We currently use the traditional SI-like prefixes to represent
binary multipliers in some contexts. This is ambiguous in many cases
since they overload the meaning of the SI prefix.
Here are some examples of commonly used in the industry:
* Storage vendors define 1 MB as 10**6 bytes
* Memory vendors define 1 MB as 2**20 bytes
* Network equipment treats 1Mbit/s as 10**6 bits/s
* Memory vendors define 1Mbit as 2**20 bits
In practice, this means that a FLASH chip on a storage bus uses
decimal prefixes, but that same flash chip on a memory bus uses binary
prefixes. It would also be reasonable to assume that the contents of a
1Mbit FLASH chip would take 0.1s to transfer over a 10Mbit Ethernet
link. That's however not the case due to different meanings of the
prefix.
The quantity 2MX is treated differently by gem5 depending on the unit
X:
* Physical quantities (s, Hz, V, A, J, K, C, F) use decimal prefixes.
* Interconnect and NoC bandwidths (B/s) use binary prefixes.
* Network bandwidths (bps) use decimal prefixes.
* Memory sizes and storage sizes (B) use binary prefixes.
Mitigate this ambiguity by consistently using the ISO/IEC/SI prefixes
for binary multipliers for parameters and comments where appropriate.
Change-Id: I9b47194d26d71c8ebedda6c31a5bac54b600d3bf
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39575
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
We currently use the traditional SI-like prefixes for to represent
binary multipliers in some contexts. This is ambiguous in many cases
since they overload the meaning of the SI prefix.
Here are some examples of commonly used in the industry:
* Storage vendors define 1 MB as 10**6 bytes
* Memory vendors define 1 MB as 2**20 bytes
* Network equipment treats 1Mbit/s as 10**6 bits/s
* Memory vendors define 1Mbit as 2**20 bits
In practice, this means that a FLASH chip on a storage bus uses
decimal prefixes, but that same flash chip on a memory bus uses binary
prefixes. It would also be reasonable to assume that the contents of a
1Mbit FLASH chip would take 0.1s to transfer over a 10Mbit Ethernet
link. That's however not the case due to different meanings of the
prefix.
The quantity 2MX is treated differently by gem5 depending on the unit
X:
* Physical quantities (s, Hz, V, A, J, K, C, F) use decimal prefixes.
* Interconnect and NoC bandwidths (B/s) use binary prefixes.
* Network bandwidths (bps) use decimal prefixes.
* Memory sizes and storage sizes (B) use binary prefixes.
Mitigate this ambiguity by consistently using the ISO/IEC/SI prefixes
for binary multipliers for parameters and comments where appropriate.
Change-Id: I6ab03934af850494d95a37dcda5c2000794b4d3a
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39578
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
When in non-caching mode, performance metrics are not meaningful, and
we're just interested in functional level behavior. Going through the
DMA FIFO in the HDLCD controller is very inefficient, and prevents
reading a batch of pixels from memory all in one go.
Change-Id: I3fb6d4d06730b5a94b5399f01aa02186baa5c9b3
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38721
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Before the commit, the bootloader had a hardcoded entry point that it
would jump to.
However, the Linux kernel arm64 v5.8 forced us to change the kernel
entry point because the required memory alignment has changed at:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
commit/?h=v5.8&id=cfa7ede20f133cc81cef01dc3a516dda3a9721ee
Therefore the only way to have a single bootloader that boots both
pre-v5.8 and post-v5.8 kernels is to pass that information from gem5
to the bootloader, which we do in this patch via registers.
This approach was already used by the 32-bit bootloader, which passed
that value via r3, and we try to use the same register x3 in 64-bit.
Since we are now passing this information, the this patch also removes
the hardcoding of DTB and cpu-release-addr, and also passes those
values via registers.
We store the cpu-release-addr in x5 as that value appears to have a
function similar to flags_addr, which is used only in 32-bit arm and
gets stored in r5.
This commit renames atags_addr to dtb_addr, since both are mutually
exclusive, and serve a similar purpose, DTB being the newer recommended
approach.
Similarly, flags_addr is renamed to cpu_release_addr, and it is moved
from ArmSystem into ArmFsWorkload, since it is not an intrinsic system
property, and should be together with dtb_addr instead.
Before this commit, flags_addr was being set from FSConfig.py and
configs/example/arm/devices.py to self.realview.realview_io.pio_addr
+ 0x30. This commit moves that logic into RealView.py instead, and
sets the flags address 8 bytes before the start of the DTB address.
