moved from the stack into the tag structure. In retrospect that was a bad
idea, because nothing protects that array from concurrent access by
multiple threads.
This change moves the array to the map structure (actually it's allocated
following the structure, but all in a single malloc() call).
This also establishes a "sane" limit of 4096 segments per map. This is
mostly to prevent trying to allocate all of memory if someone accidentally
uses a tag with nsegments set to BUS_SPACE_UNRESTRICTED. If there's ever
a genuine need for more than 4096, don't hesitate to increase this (or
maybe make it tunable).
Reviewed by: cognet
triggers a need to bounce due to cacheline alignment. These buffers
are always aligned to cacheline boundaries, and even when the DMA operation
starts at an offset within the buffer or doesn't extend to the end of the
buffer, it's safe to flush the complete cachelines that were only partially
involved in the DMA. This is because there's a very strict rule on these
types of buffers that there will not be concurrent access by the CPU and
one or more DMA transfers within the buffer.
Reviewed by: cognet
functions, it has evolved to make a variety of decisions about whether
the DMA needs to bounce, so rename it to must_bounce(). Rewrite it to
perform checks outside of the ancestor loop if they're based on information
that's wholly contained within the original tag. Now the loop only checks
exclusion zones in ancestor tags.
Also, add a new function, might_bounce() which does a fast inline check
of flags within the tag and map to quickly eliminate the need to call
the more expensive must_bounce() for each page in the DMA operation.
Within the mapping loops, use map->pagesneeded != 0 as a proxy for all
the various checks on whether bouncing might be required. If no pages
were reserved for bouncing during the checks before the mapping loop,
then there's no need to re-check any of the conditions that can lead
to bouncing -- all those checks already decided there would be no bouncing.
Reviewed by: cognet
exclusion zones and phsyical memory. The phys_avail[i] entries are the
address of the first byte of ram in the region, and phys_avail[i+1]
entries are the address of the first byte of ram in the next region
(i.e., they're not included in the region that starts at phys_avail[i]).
Reviewed by: cognet
unchanging values in the phys_avail array, so do the comparisons just once
at tag creation time and set a flag to remember the result.
Reviewed by: cognet
DMA on arm can bounce for several reasons, and _bus_dma_can_bounce() only
checks for the lowaddr/highaddr exclusion ranges in the dma tag, so now
it's named exclusion_bounce(). The other reasons for bouncing are checked
by the new functions alignment_bounce() and cacheline_bounce().
Reviewed by: cognet
requires the return value of telldir() to equal the value passed to
seekdir(). The current seekdir code with SINGLEUSE enabled breaks
this case as each call to telldir() allocates a new cookie. Instead,
remove the SINGLEUSE code and change telldir() to look for an existing
cookie for the directory's current location rather than always creating
a new cookie.
CR: https://phabric.freebsd.org/D490
PR: 121656
Reviewed by: jilles
MFC after: 1 week
postponing it to zfs_vget(). zfs_root() returned vnode with the
default value of v_hash, which caused inconsistent v_hash value when
root vnode was obtained from zfs_vget().
Nullfs allocated two upper vnodes for the root zfs vnode due to
different hashes, causing consistency problems.
Reported and tested by: Harald Schmalzbauer <h.schmalzbauer@omnilan.de>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
ping6(8) would quit before the remote side gets a chance to respond.
Solve this by resetting the itimer when we have reached the maximum packet
number have reached, but let the other handling to continue.
PR: bin/151023
Submitted by: tjmao at tjmao.net
MFC after: 2 weeks
place for the NFS-based PXE loader. Information like rootpath
or rootip aren't that useful for TFTP and the gateway IP is
typically already printed by the firmware.
2. Only set boot.nfsroot.* environment variables for NFS. This
makes it possible for the OS to work either way by checking
for the presence or absence of environment variables.
3. Set boot.netif.server when using TFTP so that the OS can fetch
files as well. A typical use case for this is network-based
installations with the installation process implemented on
top of FreeBSD.
4. The pxelinux loader has a set of alternative names it tries
for configuration files. Make it easier to do something
similar in Forth by providing the IP address as a 32-bit hex
number in the pxeboot.ip variable and the MAC address with
dashes in the pxeboot.hwaddr environment variable.
Obtained from: Juniper Networks, Inc.
particular, allow loaders to define the name of the RC script the
interpreter needs to use. Use this new-found control to have the
PXE loader (when compiled with TFTP support and not NFS support)
read from ${bootfile}.4th, where ${bootfile} is the name of the
file fetched by the PXE firmware.
The normal startup process involves reading the following files:
1. /boot/boot.4th
2. /boot/loader.rc or alternatively /boot/boot.conf
When these come from a FreeBSD-defined file system, this is all
good. But when we boot over the network, subdirectories and fixed
file names are often painful to administrators and there's really
no way for them to change the behaviour of the loader.
Obtained from: Juniper Networks, Inc.
be able to claim I know how the UART code works."
* Just return 115200 as the current baud rate. I should cache it in the
device struct and return that but I'm lazy right now.
* don't error out on other ioctl settings for now, just silently ignore them.
* remove some code that was copied from the 8250 driver that isn't needed
any longer.
Tested:
* AR9331, Carambola-2 board.
