ANDROID: ufs, block: fix crypto power management and move into block layer

The call to pm_runtime_get_sync() in ufshcd_program_key() can deadlock
because it waits for the UFS controller to be resumed, but it can itself
be reached while resuming the UFS controller via:

- ufshcd_runtime_resume()
  - ufshcd_resume()
    - ufshcd_reset_and_restore()
      - ufshcd_host_reset_and_restore()
        - ufshcd_hba_enable()
          - ufshcd_hba_execute_hce()
            - ufshcd_hba_start()
              - ufshcd_crypto_enable()
                - keyslot_manager_reprogram_all_keys()
                  - ufshcd_crypto_keyslot_program()
                    - ufshcd_program_key()

But pm_runtime_get_sync() *is* needed when evicting a key.  Also, on
pre-4.20 kernels it's needed when programming a keyslot for a bio since
the block layer used to resume the device in a different place.

Thus, it's hard for drivers to know what to do in .keyslot_program() and
.keyslot_evict().  In old kernels it may even be impossible unless we
were to pass more information down from the keyslot_manager.

There's also another possible deadlock: keyslot programming and eviction
take ksm->lock for write and then resume the device, which may result in
ksm->lock being taken again via the above call stack.  To fix this, we
should resume the device before taking ksm->lock.

Fix these problems by moving to a better design where the block layer
(namely, the keyslot manager) handles runtime power management instead
of drivers.  This is analogous to the block layer's existing runtime
power management support (blk-pm), which handles resuming devices when
bios are submitted to them so that drivers don't need to handle it.

Test: Tested on coral with:
        echo 5 > /sys/bus/platform/devices/1d84000.ufshc/rpm_lvl
        sleep 30
        touch /data && sync  # hangs before this fix
  Also verified via kvm-xfstests that blk-crypto-fallback continues
  to work both with and without CONFIG_PM=y.

Bug: 137270441
Bug: 149368295
Change-Id: I6bc9fb81854afe7edf490d71796ee68a61f7cbc8
Signed-off-by: Eric Biggers <ebiggers@google.com>
Git-Commit: 8d97219e60d4b11b9592b178627a557a0683a841
Git-Repo: https://android.googlesource.com/kernel/common
[neersoni@codeaurora.org]: fixed compilation issues.
Signed-off-by: Neeraj Soni <neersoni@codeaurora.org>

0 files changed, 0 insertions, 0 deletions