opnsense-src/sys
Kenneth D. Merry 504e85ade1 mpr, mps: Establish busdma boundaries for memory pools
Most all of the memory used by the cards in the mpr(4) and mps(4)
drivers is required, according to the specs and Broadcom developers,
to be within a 4GB segment of memory.

This includes:

System Request Message Frames pool
Reply Free Queues pool
ReplyDescriptorPost Queues pool
Chain Segments pool
Sense Buffers pool
SystemReply message pool

We got a bug report from Dwight Engen, who ran into data corruption
in the BAE port of FreeBSD:

> We have a port of the FreeBSD mpr driver to our kernel and recently
> I found an issue under heavy load where a DMA may go to the wrong
> address. The test system is a Supermicro X10SRH-CLN4F with the
> onboard SAS3008 controller setup with 2 enterprise Micron SSDs in
> RAID 0 (striped). I have debugged the issue and narrowed down that
> the errant DMA is one that has a segment that crosses a 4GB
> physical boundary.  There are more details I can provide if you'd
> like, but with the attached patch in place I can no longer
> re-create the issue.

> I'm not sure if this is a known limit of the card (have not found a
> datasheet/programming docs for the chip) or our system is just
> doing something a bit different. Any helpful info or insight would
> be welcome.

> Anyway, just thought this might be helpful info if you want to
> apply a similar fix to FreeBSD. You can ignore/discard the commit
> message as it is my internal commit (blkio is our own tool we use
> to write/read every block of a device with CRC verification which
> is how I found the problem).

The commit message was:

> [PATCH 8/9] mpr: fix memory corrupting DMA when sg segment crosses
> 4GB boundary

> Test case was two SSD's in RAID 0 (stripe). The logical disk was
> then partitioned into two partitions. One partition had lots of
> filesystem I/O and the other was initially filled using blkio with
> CRCable data and then read back with blkio CRC verify in a loop.
> Eventually blkio would report a bad CRC block because the physical
> page being read-ahead into didn't contain the right data. If the
> physical address in the arq/segs was for example 0x500003000 the
> data would actually be DMAed to 0x400003000.

The original patch was against mpr(4) before busdma templates were
introduced, and only affected the buffer pool (sc->buffer_dmat) in
the mpr(4) driver. After some discussion with Dwight and the
LSI/Broadcom developers and looking through the driver, it looks
like most of the queues in the driver are ok, because they limit
the memory used to memory below 4GB. The buffer queue and the chain
frames seem to be the exceptions.

This is pretty much the same between the mpr(4) and mps(4) drivers.

So, apply a 4GB boundary limitation for the buffer and chain frame pools
in the mpr(4) and mps(4) drivers.

Reported by:	Dwight Engen <dwight.engen@gmail.com>
Reviewed by:	imp
Obtained from:	Dwight Engen <dwight.engen@gmail.com>
Differential Revision:	<https://reviews.freebsd.org/D43008>

(cherry picked from commit 264610a86e14f8e123d94c3c3bd9632d75c078a3)
2023-12-20 10:40:42 -05:00
..
amd64 makesyscalls: don't make syscall.mk by default 2023-12-13 23:07:06 +00:00
arm arm: Disable the VFP during boot 2023-12-17 21:07:49 -05:00
arm64 arm64: lop off another 24MB of KVA for early device mappings 2023-12-14 18:58:08 -06:00
bsm
cam ctl_ha: don't shutdown threads if scheduler is stopped 2023-12-08 18:02:44 -04:00
cddl
compat sysvipc: Fix 32-bit compat on !i386 2023-12-13 23:10:53 +00:00
conf arm: Compile vfp.c conditionally rather than using an ifdef 2023-12-17 21:07:45 -05:00
contrib x86emu: remove localy added __FBSDID 2023-12-13 23:08:51 +00:00
crypto ossl: Fix some bugs in the fallback AES-GCM implementation 2023-12-03 12:48:09 -05:00
ddb
dev mpr, mps: Establish busdma boundaries for memory pools 2023-12-20 10:40:42 -05:00
dts
fs nfscl: Fix comment for commit 6aded1e6b2e5 2023-12-17 12:32:08 -08:00
gdb
geom shutdown: audit shutdown_post_sync event callbacks 2023-12-08 18:02:44 -04:00
gnu
i386 makesyscalls: don't make syscall.mk by default 2023-12-13 23:07:06 +00:00
isa
kern kthread: Set *newtdp earlier in kthread_add1() 2023-12-17 21:20:13 -05:00
kgssapi
libkern
modules zfs: merge openzfs/zfs@494aaaed8 (zfs-2.2-release) into stable/14 2023-12-01 12:31:24 +01:00
net if_tun: check device name 2023-12-19 02:28:47 +02:00
net80211 net80211: remove ieee80211_unref_node() 2023-11-30 00:36:58 +00:00
netgraph ng_ksocket: fix accept(2) 2023-11-30 09:01:40 -08:00
netinet tcp: add PRR 6937bis heuristic and retire prr_conservative sysctl 2023-12-15 09:25:07 +01:00
netinet6
netipsec
netlink
netpfil pf: fix mem leaks upon vnet destroy 2023-12-06 10:08:25 +01:00
netsmb
nfs
nfsclient
nfsserver
nlm
ofed
opencrypto
powerpc powerpc: better handling of shutdown flags 2023-12-08 18:02:44 -04:00
riscv busdma: emit a warning for use of filters 2023-12-06 19:23:14 -04:00
rpc libc/libc/rpc: refactor some global variables 2023-11-29 20:16:16 -07:00
security
sys kmsan: Add kmsan_check_uio() 2023-12-14 09:44:38 -05:00
teken
tests
tools makesyscalls: don't make syscall.mk by default 2023-12-13 23:07:06 +00:00
ufs ufs: do not leave around empty buffers shadowing disk content 2023-12-20 10:29:55 +02:00
vm uma: Micro-optimize memory trashing 2023-12-08 21:32:43 -05:00
x86 busdma: emit a warning for use of filters 2023-12-06 19:23:14 -04:00
xdr
xen
Makefile
README.md

FreeBSD Kernel Source:

This directory contains the source files and build glue that make up the FreeBSD kernel and its modules, including both original and contributed software.

Kernel configuration files are located in the conf/ subdirectory of each architecture. GENERIC is the configuration used in release builds. NOTES contains documentation of all possible entries. LINT is a compile-only configuration used to maximize build coverage and detect regressions.

Documentation:

Source code documentation is maintained in a set of man pages, under section 9. These pages are located in share/man/man9, from the top-level of the src tree. Consult intro(9) for an overview of existing pages.

Some additional high-level documentation of the kernel is maintained in the Architecture Handbook.

Source Roadmap:

Directory Description
amd64 AMD64 (64-bit x86) architecture support
arm 32-bit ARM architecture support
arm64 64-bit ARM (AArch64) architecture support
cam Common Access Method storage subsystem - cam(4) and ctl(4)
cddl CDDL-licensed optional sources such as DTrace
conf kernel build glue
compat Linux compatibility layer, FreeBSD 32-bit compatibility
contrib 3rd-party imported software such as OpenZFS
crypto crypto drivers
ddb interactive kernel debugger - ddb(4)
fs most filesystems, excluding UFS, NFS, and ZFS
dev device drivers and other arch independent code
gdb kernel remote GDB stub - gdb(4)
geom GEOM framework - geom(4)
i386 i386 (32-bit x86) architecture support
kern main part of the kernel
libkern libc-like and other support functions for kernel use
modules kernel module infrastructure
net core networking code
net80211 wireless networking (IEEE 802.11) - net80211(4)
netgraph graph-based networking subsystem - netgraph(4)
netinet IPv4 protocol implementation - inet(4)
netinet6 IPv6 protocol implementation - inet6(4)
netipsec IPsec protocol implementation - ipsec(4)
netpfil packet filters - ipfw(4), pf(4), and ipfilter(4)
opencrypto OpenCrypto framework - crypto(7)
powerpc PowerPC/POWER (32 and 64-bit) architecture support
riscv 64-bit RISC-V architecture support
security security facilities - audit(4) and mac(4)
sys kernel headers
tests kernel unit tests
ufs Unix File System - ffs(7)
vm virtual memory system
x86 code shared by AMD64 and i386 architectures