The DT fragment will select the ohci-platform driver, since that can
handle the JZ4740 OHCI just fine. While I don't have a JZ4740-based
board with anything connected to the USB host controller, I did test
the generic OHCI driver successfully on a JZ4770-based board.
The device is disabled by default; boards that want to use it can
override the "status" property. The mass-production Qi LB60 boards
don't use the USB host controller.
Signed-off-by: Maarten ter Huurne <maarten@treewalker.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13104/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Some wakeups should not be considered a sucessful poll. For example on
s390 I/O interrupts are usually floating, which means that _ALL_ CPUs
would be considered runnable - letting all vCPUs poll all the time for
transactional like workload, even if one vCPU would be enough.
This can result in huge CPU usage for large guests.
This patch lets architectures provide a way to qualify wakeups if they
should be considered a good/bad wakeups in regard to polls.
For s390 the implementation will fence of halt polling for anything but
known good, single vCPU events. The s390 implementation for floating
interrupts does a wakeup for one vCPU, but the interrupt will be delivered
by whatever CPU checks first for a pending interrupt. We prefer the
woken up CPU by marking the poll of this CPU as "good" poll.
This code will also mark several other wakeup reasons like IPI or
expired timers as "good". This will of course also mark some events as
not sucessful. As KVM on z runs always as a 2nd level hypervisor,
we prefer to not poll, unless we are really sure, though.
This patch successfully limits the CPU usage for cases like uperf 1byte
transactional ping pong workload or wakeup heavy workload like OLTP
while still providing a proper speedup.
This also introduced a new vcpu stat "halt_poll_no_tuning" that marks
wakeups that are considered not good for polling.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Radim Krčmář <rkrcmar@redhat.com> (for an earlier version)
Cc: David Matlack <dmatlack@google.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
[Rename config symbol. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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>
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>
Release 6 of the MIPS architecture introduced the bitswap instruction,
which reverses the bits within each byte of a word. Make use of this
instruction to implement the __arch_bitrev* functions, which should be
faster for most MIPSr6 CPUs, reduces code size slightly and allows us to
avoid the lookup table used by the generic implementation, saving 256
bytes in the kernel binary by dropping that.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13204/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
SEGBITS is 40 bits or more, depending on CPU type. Introduces optional
support for 48 bits of application virtual address space. Only 16K and
64K pages are supported.
Enabling will result in a memory overhead of a small number of pages for
small applications. For 64K pages a 3rd level of page tables is required
which has some impact during software TLB refill.
[ralf@linux-mips.org: Fixed things raised in the review of the version
posted and changed kconfig to be a bit more userfriendly.]
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: aleksey.makarov@auriga.com
Cc: james.hogan@imgtec.com
Cc: paul.burton@imgtec.com
Cc: david.daney@cavium.com
Cc: peterz@infradead.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: davidlohr@hp.com
Cc: kirill@shutemov.name
Cc: akpm@linux-foundation.org
Cc: mingo@kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10051/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
New Loongson 3 CPU (since Loongson-3A R2, as opposed to Loongson-3A R1,
Loongson-3B R1 and Loongson-3B R2) has many enhancements, such as FTLB,
L1-VCache, EI/DI/Wait/Prefetch instruction, DSP/DSPv2 ASE, User Local
register, Read-Inhibit/Execute-Inhibit, SFB (Store Fill Buffer), Fast
TLB refill support, etc.
This patch introduce a config option, CONFIG_LOONGSON3_ENHANCEMENT, to
enable those enhancements which are not probed at run time. If you want
a generic kernel to run on all Loongson 3 machines, please say 'N'
here. If you want a high-performance kernel to run on new Loongson 3
machines only, please say 'Y' here.
Some additional explanations:
1) SFB locates between core and L1 cache, it causes memory access out
of order, so writel/outl (and other similar functions) need a I/O
reorder barrier.
2) Loongson 3 has a bug that di instruction can not save the irqflag,
so arch_local_irq_save() is modified. Since CPU_MIPSR2 is selected
by CONFIG_LOONGSON3_ENHANCEMENT, generic kernel doesn't use ei/di
at all.
3) CPU_HAS_PREFETCH is selected by CONFIG_LOONGSON3_ENHANCEMENT, so
MIPS_CPU_PREFETCH (used by uasm) probing is also put in this patch.
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/12755/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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>
Since commit 8cb48fe169 ("MIPS: Provide correct siginfo_t.si_stime"),
MIPS' uapi/asm/siginfo.h has included uapi/asm-generic/siginfo.h
directly before defining MIPS' struct siginfo, in order to get the
necessary definitions needed for the siginfo struct without the generic
copy_siginfo() hitting compiler errors due to struct siginfo not yet
being defined.
