Starting at IPA v4.5, almost all GSI registers had their offsets
changed by a fixed amount (shifted downward by 0xd000). Rather than
defining offsets for all those registers dependent on version, an
adjustment was applied for most register accesses. This was
implemented in commit cdeee49f3e ("net: ipa: adjust GSI register
addresses"). It was later modified to be a bit more obvious about
the adjusment, in commit 571b1e7e58 ("net: ipa: use a separate
pointer for adjusted GSI memory").
We now are able to define every GSI register with its own offset, so
there's no need to implement this special adjustment.
So get rid of the "virt_raw" pointer, and just maintain "virt" as
the (non-adjusted) base address of I/O mapped GSI register memory.
Redefine the offsets of all GSI registers (other than the INTER_EE
ones, which were not subject to the adjustment) for IPA v4.5+,
subtracting 0xd000 from their defined offsets instead.
Move the ERROR_LOG and ERROR_LOG_CLR definitions further down in the
register definition files so all registers are defined in order of
their offset.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Create a new register definition file in the "reg" subdirectory,
and begin populating it with GSI register definitions based on IPA
version. The GSI registers haven't changed much, so several IPA
versions can share the same GSI register definitions.
As with IPA registers, an array of pointers indexed by GSI register ID
refers to these register definitions, and a new "regs" field in the
GSI structure is initialized in gsi_reg_init() to refer to register
information based on the IPA version (though for now there's only
one). The new function gsi_reg() returns register information for
a given GSI register, and the result can be used to look up that
register's offset.
This patch is meant only to put the infrastructure in place, so only
eon register (CH_C_QOS) is defined for each version, and only the
offset and stride are defined for that register. Use new function
gsi_reg() to look up that register's information to get its offset,
This makes the GSI_CH_C_QOS_OFFSET() unnecessary, so get rid of it.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some source files state copyright dates that are earlier than the
last modification of the file. Change the copyright year to 2022 in
all such cases.
Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20220930224549.3503434-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Move the definition of the gsi_ee_id enumerated type out of "gsi.h"
and into "ipa_version.h". That latter header file isolates the
definition of the ipa_version enumerated type, allowing it to be
included in both IPA and GSI code. We have the same requirement for
gsi_ee_id, and moving it here makes it easier to get only that
definition without everything else defined in "gsi.h".
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
None of the transaction lists are actually needed any more, because
transaction IDs (which have been shown to be equivalent) are used
instead. So we can remove all of them, as well as the spinlock
that protects updates to them.
Not requiring a lock simplifies gsi_trans_free() as well; we only
need to check the reference count once to decide whether we've hit
the last reference.
This makes the links field in the gsi_trans structure unused, so get
rid of that as well.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The only place the trans_info->alloc list is used is when
initializing it, when adding a transaction to it when allocation
finishes, and when moving a transaction from that list to the
committed list.
We can just skip putting a transaction on the allocated list, and
add it (rather than move it) to the committed list when it is
committed.
On additional caveat is that an allocated transaction that's
committed without any TREs added will be immediately freed. Because
we aren't adding allocated transactions to a list any more, the
list links need to be initialized to ensure they're valid at the
time list_del() is called for the transaction.
Then we can safely eliminate the allocated transaction list.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a transaction ID to track the first element in the transaction
array that has been polled. Advance the ID when we are releasing a
transaction.
Temporarily add warnings that verify that the first polled
transaction tracked by the ID matches the first element on the
polled list, both when polling and freeing.
Remove the temporary warnings added by the previous commit.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a transaction ID field to track the first element in the
transaction array that has completed but has not yet been polled.
Advance the ID when we are processing a transaction in the NAPI
polling loop (where completed transactions become polled).
Temporarily add warnings that verify that the first completed
transaction tracked by the ID matches the first element on the
completed list, both when pending and completing.
Remove the temporary warnings added by the previous commit.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a transaction ID field to track the first element in the
transaction array that is pending (sent to hardware) but not yet
complete. Advance the ID when a completion event for a channel
indicates that transactions have completed.
Temporarily add warnings that verify that the first pending
transaction tracked by the ID matches the first element on the
pending list, both when pending and completing, as well as when
resetting the channel.
Remove the temporary warnings added by the previous commit.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a transaction ID field to track the first element in a channel's
transaction array that has been committed, but not yet passed to the
hardware. Advance the ID when the hardware is notified via doorbell
that TREs from a transaction are ready for consumption.
Temporarily add warnings that verify that the first committed
transaction tracked by the ID matches the first element on the
committed list, both when committing and pending (at doorbell).
Remove the temporary warnings added by the previous commit.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Transactions for a channel are now managed in an array, with a free
transaction ID indicating which is the next one free.
