Adds the clock bindings for Freescale PowerPC CoreNet platforms
Signed-off-by: NTang Yuantian <Yuantian.Tang@freescale.com>
Signed-off-by: NLi Yang <leoli@freescale.com>
[scottwood@freescale.com: fixed clock-frequency in example]
Signed-off-by: NScott Wood <scottwood@freescale.com>

...and make CONFIG_PPC_FSL_BOOK3E conflict with CONFIG_PPC_64K_PAGES.

This fixes a build break with CONFIG_PPC_64K_PAGES on 64-bit book3e,
that was introduced by commit 28efc35f
("powerpc/e6500: TLB miss handler with hardware tablewalk support").
Signed-off-by: NScott Wood <scottwood@freescale.com>

Freescale updates from Scott:

<<
Highlights include 32-bit booke relocatable support, e6500 hardware
tablewalk support, various e500 SPE fixes, some new/revived boards, and
e6500 deeper idle and altivec powerdown modes.
>>

Currently, if a process starts a transaction and then takes an
exception because the FPU, VMX or VSX unit is unavailable to it,
we end up corrupting any FP/VMX/VSX state that was valid before
the interrupt.  For example, if the process starts a transaction
with the FPU available to it but VMX unavailable, and then does
a VMX instruction inside the transaction, the FP state gets
corrupted.

Loading up the desired state generally involves doing a reclaim
and a recheckpoint.  To avoid corrupting already-valid state, we have
to be careful not to reload that state from the thread_struct
between the reclaim and the recheckpoint (since the thread_struct
values are stale by now), and we have to reload that state from
the transact_fp/vr arrays after the recheckpoint to get back the
current transactional values saved there by the reclaim.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently, when we have a process using the transactional memory
facilities on POWER8 (that is, the processor is in transactional
or suspended state), and the process enters the kernel and the
kernel then uses the floating-point or vector (VMX/Altivec) facility,
we end up corrupting the user-visible FP/VMX/VSX state.  This
happens, for example, if a page fault causes a copy-on-write
operation, because the copy_page function will use VMX to do the
copy on POWER8.  The test program below demonstrates the bug.

The bug happens because when FP/VMX state for a transactional process
is stored in the thread_struct, we store the checkpointed state in
.fp_state/.vr_state and the transactional (current) state in
.transact_fp/.transact_vr.  However, when the kernel wants to use
FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(),
which saves the current state in .fp_state/.vr_state.  Furthermore,
when we return to the user process we return with FP/VMX/VSX
disabled.  The next time the process uses FP/VMX/VSX, we don't know
which set of state (the current register values, .fp_state/.vr_state,
or .transact_fp/.transact_vr) we should be using, since we have no
way to tell if we are still in the same transaction, and if not,
whether the previous transaction succeeded or failed.

Thus it is necessary to strictly adhere to the rule that if FP has
been enabled at any point in a transaction, we must keep FP enabled
for the user process with the current transactional state in the
FP registers, until we detect that it is no longer in a transaction.
Similarly for VMX; once enabled it must stay enabled until the
process is no longer transactional.

In order to keep this rule, we add a new thread_info flag which we
test when returning from the kernel to userspace, called TIF_RESTORE_TM.
This flag indicates that there is FP/VMX/VSX state to be restored
before entering userspace, and when it is set the .tm_orig_msr field
in the thread_struct indicates what state needs to be restored.
The restoration is done by restore_tm_state().  The TIF_RESTORE_TM
bit is set by new giveup_fpu/altivec_maybe_transactional helpers,
which are called from enable_kernel_fp/altivec, giveup_vsx, and
flush_fp/altivec_to_thread instead of giveup_fpu/altivec.

The other thing to be done is to get the transactional FP/VMX/VSX
state from .fp_state/.vr_state when doing reclaim, if that state
has been saved there by giveup_fpu/altivec_maybe_transactional.
Having done this, we set the FP/VMX bit in the thread's MSR after
reclaim to indicate that that part of the state is now valid
(having been reclaimed from the processor's checkpointed state).

Finally, in the signal handling code, we move the clearing of the
transactional state bits in the thread's MSR a bit earlier, before
calling flush_fp_to_thread(), so that we don't unnecessarily set
the TIF_RESTORE_TM bit.

