linux-stable.git/drivers/net/ipa/ipa_endpoint.c, branch linux-5.15.y

net: ipa: fix page free in ipa_endpoint_replenish_one()

2022-06-09T08:23:30+00:00

commit 70132763d5d2e94cd185e3aa92ac6a3ba89068fa upstream.

Currently the (possibly compound) pages used for receive buffers are
freed using __free_pages().  But according to this comment above the
definition of that function, that's wrong:
    If you want to use the page's reference count to decide
    when to free the allocation, you should allocate a compound
    page, and use put_page() instead of __free_pages().

Convert the call to __free_pages() in ipa_endpoint_replenish_one()
to use put_page() instead.

Fixes: 6a606b90153b8 ("net: ipa: allocate transaction in replenish loop")
Signed-off-by: Alex Elder 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

net: ipa: fix page free in ipa_endpoint_trans_release()

2022-06-09T08:23:30+00:00

commit 155c0c90bca918de6e4327275dfc1d97fd604115 upstream.

Currently the (possibly compound) page used for receive buffers are
freed using __free_pages().  But according to this comment above the
definition of that function, that's wrong:
    If you want to use the page's reference count to decide when
    to free the allocation, you should allocate a compound page,
    and use put_page() instead of __free_pages().

Convert the call to __free_pages() in ipa_endpoint_trans_release()
to use put_page() instead.

Fixes: ed23f02680caa ("net: ipa: define per-endpoint receive buffer size")
Signed-off-by: Alex Elder 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

net: ipa: ignore endianness if there is no header

2022-06-09T08:22:39+00:00

[ Upstream commit 332ef7c814bdd60f08d0d9013d0e1104798b2d23 ]

If we program an RX endpoint to have no header (header length is 0),
header-related endpoint configuration values are meaningless and are
ignored.

The only case we support that defines a header is QMAP endpoints.
In ipa_endpoint_init_hdr_ext() we set the endianness mask value
unconditionally, but it should not be done if there is no header
(meaning it is not configured for QMAP).

Set the endianness conditionally, and rearrange the logic in that
function slightly to avoid testing the qmap flag twice.

Delete an incorrect comment in ipa_endpoint_init_aggr().

Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: ipa: compute proper aggregation limit

2022-06-06T06:43:37+00:00

commit c5794097b269f15961ed78f7f27b50e51766dec9 upstream.

The aggregation byte limit for an endpoint is currently computed
based on the endpoint's receive buffer size.

However, some bytes at the front of each receive buffer are reserved
on the assumption that--as with SKBs--it might be useful to insert
data (such as headers) before what lands in the buffer.

The aggregation byte limit currently doesn't take into account that
reserved space, and as a result, aggregation could require space
past that which is available in the buffer.

Fix this by reducing the size used to compute the aggregation byte
limit by the NET_SKB_PAD offset reserved for each receive buffer.

Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipa: prevent concurrent replenish

2022-02-05T11:38:56+00:00

commit 998c0bd2b3715244da7639cc4e6a2062cb79c3f4 upstream.

We have seen cases where an endpoint RX completion interrupt arrives
while replenishing for the endpoint is underway.  This causes another
instance of replenishing to begin as part of completing the receive
transaction.  If this occurs it can lead to transaction corruption.

Use a new flag to ensure only one replenish instance for an endpoint
executes at a time.

Fixes: 84f9bd12d46db ("soc: qcom: ipa: IPA endpoints")
Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipa: use a bitmap for endpoint replenish_enabled

2022-02-05T11:38:56+00:00

commit c1aaa01dbf4cef95af3e04a5a43986c290e06ea3 upstream.

Define a new replenish_flags bitmap to contain Boolean flags
associated with an endpoint's replenishing state.  Replace the
replenish_enabled field with a flag in that bitmap.  This is to
prepare for the next patch, which adds another flag.

Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipa: fix atomic update in ipa_endpoint_replenish()

2022-01-27T10:05:39+00:00

commit 6c0e3b5ce94947b311348c367db9e11dcb2ccc93 upstream.

In ipa_endpoint_replenish(), if an error occurs when attempting to
replenish a receive buffer, we just quit and try again later.  In
that case we increment the backlog count to reflect that the attempt
was unsuccessful.  Then, if the add_one flag was true we increment
the backlog again.

This second increment is not included in the backlog local variable
though, and its value determines whether delayed work should be
scheduled.  This is a bug.

Fix this by determining whether 1 or 2 should be added to the
backlog before adding it in a atomic_add_return() call.

Reviewed-by: Matthias Kaehlcke 
Fixes: 84f9bd12d46db ("soc: qcom: ipa: IPA endpoints")
Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipa: kill ipa_cmd_pipeline_clear()

2021-12-01T08:04:51+00:00

[ Upstream commit e4e9bfb7c93d7e78aa4ad7e1c411a8df15386062 ]

Calling ipa_cmd_pipeline_clear() after stopping the channel
underlying the AP<-modem RX endpoint can lead to a deadlock.

This occurs in the ->runtime_suspend device power operation for the
IPA driver.  While this callback is in progress, any other requests
for power will block until the callback returns.

Stopping the AP<-modem RX channel does not prevent the modem from
sending another packet to this endpoint.  If a packet arrives for an
RX channel when the channel is stopped, an SUSPEND IPA interrupt
condition will be pending.  Handling an IPA interrupt requires
power, so ipa_isr_thread() calls pm_runtime_get_sync() first thing.

The problem occurs because a "pipeline clear" command will not
complete while such a SUSPEND interrupt condition exists.  So the
SUSPEND IPA interrupt handler won't proceed until it gets power;
that won't happen until the ->runtime_suspend callback (and its
"pipeline clear" command) completes; and that can't happen while
the SUSPEND interrupt condition exists.

It turns out that in this case there is no need to use the "pipeline
clear" command.  There are scenarios in which clearing the pipeline
is required while suspending, but those are not (yet) supported
upstream.  So a simple fix, avoiding the potential deadlock, is to
stop calling ipa_cmd_pipeline_clear() in ipa_endpoint_suspend().
This removes the only user of ipa_cmd_pipeline_clear(), so get rid
of that function.  It can be restored again whenever it's needed.

This is basically a manual revert along with an explanation for
commit 6cb63ea6a39ea ("net: ipa: introduce ipa_cmd_tag_process()").

Fixes: 6cb63ea6a39ea ("net: ipa: introduce ipa_cmd_tag_process()")
Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: ipa: disable HOLB drop when updating timer

2021-11-25T08:48:34+00:00

[ Upstream commit 816316cacad2b5abd5b41423cf04e4845239abd4 ]

The head-of-line blocking timer should only be modified when
head-of-line drop is disabled.

One of the steps in recovering from a modem crash is to enable
dropping of packets with timeout of 0 (immediate).  We don't know
how the modem configured its endpoints, so before we program the
timer, we need to ensure HOL_BLOCK is disabled.

Fixes: 84f9bd12d46db ("soc: qcom: ipa: IPA endpoints")
Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: ipa: HOLB register sometimes must be written twice

2021-11-25T08:48:34+00:00

[ Upstream commit 6e228d8cbb1cc6ba78022d406340e901e08d26e0 ]

Starting with IPA v4.5, the HOL_BLOCK_EN register must be written
twice when enabling head-of-line blocking avoidance.

Fixes: 84f9bd12d46db ("soc: qcom: ipa: IPA endpoints")
Signed-off-by: Alex Elder 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin