linux-stable.git/drivers/net/ipa, branch v5.10

net: ipa: pass the correct size when freeing DMA memory

2020-12-04T22:38:44+00:00

When the coherent memory is freed in gsi_trans_pool_exit_dma(), we
are mistakenly passing the size of a single element in the pool
rather than the actual allocated size.  Fix this bug.

Fixes: 9dd441e4ed575 ("soc: qcom: ipa: GSI transactions")
Reported-by: Stephen Boyd 
Tested-by: Sujit Kautkar 
Signed-off-by: Alex Elder 
Reviewed-by: Bjorn Andersson 
Link: https://lore.kernel.org/r/20201203215106.17450-1-elder@linaro.org
Signed-off-by: Jakub Kicinski

net: ipa: lock when freeing transaction

2020-11-17T01:32:22+00:00

Transactions sit on one of several lists, depending on their state
(allocated, pending, complete, or polled).  A spinlock protects
against concurrent access when transactions are moved between these
lists.

Transactions are also reference counted.  A newly-allocated
transaction has an initial count of 1; a transaction is released in
gsi_trans_free() only if its decremented reference count reaches 0.
Releasing a transaction includes removing it from the polled (or if
unused, allocated) list, so the spinlock is acquired when we release
a transaction.

The reference count is used to allow a caller to synchronously wait
for a committed transaction to complete.  In this case, the waiter
takes an extra reference to the transaction *before* committing it
(so it won't be freed), and releases its reference (calls
gsi_trans_free()) when it is done with it.

Similarly, gsi_channel_update() takes an extra reference to ensure a
transaction isn't released before the function is done operating on
it.  Until the transaction is moved to the completed list (by this
function) it won't be freed, so this reference is taken "safely."

But in the quiesce path, we want to wait for the "last" transaction,
which we find in the completed or polled list.  Transactions on
these lists can be freed at any time, so we (try to) prevent that
by taking the reference while holding the spinlock.

Currently gsi_trans_free() decrements a transaction's reference
count unconditionally, acquiring the lock to remove the transaction
from its list *only* when the count reaches 0.  This does not
protect the quiesce path, which depends on the lock to ensure its
extra reference prevents release of the transaction.

Fix this by only dropping the last reference to a transaction
in gsi_trans_free() while holding the spinlock.

Fixes: 9dd441e4ed575 ("soc: qcom: ipa: GSI transactions")
Reported-by: Stephen Boyd 
Signed-off-by: Alex Elder 
Link: https://lore.kernel.org/r/20201114182017.28270-1-elder@linaro.org
Signed-off-by: Jakub Kicinski

net: ipa: command payloads already mapped

2020-10-24T01:28:52+00:00

IPA transactions describe actions to be performed by the IPA
hardware.  Three cases use IPA transactions:  transmitting a socket
buffer; providing a page to receive packet data; and issuing an IPA
immediate command.  An IPA transaction contains a scatter/gather
list (SGL) to hold the set of actions to be performed.

We map buffers in the SGL for DMA at the time they are added to the
transaction.  For skb TX transactions, we fill the SGL with a call
to skb_to_sgvec().  Page RX transactions involve a single page
pointer, and that is recorded in the SGL with sg_set_page().  In
both of these cases we then map the SGL for DMA with a call to
dma_map_sg().

Immediate commands are different.  The payload for an immediate
command comes from a region of coherent DMA memory, which must
*not* be mapped for DMA.  For that reason, gsi_trans_cmd_add()
sort of hand-crafts each SGL entry added to a command transaction.

This patch fixes a problem with the code that crafts the SGL entry
for an immediate command.  Previously a portion of the SGL entry was
updated using sg_set_buf().  However this is not valid because it
includes a call to virt_to_page() on the buffer, but the command
buffer pointer is not a linear address.

Since we never actually map the SGL for command transactions, there
are very few fields in the SGL we need to fill.  Specifically, we
only need to record the DMA address and the length, so they can be
used by __gsi_trans_commit() to fill a TRE.  We additionally need to
preserve the SGL flags so for_each_sg() still works.  For that we
can simply assign a null page pointer for command SGL entries.

Fixes: 9dd441e4ed575 ("soc: qcom: ipa: GSI transactions")
Reported-by: Stephen Boyd 
Tested-by: Stephen Boyd 
Signed-off-by: Alex Elder 
Link: https://lore.kernel.org/r/20201022010029.11877-1-elder@linaro.org
Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-10-15T19:43:21+00:00

Minor conflicts in net/mptcp/protocol.h and
tools/testing/selftests/net/Makefile.

In both cases code was added on both sides in the same place
so just keep both.

Signed-off-by: Jakub Kicinski

net: ipa: skip suspend/resume activities if not set up

2020-10-09T23:04:07+00:00

When processing a system suspend request we suspend modem endpoints
if they are enabled, and call ipa_cmd_tag_process() (which issues
IPA commands) to ensure the IPA pipeline is cleared.  It is an error
to attempt to issue an IPA command before setup is complete, so this
is clearly a bug.  But we also shouldn't suspend or resume any
endpoints that have not been set up.

Have ipa_endpoint_suspend() and ipa_endpoint_resume() immediately
return if setup hasn't completed, to avoid any attempt to configure
endpoints or issue IPA commands in that case.

Fixes: 84f9bd12d46d ("soc: qcom: ipa: IPA endpoints")
Tested-by: Matthias Kaehlcke 
Signed-off-by: Alex Elder 
Signed-off-by: Jakub Kicinski

net: ipa: fix two comments

2020-09-29T01:34:56+00:00

In ipa_uc_response_hdlr() a comment uses the wrong function name
when it describes where a clock reference is taken.  Fix this.

Also fix the comment in ipa_uc_response_hdlr() to correctly refer to
ipa_uc_setup(), which is where the clock reference described here is
taken.

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

net: ipa: rename a phandle variable

2020-09-29T01:34:56+00:00

When "W=2" is supplied to the build command, we get a warning about
shadowing a global declaration (of a typedef) for a variable defined
in ipa_probe().  Rename the variable to get rid of the warning.

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

net: ipa: fix two mild warnings

2020-09-29T01:34:56+00:00

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 
Signed-off-by: David S. Miller

net: ipa: share field mask values for GSI general interrupt

2020-09-29T01:34:56+00:00

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 
Signed-off-by: David S. Miller

net: ipa: share field mask values for GSI global interrupt

2020-09-29T01:34:56+00:00

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 
Signed-off-by: David S. Miller