This is the test program:

/* Michael Neuling 4/12/2013
 *
 * See if the altivec state is leaked out of an aborted transaction due to
 * kernel vmx copy loops.
 *
 *   gcc -m64 htm_vmxcopy.c -o htm_vmxcopy
 *
 */

/* We don't use all of these, but for reference: */

int main(int argc, char *argv[])
{
	long double vecin = 1.3;
	long double vecout;
	unsigned long pgsize = getpagesize();
	int i;
	int fd;
	int size = pgsize*16;
	char tmpfile[] = "/tmp/page_faultXXXXXX";
	char buf[pgsize];
	char *a;
	uint64_t aborted = 0;

	fd = mkstemp(tmpfile);
	assert(fd >= 0);

	memset(buf, 0, pgsize);
	for (i = 0; i < size; i += pgsize)
		assert(write(fd, buf, pgsize) == pgsize);

	unlink(tmpfile);

	a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
	assert(a != MAP_FAILED);

	asm __volatile__(
		"lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value
		TBEGIN
		"beq	3f ;"
		TSUSPEND
		"xxlxor 40,40,40 ; " // set 40 to 0
		"std	5, 0(%[map]) ;" // cause kernel vmx copy page
		TABORT
		TRESUME
		TEND
		"li	%[res], 0 ;"
		"b	5f ;"
		"3: ;" // Abort handler
		"li	%[res], 1 ;"
		"5: ;"
		"stxvd2x 40,0,%[vecoutptr] ; "
		: [res]"=r"(aborted)
		: [vecinptr]"r"(&vecin),
		  [vecoutptr]"r"(&vecout),
		  [map]"r"(a)
		: "memory", "r0", "r3", "r4", "r5", "r6", "r7");

	if (aborted && (vecin != vecout)){
		printf("FAILED: vector state leaked on abort %f != %f\n",
		       (double)vecin, (double)vecout);
		exit(1);
	}

	munmap(a, size);

	close(fd);

	printf("PASSED!\n");
	return 0;
}
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

TIF_PERFMON_WORK and TIF_PERFMON_CTXSW are completely unused.  They
appear to be related to the old perfmon2 code, which has been
superseded by the perf_event infrastructure.  This removes their
definitions so that the bits can be used for other purposes.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

If we set irq_work on a processor and immediately afterward, before the
irq work has a chance to be processed, we change the decrementer value,
we can seriously delay the handling of that irq_work.

Fix it by checking in a few places for pending irq work, first before
changing the decrementer in decrementer_set_next_event() and after
changing it in the same function and in timer_interrupt().
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Huge Dickins reported an issue that b5ff4211
"powerpc/book3s: Queue up and process delayed MCE events" breaks the
PowerMac G5 boot. This patch fixes it by moving the mce even processing
away from syscall exit, which was wrong to do that in first place, and
using irq work framework to delay processing of mce event.

Reported-by: Hugh Dickins <hughd@google.com
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Commit fbd7740f(powerpc: Simplify pSeries idle loop) switched pseries cpu
idle handling from complete idle loops to ppc_md.powersave functions. Earlier to
this switch, ppc64_runlatch_off() had to be called in each of the idle routines.
But after the switch, this call is handled in arch_cpu_idle(),just before the call
to ppc_md.powersave, where platform specific idle routines are called.

As a consequence, the call to ppc64_runlatch_off() got duplicated in the
arch_cpu_idle() routine as well as in the some of the idle routines in
pseries and commit fbd7740f missed to get rid of these redundant
calls. These calls were carried over subsequent enhancements to the pseries
cpuidle routines.

Although multiple calls to ppc64_runlatch_off() is harmless, there is still some
overhead due to it. Besides that, these calls could also make way for a
misunderstanding that it is *necessary* to call ppc64_runlatch_off() multiple
times, when that is not the case. Hence this patch takes care of eliminating
this redundancy.
Signed-off-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

add_system_ram_resources() is a subsys_initcall.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This makes ppc64_defconfig bootable without initrd on pasemi systems,
most of whom have MV SATA controllers. Some have SIL24, but that driver
is already enabled.
Signed-off-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

At present we assume candidate image is <= 256MB. But in P8,
candidate image size can go up to 750MB. Hence increasing
candidate image max size to 1GB.
Signed-off-by: NVasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

There have been some weird bugs in the past where the kernel tried to associate
threads of the same core to different NUMA nodes, and things went haywire after
that point (as expected).