Add another transaction ID field to track the first element in the
array that has been allocated. Advance it when a transaction is
committed (because that is when that transaction leaves allocated
state).
Temporarily add warnings that verify that the first allocated
transaction tracked by the ID matches the first element on the
allocated list, both when allocating and committing a transaction.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Transactions are always allocated one at a time. The maximum number
of them we could ever need occurs if each TRE is assigned to a
transaction. So a channel requires no more transactions than the
number of TREs in its transfer ring. That number is known to be a
power-of-2 less than 65536.
The transaction pool abstraction is used for other things, but for
transactions we can use a simple array of transaction structures,
and use a free index to indicate which entry in the array is the
next one free for allocation.
By having the number of elements in the array be a power-of-2, we
can use an ever-incrementing 16-bit free index, and use it modulo
the array size. Distinguish a "trans_id" (whose value can exceed
the number of entries in the transaction array) from a "trans_index"
(which is less than the number of entries).
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The transaction map is really associated with the transaction pool;
move its definition earlier in the gsi_trans_info structure.
Rearrange initialization in gsi_channel_trans_init() so it
sets the tre_avail value first, then initializes the transaction
pool, and finally allocating the transaction map.
Update comments.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We currently put a transaction on the pending list when it has
been committed. But until the channel's doorbell rings, these
transactions aren't actually "owned" by the hardware yet.
Add a new "committed" state (and list), to represent transactions
that have been committed but not yet sent to hardware. Define
"pending" to mean committed transactions that have been sent
to hardware but have not yet completed.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When a GSI channel is initially allocated, and after it has been
reset, the hardware assumes its ring index is 0. And although we
do initialize channels this way, the comments in the IPA code don't
really explain this. For event rings, it doesn't matter what value
we use initially, so using 0 is just fine.
Add some information about the assumptions made by hardware above
the definition of the gsi_ring structure in "gsi.h".
Zero the index field for all rings (channel and event) when the ring
is allocated. As a result, that function initializes all fields in
the structure.
Stop zeroing the index the top of gsi_channel_program(). Initially
we'll use the index value set when the channel ring was allocated.
And we'll explicitly zero the index value in gsi_channel_reset()
before programming the hardware, adding a comment explaining why
it's required.
For event rings, use the index initialized by gsi_ring_alloc()
rather than 0 when ringing the doorbell in gsi_evt_ring_program().
(It'll still be zero, but we won't assume that to be the case.)
Use a local variable in gsi_evt_ring_program() that represents the
address of the event ring's ring structure.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In gsi_evt_ring_rx_update(), we update each transaction so its len
field reflects the actual number of bytes received. In the process,
the total number of transactions and bytes processed on the channel
are summed, and added to a running total for the channel.
But we don't actually use those running totals for RX endpoints.
They're maintained for TX channels to support CoDel when they are
associated with a "real" network device.
So stop maintaining these totals for RX endpoints, and update the
comment where the fields are defined to make it clear they're only
valid for TX channels.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Each GSI channel has a TLV FIFO of a certain size, specified in the
configuration data for an AP channel. That size dictates the
maximum number of TREs that are allowed in a single transaction.
The only way that value is used after initialization is as a limit
on the number of TREs in a transaction; calling it "tlv_count"
isn't helpful, and in fact gsi_channel_trans_tre_max() exists to
sort of abstract it.
Instead, rename the channel->tlv_count field trans_tre_max, and get
rid of the helper function. Update a couple of comments as well.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ipa_cmd_info structure now contains only one field, and it's an
enumerated type whose values all fit in 8 bits. Currently we'll
never use more than 8 TREs in a command transaction, and we can
represent that number of command opcodes in the same space as a 64
bit pointer to an ipa_cmd_info structure.
Define IPA_COMMAND_TRANS_TRE_MAX as the maximum number of TREs that
can be in a command transaction. Replace the info pointer in a
transaction with a fixed-size array named cmd_opcode[] of that many
bytes. Store the opcode in this array when adding a command TRE to
a transaction, as was done previously for the info array. This
makes the ipa_cmd_info unused, so get rid of it.
When committing an immediate command transaction, use the channel's
Boolean command flag to determine whether to fill in the opcode,
which will be taken (as before) from the array in the transaction.
This makes the command info pool unnecessary, so get rid of it.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPA v4.2 introduced GSI channel flow control, used instead of IPA
endpoint DELAY mode to prevent a TX channel from injecting packets
into the IPA core. It used a new FLOW_CONTROLLED channel state
which could be entered using GSI generic commands.
IPA v4.11 extended the channel flow control model. Rather than
having a distinct FLOW_CONTROLLED channel state, each channel has a
"flow control" property that can be enabled or not--independent of
the channel state. The AP (or modem) can modify this property using
the same GSI generic commands as before.
The AP only uses channel flow control on modem TX channels, and only
when recovering from a modem crash. The AP has no way to discover
the state of a modem channel, so the fact that (starting with IPA
v4.11) flow control no longer uses a distinct channel state is
invisible to the AP. So enhanced flow control generally does not
change the way AP uses flow control.
There are a few small differences, however:
- There is a notion of "primary" or "secondary" flow control, and
when enabling or disabling flow control that must be specified
in a new field in the GSI generic command register. For now, we
always specify 0 (meaning "primary").
- When disabling flow control, it's possible a request will need
to be retried. We retry up to 5 times in this case.
- Another new generic command allows the current flow control
state to be queried. We do not use this.
Other than the need for retries, the code essentially works the same
way as before.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
One quirk for certain versions of IPA is that endpoint DELAY mode
does not work properly. IPA DELAY mode prevents any packets from
being delivered to the IPA core for processing on a TX endpoint.
The AP uses DELAY mode when the modem crashes, to prevent modem TX
endpoints from generating traffic during crash recovery. Without
this, there is a chance the hardware will stall during recovery from
a modem crash.
To achieve a similar effect, a GSI FLOW_CONTROLLED channel state
was created. A STARTED TX channel can be placed in FLOW_CONTROLLED
state, which prevents the transfer of any more packets. A channel
in FLOW_CONTROLLED state can be either returned to STARTED state, or
can be transitioned to STOPPED state.
Because this operates on GSI channels, two generic commands were
added to allow the AP to control this state for modem channels
(similar to the ALLOCATE and HALT channel commands).
Previously the code assumed this quirk only applied to IPA v4.2.
In fact, channel flow control (rather than endpoint DELAY mode)
should be used for all versions *starting* with IPA v4.2.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The dummy net_device is a large field in the GSI structure, but it
is not at all interesting from the perspective of debugging. Move
it to the end of the GSI structure so the other fields are easier to
find in memory.
The channel and event ring arrays are also very large, so move them
near the end of the structure as well.
Swap the position of the result and completion fields to improve
structure packing.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
A mutex ensures we never submit more than one GSI command of any
kind at once. This means the per-channel and per-event ring
completion structures provide no benefit. Instead, just use the
single (existing) GSI completion to signal the completion of GSI
commands of all types.
This makes gsi_evt_ring_init() a trivial function with no inverse,
so open-code it in its sole caller and get rid of the function.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Introduce new functions gsi_suspend() and gsi_resume(), which will
disable the GSI interrupt handler after all endpoints are suspended
and re-enable it before endpoints are resumed. This will ensure no
GSI interrupt handler will fire when the hardware is suspended.
Here's a little further explanation. There are seven GSI interrupt
types, and most are disabled except when needed.
- These two are not used (never enabled):
GSI_INTER_EE_CH_CTRL
GSI_INTER_EE_EV_CTRL
- These two are only used to implement channel and event ring
commands, and are only enabled while a command is underway:
GSI_CH_CTRL
GSI_EV_CTRL
- The IEOB interrupt signals I/O completion. It will not fire
when a channel is stopped (or "suspended").
GSI_IEOB
- This interrupt is used to allocate or halt modem channels,
and is only enabled while such a command is underway.
GSI_GLOB_EE
However it also is used to signal certain errors, and this could
occur at any time.
- The general interrupt signals general errors, and could occur at
any time.
GSI_GENERAL
The purpose for this change is to ensure no global or general
interrupts fire due to errors while the hardware is suspended.
We enable the clock on resume, and at that time we can "handle"
(at least report) these error conditions.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The GSI layer has the IPA version now, so there's no need for
version-specific flags to be passed from IPA. One instance of
this is in gsi_channel_suspend() and gsi_channel_resume(), which
indicate whether or not the endpoint suspend is implemented by
GSI stopping the channel. We can make that determination based
on gsi->version, eliminating the need for a Boolean flag in those
functions.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Prior to IPA v3.5.1, there is no HW_PARAM_2 GSI register, which we
use to determine the number of channels and endpoints per execution
environment. In that case, we will just assume the number supported
is the maximum supported by the driver.
Introduce gsi_ring_setup() to encapsulate the code that determines
the number of channels and endpoints.
Update GSI_EVT_RING_COUNT_MAX so it is big enough to handle any
available channel for all supported hardware (IPA v4.9 can have 23
channels and 24 event rings).
Signed-off-by: Alex Elder <elder@linaro.org>
Acked-by: AngeloGioacchino Del Regno
Signed-off-by: David S. Miller <davem@davemloft.net>
Increase the maximum number of channels and event rings supported by
the driver, to allow the maximum available on the SDX55.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch actually fixes a bug, though it doesn't affect the two
platforms supported currently. The fix implements GSI memory
pointers a bit differently.
