We have a bad habit of duplicating contents of files that are sourced from
/dev/null and applied more than once... take the more sane (in most ways)
GNU route and complain if the file exists and offer reversal options.
This still falls short a little bit as selecting "don't reverse, apply
anyway" will still give you duplicated file contents. There's probably other
issues as well, but awareness is the first step to happiness.
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D21535
tlb1_mapin_region() and pmap_mapdev_attr() do roughly the same thing -- map
a chunk of physical address space(memory or MMIO) into virtual, but do it in
differing ways. Unify the code, settling on pmap_mapdev_attr()'s algorithm,
to simplify and unify the logic. This fixes a bug with growing the kernel
mappings in mmu_booke_bootstrap(), where part of the mapping was not getting
done, leading to a hang when the unmapped VAs were accessed.
Some userland libraries incude machine/pcb.h and this needs the full
definition of struct debug_monitor_state. To allow this to work move
stuct debug_monitor_state out of the _KERNEL guard.
Sponsored by: DARPA, AFRL
Handle error bits of INTR_STAT and TX_ABORT registers.
Move interrupt clearing from interrupt handler to polling loop to get
common execution path with polled mode.
Do not clear interrupts with reading of IG4_REG_CLR_INTR register as
interrupts, triggered during the period from reg_read(IG4_REG_INTR_STAT)
to reg_read(IG4_REG_CLR_INTR) will be missed.
Instead, read each IG4_REG_CLR_* register separately.
INTR_STAT register exposes more useful informaton then STA register does
e.g. it exposes error and I2C bus STOP conditions. Make it a main source
of I2C transfer state.
In this mode DATA_CMD register reads and writes are performed in
TX/RX FIFO-sized bursts to increase I2C bus utilization.
That reduces read time from 60us to 30us per byte when read data is fit
in to RX FIFO buffer in FAST speed mode in my setup.
IC clock rates are varied between different controller models so we have
to adjust timing registers in each case individually. Borrow intresting
constants and formulas from Intel specs, i2c-designware and lpss_intel
drivers and apply them to FreeBSD supported controller models.
Implement fetching of timing data via ACPI methods execution if available.
After recent ig4 changes cyapa driver can be attached before timers
initialization is completed. Start polling thread from config_intrhook
to avoid busy loops in that case.
as the driver is fully functional on a cold boot through utilization of
polled mode.
As a side effect, ig4 children probe and attach methods can be called
earlier in the boot sequence, so now it is up to the child drivers
to wait for a kernel initialization completion if it is required.
If controller is allocated with IIC_NOWAIT option ig4 enables polled mode
for a period of allocation that makes possible to start I2C transfers
from the contexts where sleeping is not allowed e.g. from ithreads or
callouts.
Currently ig4 internally depends on it's own interrupts and uses mtx_sleep()
to wait for them. That means it can not be used from any context where
sleeping is disallowed e.g. on cold boot, from DDB/KDB, from other device
driver's interrupt handlers and so on.
This change replaces sleeps with busy loops in cold boot and DDB cases.
Setting the IG4_REG_RX_TL register to 1 was actually generating an
interrupt after 2 bytes were available in the Rx fifo. We need to set the
register to 0 to get an interrupt for 1 byte already.
Obtained from: DragonflyBSD (02f0bf2)
Now io_lock is used as condition variable to synchronize active process with
the interrupt handler. It is not used for tasks other than waiting for
interrupt and passing parameters to and from it's handler.
Specs shows no dedicated interrupt firing on disable of the controller.
Remove io lock acquisitions around set_controller() calls as they are
not needed anymore.
There is no need to read all controller's RX FIFO data to clear RX_FULL
bit in interrupt handler as interrupts are masked permanently since
previous commit.
This avoids possible interrupt storms, depending on the state of the I2C
controller before the driver attached.
During attaching this clears the interrupt mask.
Revert r338215 as this change makes it no-op.
Obtained from: DragonflyBSD (d7c8555)
Fail the attach on controller startup errors. For some reason the
dell xps 13 says there's I2C controller, but the controller appears
to be permanente disabled and will refuse to enable.
Obtained from: DragonflyBSD (509820b)
They share common device driver code with different bus attachments
This commit starts a bunch of changes which have following properties:
Reviewed by: imp (previous version)
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D22016
It's on the chopping block in two months, the CI tinderbox doesn't bother with
it anymore either, and buildworld fails today due to an issue linking clang.
It's not worth investigating and it just eats up CPU cycles running universe
builds.
If a VM is flooded with more ingress packets than the guest OS
can handle, the current virtio-net code will keep reading those
packets and drop most of them as no space is available in the
receive queue. This is an undesirable receive livelock, which
is a waste of CPU and memory resources and potentially opens to
DoS attacks.
With this change, virtio-net uses the new netbe_rx_disable()
function to disable ingress operation in the backend while the
guest is short on RX buffers. Once the guest makes more buffers
available to the RX virtqueue, ingress operation is enabled again
by calling netbe_rx_enable().
Reviewed by: bryanv, jhb
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20987
switching. The indirect costs being unnecessary TLB misses that are
incurred when ASIDs are not used. In fact, currently, when we perform a
context switch on one processor, we issue a broadcast TLB invalidation that
flushes the TLB contents on every processor.
Mark all user-space ("ttbr0") page table entries with the non-global flag so
that they are cached in the TLB under their ASID.
Correct an error in pmap_pinit0(). The pointer to the root of the page
table was being initialized to the root of the kernel-space page table
rather than a user-space page table. However, the root of the page table
that was being cached in process 0's md_l0addr field correctly pointed to a
user-space page table. As long as ASIDs weren't being used, this was
harmless, except that it led to some unnecessary page table switches in
pmap_switch(). Specifically, other kernel processes besides process 0 would
have their md_l0addr field set to the root of the kernel-space page table,
and so pmap_switch() would actually change page tables when switching
between process 0 and other kernel processes.
Implement a workaround for Cavium erratum 27456 affecting ThunderX machines.
(I would like to thank andrew@ for providing the code to detect the affected
machines.)
Address integer overflow in the definition of TCR_ASID_16.
Setup TCR according to the PARange and ASIDBits fields from
ID_AA64MMFR0_EL1. Previously, TCR_ASID_16 was unconditionally set.
Modify build_l1_block_pagetable so that lower attributes, such as ATTR_nG,
can be specified as a parameter.
Eliminate some unused code.
Earlier versions were tested to varying degrees by: andrew, emaste, markj
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D21922
Implement get/fill_dbregs on arm64. This is used by ptrace with the
PT_GETDBREGS and PT_SETDBREGS requests. It allows userspace to set hardware
breakpoints.
The struct dbreg is based on Linux to ease adding hardware breakpoint
support to debuggers.
Reviewed by: jhb
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D22195