But unfortunately, root-causing such issues have been quite challenging, due to
the lack of appropriate debug checks in the kernel. These bugs usually lead to
some odd soft-lockups in the scheduler's build-sched-domain code in the CPU
hotplug path, which makes it very hard to trace it back to the incorrect
cpu-to-node mappings.

So add appropriate debug checks to catch such invalid cpu-to-node mappings
as early as possible.
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On POWER platforms, the hypervisor can notify the guest kernel about dynamic
changes in the cpu-numa associativity (VPHN topology update). Hence the
cpu-to-node mappings that we got from the firmware during boot, may no longer
be valid after such updates. This is handled using the arch_update_cpu_topology()
hook in the scheduler, and the sched-domains are rebuilt according to the new
mappings.

But unfortunately, at the moment, CPU hotplug ignores these updated mappings
and instead queries the firmware for the cpu-to-numa relationships and uses
them during CPU online. So the kernel can end up assigning wrong NUMA nodes
to CPUs during subsequent CPU hotplug online operations (after booting).

Further, a particularly problematic scenario can result from this bug:
On POWER platforms, the SMT mode can be switched between 1, 2, 4 (and even 8)
threads per core. The switch to Single-Threaded (ST) mode is performed by
offlining all except the first CPU thread in each core. Switching back to
SMT mode involves onlining those other threads back, in each core.

Now consider this scenario:

1. During boot, the kernel gets the cpu-to-node mappings from the firmware
   and assigns the CPUs to NUMA nodes appropriately, during CPU online.

2. Later on, the hypervisor updates the cpu-to-node mappings dynamically and
   communicates this update to the kernel. The kernel in turn updates its
   cpu-to-node associations and rebuilds its sched domains. Everything is
   fine so far.

3. Now, the user switches the machine from SMT to ST mode (say, by running
   ppc64_cpu --smt=1). This involves offlining all except 1 thread in each
   core.

4. The user then tries to switch back from ST to SMT mode (say, by running
   ppc64_cpu --smt=4), and this involves onlining those threads back. Since
   CPU hotplug ignores the new mappings, it queries the firmware and tries to
   associate the newly onlined sibling threads to the old NUMA nodes. This
   results in sibling threads within the same core getting associated with
   different NUMA nodes, which is incorrect.

   The scheduler's build-sched-domains code gets thoroughly confused with this
   and enters an infinite loop and causes soft-lockups, as explained in detail
   in commit 3be7db6a (powerpc: VPHN topology change updates all siblings).

So to fix this, use the numa_cpu_lookup_table to remember the updated
cpu-to-node mappings, and use them during CPU hotplug online operations.
Further, we also need to ensure that all threads in a core are assigned to a
common NUMA node, irrespective of whether all those threads were online during
the topology update. To achieve this, we take care not to use cpu_sibling_mask()
since it is not hotplug invariant. Instead, we use cpu_first_sibling_thread()
and set up the mappings manually using the 'threads_per_core' value for that
particular platform. This helps us ensure that we don't hit this bug with any
combination of CPU hotplug and SMT mode switching.

Cc: stable@vger.kernel.org
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Some devices, for example PCI root port, don't have IOMMU table and
group. We needn't detach them from their IOMMU group. Otherwise, it
potentially incurs kernel crash because of referring NULL IOMMU group
as following backtrace indicates:

  .iommu_group_remove_device+0x74/0x1b0
  .iommu_bus_notifier+0x94/0xb4
  .notifier_call_chain+0x78/0xe8
  .__blocking_notifier_call_chain+0x7c/0xbc
  .blocking_notifier_call_chain+0x38/0x48
  .device_del+0x50/0x234
  .pci_remove_bus_device+0x88/0x138
  .pci_stop_and_remove_bus_device+0x2c/0x40
  .pcibios_remove_pci_devices+0xcc/0xfc
  .pcibios_remove_pci_devices+0x3c/0xfc
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When EEH error comes to one specific PCI device before its driver
is loaded, we will apply hotplug to recover the error. During the
plug time, the PCI device will be probed and its driver is loaded.
Then we wrongly calls to the error handlers if the driver supports
EEH explicitly.

