misc: fastrpc: Pass bitfield into qcom_scm_assign_mem

misc: fastrpc: Pass bitfield into qcom_scm_assign_mem

The srcvm parameter of qcom_scm_assign_mem is a pointer to a bitfield of
VMIDs. The  bitfield is updated with which VMIDs have permissions
after the qcom_scm_assign_mem call. This makes it simpler for clients to
make qcom_scm_assign_mem calls later, they always pass in same srcvm
bitfield and do not need to closely track whether memory was originally
shared.

When restoring permissions to HLOS, fastrpc is incorrectly using the
first VMID directly -- neither the BIT nor the other possible VMIDs the
memory was already assigned to.  We already have a field intended for
this purpose: "perms" in the struct fastrpc_channel_ctx, but it was
never used. Start using the perms field.

Cc: Abel Vesa <abel.vesa@linaro.org>
Cc: Vamsi Krishna Gattupalli <quic_vgattupa@quicinc.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Fixes: e90d91190619 ("misc: fastrpc: Add support to secure memory map")
Fixes: 0871561055e6 ("misc: fastrpc: Add support for audiopd")
Fixes: 532ad70c6d44 ("misc: fastrpc: Add mmap request assigning for static PD pool")
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
drivers/misc/fastrpc.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

Link: https://lore.kernel.org/r/20230112182313.521467-1-quic_eberman@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>