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| author | Marc Bonnici <marc.bonnici@arm.com> | 2021-10-15 17:57:42 +0100 |
|---|---|---|
| committer | Sudeep Holla <sudeep.holla@arm.com> | 2021-10-18 13:11:06 +0100 |
| commit | 82a8daaecfd9382e9450a05f86be8a274cf69a27 (patch) | |
| tree | d7eb418850dc994495b0cd06f1ff0f30ef1bbc3e /drivers/firmware | |
| parent | 8e3f9da608f14cfebac2659d8dd8737b79d01308 (diff) | |
| download | lwn-82a8daaecfd9382e9450a05f86be8a274cf69a27.tar.gz lwn-82a8daaecfd9382e9450a05f86be8a274cf69a27.zip | |
firmware: arm_ffa: Add support for MEM_LEND
As part of the FF-A spec, an endpoint is allowed to transfer access of,
or lend, a memory region to one or more borrowers.
Extend the existing memory sharing implementation to support
FF-A MEM_LEND functionality and expose this to other kernel drivers.
Note that upon a successful MEM_LEND request the caller must ensure that
the memory region specified is not accessed until a successful
MEM_RECALIM call has been made. On systems with a hypervisor present
this will been enforced, however on systems without a hypervisor the
responsibility falls to the calling kernel driver to prevent access.
Link: https://lore.kernel.org/r/20211015165742.2513065-1-marc.bonnici@arm.com
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Marc Bonnici <marc.bonnici@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/arm_ffa/driver.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c index 6e0c883ab708..12f4c87c4555 100644 --- a/drivers/firmware/arm_ffa/driver.c +++ b/drivers/firmware/arm_ffa/driver.c @@ -613,6 +613,22 @@ ffa_memory_share(struct ffa_device *dev, struct ffa_mem_ops_args *args) return ffa_memory_ops(FFA_FN_NATIVE(MEM_SHARE), args); } +static int +ffa_memory_lend(struct ffa_device *dev, struct ffa_mem_ops_args *args) +{ + /* Note that upon a successful MEM_LEND request the caller + * must ensure that the memory region specified is not accessed + * until a successful MEM_RECALIM call has been made. + * On systems with a hypervisor present this will been enforced, + * however on systems without a hypervisor the responsibility + * falls to the calling kernel driver to prevent access. + */ + if (dev->mode_32bit) + return ffa_memory_ops(FFA_MEM_LEND, args); + + return ffa_memory_ops(FFA_FN_NATIVE(MEM_LEND), args); +} + static const struct ffa_dev_ops ffa_ops = { .api_version_get = ffa_api_version_get, .partition_info_get = ffa_partition_info_get, @@ -620,6 +636,7 @@ static const struct ffa_dev_ops ffa_ops = { .sync_send_receive = ffa_sync_send_receive, .memory_reclaim = ffa_memory_reclaim, .memory_share = ffa_memory_share, + .memory_lend = ffa_memory_lend, }; const struct ffa_dev_ops *ffa_dev_ops_get(struct ffa_device *dev) |