The patch intends to fix by introducing flag EEH_DEV_NO_HANDLER and
set it before we remove the PCI device. In turn, we can avoid wrongly
calls the error handlers of the PCI device after its driver loaded.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch implements the EEH operation backend restore_config()
for PowerNV platform. That relies on OPAL API opal_pci_reinit()
where we reinitialize the error reporting properly after PE or
PHB reset.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

After reset on the specific PE or PHB, we never configure AER
correctly on PowerNV platform. We needn't care it on pSeries
platform. The patch introduces additional EEH operation eeh_ops::
restore_config() so that we have chance to configure AER correctly
for PowerNV platform.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We don't have IO ports on PHB3 and the assignment of variable
"iomap_off" on PHB3 is meaningless. The patch just removes the
unnecessary assignment to the variable. The code change should
have been part of commit c35d2a8c ("powerpc/powernv: Needn't IO
segment map for PHB3").
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

After reverting 25ebc45b
("powerpc/pseries/iommu: remove default window before attempting DDW
manipulation"), we no longer remove the base window in enable_ddw.
Therefore, we no longer need to reset the DMA window state in
find_existing_ddw_windows(). We can instead go back to what was done
before, which simply reuses the previous configuration, if any. Further,
this removes the final caller of the reset-pe-dma-windows call, so
remove those functions.

This fixes an EEH on kdump with the ipr driver. The EEH occurs, because
the initcall removes the DDW configuration (64-bit DMA window), but
doesn't ensure the ops are via the IOMMU -- a DMA operation occurs
during probe (still investigating this) and we EEH.

This reverts commit 14b6f00f.
Signed-off-by: NNishanth Aravamudan <nacc@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Ben rightfully pointed out that there is a race in the "newer" DDW code.
Presuming we are running on recent enough firmware that supports the
"reset" DDW manipulation call, we currently always remove the base
32-bit DMA window in order to maximize the resources for Phyp when
creating the 64-bit window. However, this can be problematic for the
case where multiple functions are in the same PE (partitionable
endpoint), where some funtions might be 32-bit DMA only. All of a
sudden, the only functional DMA window for such functions is gone. We
will have serious errors in such situations. The best solution is simply
to revert the extension to the DDW code where we ever remove the base
DMA window.

This reverts commit 25ebc45b.
Signed-off-by: NNishanth Aravamudan <nacc@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>.  Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

The one instance where we add an include for init.h covers off
a case where that file was implicitly getting it from another
header which itself didn't need it.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

GCC 4.8 now generates out-of-line vr save/restore functions when
optimizing for size.  They are needed for the raid6 altivec support.
Signed-off-by: NAndreas Schwab <schwab@linux-m68k.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

There are much pci compatible with version on existing platforms.
To stop putting version numbers in device tree later, we add a
generic compatible 'fsl,qoriq-pcie'.
The version number is readable directly from a register.
Signed-off-by: NShengzhou Liu <Shengzhou.Liu@freescale.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>

Add elo3-dma-2.dtsi to support the third DMA controller.
This is used on T2080, T4240, B4860, etc.

FSL MPIC v4.3 adds a new discontiguous address range for internal interrupts,
e.g. internal interrupt 0 is at offset 0x200 and thus interrupt number is:
0x200 >> 5 = 16 in the device tree.  DMA controller 3 channel 0 internal
interrupt 240 is at offset 0x3a00, and thus the corresponding interrupt
number is: 0x3a00 >> 5 = 464, it's similar for other 7 interrupt numbers
of DMA 3 channels.
Signed-off-by: NShengzhou Liu <Shengzhou.Liu@freescale.com>
Signed-off-by: NHongbo Zhang <hongbo.zhang@freescale.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>

On Freescale e6500 cores EPCR[DGTMI] controls whether guest supervisor
state can execute TLB management instructions. If EPCR[DGTMI]=0
tlbwe and tlbilx are allowed to execute normally in the guest state.

A hypervisor may choose to virtualize TLB1 and for this purpose it
may use IPROT to protect the entries for being invalidated by the
guest. However, because tlbwe and tlbilx execution in the guest state
are sharing the same bit, it is not possible to have a scenario where
tlbwe is allowed to be executed in guest state and tlbilx traps. When
guest TLB management instructions are allowed to be executed in guest
state the guest cannot use tlbilx to invalidate TLB1 guest entries.