For IPA version 4.5 and above, the address space for almost all GSI
registers is adjusted downward by a fixed amount. This is currently
handled by adjusting the I/O virtual address pointer after it has
been mapped. The bug is that the pointer is not "de-adjusted" as it
should be when it's unmapped.
This patch fixes that error, but it does so by maintaining one "raw"
pointer for the mapped memory range. This is assigned when the
memory is mapped and used to unmap the memory. This pointer is also
used to access the two registers that do *not* sit in the "adjusted"
memory space.
Rather than adjusting *that* pointer, we maintain a separate pointer
that's an adjusted copy of the "raw" pointer, and that is used for
most GSI register accesses.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
An event ring's state only needs to be known when it is allocated,
reset, or deallocated. We check an event ring's state both before
and after performing an event ring control command that changes
its state. These are only issued at startup and shutdown, so there
is very little value in caching the state.
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: Jakub Kicinski <kuba@kernel.org>
When stopping an AP RX channel, there can be a transient period
while the channel enters STOP_IN_PROC state before reaching the
final STOPPED state. In that case we make another attempt to stop
the channel.
Similarly, when stopping a modem channel (using a GSI generic
command issued from the AP), it's possible that multiple attempts
will be required before the channel reaches STOPPED state.
Add a field to the GSI structure to record an errno representing the
result code provided when a generic command completes. If the
result learned in gsi_isr_gp_int1() is RETRY, record -EAGAIN in the
result code, otherwise record 0 for success, or -EIO for any other
result.
If we time out nf gsi_generic_command() waiting for the command to
complete, return -ETIMEDOUT (as before). Otherwise return the
result stashed by gsi_isr_gp_int1().
Add a loop in gsi_modem_channel_halt() to reissue the HALT command
if the result code indicates -EAGAIN. Limit this to 10 retries
(after the initial attempt).
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Consistently define numeric values for enumerated type members using
hexidecimal (rather than decimal) format values. Align the values
assigned in the same column in each file.
Only assign values where they really matter, for example don't
assign IPA_ENDPOINT_AP_MODEM_TX the value 0.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Keep track of the set of GSI interrupt types that are currently
enabled by recording the mask value to write (or last written) to
the TYPE_IRQ_MSK register.
Create a new helper function gsi_irq_type_update() to handle
actually writing the register.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Rename the "event_enable_bitmap" field of the GSI structure to be
"ieob_enabled_bitmap". An upcoming patch will cache the last value
stored for another interrupt mask and this is a more direct naming
convention to follow.
Add a few comments to explain the bitmap fields in the GSI structure.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We enable a channel doorbell engine only for IPA v3.5.1, and that is
now handled directly by gsi_channel_program().
When initially setting up a channel, we want that doorbell engine
enabled, and we can request that independent of the IPA version.
Doing that makes the "legacy" argument to gsi_channel_setup_one()
unnecessary. And with that gone we can get rid of the "legacy"
argument to gsi_channel_setup(), and gsi_setup() as well.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Use the IPA version in gsi_channel_program() to determine whether
we should enable the GSI doorbell engine when requested. This way,
callers only say whether or not it should be enabled if needed,
regardless of hardware version.
Rename the "legacy" argument to gsi_channel_reset(), and have
it indicate whether the doorbell engine should be enabled when
reprogramming following the reset.
Change all callers of gsi_channel_reset() to indicate whether to
enable the doorbell engine after reset, independent of hardware
version.
Rework a little logic in ipa_endpoint_reset() to get rid of the
"legacy" variable previously passed to gsi_channel_reset().
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Record the IPA version passed to gsi_init() in the GSI structure.
This allows that value to be used directly where needed, rather than
passing and storing certain flag arguments through the code.
In particular, for all but one supported version of IPA, the command
channel is programmed to only use an "escape buffer". By storing
the IPA version, we can do a simple version check in one location,
and avoid storing a flag field in every channel (and passing a flag
along while initializing channels to set that field properly).
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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>
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>
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>
The Generic Software Interface is a layer of the IPA driver that
abstracts the underlying hardware. The next patch includes the
main code for GSI (including some additional documentation). This
patch just includes three GSI header files.
- "gsi.h" is the top-level GSI header file. This structure is
is embedded within the IPA structure. The main abstraction
implemented by the GSI code is the channel, and this header
exposes several operations that can be performed on a GSI channel.
- "gsi_private.h" exposes some definitions that are intended to be
private, used only by the main GSI code and the GSI transaction
code (defined in an upcoming patch).
- Like "ipa_reg.h", "gsi_reg.h" defines the offsets of the 32-bit
registers used by the GSI layer, along with masks that define the
position and width of fields less than 32 bits located within
these registers.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
