Although GSI is integral to IPA, it is a separate hardware component
and the IPA code supporting it has been structured to avoid explicit
dependence on IPA details. An example of this is that gsi_init() is
passed a number of Boolean flags to indicate special behaviors,
whose values are dependent on the IPA hardware version. Looking
ahead, newer hardware versions would require even more such special
behaviors.
For any given version of IPA hardware (like 3.5.1 or 4.2), the GSI
hardware version is fixed (in this case, 1.3 and 2.2, respectively).
So the IPA version *implies* the GSI version, and the IPA version
can be used as effectively the equivalent of the GSI hardware version.
Rather than proliferating new special behavior flags, just provide
the IPA version to the GSI layer when it is initialized. The GSI
code can then use that directly to determine whether special
behaviors are required. The IPA version enumerated type is already
isolated to its own header file, so the exposure of this IPA detail
is very limited.
For now, just change gsi_init() to pass the version rather than the
Boolean flags, and set the flag values internal to that function.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Fix two spots where a variable "channel_id" is unnecessarily
redefined inside loops in "gsi.c". This is warned about if
"W=2" is added to the build command.
Note that this problem is harmless, so there's no need to backport
it as a bugfix.
Remove a comment in gsi_init() about waking the system; the GSI
interrupt does not wake the system any more.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The GSI general interrupt is managed by three registers: enable;
status; and clear. The three registers have same set of field bits
at the same locations. Use a common set of field masks for all
three registers to avoid duplication.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The GSI global interrupt is managed by three registers: enable;
status; and clear. The three registers have same set of field bits
at the same locations. Use a common set of field masks for all
three registers to avoid duplication.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The GSI interrupt type register and interrupt type mask register
have the same field bits at the same locations. Use a common set of
field masks for both registers rather than essentially duplicating
them. The only place the interrupt mask register uses any of these
is in gsi_irq_enable().
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We now trigger a system resume when we receive an IPA SUSPEND
interrupt. We should *not* wake up on GSI interrupts.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit affects comments (and in one case, whitespace) only.
Throughout the IPA code, return statements are documented using
"@Return:", whereas they should use "Return:" instead. Fix these
mistakes.
In function definitions, some parameters are missing their comment
to describe them. And in structure definitions, some fields are
missing their comment to describe them. Add these missing
descriptions.
Some arguments changed name and type along the way, but their
descriptions were not updated (an endpoint pointer is now used in
many places that previously used an endpoint ID). Fix these
incorrect parameter descriptions.
In the description for the ipa_clock structure, one field had a
semicolon instead of a colon in its description. Fix this.
Add a missing function description for ipa_gsi_endpoint_data_empty().
All of these issues were identified when building with "W=1".
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make minor updates to error messages reported in "gsi.c":
- Use local variables to reduce multi-line function calls
- Don't use parentheses in messages
- Do some slight rewording in a few cases
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We check the state of an event ring or channel both before and after
any GSI command issued that will change that state. In most--but
not all--cases, if the state is something different than expected we
report an error message.
Add error messages where missing, so that all unexpected states
provide information about what went wrong. Drop the parentheses
around the state value shown in all cases.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In gsi_channel_stop(), there's a check to see if the channel might
have entered STOPPED state since a previous call, which might have
timed out before stopping completed.
That check actually belongs in gsi_channel_stop_command(), which is
called repeatedly by gsi_channel_stop() for RX channels.
Fixes: 650d160382 ("soc: qcom: ipa: the generic software interface")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change "transactio" -> "transaction". Also an alignment correction.
Signed-off-by: Wang Wenhu <wenhu.wang@vivo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The MSCC bug fix in 'net' had to be slightly adjusted because the
register accesses are done slightly differently in net-next.
Signed-off-by: David S. Miller <davem@davemloft.net>
In gsi_channel_start() there is harmless-looking comment "Clear the
channel's event ring interrupt in case it's pending". The intent
was to avoid getting spurious interrupts when first bringing up a
channel.
However we now use channel stop/start to implement suspend and
resume, and an interrupt pending at the time we resume is actually
something we don't want to ignore.
The very first time we bring up the channel we do not expect an
interrupt to be pending, and even if it were, the effect would
simply be to schedule NAPI on that channel, which would find nothing
to do, which is not a problem.
Stop clearing any pending IEOB interrupt in gsi_channel_start().
That leaves one caller of the trivial function gsi_isr_ieob_clear().
Get rid of that function and just open-code it in gsi_isr_ieob()
instead.
This fixes a problem where suspend/resume IPA v4.2 would get stuck
when resuming after a suspend.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The iteration count value used in gsi_channel_poll() is intended to
limit poll iterations to the budget supplied as an argument. But
it's never updated.
Fix this bug by incrementing the count each time through the loop.
Reported-by: Sharath Chandra Vurukala <sharathv@codeaurora.com>
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In gsi_channel_reset(), RX channels are subjected to two consecutive
CHANNEL_RESET commands. This workaround should only be used for IPA
version 3.5.1, and for newer hardware "can lead to unwanted behavior."
Only issue the second CHANNEL_RESET command for legacy hardware.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In several places, a Boolean flag is used in the GSI code to
indicate whether the "doorbell engine" should be enabled or not
when a channel is configured. This is basically done to abstract
this property from the IPA version; the GSI code doesn't otherwise
"know" what the IPA hardware version is. The doorbell engine is
enabled only for IPA v3.5.1, not for IPA v4.0 and later.
The next patch makes another change that affects behavior during
channel reset (which also involves programming the channel). It
also distinguishes IPA v3.5.1 hardware from newer hardware.
Rather than creating another flag whose value matches the "db_enable"
value, just rename "db_enable" to be "legacy" so it can be used to
signal more than just the special doorbell handling.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
It is possible for a GSI channel's state to be changed as a result
of an action by a different execution environment. Specifically,
the modem is able to issue a GSI generic command that causes a state
change on a GSI channel associated with the AP.
A channel's state only needs to be known when a channel is allocated
or deallocaed, started or stopped, or reset. So there is little
value in caching the state anyway.
Stop recording a copy of the channel's last known state, and instead
fetch the true state from hardware whenever it's needed. In such
cases, *do* record the state in a local variable, in case an error
message reports it (so the value reported is the value seen).
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass a channel pointer rather than a GSI pointer and channel ID to
gsi_channel_state().
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Zero the result code stored in a field of the scratch 0 register
before issuing a generic EE command. This just guarantees that
the value we read later was actually written as a result of the
command.
Also add the definitions of two more possible result codes that can
be returned when issuing flow control enable or disable commands:
INCORRECT_CHANNEL_STATE: - channel must be in started state
INCORRECT_DIRECTION - flow control is only valid for TX channels
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
An error message about limiting the number of TREs used prints the
wrong value. Fix this bug.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch includes "gsi.c", which implements the generic software
interface (GSI) for IPA. The generic software interface abstracts
channels, which provide a means of transferring data either from the
AP to the IPA, or from the IPA to the AP. A ring buffer of "transfer
elements" (TREs) is used to describe data transfers to perform. The
AP writes a doorbell register associated with a channel to let it know
it has added new entries (for an AP->IPA channel) or has finished
processing entries (for an IPA->AP channel).
Each channel also has an event ring buffer, used by the IPA to
communicate information about events related to a channel (for
example, the completion of TREs). The IPA writes its own doorbell
register, which triggers an interrupt on the AP, to signal that
new event information has arrived.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
