an NVidia Tegra 2 CPU.
Tegra 2 needs an external patch to pmap for atomic operations to work. Even
with this the Kernel only gets to the mount root prompt. As such Tegra
support is considered experimental, however adding the kernel config will
help ensure the Tegra code builds.
such that when commenting/uncommentting lines, horizontal spacing is
maintained...
Also fix some minor comment formatting to line things up, etc...
Reviewed by: gnn, imp
MFC after: 1 week
MSI are implemented via Inbound Shared Doorbell 1 interrupts. Interrupts
are triggered by writing to Software Triggered Interrupt registeri (PCIe
card using physical address of this register in BAR0 space). There are 32
interrupts available. It can be increased by using Doorbell 2 and
Doorbell 3 registers to 96 interrupts.
Obtained from: Marvell, Semihalf
MSI are implemented via software interrupt. PCIe cards will write
into software interrupt register which will cause inbound shared
interrupt which will be interpreted as a MSI.
Obtained from: Marvell, Semihalf
- Add functions to calculate clocks instead using hardcoded values
- Update reset and timers functions
- Update number of interrupts
- Change name of platform from db88f78100 to db78460
- Correct DRAM size and PCI IRQ routing in dts file.
Obtained from: Semihalf
to this pmap.
Revise some comments.
The file vm/vm_param.h includes the file machine/vmparam.h, so there is no
need to directly include it.
Tested by: andrew
allocating them on the stack of various bus_dmamap_load*() functions. The
S/G lists are stored in the DMA tags. This matches the implementation on
all other platforms.
Discussed with: scottl, gibbs
Tested by: stas (arm@)
pmap_get_pv_entry(). In fact, some callers already held it around calls.
(In earlier versions, the same statements would apply to the page queues
lock.)
While I'm here tidy up the style of a few nearby statements and revise
some comments.
Tested by: Ian Lepore
o Disable multi-block operations: they sometimes fail.
o Don't use the PROOF bits yet: they hang the system hard.
o Disable the the multi-block operations for !rm9200, but it
still doesn't help.
o Fix writing < 12 bytes errata to actually work.
o Enable, for the moment, reporting extra bytes soaked up.
restructuring of the driver. I've tried to preserve the other silicon
workarounds that we've added over the years, but haven't had a chance
to extensively test on other hardware. On my AT91RM9200 with 30MHz/1
wire/64 block transfers, I've been able to go from ~.66MB/s to
2.25MB/s in the simple tests I performed, almost a 3.5x improvement.
This cuts the boot time almost in half when everything else goes
right (timed from rtc message to login: prompt).
PR: 155214
Submitted by: Ian Lapore
explicltly enable that. The driver chose to use 60MHz / 2 (30MHz)
most of the time rather than 60MHz / 4 (15MHz) based on the Linux
driver of the time. This pushes the spec a little in order to not
suffer the penalty of running at 15MHz. However, when other bus
masters are active in the system, and the user tries 4-wire mode, the
internal bus arbitration would fail with data loss as a result.
# Comments from PR were reworked to reflect my historical perspective
PR: 155214 (partial)
Submitted by: Ian Lepore
BUS_DMA_COHERENT attribute
The minimum unit for changing "cachable" attribute is page, so call
to pmap_change_attr effectively disable cache for all pages that newly
allocated DMA memory region spans on. The problem is that general-purpose
memory could reside on these pages too and disabling cache might affect
performance. Moreover ldrex/strex operators raise Data Abort exception
when accessing memory on page with "cachable" attribute off.
BUS_DMA_COHERENT does nto require memory to be coherent. It just suggests
to do best effort for reducing synchronization overhead.
