exist (ofcourse not overlap) in TLB with a
new bit "SZ" in TLB page desciptor to distinguish between them.
Super Page size is configurable in hardware (4K to 16M), but fixed once
RTL builds.

The exact THP size a Linx configuration will support is a function of:
 - MMU page size (typical 8K, RTL fixed)
 - software page walker address split between PGD:PTE:PFN (typical
   11:8:13, but can be changed with 1 line)

So for above default, THP size supported is 8K * 256 = 2M

Default Page Walker is 2 levels, PGD:PTE:PFN, which in THP regime
reduces to 1 level (as PTE is folded into PGD and canonically referred
to as PMD).

Thus thp PMD accessors are implemented in terms of PTE (just like sparc)
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

ARC doesn't need the runtime detection of futex cmpxchg op

Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>