JIRA: https://gem5.atlassian.net/browse/GEM5-787
Change-Id: If70bea9690be04b84e6040e256a9b03e46710e10
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35076
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This is implemented similary to the NonCachingSimpleCPU, except that
both the normal atomic and noncaching atomic behaviors are implemented
by the same class. The sendDma function now dispatches to a method which
implements one or the other behavior since that function was getting too
big and complex.
Change-Id: I7972971ef41d1373424e587cf67c8444d50de748
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38719
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Instead of generating all of the DMA packets when a request is
initiated, keep track of the necessary properties and generate them as
needed.
The primary benefit of this approach is that if we don't actually need
packets, for instance if we can satisfy the request using a memory
backdoor, we can just skip them. Otherwise we'll have wasted time
creating them, and then have to clean them up.
Change-Id: I04d399fb7bce1ff9a44979c311be356baf2db555
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38717
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This function had a comment claiming that returning an arbitrary request
from the call was necessary for page table walker statistics, but
looking at the actual code, the return type was never used. Also
returning whatever the last request happens to be seems arbitrary, and a
bad boundary for modularization. The page table walker should not depend
on the internal implementation of the DMA port.
Change-Id: I00281fbaf6aeb85b15baf54f3d4a23ca1ac72b8b
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38716
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The existing device tree generation method would use the default
frequency as both the min and max frequency when setting up the OSC
device tree nodes. This would sort of work, except it seems that if
the kernel needed to adjust a frequency, it would fail to do so since
it would assume the new frequency was out of range.
Since the existing property is used to set the initial frequency of
those clocks, and because the default, min and max frequencies are all
mostly independent variables (other than obvious ordering restrictions),
two new properties were added, min_freq and max_freq, which are only
there to fill in the frequency range property in the device tree. If
they aren't set, then the device tree generation method falls back to
the old way of using the default frequency as both min and max.
Change-Id: Ie907bd673f8bcb149e69e45c5b486863149b8a68
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/37935
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
HSA packet processor will now accept and process agent packets.
Type field in packet is command type.
For now:
AgentCmd::Nop = 0
AgentCmd::Steal = 1
Steal command steals the completion signal for a running kernel.
This enables a benchmark to use hsa primitives to send an agent
packet to steal the signal, then wait on that signal.
Minimal working example to be added in gem5-resources.
Change-Id: I37f8a4b7ea1780b471559aecbf4af1050353b0b1
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/37015
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This gets rid of the requirement to only modify one byte register at a
time, and builds some structure around individual DMA channels.
The one small feature of the i8237 that was implemented is still
implemented, but now with a method of the i8237.
Change-Id: Ibc2b2d75f2a3b860da3f28ae649c6f1a099bdf7d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/36815
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
A memory willing to autogenerate child nodes can do that directly in
the generateDeviceTree method. However sometimes portions of memory
(child nodes) are tagged for specific applications. Hardcoding the
child node in the parent memory class is not flexible, so we delegate
this to the application model, which is registering the generator
helper via the ParentMem interface
JIRA: https://gem5.atlassian.net/browse/GEM5-768
Change-Id: I5fa5bac0decf5399dbaa3804569998dc5e6d7bc0
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/34376
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
This is a scoped enum meant to be used mainly in the python world
for DTB autogeneration. By making an ArmInterruptPin self aware of
its own type, we can use it in the C++ world when modelling devices.
For example if a device spec is enforcing a specific triggering behaviour,
its gem5 implementation can query the interrupt type and panic if its
expectations are not met. In this way we are sure what the Linux kernel
sees in the DTB is in sync with how the model really behaves
Change-Id: I66ae3cfbc7b1ed94804f1f882c12eb31f70840da
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35395
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
In python, the BARs had been configured using three arrays and a scalar
parameter. The arrays tracked the BAR value in the config, whether the
BAR was for a "legacy" IO range, and the size of the BAR, and the
scalar parameter was an offset for the "legacy" IO addresses to map
into the host physical address space. The nature of a BAR was implied
by its raw config space value, with each of the control bits (IO vs.
memory, 64 bit, reserved bits) encoded directly in the value.
Now, the BARs are represented by objects which have different types
depending on what type of BAR they are. There's one for IO, one for
memory, one for the upper 32 bits of a 64 bit BAR (so indices work
out), and one for legacy IO ranges. Each type has parameters which
are appropriate for it, and they're parameters are all grouped together
as a unit instead of being spread across all the previous values.
