Commit Graph

199 Commits

Author SHA1 Message Date
Paul Burton 4bcb4ad663
MIPS: Consistently declare TLB functions
Since at least the beginning of the git era we've declared our TLB
exception handling functions inconsistently. They're actually functions,
but we declare them as arrays of u32 where each u32 is an encoded
instruction. This has always been the case for arch/mips/mm/tlbex.c, and
has also been true for arch/mips/kernel/traps.c since commit
86a1708a9d ("MIPS: Make tlb exception handler definitions and
declarations match.") which aimed for consistency but did so by
consistently making the our C code inconsistent with our assembly.

This is all usually harmless, but when using GCC 7 or newer to build a
kernel targeting microMIPS (ie. CONFIG_CPU_MICROMIPS=y) it becomes
problematic. With microMIPS bit 0 of the program counter indicates the
ISA mode. When bit 0 is zero instructions are decoded using the standard
MIPS32 or MIPS64 ISA. When bit 0 is one instructions are decoded using
microMIPS. This means that function pointers become odd - their least
significant bit is one for microMIPS code. We work around this in cases
where we need to access code using loads & stores with our
msk_isa16_mode() macro which simply clears bit 0 of the value it is
given:

  #define msk_isa16_mode(x) ((x) & ~0x1)

For example we do this for our TLB load handler in
build_r4000_tlb_load_handler():

  u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbl);

We then write code to p, expecting it to be suitably aligned (our LEAF
macro aligns functions on 4 byte boundaries, so (ulong)handle_tlbl will
give a value one greater than a multiple of 4 - ie. the start of a
function on a 4 byte boundary, with the ISA mode bit 0 set).

This worked fine up to GCC 6, but GCC 7 & onwards is smart enough to
presume that handle_tlbl which we declared as an array of u32s must be
aligned sufficiently that bit 0 of its address will never be set, and as
a result optimize out msk_isa16_mode(). This leads to p having an
address with bit 0 set, and when we go on to attempt to store code at
that address we take an address error exception due to the unaligned
memory access.

This leads to an exception prior to the kernel having configured its own
exception handlers, so we jump to whatever handlers the bootloader
configured. In the case of QEMU this results in a silent hang, since it
has no useful general exception vector.

Fix this by consistently declaring our TLB-related functions as
functions. For handle_tlbl(), handle_tlbs() & handle_tlbm() we do this
in asm/tlbex.h & we make use of the existing declaration of
tlbmiss_handler_setup_pgd() in asm/mmu_context.h. Our TLB handler
generation code in arch/mips/mm/tlbex.c is adjusted to deal with these
definitions, in most cases simply by casting the function pointers to
u32 pointers.

This allows us to include asm/mmu_context.h in arch/mips/mm/tlbex.c to
get the definitions of tlbmiss_handler_setup_pgd & pgd_current, removing
some needless duplication. Consistently using msk_isa16_mode() on
function pointers means we no longer need the
tlbmiss_handler_setup_pgd_start symbol so that is removed entirely.

Now that we're declaring our functions as functions GCC stops optimizing
out msk_isa16_mode() & a microMIPS kernel built with either GCC 7.3.0 or
8.1.0 boots successfully.

Signed-off-by: Paul Burton <paul.burton@mips.com>
2018-08-10 17:27:53 -07:00
Paul Burton b29fea3676
MIPS: Export tlbmiss_handler_setup_pgd near its definition
We export tlbmiss_handler_setup_pgd in arch/mips/mm/tlbex.c close to a
declaration of it, rather than close to its definition as is standard.

We've supported exporting symbols in assembly code since commit
22823ab419 ("EXPORT_SYMBOL() for asm"), so move the export to follow
the function's (stub) definition.

Signed-off-by: Paul Burton <paul.burton@mips.com>
2018-08-10 17:27:51 -07:00
Paul Burton b023a93960
MIPS: Avoid using array as parameter to write_c0_kpgd()
Passing an array (swapper_pg_dir) as the argument to write_c0_kpgd() in
setup_pw() will become problematic if we modify __write_64bit_c0_split()
to cast its val argument to unsigned long long, because for 32-bit
kernel builds the size of a pointer will differ from the size of an
unsigned long long. This would fall foul of gcc's pointer-to-int-cast
diagnostic.

Cast the value to a long, which should be the same width as the pointer
that we ultimately want & will be sign extended if required to the
unsigned long long that __write_64bit_c0_split() ultimately needs.

Signed-off-by: Paul Burton <paul.burton@mips.com>
2018-08-06 18:44:09 -07:00
Paul Burton 3b2db173f0 MIPS: Remove unused R6000 support
The kernel contains a small amount of incomplete code aimed at
supporting old R6000 CPUs. This is:

  - Unused, as no machine selects CONFIG_SYS_HAS_CPU_R6000.

  - Broken, since there are glaring errors such as r6000_fpu.S moving
    the FCSR register to t1, then ignoring it & instead saving t0 into
    struct sigcontext...

  - A maintenance headache, since it's code that nobody can test which
    nevertheless imposes constraints on code which it shares with other
    machines.

