Such situation is defined as UNPREDICTABLE by arm arm manual.
This patch fixes all explicit TLB fetches which could cause this issue
and speculative TLB fetches for sections mapped in user address space.
Speculative TLB fetches for sections mapped in kernel address space are
not fixed yet as the break-before-make approach must be implemented for
kernel mappings too. This means that promoted/demoted section will be
unmapped for a while. Either kernel stack the promotion/demotion is
being done on or L1 page table(s) which must be modified may be mapped
by this section. Thus the fix will not be so simple like for userland
mappings.
The issue was detectable only on Cortex-A8 platforms and only very
rarely. It was reported few times. First, it was by Mikael Urankar
in June 2015. He helped to identify the mechanism of this issue, but
we were not sure how to fix it correctly until now.
PR: 208381
Reported by: Mikael Urankar (mikael.urankar at gmail.com)
Reviewed by: kib
and R/W emulation aborts under pmap lock.
There were two reasons for using of atomic operations:
(1) the pmap code is based on i386 one where they are used,
(2) there was an idea that access and R/W emulation aborts should be
handled as quick as possible, without pmap locking.
However, the atomic operations in i386 pmap code are used only because
page table entries may be modified by hardware. At the beginning, we
were not sure that it's the only reason. So even if arm hardware does
not modify them, we did not risk to not use them at that time. Further,
it turns out after some testing that using of pmap lock for access and
R/W emulation aborts does not bring any extra cost and there was no
measurable difference. Thus, we have decided finally to use pmap lock
for all operations on page table entries and so, there is no reason for
atomic operations on them. This makes the code cleaner and safer.
This decision introduce a question if it's safe to use pmap lock for
access and R/W emulation aborts. Anyhow, there may happen two cases in
general:
(A) Aborts while the pmap lock is locked already - this should not
happen as pmap lock is not recursive. However, under pmap lock only
internal kernel data should be accessed and such data should be mapped
with A bit set and NM bit cleared. If double abort happens, then
a mapping of data which has caused it must be fixed.
(B) Aborts while another lock(s) is/are locked - this already can
happen. There is no difference here if it's either access or R/W
emulation abort, or if it's some other abort.
Reviewed by: kib
(PL1) and unprivileged (PL0) read/write access. As cp15 virtual to
physical address translation operations are used, interrupts must be
disabled to get consistent result when they are called.
These functions should be used only in very specific occasions like
during abort handling or kernel debugging. One of them is going to be
used in pmap_fault(). However, complete function set is added. It cost
nothing, as they are inlined.
While here, fix comment of #endif.
Reviewed by: kib
rounddown2 tends to produce longer lines than the original code
and when the code has a high indentation level it was not really
advantageous to do the replacement.
This tries to strike a balance between readability using the macros
and flexibility of having the expressions, so not everything is
converted.
bcm2835_mbox_fb_init sets configuration so SET_VIRTUAL_OFFSET should be used
instead of GET_VIRTUAL_OFFSET
Submitted by: Sylvain Garrigues <sylvain@sylvaingarrigues.com>
VideoCore reports garbage in viewport geometry fields unless
viewport was set previously by earlier stage boot loader. So
when booting FreeBSD kernel directly from VideoCore's start.elf
framebuffer intialization fails due to invalid vxres, vyres
values. Make sure we request viewport to be equal to physical
resolution
Submitted by: Sylvain Garrigues <sylvain@sylvaingarrigues.com>
write to the End of Interrupt (EOI) register before handling the interrupt.
This should be a noop as it will be set for all edge triggered interrupts,
however this will not be the case for MSI interrupts. These are also edge
triggered, however we should not write to the EOI register until later in
arm_gic_pre_ithread.
Obtained from: ABT Systems Ltd
Sponsored by: The FreeBSD Foundation
support MSI and MSI-X interrupts, however intrng needs updates before this
can happen.
For now we just attach the driver until the MSI API is ready.
Obtained from: ABT Systems Ltd
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5950
- Pre-buffer audio data to VideoCore so there are no audible glitches when
driver is too late to provide samples
- Start actual playback when there is some prebuffered audio,
it fixes audible noisy click in the beginning of playback
- Use #defines instead of hardcoded values where appropriate
- Fix copy-pasted comment
PR: 208678
value that can't ever be in an inconsistant intermediate state even when
some other thread is in the middle of writing the value/register.
Locking of the hardware remains in the few places that do r-m-w operations.
Locking of metadata access is restricted to places using memcpy or sprintf
to modify the metadata.
oddly separated from related functionality. This just moves some blocks
of code around so that setup_intr and teardown_intr are near each other
again, and likewise for enable/disable_intr. No functional changes.
The PLL_X, base CPU frequency source, doesn't have a bypass switch and thus
we must use another frequency source for CPU while changing its frequency.
PLL_P is ideal for this, it runs at 480MHz and CPU can be clocked at this
frequency at any CPU voltage.
many SoCs these two are the same, however there is no requirement for this
to be the case, e.g. on the ARM Juno we boot on what the GIC thinks of as
CPU 2, but FreeBSD numbers it CPU 0.
Obtained from: ABT Systems Ltd
Sponsored by: The FreeBSD Foundation
a child of it. This is done in conformity with Linux dts files and
as preparation for rework of BCM2836 interrupt controller for INTRNG.
Reviewed by: gonzo
Differential Revision: https://reviews.freebsd.org/D5807
universal.
(1) New struct intr_map_data is defined as a container for arbitrary
description of an interrupt used by a device. Typically, an interrupt
number and configuration relevant to an interrupt controller is encoded
in such description. However, any additional information may be encoded
too like a set of cpus on which an interrupt should be enabled or vendor
specific data needed for setup of an interrupt in controller. The struct
intr_map_data itself is meant to be opaque for INTRNG.
(2) An intr_map_irq() function is created which takes an interrupt
controller identification and struct intr_map_data as arguments and
returns global interrupt number which identifies an interrupt.
(3) A set of functions to be used by bus drivers is created as well as
a corresponding set of methods for interrupt controller drivers. These
sets take both struct resource and struct intr_map_data as one of the
arguments. There is a goal to keep struct intr_map_data in struct
resource, however, this way a final solution is not limited to that.
(4) Other small changes are done to reflect new situation.
This is only first step aiming to create stable interface for interrupt
controller drivers. Thus, some temporary solution is taken. Interrupt
descriptions for devices are stored in INTRNG and two specific mapping
function are created to be temporary used by bus drivers. That's why
the struct intr_map_data is not opaque for INTRNG now. This temporary
solution will be replaced by final one in next step.
Differential Revision: https://reviews.freebsd.org/D5730
separate driver. Add support for activating clock and hwreset resources
for these devices when the EXT_RESOURCES option is present.
Reviewed by: andrew, mmel, Emmanuel Vadot <manu@bidouilliste.com>
Approved by: adrian (mentor)
Differential Revision: https://reviews.freebsd.org/D5749
This driver works in PIO mode for now, interrupts are available only when
FIFO is enabled. The FIFO cannot be used with arbitrary sizes which defeat
its general use.
At some point we can add DMA transfers where the FIFO can be more useful.
Tested on uBMC (microBMC) and BBB.
Sponsored by: Rubicon Communications (Netgate)
different ID space than the kernel. Because of this we need to read the
ID from the hardware. The hardware will provide this value to the CPU by
reading any of the first 8 Interrupt Processor Targets Registers.
Obtained from: ABT Systems Ltd
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5706
