net: ipa: compute DMA pool size properly

In gsi_trans_pool_init_dma(), the total size of a pool of memory
used for DMA transactions is calculated. However the calculation is
done incorrectly.

For

net: ipa: compute DMA pool size properly

In gsi_trans_pool_init_dma(), the total size of a pool of memory
used for DMA transactions is calculated. However the calculation is
done incorrectly.

For 4KB pages, this total size is currently always more than one
page, and as a result, the calculation produces a positive (though
incorrect) total size. The code still works in this case; we just
end up with fewer DMA pool entries than we intended.

Bjorn Andersson tested booting a kernel with 16KB pages, and hit a
null pointer derereference in sg_alloc_append_table_from_pages(),
descending from gsi_trans_pool_init_dma(). The cause of this was
that a 16KB total size was going to be allocated, and with 16KB
pages the order of that allocation is 0. The total_size calculation
yielded 0, which eventually led to the crash.

Correcting the total_size calculation fixes the problem.

Reported-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Tested-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Fixes: 9dd441e4ed57 ("soc: qcom: ipa: GSI transactions")
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20230328162751.2861791-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: Proactively round up to kmalloc bucket size

Instead of discovering the kmalloc bucket size _after_ allocation, round
up proactively so the allocation is explicitly made for the full size,

net: ipa: Proactively round up to kmalloc bucket size

Instead of discovering the kmalloc bucket size _after_ allocation, round
up proactively so the allocation is explicitly made for the full size,
allowing the compiler to correctly reason about the resulting size of
the buffer through the existing __alloc_size() hint.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
Reviewed-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/lkml/4d75a9fd-1b94-7208-9de8-5a0102223e68@ieee.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221018092724.give.735-kees@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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net: ipa: update copyrights

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: Ale

net: ipa: update copyrights

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>

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net: ipa: update comments

This patch just updates comments throughout the IPA code.

Transaction state is now tracked using indexes into an array rather
than linked lists, and a few comments refer t

net: ipa: update comments

This patch just updates comments throughout the IPA code.

Transaction state is now tracked using indexes into an array rather
than linked lists, and a few comments refer to the "old way" of
doing things. The description of how transactions are used was
changed to refer to "operations" rather than "commands", to
(hopefully) remove a possible ambiguity.

IPA register offsets and fields are now handled differently as well,
and the register documentation is updated to better describe the
code.

A few minor updates to comments were made (e.g., adding a missing
word, fixing a typo or punctuation, etc.).

Finally, the local macro atomic_dec_not_zero() is no longer used, so
it is deleted.

Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20220930224527.3503404-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: don't have gsi_channel_update() return a value

If it finds no completed transactions, gsi_channel_trans_complete()
calls gsi_channel_update() to check hardware. If new transactions
have c

net: ipa: don't have gsi_channel_update() return a value

If it finds no completed transactions, gsi_channel_trans_complete()
calls gsi_channel_update() to check hardware. If new transactions
have completed, gsi_channel_update() records that, then calls
gsi_channel_trans_complete() to return the first of those found.
This recursion won't go any further, but can be avoided if we
have gsi_channel_update() only be responsible for updating state
after accessing hardware.

Change gsi_channel_update() so it simply checks for and handles
new completions, without returning a value. If it needs to call
that function, have gsi_channel_trans_complete() determine whether
there are new transactions available after the update.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: ipa: update channel in gsi_channel_trans_complete()

Have gsi_channel_trans_complete() update the known state from
hardware rather than doing so in gsi_channel_poll_one().

Signed-off-by: Alex E

net: ipa: update channel in gsi_channel_trans_complete()

Have gsi_channel_trans_complete() update the known state from
hardware rather than doing so in gsi_channel_poll_one().

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: ipa: kill all other transaction lists

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 r

net: ipa: kill all other transaction lists

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>

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net: ipa: kill the allocated transaction list

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 t

net: ipa: kill the allocated transaction list

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>

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net: ipa: always use transaction IDs instead of lists

In gsi_channel_trans_complete(), use the completed and pending IDs
to determine whether there are any transactions in completed state.

Similarl

net: ipa: always use transaction IDs instead of lists

In gsi_channel_trans_complete(), use the completed and pending IDs
to determine whether there are any transactions in completed state.

Similarly, in gsi_channel_trans_cancel_pending(), use the pending
and committed IDs to mark pending transactions cancelled. Rearrange
the logic a bit there for a simpler result.

This removes the only user of list_last_entry_or_null(), so get rid
of that macro.

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>

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net: ipa: verify a few more IDs

The completed transaction list is used in gsi_channel_trans_complete()
to return the next transaction in completed state.