Remove this incomplete & broken R6000 CPU support in order to clean up
and in preparation for changes which will no longer need to consider
dragging the pretense of R6000 support along with them.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16236/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-29 15:21:51 +02:00
Paul Burton 5f930860e7 MIPS: Use current_cpu_type() in m4kc_tlbp_war()
Use current_cpu_type() to check for 4Kc processors instead of checking
the PRID directly. This will allow for the 4Kc case to be optimised out
of kernels that can't run on 4KC processors, thanks to __get_cpu_type()
and its unreachable() call.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16205/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-06-29 02:42:29 +02:00
Paul Burton f39878cc5b MIPS: Handle tlbex-tlbp race condition
In systems where there are multiple actors updating the TLB, the
potential exists for a race condition wherein a CPU hits a TLB exception
but by the time it reaches a TLBP instruction the affected TLB entry may
have been replaced. This can happen if, for example, a CPU shares the
TLB between hardware threads (VPs) within a core and one of them
replaces the entry that another has just taken a TLB exception for.

We handle this race in the case of the Hardware Table Walker (HTW) being
the other actor already, but didn't take into account the potential for
multiple threads racing. Include the code for aborting TLB exception
handling in affected multi-threaded systems, those being the I6400 &
I6500 CPUs which share TLB entries between VPs.

In the case of using RiXi without dedicated exceptions we have never
handled this race even for HTW. This patch adds WARN()s to these cases
which ought never to be hit because all CPUs with either HTW or shared
FTLB RAMs also include dedicated RiXi exceptions, but the WARN()s will
ensure this is always the case.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16203/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-06-29 02:42:29 +02:00
Alex Belits 3377e227af MIPS: Add 48-bit VA space (and 4-level page tables) for 4K pages.
Some users must have 4K pages while needing a 48-bit VA space size.
The cleanest way do do this is to go to a 4-level page table for this
case.  Each page table level using order-0 pages adds 9 bits to the
VA size (at 4K pages, so for four levels we get 9 * 4 + 12 == 48-bits.

For the 4K page size case only we add support functions for the PUD
level of the page table tree, also the TLB exception handlers get an
extra level of tree walk.

[david.daney@cavium.com: Forward port to v4.10.]
[david.daney@cavium.com: Forward port to v4.11.]

Signed-off-by: Alex Belits <alex.belits@cavium.com>
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Alex Belits <alex.belits@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/15312/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-04-10 11:56:06 +02:00
Huacai Chen 0115f6cbf2 MIPS: Flush wrong invalid FTLB entry for huge page
On VTLB+FTLB platforms (such as Loongson-3A R2), FTLB's pagesize is
usually configured the same as PAGE_SIZE. In such a case, Huge page
entry is not suitable to write in FTLB.

Unfortunately, when a huge page is created, its page table entries
haven't created immediately. Then the TLB refill handler will fetch an
invalid page table entry which has no "HUGE" bit, and this entry may be
written to FTLB. Since it is invalid, TLB load/store handler will then
use tlbwi to write the valid entry at the same place. However, the
valid entry is a huge page entry which isn't suitable for FTLB.

Our solution is to modify build_huge_handler_tail. Flush the invalid
old entry (whether it is in FTLB or VTLB, this is in order to reduce
branches) and use tlbwr to write the valid new entry.

Signed-off-by: Rui Wang <wangr@lemote.com>
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J . Hill <Steven.Hill@caviumnetworks.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/15754/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-03-21 21:58:50 +01:00
James Hogan f700a42008 Merge tag 'mips_kvm_4.11_1' into mips-for-linux-next
MIPS dependencies for KVM

Miscellaneous MIPS architecture changes depended on by the MIPS KVM
changes in the KVM tree.

- Move pgd_alloc() out of header.
- Exports so KVM can access page table management and TLBEX functions.
- Add return errors to protected cache ops.
2017-02-13 18:57:31 +00:00
James Hogan 722b454431 MIPS: Export some tlbex internals for KVM to use
Export to TLB exception code generating functions so that KVM can
construct a fast TLB refill handler for guest context without
reinventing the wheel quite so much.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
2017-02-03 15:19:01 +00:00
James Hogan ccf015166d MIPS: Export pgd/pmd symbols for KVM
Export pmd_init(), invalid_pmd_table and tlbmiss_handler_setup_pgd to
GPL kernel modules so that MIPS KVM can use the inline page table
management functions and switch between page tables:

- pmd_init() will be used directly by KVM to initialise newly allocated
  pmd tables with invalid lower level table pointers.

- invalid_pmd_table is used by pud_present(), pud_none(), and
  pud_clear(), which KVM will use to test and clear pud entries.