The legacy IO offset has been removed, since these addresses can be
offset like any other IO address. They can be represented naturally
in the config using their typical IO port numbers, and still be turned
into an address that gem5 will handle correctly in the back end.
Unfortunately, this exposes a problem in the config system where
a VectorParam can't be overwritten successfully one element at a time,
at least when dealing with SimObject classes. It might work with
actual SimObjects in a config, but I haven't tried it. If you were
to do that to, for instance, update the BARs for x86 so that they
used legacy IO ports for the IDE controller, it would complain that
you were trying to instantiate orphaned nodes. Replacing the whole
VectorParam with a new list of BAR objects seems to work, so that's
what's implemented in this change.
On the C++ side, BARs in the config space are treated as flat values
on reads, and are stored in the config structure associated with each
PCI device. On writes, the value is first passed to the BAR object,
and it has a chance to mask any bits which are fixed in hardware and
update its idea of what range it corresponds to in memory.
When sending AddrRanges up to the parent bus to set up routing, the
BARs generate each AddrRange if and only if their type has been
enabled in the config space command register. The BAR object which
represents the upper 32 bits of a 64 bit BAR does not claim to be
IO or memory, and so doesn't contribute a range. It communicates with
the BAR which represents the lower 32 bits, so that that BAR has the
whole base address.
Since the IO or memory BAR enable bits in the command register are now
handled by the PCI device base class, the IDE controller no longer has
to handle that manually. It does still need to keep track of whether
the bus master functionality has been enabled though, which it can
check when those registers are accessed.
There was already a mechanism for decoding addresses based on BARs
in the PCI device base class, but it was overly complicated and not
used consistently across devices. It's been consolidated, and used in
most places where it makes sense.
Finally, a few unnecessary values have been dropped from the base PCI
device's and IDE controller's checkpoint output. These were just local
copies of information already in the BARs, which in turn are already
stored along with the data in the device's config space.
Change-Id: I16d5f8cdf86d7a2d02a6b04d1f9e1b3eb1dd189d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35516
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The create() method on Params structs usually instantiate SimObjects
using a constructor which takes the Params struct as a parameter
somehow. There has been a lot of needless variation in how that was
done, making it annoying to pass Params down to base classes. Some of
the different forms were:
const Params &
Params &
Params *
const Params *
Params const*
This change goes through and fixes up every constructor and every
create() method to use the const Params & form. We use a reference
because the Params struct should never be null. We use const because
neither the create method nor the consuming object should modify the
record of the parameters as they came in from the config. That would
make consuming them not idempotent, and make it impossible to tell what
the actual simulation configuration was since it would change from any
user visible form (config script, config.ini, dot pdf output).
Change-Id: I77453cba52fdcfd5f4eec92dfb0bddb5a9945f31
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35938
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Before, for historical reasons, the PCI host device was the default
responder on the IO bus, meaning that when there was any type of
transaction which didn't have a device to go to, it would end up
looking like a PCI config transaction. It's very unlikely that this is
what it actually was, and what would happen would be arbitrary and
probably not helpful.
Also, there was no device in place to respond to accesses in x86's IO
port address space. On a real system, these accesses just return junk
and are otherwise legal. On systems where there would be physical bus
wires they would probably return whatever the last data on the bus was.
This would have been helpful when the platform was first being set up
because it would make it obvious when the OS tried to access a device
that wasn't implemented, but there were a few cases where it would
purposefully fiddle with ports with nothing on them. These had one off
backing devices in the config which would handle the accesses
harmlessly, but if the OS changed and tried to access other ports, the
configs would need to be updated.
Now, the PCI host is just another device on the bus. It claims all of
the PCI config space addresses, so any config access, even ones which
don't go with a device, will go to it, and it can respond with all 1s
like it's supposed to.
In it's place, the default responder is now a bus. On that bus is
a device which responds to the entire IO port address range with 0s.
The default on *that* bus is a device which will mark any accesses
as bad.
With this setup, accesses which don't go to a device, including a
device on the IO port address space, will go to the IO bus's default
port. There, if the access was an IO access, it will go to the device
which replies successfully with all 0s. If not, it's marked as an
error.
The device which backs the entire IO address space doesn't conflict
with the actual IO devices, since the access will only go towards it
if it's otherwise unclaimed, and the devices on the default bus don't
participate in routing on the higher level IO bus.
Change-Id: Ie02ad7165dfad3ee6f4a762e2f01f7f1b8225168
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35515
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