Now that the generic copy_siginfo() is moved out to linux/signal.h we
can safely include asm-generic/siginfo.h before defining the MIPS
specific struct siginfo, which avoids the uapi/ include as well as
breakage due to generic copy_siginfo() being defined before struct
siginfo.
Reported-by: Christopher Ferris <cferris@google.com>
Fixes: 8cb48fe169 ("MIPS: Provide correct siginfo_t.si_stime")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Petr Malat <oss@malat.biz>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.0-
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
BMIPS_GENERIC being multiplatform and intended to support BMIPS3200,
BMIPS3300, BMIPS4350, BMIPS4380 and BMIPS5000-class processors, there is
not much more we can put in there since they do not share the same I and
D cache line sizes at all (doubled for every new generation
essentially), some processors have a S-cache, some don't, some have a
FPU, some don't.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13013/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
It's possible for pages to become visible prior to update_mmu_cache
running if a thread within the same address space preempts the current
thread or runs simultaneously on another CPU. That is, the following
scenario is possible:
CPU0 CPU1
write to page
flush_dcache_page
flush_icache_page
set_pte_at
map page
update_mmu_cache
If CPU1 maps the page in between CPU0's set_pte_at, which marks it valid
& visible, and update_mmu_cache where the dcache flush occurs then CPU1s
icache will fill from stale data (unless it fills from the dcache, in
which case all is good, but most MIPS CPUs don't have this property).
Commit 4d46a67a3e ("MIPS: Fix race condition in lazy cache flushing.")
attempted to fix that by performing the dcache flush in
flush_icache_page such that it occurs before the set_pte_at call makes
the page visible. However it has the problem that not all code that
writes to pages exposed to userland call flush_icache_page. There are
many callers of set_pte_at under mm/ and only 2 of them do call
flush_icache_page. Thus the race window between a page becoming visible
& being coherent between the icache & dcache remains open in some cases.
To illustrate some of the cases, a WARN was added to __update_cache with
this patch applied that triggered in cases where a page about to be
flushed from the dcache was not the last page provided to
flush_icache_page. That is, backtraces were obtained for cases in which
the race window is left open without this patch. The 2 standout examples
follow.
When forking a process:
[ 15.271842] [<80417630>] __update_cache+0xcc/0x188
[ 15.277274] [<80530394>] copy_page_range+0x56c/0x6ac
[ 15.282861] [<8042936c>] copy_process.part.54+0xd40/0x17ac
[ 15.289028] [<80429f80>] do_fork+0xe4/0x420
[ 15.293747] [<80413808>] handle_sys+0x128/0x14c
When exec'ing an ELF binary:
[ 14.445964] [<80417630>] __update_cache+0xcc/0x188
[ 14.451369] [<80538d88>] move_page_tables+0x414/0x498
[ 14.457075] [<8055d848>] setup_arg_pages+0x220/0x318
[ 14.462685] [<805b0f38>] load_elf_binary+0x530/0x12a0
[ 14.468374] [<8055ec3c>] search_binary_handler+0xbc/0x214
[ 14.474444] [<8055f6c0>] do_execveat_common+0x43c/0x67c
[ 14.480324] [<8055f938>] do_execve+0x38/0x44
[ 14.485137] [<80413808>] handle_sys+0x128/0x14c
These code paths write into a page, call flush_dcache_page then call
set_pte_at without flush_icache_page inbetween. The end result is that
the icache can become corrupted & userland processes may execute
unexpected or invalid code, typically resulting in a reserved
instruction exception, a trap or a segfault.
Fix this race condition fully by performing any cache maintenance
required to keep the icache & dcache in sync in set_pte_at, before the
page is made valid. This has the added bonus of ensuring the cache
maintenance always happens in one location, rather than being duplicated
in flush_icache_page & update_mmu_cache. It also matches the way other
architectures solve the same problem (see arm, ia64 & powerpc).
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reported-by: Ionela Voinescu <ionela.voinescu@imgtec.com>
Cc: Lars Persson <lars.persson@axis.com>
Fixes: 4d46a67a3e ("MIPS: Fix race condition in lazy cache flushing.")
Cc: Steven J. Hill <sjhill@realitydiluted.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@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
Cc: stable <stable@vger.kernel.org> # v4.1+
Patchwork: https://patchwork.linux-mips.org/patch/12722/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The flush_kernel_dcache_page function was previously essentially a nop.
This is incorrect for MIPS, where if a page has been modified & either
it aliases or it's executable & the icache doesn't fill from dcache then
the content needs to be written back from dcache to the next level of
the cache hierarchy (which is shared with the icache).
Implement this by simply calling flush_dcache_page, treating this
kmapped cache flush function (flush_kernel_dcache_page) exactly the same
as its non-kmapped counterpart (flush_dcache_page).
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Lars Persson <lars.persson@axis.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12719/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