- tlbmiss_handler_setup_pgd() will be called by KVM entry code to switch
  to the appropriate GVA page tables.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
2017-02-03 15:18:56 +00:00
Paul Burton 2c0e57eaef MIPS: tlbex: Clear ISA bit when writing to handle_tlb{l,m,s}
When generating TLB exception handling code we write to memory reserved
at the handle_tlbl, handle_tlbm & handle_tlbs symbols. Up until now the
ISA bit has always been clear simply because the assembly code reserving
the space for those functions places no instructions in them. In
preparation for marking all LEAF functions as containing code,
explicitly clear the ISA bit when calculating the addresses at which to
write TLB exception handling code.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14507/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-01-03 16:34:49 +01:00
Linus Torvalds 4305f42401 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle:
 "This is the main pull request for MIPS for 4.8.  Also includes is a
  minor SSB cleanup as SSB code traditionally is merged through the MIPS
  tree:

  ATH25:
    - MIPS: Add default configuration for ath25

  Boot:
    - For zboot, copy appended dtb to the end of the kernel
    - store the appended dtb address in a variable

  BPF:
    - Fix off by one error in offset allocation

  Cobalt code:
    - Fix typos

  Core code:
    - debugfs_create_file returns NULL on error, so don't use IS_ERR for
      testing for errors.
    - Fix double locking issue in RM7000 S-cache code.  This would only
      affect RM7000 ARC systems on reboot.
    - Fix page table corruption on THP permission changes.
    - Use compat_sys_keyctl for 32 bit userspace on 64 bit kernels.
      David says, there are no compatibility issues raised by this fix.
    - Move some signal code around.
    - Rewrite r4k count/compare clockevent device registration such that
      min_delta_ticks/max_delta_ticks files are guaranteed to be
      initialized.
    - Only register r4k count/compare as clockevent device if we can
      assume the clock to be constant.
    - Fix MSA asm warnings in control reg accessors
    - uasm and tlbex fixes and tweaking.
    - Print segment physical address when EU=1.
    - Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO.
    - CP: Allow booting by VP other than VP 0
    - Cache handling fixes and optimizations for r4k class caches
    - Add hotplug support for R6 processors
    - Cleanup hotplug bits in kconfig
    - traps: return correct si code for accessing nonmapped addresses
    - Remove cpu_has_safe_index_cacheops

  Lantiq:
    - Register IRQ handler for virtual IRQ number
    - Fix EIU interrupt loading code
    - Use the real EXIN count
    - Fix build error.

  Loongson 3:
    - Increase HPET_MIN_PROG_DELTA and decrease HPET_MIN_CYCLES

  Octeon:
    - Delete built-in DTB pruning code for D-Link DSR-1000N.
    - Clean up GPIO definitions in dlink_dsr-1000n.dts.
    - Add more LEDs to the DSR-100n DTS
    - Fix off by one in octeon_irq_gpio_map()
    - Typo fixes
    - Enable SATA by default in cavium_octeon_defconfig
    - Support readq/writeq()
    - Remove forced mappings of USB interrupts.
    - Ensure DMA descriptors are always in the low 4GB
    - Improve USB reset code for OCTEON II.

  Pistachio:
    - Add maintainers entry for pistachio SoC Support
    - Remove plat_setup_iocoherency

  Ralink:
    - Fix pwm UART in spis group pinmux.

  SSB:
    - Change bare unsigned to unsigned int to suit coding style

  Tools:
    - Fix reloc tool compiler warnings.

  Other:
    - Delete use of ARCH_WANT_OPTIONAL_GPIOLIB"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (61 commits)
  MIPS: mm: Fix definition of R6 cache instruction
  MIPS: tools: Fix relocs tool compiler warnings
  MIPS: Cobalt: Fix typo
  MIPS: Octeon: Fix typo
  MIPS: Lantiq: Fix build failure
  MIPS: Use CPHYSADDR to implement mips32 __pa
  MIPS: Octeon: Dlink_dsr-1000n.dts: add more leds.
  MIPS: Octeon: Clean up GPIO definitions in dlink_dsr-1000n.dts.
  MIPS: Octeon: Delete built-in DTB pruning code for D-Link DSR-1000N.
  MIPS: store the appended dtb address in a variable
  MIPS: ZBOOT: copy appended dtb to the end of the kernel
  MIPS: ralink: fix spis group pinmux
  MIPS: Factor o32 specific code into signal_o32.c
  MIPS: non-exec stack & heap when non-exec PT_GNU_STACK is present
  MIPS: Use per-mm page to execute branch delay slot instructions
  MIPS: Modify error handling
  MIPS: c-r4k: Use SMP calls for CM indexed cache ops
  MIPS: c-r4k: Avoid small flush_icache_range SMP calls
  MIPS: c-r4k: Local flush_icache_range cache op override
  MIPS: c-r4k: Split r4k_flush_kernel_vmap_range()
  ...
2016-08-06 09:13:11 -04:00
Masahiro Yamada 97f2645f35 tree-wide: replace config_enabled() with IS_ENABLED()
The use of config_enabled() against config options is ambiguous.  In
practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the
author might have used it for the meaning of IS_ENABLED().  Using
IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc.  makes the intention
clearer.

This commit replaces config_enabled() with IS_ENABLED() where possible.
This commit is only touching bool config options.

I noticed two cases where config_enabled() is used against a tristate
option:

 - config_enabled(CONFIG_HWMON)
  [ drivers/net/wireless/ath/ath10k/thermal.c ]

 - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE)
  [ drivers/gpu/drm/gma500/opregion.c ]

I did not touch them because they should be converted to IS_BUILTIN()
in order to keep the logic, but I was not sure it was the authors'
intention.

Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Stas Sergeev <stsp@list.ru>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: "Dmitry V. Levin" <ldv@altlinux.org>
Cc: yu-cheng yu <yu-cheng.yu@intel.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Will Drewry <wad@chromium.org>
Cc: Nikolay Martynov <mar.kolya@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Rafal Milecki <zajec5@gmail.com>
Cc: James Cowgill <James.Cowgill@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Mikko Rapeli <mikko.rapeli@iki.fi>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Kalle Valo <kvalo@qca.qualcomm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Tony Wu <tung7970@gmail.com>
Cc: Huaitong Han <huaitong.han@intel.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Rabin Vincent <rabin@rab.in>
Cc: "Maciej W. Rozycki" <macro@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-04 08:50:07 -04:00
James Hogan 2f8f8c04e8 MIPS: tlbex: Avoid duplicated single_insn_swpd
The expression "uasm_in_compat_space_p(swpd) && !uasm_rel_lo(swpd)" is
used twice in build_get_pgd_vmalloc64(), one of which is assigned to the
local variable single_insn_swpd. Update the other use to just use
single_insn_swpd instead to remove the duplication.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13779/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-07-24 13:16:00 +02:00
James Hogan aa76042a01 MIPS: Fix 64-bit HTW configuration
The Hardware page Table Walker (HTW) is being misconfigured on 64-bit
kernels. The PWSize.PS (pointer size) bit determines whether pointers
within directories are loaded as 32-bit or 64-bit addresses, but was
never being set to 1 for 64-bit kernels where the unsigned long in pgd_t
is 64-bits wide.

This actually reduces rather than improves performance when the HTW is
enabled on P6600 since the HTW is initiated lots, but walks are all
aborted due I think to bad intermediate pointers.

Since we were already taking the width of the PTEs into account by
setting PWSize.PTEW, which is the left shift applied to the page table
index *in addition to* the native pointer size, we also need to reduce
PTEW by 1 when PS=1. This is done by calculating PTEW based on the
relative size of pte_t compared to pgd_t.

Finally in order for the HTW to be used when PS=1, the appropriate
XK/XS/XU bits corresponding to the different 64-bit segments need to be
set in PWCtl. We enable only XU for now to enable walking for XUSeg.

Supporting walking for XKSeg would be a bit more involved so is left for
a future patch. It would either require the use of a per-CPU top level
base directory if supported by the HTW (a bit like pgd_current but with
a second entry pointing at swapper_pg_dir), or the HTW would prepend bit
63 of the address to the global directory index which doesn't really
match how we split user and kernel page directories.

Fixes: cab25bc753 ("MIPS: Extend hardware table walking support to MIPS64")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13364/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28 12:35:11 +02:00
James Hogan 6446e6cf44 MIPS: Add 64-bit HTW fields
Add field definitions for some of the 64-bit specific Hardware page
Table Walker (HTW) register fields in PWSize and PWCtl, in preparation
for fixing the 64-bit HTW configuration.

Also print these fields out along with the others in print_htw_config().

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13363/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28 12:35:11 +02:00
Paul Burton e56c7e1881 MIPS: mm: Panic if an XPA kernel is run without RIXI
XPA kernels hardcode for the presence of RIXI - the PTE format & its
handling presume RI & XI bits. Make this dependence explicit by panicing
if we run on a system that violates it.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13125/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 15:30:25 +02:00
James Hogan 4b6f99d307 MIPS: mm: Don't do MTHC0 if XPA not present
Performing an MTHC0 instruction without XPA being present will trigger a
reserved instruction exception, therefore conditionalise the use of this
instruction when building TLB handlers (build_update_entries()), and in
__update_tlb().

This allows an XPA kernel to run on non XPA hardware without that
instruction implemented, just like it can run on XPA capable hardware
without XPA in use (with the noxpa kernel argument) or with XPA not
configured in hardware.

[paul.burton@imgtec.com:
  - Rebase atop other TLB work.
  - Add "mm" to subject.
  - Handle the __kmap_pgprot case.]

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: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jerome Marchand <jmarchan@redhat.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/13124/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 15:30:25 +02:00
Paul Burton 2caa89b49b MIPS: mm: Simplify build_update_entries
We can simplify build_update_entries by unifying the code for the 36 bit
physical addressing with MIPS32 case with the general case, by using
pte_off_ variables in all cases & handling the trivial
_PAGE_GLOBAL_SHIFT == 0 case in build_convert_pte_to_entrylo. This
leaves XPA as the only special case.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13123/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 15:30:25 +02:00
Paul Burton b4ebbb876d MIPS: mm: Be more explicit about PTE mode bit handling
The XPA case in iPTE_SW or's in software mode bits to the pte_low value
(which is what actually ends up in the high 32 bits of EntryLo...). It
does this presuming that only bits in the upper 16 bits of the 32 bit
pte_low value will be set. Make this assumption explicit with a BUG_ON.

A similar assumption is made for the hardware mode bits, which are or'd
in with a single ori instruction. Make that assumption explicit with a
BUG_ON too.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13122/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 15:30:25 +02:00
Paul Burton bbeeffec6f MIPS: mm: Pass scratch register through to iPTE_SW
Rather than hardcode a scratch register for the XPA case in iPTE_SW,
pass one through from the work registers allocated by the caller. This
allows for the XPA path to function correctly regardless of the work
registers in use.

