The GuestCtl1 CP0 register can contain the GuestID used for root TLB
operations, which affects TLB matching. The other TLB registers are
already dumped out to the log on a machine check exception due to
multiple matching TLB entries, so also dump the value of the GuestCtl1
register if GuestIDs are supported.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13232/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The GuestID for root TLB operations (GuestCtl1.RID) is modified by TLB
reads, so needs preserving by dump_tlb() like the ASID field of EntryHi.
Also dump the GuestID of each entry if it exists alongside the ASID, as
it forms an important part of the TLB entry when VZ guests are used.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13230/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add a few new cpu-features.h definitions for VZ sub-features, namely the
existence of the CP0_GuestCtl0Ext, CP0_GuestCtl1, and CP0_GuestCtl2
registers, and support for GuestID to dialias TLB entries belonging to
different guests.
Also add certain features present in the guest, with the naming scheme
cpu_guest_has_*. These are added separately to the main options bitfield
since they generally parallel similar features in the root context. A
few of these (FPU, MSA, watchpoints, perf counters, CP0_[X]ContextConfig
registers, MAAR registers, and probably others in future) can be
dynamically configured in the guest context, for which the
cpu_guest_has_dyn_* macros are added.
[ralf@linux-mips.org: Resolve merge conflict.]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13231/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add CPU feature for standard MIPS r2 performance counters, as determined
by the Config1.PC bit. Both perf_events and oprofile probe this bit, so
lets combine the probing and change both to use cpu_has_perf.
This will also be used for VZ support in KVM to know whether performance
counters exist which can be exposed to guests.
[ralf@linux-mips.org: resolve conflict.]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Robert Richter <rric@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: oprofile-list@lists.sf.net
Patchwork: https://patchwork.linux-mips.org/patch/13226/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The CP0_[X]ContextConfig registers are present if CP0_Config3.CTXTC or
CP0_Config3.SM are set, and provide more control over which bits of
CP0_[X]Context are set to the faulting virtual address on a TLB
exception.
KVM/VZ will need to be able to save and restore these registers in the
guest context, so add the relevant definitions and probing of the
ContextConfig feature in the root context first.
[ralf@linux-mips.org: resolve merge conflict.]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13225/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The optional CP0_BadInstr and CP0_BadInstrP registers are written with
the encoding of the instruction that caused a synchronous exception to
occur, and the prior branch instruction if in a delay slot.
These will be useful for instruction emulation in KVM, and especially
for VZ support where reading guest virtual memory is a bit more awkward.
Add CPU option numbers and cpu_has_* definitions to indicate the
presence of each registers, and add code to probe for them using bits in
the CP0_Config3 register.
[ralf@linux-mips.org: resolve merge conflict.]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13224/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The CP0_EBase register may optionally have a write gate (WG) bit to
allow the upper bits to be written, i.e. bits 31:30 on MIPS32 since r3
(to allow for an exception base outside of KSeg0/KSeg1 when segmentation
control is in use) and bits 63:30 on MIPS64 (which also implies the
extension of CP0_EBase to 64 bits long).
The presence of this feature will need to be known about for VZ support
in order to correctly save and restore all the bits of the guest
CP0_EBase register, so add CPU feature definition and probing for this
feature.
Probing the WG bit on MIPS64 can be a bit fiddly, since 64-bit COP0
register access instructions were UNDEFINED for 32-bit registers prior
to MIPS r6, and it'd be nice to be able to probe without clobbering the
existing state, so there are 3 potential paths:
- If we do a 32-bit read of CP0_EBase and the WG bit is already set, the
register must be 64-bit.
- On MIPS r6 we can do a 64-bit read-modify-write to set CP0_EBase.WG,
since the upper bits will read 0 and be ignored on write if the
register is 32-bit.
- On pre-r6 cores, we do a 32-bit read-modify-write of CP0_EBase. This
avoids the potentially UNDEFINED behaviour, but will clobber the upper
32-bits of CP0_EBase if it isn't a simple sign extension (which also
requires us to ensure BEV=1 or modifying the exception base would be
UNDEFINED too). It is hopefully unlikely a bootloader would set up
CP0_EBase to a 64-bit segment and leave WG=0.
[ralf@linux-mips.org: Resolved merge conflict.]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Tested-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13223/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Octeon machines support running in little endian mode. U-Boot usually
runs in big endian-mode. Therefore the initramfs is loaded in big endian
mode, and the kernel later tries to access it in little endian mode.
This patch fixes that by detecting byte swapped initramfs using either the
CPIO header or the header from standard compression methods, and
byte swaps it if needed. It first checks that the header doesn't match
in the native endianness to avoid false detections. It uses the kernel
decompress library so that we don't have to maintain the list of magics
if some decompression methods are added to the kernel.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Acked-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13219/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
For XPA kernels build_update_entries() uses $1 (at) as a scratch
register, but doesn't arrange for it to be preserved, so it will always
be clobbered by the TLB refill exception. Although this register
normally has a very short lifetime that doesn't cross memory accesses,
TLB refills due to instruction fetches (either on a page boundary or
after preemption) could clobber live data, and its easy to reproduce
the clobber with a little bit of assembler code.
