could trigger an error interrupt that we can't actually to do anything
against as soon as enabling the error handlers.
While at it don't bother about writing only to the write-one-to-clear
bits when clearing error bits.
with the INTR_FILTER-enabled MI code. Basically this consists of
registering an interrupt controller (of which there can be multiple
and optionally different ones either per host-to-foo bridge or shared
amongst host-to-foo bridges in any one machine) along with an interrupt
vector as specific argument for all the interrupt vectors used by a
given host-to-foo bridge (roughly similar to registering interrupt
sources on amd64 and i386), providing functions to enable, clear and
disable the interrupts of the children beneath the bridge.
This also includes:
- No longer entering a critical section in tl0_intr() and tl1_intr()
for executing interrupt handlers but rather let the handlers enter
it themselves so in the case of intr_event_handle() we don't enter
a nested critical section.
- Adding infrastructure for binding delivery of interrupt vectors to
specific CPUs which later on can be interfaced with the code from
amd64/i386 for binding interrupts to specific CPUs.
- Getting rid of the wrapper hack introduced along the lines of the
API changes for INTR_FILTER which as a side-effect caused interrupts
associated with ithread handlers only to get the elevated priority
of those associated with filters ("fast handlers") (this removes the
hack also in the non-INTR_FILTER case).
- Disabling (by not clearing) an interrupt in the interrupt controller
until all associated handlers have been executed, which is crucial
for the typical locking strategy of NIC drivers in order to work
correctly in case of shared interrupts. This was a more or less
theoretical problem on sparc64 though, as shared interrupts are
rather uncommon there except for the on-board SCCs and UARTs.
Note that due to the behavior of at least of some of the interrupt
controllers used on sparc64 an enable+EOI instead of a disable+EOI
approach (as implied by the INTR_FILTER MI code and implemented on
other architectures) is used as the latter can cause lost interrupts
or in the worst case interrupt starvation.
o Correct a typo in sbus_alloc_resource() which caused (pass-through)
allocations to only work down to the grandchildren of the bus, which
wasn't a real problem so far as we don't support any devices which are
great-grandchildren or greater of a U2S bridge, yet.
o In fhc(4) use bus_{read,write}_4() instead of bus_space_{read,write}_4()
in order to get rid of sc_bh and sc_bt in the fhc_softc. Also get rid
of some other unneeded members in fhc_softc.
Reviewed by: marcel (earlier version)
Approved by: re (kensmith)
instead of per IOMMU, so we no longer need to program all of them
identically in systems having multiple IOMMUs. This continues the
rototilling of the nexus(4) done about 5 months ago, which amongst
others changed nexus(4) and the drivers for host-to-foo bridges
to provide bus_get_dma_tag methods, allowing to handle DMA tags in
a hierarchical way and to link them with devices.
This still doesn't move the silicon bug workarounds for Sabre (and
in the uncommitted schizo(4) for Tomatillo) bridges into special
bus_dma_tag_create() and bus_dmamap_sync() methods though, as w/o
fully newbus'ified bus_dma_tag_create() and bus_dma_tag_destroy()
this still requires too much hackery, i.e. per-child parent DMA
tags in the parent driver.
- Let the host-to-foo drivers supply the maximum physical address
of the IOMMU accompanying the bridges. Previously iommu(4) hard-
coded an upper limit of 16GB, which actually only applies to the
IOMMUs of the Hummingbird and Sabre bridges. The Psycho variants
as well as the U2S in fact can can translate to up to 2TB, i.e.
translate to 41-bit physical addresses. According to the recently
available Tomatillo documentation these bridges even translate to
43-bit physical addresses and hints at the Schizo bridges doing
43 bits as well.
This fixes the issue the FreeBSD 6.0 todo list item "Max RAM on
sparc64" was refering to and pretty much obsoletes the lack of
support for bounce buffers on sparc64.
Thanks to Nathan Whitehorn for pointing me at the Tomatillo manual.
Approved by: re (kensmith)
- Clear the PCI AFSR and status error bits as previous errors still
might be indicated.