Without doing this there are cases (where KScratch registers are
unavailable) in which iPTE_SW will incorrectly clobber $1 despite it
already being in use for the PTE or PTE pointer.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13121/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 15:30:25 +02:00
James Hogan f383219674 MIPS: mm: Don't clobber $1 on XPA TLB refill
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>
2016-05-13 15:30:25 +02:00
Paul Burton 7b2cb64f91 MIPS: mm: Fix MIPS32 36b physical addressing (alchemy, netlogic)
There are 2 distinct cases in which a kernel for a MIPS32 CPU
(CONFIG_CPU_MIPS32=y) may use 64 bit physical addresses
(CONFIG_PHYS_ADDR_T_64BIT=y):

  - 36 bit physical addressing as used by RMI Alchemy & Netlogic XLP/XLR
    CPUs.

  - MIPS32r5 eXtended Physical Addressing (XPA).

These 2 cases are distinct in that they require different behaviour from
the kernel - the EntryLo registers have different formats. Until Linux
v4.1 we only supported the first case, with code conditional upon the 2
aforementioned Kconfig variables being set. Commit c5b367835c ("MIPS:
Add support for XPA.") added support for the second case, but did so by
modifying the code that existed for the first case rather than treating
the 2 cases as distinct. Since the EntryLo registers have different
formats this breaks the 36 bit Alchemy/XLP/XLR case. Fix this by
splitting the 2 cases, with XPA cases now being conditional upon
CONFIG_XPA and the non-XPA case matching the code as it existed prior to
commit c5b367835c ("MIPS: Add support for XPA.").

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reported-by: Manuel Lauss <manuel.lauss@gmail.com>
Tested-by: Manuel Lauss <manuel.lauss@gmail.com>
Fixes: c5b367835c ("MIPS: Add support for XPA.")
Cc: James Hogan <james.hogan@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: stable@vger.kernel.org # v4.1+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13119/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 15:30:25 +02:00
Paul Burton 780602d740 MIPS: mm: Standardise on _PAGE_NO_READ, drop _PAGE_READ
Ever since support for RI/XI was implemented by commit 6dd9344cfc
("MIPS: Implement Read Inhibit/eXecute Inhibit") we've had a mixture of
_PAGE_READ & _PAGE_NO_READ bits. Rather than keep both around, switch
away from using _PAGE_READ to determine page presence & instead invert
the use to _PAGE_NO_READ. Wherever we formerly had no definition for
_PAGE_NO_READ, change what was _PAGE_READ to _PAGE_NO_READ. The end
result is that we consistently use _PAGE_NO_READ to determine whether a
page is readable, regardless of whether RI/XI is implemented.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.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/13116/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 15:30:25 +02:00
James Hogan 14bc241443 MIPS: Fix HTW config on XPA kernel without LPA enabled
The hardware page table walker (HTW) configuration is broken on XPA
kernels where XPA couldn't be enabled (either nohtw or the hardware
doesn't support it). This is because the PWSize.PTEW field (PTE width)
was only set to 8 bytes (an extra shift of 1) in config_htw_params() if
PageGrain.ELPA (enable large physical addressing) is set. On an XPA
kernel though the size of PTEs is fixed at 8 bytes regardless of whether
XPA could actually be enabled.

Fix the initialisation of this field based on sizeof(pte_t) instead.

Fixes: c5b367835c ("MIPS: Add support for XPA.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Steven J. Hill <sjhill@realitydiluted.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13113/
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 14:02:24 +02:00
Huacai Chen 380cd582c0 MIPS: Loongson-3: Fast TLB refill handler
Loongson-3A R2 has pwbase/pwfield/pwsize/pwctl registers in CP0 (this
is very similar to HTW) and lwdir/lwpte/lddir/ldpte instructions which
can be used for fast TLB refill.

[ralf@linux-mips.org: Resolve conflict.]

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J . Hill <sjhill@realitydiluted.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12754/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 14:02:15 +02:00
Adam Buchbinder 92a76f6d85 MIPS: Fix misspellings in comments.
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12617/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-04-03 12:32:09 +02:00
Linus Torvalds e2464688b5 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle:
 "This is the main pull request for MIPS for 4.5 plus some 4.4 fixes.

  The executive summary:

   - ATH79 platform improvments, use DT bindings for the ATH79 USB PHY.
   - Avoid useless rebuilds for zboot.
   - jz4780: Add NEMC, BCH and NAND device tree nodes
   - Initial support for the MicroChip's DT platform.  As all the device
     drivers are missing this is still of limited use.
   - Some Loongson3 cleanups.
   - The unavoidable whitespace polishing.
   - Reduce clock skew when synchronizing the CPU cycle counters on CPU
     startup.
   - Add MIPS R6 fixes.
   - Lots of cleanups across arch/mips as fallout from KVM.
   - Lots of minor fixes and changes for IEEE 754-2008 support to the
     FPU emulator / fp-assist software.
   - Minor Ralink, BCM47xx and bcm963xx platform support improvments.
   - Support SMP on BCM63168"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (84 commits)
  MIPS: zboot: Add support for serial debug using the PROM
  MIPS: zboot: Avoid useless rebuilds
  MIPS: BMIPS: Enable ARCH_WANT_OPTIONAL_GPIOLIB
  MIPS: bcm63xx: nvram: Remove unused bcm63xx_nvram_get_psi_size() function
  MIPS: bcm963xx: Update bcm_tag field image_sequence
  MIPS: bcm963xx: Move extended flash address to bcm_tag header file
  MIPS: bcm963xx: Move Broadcom BCM963xx image tag data structure
  MIPS: bcm63xx: nvram: Use nvram structure definition from header file
  MIPS: bcm963xx: Add Broadcom BCM963xx board nvram data structure
  MAINTAINERS: Add KVM for MIPS entry
  MIPS: KVM: Add missing newline to kvm_err()
  MIPS: Move KVM specific opcodes into asm/inst.h
  MIPS: KVM: Use cacheops.h definitions
  MIPS: Break down cacheops.h definitions
  MIPS: Use EXCCODE_ constants with set_except_vector()
  MIPS: Update trap codes
  MIPS: Move Cause.ExcCode trap codes to mipsregs.h
  MIPS: KVM: Make kvm_mips_{init,exit}() static
  MIPS: KVM: Refactor added offsetof()s
  MIPS: KVM: Convert EXPORT_SYMBOL to _GPL
  ...
2016-01-24 12:50:56 -08:00
Huacai Chen 4f33f6c522 MIPS: Fix some missing CONFIG_CPU_MIPSR6 #ifdefs
Commit be0c37c985 (MIPS: Rearrange PTE bits into fixed positions.)
defines fixed PTE bits for MIPS R2. Then, commit d7b631419b
(MIPS: pgtable-bits: Fix XPA damage to R6 definitions.) adds the MIPS
R6 definitions in the same way as MIPS R2. But some R6 #ifdefs in the
later commit are missing, so in this patch I fix that.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12164/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-01-24 01:32:25 +01:00
Kirill A. Shutemov b27873702b mips, thp: remove infrastructure for handling splitting PMDs
With new refcounting we don't need to mark PMDs splitting.  Let's drop
code to handle this.

pmdp_splitting_flush() is not needed too: on splitting PMD we will do
pmdp_clear_flush() + set_pte_at().  pmdp_clear_flush() will do IPI as
needed for fast_gup.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15 17:56:32 -08:00
Paul Burton cab25bc753 MIPS: Extend hardware table walking support to MIPS64
Extend the existing support for Hardware Table Walking (HTW) to MIPS64
systems by supporting PMDs & setting the pointer size bit in PWSize,
then ceasing to blacklist HTW on MIPS64 systems.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-kernel@vger.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11224/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-11-11 08:35:54 +01:00
Paul Burton 00bf1c691d MIPS: tlbex: Avoid placing software PTE bits in Entry* PFN fields
Commit 748e787eb6 ("MIPS: Optimize TLB refill for RI/XI
configurations.") stopped explicitly clearing the bits used by software
in PTEs by making use of a rotate instruction that rotates them into the
fill bits of the Entry{Lo,Hi} register. This can only work if there are
actually enough fill bits in the register to cover the software
maintained bits, otherwise we end up writing those bits into the upper
bits of the PFN or PFNX field of the Entry{Lo,Hi} register.

Fix this by detecting the number of fill bits present in the
Entry{Lo,Hi} registers & explicitly clearing the software bits where
necessary.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-kernel@vger.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11218/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-11-11 08:35:36 +01:00
Paul Burton c676589b05 MIPS: tlbex: Share MIPS32 32 bit phys & MIPS64 64 bit phys code
The code in build_update_entries for 64 bit physical addresses on a
MIPS64 CPU and 32 bit physical addresses on a MIPS32 CPU is now
identical, with the exception of r4k bug workaround in the latter which
would simply not apply to the former. Remove the duplication and some

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-kernel@vger.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11216/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-11-11 08:35:30 +01:00
Paul Burton 974a0b6a2c MIPS: tlbex: Remove some RIXI redundancy
The cpu_has_rixi cases in build_update_entries are now identical to the
non-RIXI cases with the one exception of the r45k_bvahwbug case which is
hardcoded as never happening anyway & presumably was either missed from
the RIXI path or would never happen on a CPU with RIXI support. Remove
the redundant checks & duplication.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-kernel@vger.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11215/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-11-11 08:35:28 +01:00
Paul Burton dbfd657ad1 MIPS: tlbex: Stop open-coding build_convert_pte_to_entrylo
Make use of build_convert_pte_to_entrylo in the RIXI cases within
build_update_entries rather than open-coding it 4 times.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-kernel@vger.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11214/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-11-11 08:35:24 +01:00
James Hogan 8fe4908b83 MIPS: tlbex: Avoid unnecessary _PAGE_PRESENT shifts
Commit c5b367835c ("MIPS: Add support for XPA.") added generation of a
shift by _PAGE_PRESENT_SHIFT in build_pte_present() and
build_pte_writable(), however except for the XPA case this is always
zero making it unnecessary.

