From 82a8daaecfd9382e9450a05f86be8a274cf69a27 Mon Sep 17 00:00:00 2001 From: Marc Bonnici Date: Fri, 15 Oct 2021 17:57:42 +0100 Subject: 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 Signed-off-by: Marc Bonnici Signed-off-by: Sudeep Holla --- drivers/firmware/arm_ffa/driver.c | 17 +++++++++++++++++ include/linux/arm_ffa.h | 2 ++ 2 files changed, 19 insertions(+) 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) diff --git a/include/linux/arm_ffa.h b/include/linux/arm_ffa.h index 505c679b6a9b..85651e41ded8 100644 --- a/include/linux/arm_ffa.h +++ b/include/linux/arm_ffa.h @@ -262,6 +262,8 @@ struct ffa_dev_ops { int (*memory_reclaim)(u64 g_handle, u32 flags); int (*memory_share)(struct ffa_device *dev, struct ffa_mem_ops_args *args); + int (*memory_lend)(struct ffa_device *dev, + struct ffa_mem_ops_args *args); }; #endif /* _LINUX_ARM_FFA_H */ -- cgit v1.2.3