Add some temporary checks to verify the tra

net: ipa: verify a few more IDs

The completed transaction list is used in gsi_channel_trans_complete()
to return the next transaction in completed state.

Add some temporary checks to verify the transaction indicated by the
completed ID matches the one first in this list.

Similarly, we use the pending and completed transaction lists when
cancelling pending transactions in gsi_channel_trans_cancel_pending().

Add temporary checks there to verify the transactions indicated by
IDs match those tracked by these lists.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: ipa: rework last transaction determination

When quiescing a channel, we find the "last" transaction, which is
the latest one to have been allocated. (New transaction allocation
will have been

net: ipa: rework last transaction determination

When quiescing a channel, we find the "last" transaction, which is
the latest one to have been allocated. (New transaction allocation
will have been prevented by the time this is called.)

Currently we do this by looking for the first non-empty transaction
list in each state, then return the last entry from that last.
Instead, determine the last entry in each list (if any) and return
that entry if found.

Temporarily (locally) introduce list_last_entry_or_null() as a
helper for this, mirroring list_first_entry_or_null(). This macro
definition will be removed by an upcoming patch.

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>

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net: ipa: track polled transactions with an ID

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.

Te

net: ipa: track polled transactions with an ID

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>

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net: ipa: track completed transactions with an ID

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

net: ipa: track completed transactions with an ID

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>

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net: ipa: track pending transactions with an ID

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 I

net: ipa: track pending transactions with an ID

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>

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net: ipa: track committed transactions with an ID

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.

net: ipa: track committed transactions with an ID

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>

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net: ipa: track allocated transactions with an ID

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 I

net: ipa: track allocated transactions with an ID

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>

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net: ipa: use an array for transactions

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

net: ipa: use an array for transactions

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>

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net: ipa: fix an outdated comment

Since commit 8797972afff3d ("net: ipa: remove command info pool"),
we don't allocate "command info" entries for command channel
transactions. Fix a comment that se

net: ipa: fix an outdated comment

Since commit 8797972afff3d ("net: ipa: remove command info pool"),
we don't allocate "command info" entries for command channel
transactions. Fix a comment that seems to suggest we still do.
(Even before that commit, the comment was out of place.)

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: skip some cleanup for unused transactions

In gsi_trans_free(), there's no point in ipa_gsi_trans_release() if
a transaction is unused. No used TREs means no IPA layer resources
to clean u

net: ipa: skip some cleanup for unused transactions

In gsi_trans_free(), there's no point in ipa_gsi_trans_release() if
a transaction is unused. No used TREs means no IPA layer resources
to clean up. So only call ipa_gsi_trans_release() if at least one
TRE was used.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: rearrange transaction initialization

The transaction map is really associated with the transaction pool;
move its definition earlier in the gsi_trans_info structure.

Rearrange initializat

net: ipa: rearrange transaction initialization

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>

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net: ipa: add a transaction committed list

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

net: ipa: add a transaction committed list

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>

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net: ipa: remove unexpected word "the"

there is an unexpected word "the" in the comments that need to be removed

Signed-off-by: Jiang Jian <jiangjian@cdjrlc.com>
Reviewed-by: Alex Elder <elder@lina

net: ipa: remove unexpected word "the"

there is an unexpected word "the" in the comments that need to be removed

Signed-off-by: Jiang Jian <jiangjian@cdjrlc.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20220621085001.61320-1-jiangjian@cdjrlc.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: don't pass channel when mapping transaction

Change gsi_channel_trans_map() so it derives the channel used from
the transaction. Pass the index of the *first* TRE used by the
transaction,

net: ipa: don't pass channel when mapping transaction

Change gsi_channel_trans_map() so it derives the channel used from
the transaction. Pass the index of the *first* TRE used by the
transaction, and have the called function account for the fact that
the last one used is what's important.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: don't assume one channel per event ring

In gsi_evt_ring_rx_update(), use gsi_event_trans() repeatedly
to find the transaction associated with an event, rather than
assuming consecutive eve

net: ipa: don't assume one channel per event ring

In gsi_evt_ring_rx_update(), use gsi_event_trans() repeatedly
to find the transaction associated with an event, rather than
assuming consecutive events are associated with the same channel.
This removes the only caller of gsi_trans_pool_next(), so get rid
of it.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: introduce gsi_trans_tx_committed()

Create a new function that encapsulates recording information needed
for TX channel statistics when a transaction is committed.

Record the accumulated l

net: ipa: introduce gsi_trans_tx_committed()

Create a new function that encapsulates recording information needed
for TX channel statistics when a transaction is committed.

Record the accumulated length in the transaction before the call
(for both RX and TX), so it can be used when updating TX statistics.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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