Make the shift conditional upon _PAGE_PRESENT_SHIFT being non-zero to
save an instruction in those cases.

Fixes: c5b367835c ("MIPS: Add support for XPA.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9889/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-06-21 21:53:55 +02:00
James Hogan a3ae565a13 MIPS: tlbex: Fix broken offsets on r2 without XPA
Commit c5b367835c ("MIPS: Add support for XPA.") changed
build_pte_present() and build_pte_writable() to assume a constant offset
of _PAGE_READ and _PAGE_WRITE relative to _PAGE_PRESENT, however this is
no longer true for some MIPS32R2 builds since commit be0c37c985
("MIPS: Rearrange PTE bits into fixed positions.") which moved the
_PAGE_READ PTE bit away from the _PAGE_PRESENT bit, with the _PAGE_WRITE
bit falling into its place.

Make use of the _PAGE_READ and _PAGE_WRITE definitions to calculate the
correct mask to apply instead of hard coding 3 (for _PAGE_PRESENT |
_PAGE_READ) or 5 (for _PAGE_PRESENT | _PAGE_WRITE).

Fixes: c5b367835c ("MIPS: Add support for XPA.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9888/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-06-21 21:53:55 +02:00
Paul Gortmaker a2d25e63ee MIPS: tlbex.c: Remove new instance of __cpuinitdata that crept back in
We removed __cpuinit support (leaving no-op stubs) quite some time ago.
However a new instance was added in commit c5b367835c
("MIPS: Add support for XPA.")

Since we want to clobber the stubs soon, get this removed now.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9894/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-06-21 21:53:45 +02:00
Ralf Baechle 3e20a26b02 Merge branch '4.0-fixes' into mips-for-linux-next 2015-04-13 16:03:32 +02:00
Ralf Baechle 9eaffa84a8 Revert "MIPS: Avoid pipeline stalls on some MIPS32R2 cores."
For a discussion, see http://patchwork.linux-mips.org/patch/9539/.

This reverts commit 625c0a2170.
2015-04-10 15:41:49 +02:00
Joshua Kinard 3057739138 MIPS: Add R16000 detection
This allows the kernel to correctly detect an R16000 MIPS CPU on systems that
have those.  Otherwise, such systems will detect the CPU as an R14000, due to
similarities in the CPU PRId value.

Signed-off-by: Joshua Kinard <kumba@gentoo.org>
Cc: Linux MIPS List <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/9092/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-01 17:22:13 +02:00
Steven J. Hill c5b367835c MIPS: Add support for XPA.
Add support for extended physical addressing (XPA) so that
32-bit platforms can access equal to or greater than 40 bits
of physical addresses.

NOTE:
      1) XPA and EVA are not the same and cannot be used
         simultaneously.
      2) If you configure your kernel for XPA, the PTEs
         and all address sizes become 64-bit.
      3) Your platform MUST have working HIGHMEM support.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9355/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-19 17:39:49 +01:00
Steven J. Hill be0c37c985 MIPS: Rearrange PTE bits into fixed positions.
This patch rearranges the PTE bits into fixed positions for R2
and later cores. In the past, the TLB handling code did runtime
checking of RI/XI and adjusted the shifts and rotates in order
to fit the largest PFN value into the PTE. The checking now
occurs when building the TLB handler, thus eliminating those
checks. These new arrangements also define the largest possible
PFN value that can fit in the PTE. HUGE page support is only
available for 64-bit cores. Layouts of the PTE bits are now:

   64-bit, R1 or earlier:     CCC D V G [S H] M A W R P
   32-bit, R1 or earler:      CCC D V G M A W R P
   64-bit, R2 or later:       CCC D V G RI/R XI [S H] M A W P
   32-bit, R2 or later:       CCC D V G RI/R XI M A W P

[ralf@linux-mips.org: Fix another build error *rant* *rant*]

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9353/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-18 16:19:35 +01:00
Leonid Yegoshin 77f3ee59ee MIPS: mm: tlbex: Use cpu_has_mips_r2_exec_hazard for the EHB instruction
MIPS uses the cpu_has_mips_r2_exec_hazard macro to determine whether the
EHB instruction is available or not. This is necessary for MIPS R6
which also supports the EHB instruction.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:30 +00:00
Leonid Yegoshin 4695089f03 MIPS: Add cases for CPU_QEMU_GENERIC
Add a CPU_QEMU_GENERIC case to various switch statements.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-16 10:01:24 +00:00
Linus Torvalds c0222ac086 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle:
 "This is an unusually large pull request for MIPS - in parts because
  lots of patches missed the 3.18 deadline but primarily because some
  folks opened the flood gates.