Note that the use of a hardware page table walker will partly mask the
problem, as the TLB refill handler will not always be invoked.
This is fixed by avoiding the use of the extra scratch register. The
pte_high parts (going into the lower half of the EntryLo registers) are
loaded and manipulated separately so as to keep the PTE pointer around
for the other halves (instead of storing in the scratch register), and
the pte_low parts (going into the high half of the EntryLo registers)
are masked with 0x00ffffff using an ext instruction (instead of loading
0x00ffffff into the scratch register and AND'ing).
[paul.burton@imgtec.com:
- Rebase atop other TLB work.
- Use ext instead of an sll, srl sequence.
- Use cpu_has_xpa instead of #ifdefs.
- Modify commit subject to include "mm".]
Fixes: c5b367835c ("MIPS: Add support for XPA.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13120/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
asm/pgtable-bits.h has grown to become an unreadable mess of #ifdef
directives defining bits conditionally upon other bits all at the
preprocessing stage, for no good reason.
Instead of having quite so many #ifdef's, simply use enums to provide
sequential numbering for bit shifts, without having to keep track
manually of what the last bit defined was. Masks are defined separately,
after the shifts, which allows for most of their definitions to be
reused for all systems rather than duplicated.
This patch is not intended to make any behavioural change to the code -
all bits should be used in the same way they were before this patch.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13115/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
XPA (eXtended Physical Addressing) should be detected as a combination
of two architectural features:
- Large Physical Address (as per Config3.LPA). With XPA this will be set
on MIPS32r5 cores, but it may also be set for MIPS64r2 cores too.
- MTHC0/MFHC0 instructions (as per Config5.MVH). With XPA this will be
set, but it may also be set in VZ guest context even when Config3.LPA
in the guest context has been cleared by the hypervisor.
As such, XPA is only usable if both bits are set. Update CPU features to
separate these two features, with cpu_has_xpa requiring both to be set.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13112/
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When emulating a jalr instruction with rd == $0, the code in
isBranchInstr was incorrectly writing to GPR $0 which should actually
always remain zeroed. This would lead to any further instructions
emulated which use $0 operating on a bogus value until the task is next
context switched, at which point the value of $0 in the task context
would be restored to the correct zero by a store in SAVE_SOME. Fix this
by not writing to rd if it is $0.
Fixes: 102cedc32a ("MIPS: microMIPS: Floating point support.")
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: stable <stable@vger.kernel.org> # v3.10
Patchwork: https://patchwork.linux-mips.org/patch/13160/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The code in _sp_maddf (formerly ieee754sp_madd) appears to have been
copied verbatim from ieee754sp_add, and although it's adding the
unpacked "r" & "z" floats it kept using macros that operate on "x" &
"y". This led to the addition being carried out incorrectly on some
mismash of the product, accumulator & multiplicand fields. Typically
this would lead to the assertions "ze == re" & "ze <= SP_EMAX" failing
since ze & re hadn't been operated upon.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: e24c3bec3e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction")
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13159/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
A comment in ieee754dp_mul indicates that the code is about to perform a
32b x 32b multiplication & keep the high 32b of the result. It appears
this was copied from the single-precision multiplication code, since the
code actually goes on to perform a 64b x 64b multiplication & keep the
high 64b of the result. Fix the comment to indicate 64b.
It appears also that this comment was copied verbatim along with the
rest of the multiplication code into ieee754dp_maddf, which has since
been renamed _dp_maddf. Fix the same issue there.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13157/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The code for emulating MIPSr6 madd.d & msub.d instructions has
previously been implemented as 2 different functions, namely
ieee754dp_maddf & ieee754dp_msubf. The difference in behaviour of these
2 instructions is merely the sign of the product, so we can easily share
the code implementing them. Do this for the double precision variant,
removing the original ieee754dp_msubf in favor of reusing the code from
ieee754dp_maddf.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13155/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The code for emulating MIPSr6 madd.s & msub.s instructions has
previously been implemented as 2 different functions, namely
ieee754sp_maddf & ieee754sp_msubf. The difference in behaviour of these
2 instructions is merely the sign of the product, so we can easily share
the code implementing them. Do this for the single precision variant,
removing the original ieee754sp_msubf in favor of reusing the code from
ieee754sp_maddf.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13154/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Allow the builtin command line to be extended by what the bootloader
passes in. For example, the bootloader can pass specific arguments
depending on the boot mode, and these should override the defaults in
the builtin cmdline.
The default MIPS_CMDLINE_FROM_BOOTLOADER option prepends the
bootloader's cmdline to the builtin cmdline so is not suitable for this
purpose.
Signed-off-by: Rabin Vincent <rabinv@axis.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13181/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Various branches and jumps in noreorder parts of genex.S don't have
their delay slot instructions indented conventionally with the extra
space.
Fix these, as well as various other inconsistent whitespace problems in
this file, such as spaces used after some opcodes instead of a tab.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13196/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