Linux is using tlbilx in the boot code to invalidate the temporary
entries it creates when initializing the MMU. The patch is replacing
the usage of tlbilx in initialization code with tlbwe with VALID bit
cleared.

Linux is also using tlbilx in other contexts (like huge pages or
indirect entries) but removing the tlbilx from the initialization code
offers the possibility to have scenarios under hypervisor which are
not using huge pages or indirect entries.
Signed-off-by: NDiana Craciun <Diana.Craciun@freescale.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>

It was branching to the cleanup part of the non-bolted handler,
which would have been bad if there were any chips with tlbsrx.
that use the bolted handler.
Signed-off-by: NScott Wood <scottwood@freescale.com>

As of commit b81f18e5 ("powerpc/boot:
Only build board support files when required.") the two defconfigs
ep88xc_defconfig and storcenter_defconfig would fail final link as
follows:

  WRAP    arch/powerpc/boot/dtbImage.ep88xc
arch/powerpc/boot/wrapper.a(mpc8xx.o): In function `mpc885_get_clock':
arch/powerpc/boot/mpc8xx.c:30: undefined reference to `fsl_get_immr'
make[1]: *** [arch/powerpc/boot/dtbImage.ep88xc] Error 1

 ...and...

  WRAP    arch/powerpc/boot/cuImage.storcenter
arch/powerpc/boot/cuboot-pq2.o: In function `pq2_platform_fixups':
cuboot-pq2.c:(.text+0x324): undefined reference to `fsl_get_immr'
make[1]: *** [arch/powerpc/boot/cuImage.storcenter] Error 1

We need the fsl-soc board files built for these two platforms.

Cc: Tony Breeds <tony@bakeyournoodle.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Fixes: b81f18e5 ("powerpc/boot: Only build board support files when required.")
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>

On P1020, P1021, P1022, and P1023, eLBC event interrupts are routed
to internal interrupt 3 while ELBC error interrupts are routed to
internal interrupt 0.  We need to call request_irq for each.
Signed-off-by: NShaohui Xie <Shaohui.Xie@freescale.com>
Signed-off-by: NWang Dongsheng <dongsheng.wang@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
[scottwood@freescale.com: reworded commit message and fixed author]
Signed-off-by: NScott Wood <scottwood@freescale.com>

P1020, P1021, P1022, P1023 when the lbc get error, the error
interrupt will be triggered. The corresponding interrupt is
internal IRQ0. So system have to process the lbc IRQ0 interrupt.

The corresponding lbc general interrupt is internal IRQ3.
Signed-off-by: NWang Dongsheng <dongsheng.wang@freescale.com>
[scottwood@freescale.com: bracketed individual list elements]
Signed-off-by: NScott Wood <scottwood@freescale.com>

Add support for the Motorola/Emerson MVME5100 Single Board Computer.

The MVME5100 is a 6U form factor VME64 computer with:

	- A single MPC7410 or MPC750 CPU
	- A HAWK Processor Host Bridge (CPU to PCI) and
	  MultiProcessor Interrupt Controller (MPIC)
	- Up to 500Mb of onboard memory
	- A M48T37 Real Time Clock (RTC) and Non-Volatile Memory chip
	- Two 16550 compatible UARTS
	- Two Intel E100 Fast Ethernets
	- Two PCI Mezzanine Card (PMC) Slots
	- PPCBug Firmware

The HAWK PHB/MPIC is compatible with the MPC10x devices.

There is no onboard disk support. This is usually provided by installing a PMC
in first PMC slot.

This patch revives the board support, it was present in early 2.6
series kernels. The board support in those days was by Matt Porter of
MontaVista Software.

CSC Australia has around 31 of these boards in service. The kernel in use
for the boards is based on 2.6.31. The boards are operated without disks
from a file server.

This patch is based on linux-3.13-rc2 and has been boot tested.