- Set up the PCI control and diagnostic registers according to the
capabilities, workarounds, etc of/for specific revisions of the
supported bridges. This includes no longer setting Hummingbird-/
Sabre-specific bits in the PCI control register but preserving
what the firmware has initialized them to like OpenSolaris does.
Previously we were setting these bits according to the example in
the Sabre documentation, which I doubt is appropriate for all
Sabre based designs and especially not for Hummingbirds. This
also includes not enabling bus parking unless the firmware tells
us to.
- Set the PCI latency timer register as this isn't always done by
the firmware.
o Remove a redundant argument from psycho_set_intr() and in this
function check the return value of bus_setup_intr(). [2]
o Let psycho_setup_intr() return ENOMEM instead of 0 when it can't
allocate memory for the interrupt wrapper stub and EINVAL instead
of 0 if it can't find the interrupt vector in the interrupt map.
o Add a workaround for a bug of the Sabre-APB-combination where it
doesn't drain DMA write data for devices behind additional PCI-PCI
bridges underneath the APB PCI-PCI bridge. This workaround (do
things necessary in order to achieve a manual drain when coherency
is required) is currently implemented in psycho_setup_intr() and
psycho_intr_stub() (for easy MFC'ing) and therefore is only applied
for interrupt handlers. This should be moved to psycho(4)-specific
bus_dma_tag_create() and bus_dmamap_sync() methods, respectively,
once this driver is converted to make use of BUS_GET_DMA_TAG(), so
the workaround is also applied for polling(4) callbacks. [3]
o Fix some minor style issues.
Info from: OpenSolaris [1]
Info from: Linux, OpenBSD, OpenSolaris [3]
Suggested by: Coverity Prevent (CID 682) [2]
MFC after: 1 month
bug by explaining what the problem is and how the workaround works.
- Fix some cosmetics nits, mainly properly terminate sentences in comments,
which I missed when backporting the style changes to psycho(4) in psycho.c
rev. 1.54 due to lack of corresponding code.
- The "USIIe version of the Sabre bridge" actually is termed "Hummingbird";
name it as such in comments and messages.
between this driver and other Host-PCI bridge drivers based on this one:
- Make the code fit into 80 columns.
- Make the code adhere style(9) (don't use function calls in initializers,
use uintXX_t instead of u_intXX_t, add missing prototypes, ...).
- Remove unused and superfluous struct declaration, softc member, casts,
includes, etc.
- Use FBSDID.
- Sprinkle const.
- Try to make comments and messages consistent in style throughout the
driver.
- Use convenience macros for the number of interrupts and ranges of the
bridge.
- Use __func__ instead of hardcoded function names in panic strings and
error messages. Some of the hardcoded function names actually were
outdated through moving code around. [1]
- Rename softc members related to the PCI side of the bridge to sc_pci_*
in order to make it clear which side of the bridge they refer to (so
stuff like sc_bushandle vs. sc_bh is less confusing while reading the
code).
PR: 76052 [1]
- Fix some comments; remove numerous superfluous or outdated ones.
- Correctly pass on the requesting device when handing requests up
to the parent bus.
- Use the complete device name, including unit number, to build the
IOMMU instance name.
- Inline a function that was only used once, and was trivial.
a correctable DMA error. Failing to do so can cause the error interrupt
to be triggered over and over again.
- Clean up the comments for UEAFSR_* constants, fix a typo (UEAFSR_BLK is
(1 << 23), not (1 << 22)), and add two more. Also, add similar constants
for the CE AFSR bits.
- tweak the announce message a bit
- remove '\n's from a few panic() calls
- don't use the DVMA base adress the firmware reports; instead, figure
it out from the appropriate register on Sabres and let the IOMMU code
choose it on Psychos. This also makes the IOMMU TSB size freely
selectable.
code. Both tasks are not always performed completely by the firmware.
The former is required to get some e450 models to boot; the latter fixes
the repeated fifo underruns with hme(4)s and gem(4)s observed on some
machines (and probably performance problems with other peripherals as
well).