   - Retire the MIPS-specific phys_t with the generic phys_addr_t.
   - Improvments for the backtrace code used by oprofile.
   - Better backtraces on SMP systems.
   - Cleanups for the Octeon platform code.
   - Cleanups and fixes for the Loongson platform code.
   - Cleanups and fixes to the firmware library.
   - Switch ATH79 platform to use the firmware library.
   - Grand overhault to the SEAD3 and Malta interrupt code.
   - Move the GIC interrupt code to drivers/irqchip
   - Lots of GIC cleanups and updates to the GIC code to use modern IRQ
     infrastructures and features of the kernel.
   - OF documentation updates for the GIC bindings
   - Move GIC clocksource driver to drivers/clocksource
   - Merge GIC clocksource driver with clockevent driver.
   - Further updates to bring the GIC clocksource driver up to date.
   - R3000 TLB code cleanups
   - Improvments to the Loongson 3 platform code.
   - Convert pr_warning to pr_warn.
   - Merge a bunch of small lantiq and ralink fixes that have been
     staged/lingering inside the openwrt tree for a while.
   - Update archhelp for IP22/IP32
   - Fix a number of issues for Loongson 1B.
   - New clocksource and clockevent driver for Loongson 1B.
   - Further work on clk handling for Loongson 1B.
   - Platform work for Broadcom BMIPS.
   - Error handling cleanups for TurboChannel.
   - Fixes and optimization to the microMIPS support.
   - Option to disable the FTLB.
   - Dump more relevant information on machine check exception
   - Change binfmt to allow arch to examine PT_*PROC headers
   - Support for new style FPU register model in O32
   - VDSO randomization.
   - BCM47xx cleanups
   - BCM47xx reimplement the way the kernel accesses NVRAM information.
   - Random cleanups
   - Add support for ATH25 platforms
   - Remove pointless locking code in some PCI platforms.
   - Some improvments to EVA support
   - Minor Alchemy cleanup"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (185 commits)
  MIPS: Add MFHC0 and MTHC0 instructions to uasm.
  MIPS: Cosmetic cleanups of page table headers.
  MIPS: Add CP0 macros for extended EntryLo registers
  MIPS: Remove now unused definition of phys_t.
  MIPS: Replace use of phys_t with phys_addr_t.
  MIPS: Replace MIPS-specific 64BIT_PHYS_ADDR with generic PHYS_ADDR_T_64BIT
  PCMCIA: Alchemy Don't select 64BIT_PHYS_ADDR in Kconfig.
  MIPS: lib: memset: Clean up some MIPS{EL,EB} ifdefery
  MIPS: iomap: Use __mem_{read,write}{b,w,l} for MMIO
  MIPS: <asm/types.h> fix indentation.
  MAINTAINERS: Add entry for BMIPS multiplatform kernel
  MIPS: Enable VDSO randomization
  MIPS: Remove a temporary hack for debugging cache flushes in SMTC configuration
  MIPS: Remove declaration of obsolete arch_init_clk_ops()
  MIPS: atomic.h: Reformat to fit in 79 columns
  MIPS: Apply `.insn' to fixup labels throughout
  MIPS: Fix microMIPS LL/SC immediate offsets
  MIPS: Kconfig: Only allow 32-bit microMIPS builds
  MIPS: signal.c: Fix an invalid cast in ISA mode bit handling
  MIPS: mm: Only build one microassembler that is suitable
  ...
2014-12-11 17:56:37 -08:00
Leonid Yegoshin 070e76cb3f MIPS: tlbex: Fix potential HTW race on TLBL/M/S handlers
There is a potential race when probing the TLB in TLBL/M/S exception
handlers for a matching entry. Between the time we hit a TLBL/S/M
exception and the time we get to execute the TLBP instruction, the
HTW may have replaced the TLB entry we are interested in hence the TLB
probe may fail. However, in the existing handlers, we never checked the
status of the TLBP (ie check the result in the C0/Index register). We
fix this by adding such a check when the core implements the HTW. If
we couldn't find a matching entry, we return back and try again.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: <stable@vger.kernel.org> # v3.17+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8599/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-27 17:21:56 +01:00
Ralf Baechle 34adb28d50 MIPS: Replace MIPS-specific 64BIT_PHYS_ADDR with generic PHYS_ADDR_T_64BIT
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 22:46:44 +01:00
David Daney 9e0f162a36 MIPS: tlbex: Properly fix HUGE TLB Refill exception handler
In commit 8393c524a2 (MIPS: tlbex: Fix a missing statement for
HUGETLB), the TLB Refill handler was fixed so that non-OCTEON targets
would work properly with huge pages.  The change was incorrect in that
it broke the OCTEON case.

The problem is shown here:

    xxx0:	df7a0000 	ld	k0,0(k1)
    .
    .
    .
    xxxc0:	df610000 	ld	at,0(k1)
    xxxc4:	335a0ff0 	andi	k0,k0,0xff0
    xxxc8:	e825ffcd 	bbit1	at,0x5,0x0
    xxxcc:	003ad82d 	daddu	k1,at,k0
    .
    .
    .

In the non-octeon case there is a destructive test for the huge PTE
bit, and then at 0, $k0 is reloaded (that is what the 8393c524a2
patch added).

In the octeon case, we modify k1 in the branch delay slot, but we
never need k0 again, so the new load is not needed, but since k1 is
modified, if we do the load, we load from a garbage location and then
get a nested TLB Refill, which is seen in userspace as either SIGBUS
or SIGSEGV (depending on the garbage).

The real fix is to only do this reloading if it is needed, and never
where it is harmful.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: stable@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8151/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-10-22 19:29:08 +02:00