Only boards with 512 Mb of memory are known to work.
Signed-off-by: NStephen Chivers <schivers@csc.com>
Tested-by: NAlessio Igor Bogani <alessio.bogani@elettra.eu>
Signed-off-by: NScott Wood <scottwood@freescale.com>

This keeps usage coordinated for hugetlb and indirect entries, which
should make entry selection more predictable and probably improve overall
performance when mixing the two.
Signed-off-by: NScott Wood <scottwood@freescale.com>

There are a few things that make the existing hw tablewalk handlers
unsuitable for e6500:

 - Indirect entries go in TLB1 (though the resulting direct entries go in
   TLB0).

 - It has threads, but no "tlbsrx." -- so we need a spinlock and
   a normal "tlbsx".  Because we need this lock, hardware tablewalk
   is mandatory on e6500 unless we want to add spinlock+tlbsx to
   the normal bolted TLB miss handler.

 - TLB1 has no HES (nor next-victim hint) so we need software round robin
   (TODO: integrate this round robin data with hugetlb/KVM)

 - The existing tablewalk handlers map half of a page table at a time,
   because IBM hardware has a fixed 1MiB indirect page size.  e6500
   has variable size indirect entries, with a minimum of 2MiB.
   So we can't do the half-page indirect mapping, and even if we
   could it would be less efficient than mapping the full page.

 - Like on e5500, the linear mapping is bolted, so we don't need the
   overhead of supporting nested tlb misses.

Note that hardware tablewalk does not work in rev1 of e6500.
We do not expect to support e6500 rev1 in mainline Linux.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Cc: Mihai Caraman <mihai.caraman@freescale.com>

There is no barrier between something like ioremap() writing to
a PTE, and returning the value to a caller that may then store the
pointer in a place that is visible to other CPUs.  Such callers
generally don't perform barriers of their own.

Even if callers of ioremap() and similar things did use barriers,
the most logical choise would be smp_wmb(), which is not
architecturally sufficient when BookE hardware tablewalk is used.  A
full sync is specified by the architecture.

For userspace mappings, OTOH, we generally already have an lwsync due
to locking, and if we occasionally take a spurious fault due to not
having a full sync with hardware tablewalk, it will not be fatal
because we will retry rather than oops.
Signed-off-by: NScott Wood <scottwood@freescale.com>

The RELOCATABLE is more flexible and without any alignment restriction.
And it is a superset of DYNAMIC_MEMSTART. So use it by default for
a kdump kernel.
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>

When booting above the 64M for a secondary cpu, we also face the
same issue as the boot cpu that the PAGE_OFFSET map two different
physical address for the init tlb and the final map. So we have to use
switch_to_as1/restore_to_as0 between the conversion of these two
maps. When restoring to as0 for a secondary cpu, we only need to
return to the caller. So add a new parameter for function
restore_to_as0 for this purpose.

Use LOAD_REG_ADDR_PIC to get the address of variables which may
be used before we set the final map in cams for the secondary cpu.
Move the setting of cams a bit earlier in order to avoid the
unnecessary using of LOAD_REG_ADDR_PIC.
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>

This is always true for a non-relocatable kernel. Otherwise the kernel
would get stuck. But for a relocatable kernel, it seems a little
complicated. When booting a relocatable kernel, we just align the
kernel start addr to 64M and map the PAGE_OFFSET from there. The
relocation will base on this virtual address. But if this address
is not the same as the memstart_addr, we will have to change the
map of PAGE_OFFSET to the real memstart_addr and do another relocation
again.
Signed-off-by: NKevin Hao <haokexin@gmail.com>
[scottwood@freescale.com: make offset long and non-negative in simple case]
Signed-off-by: NScott Wood <scottwood@freescale.com>

Introduce this function so we can set both the physical and virtual
address for the map in cams. This will be used by the relocation code.
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>

For a relocatable kernel since it can be loaded at any place, there
is no any relation between the kernel start addr and the memstart_addr.
So we can't calculate the memstart_addr from kernel start addr. And
also we can't wait to do the relocation after we get the real
memstart_addr from device tree because it is so late. So introduce
a new function we can use to get the first memblock address and size
in a very early stage (before machine_init).
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>

We use the tlb1 entries to map low mem to the kernel space. In the
current code, it assumes that the first tlb entry would cover the
kernel image. But this is not true for some special cases, such as
when we run a relocatable kernel above the 64M or set
CONFIG_KERNEL_START above 64M. So we choose to switch to address
space 1 before setting these tlb entries.
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>