There's currently no situation where we want to issue a command to an AS and not wait for this command to complete. The wait is either explicitly done (LOCK, UNLOCK) or it's missing (UPDATE). So let's turn write_cmd() into as_send_cmd_and_wait() that has the wait after a command is sent.
v2: - New patch Signed-off-by: Boris Brezillon <[email protected]> --- drivers/gpu/drm/panthor/panthor_mmu.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c index 6a41dfd7aaf3..186048fc2c25 100644 --- a/drivers/gpu/drm/panthor/panthor_mmu.c +++ b/drivers/gpu/drm/panthor/panthor_mmu.c @@ -524,27 +524,29 @@ static int wait_ready(struct panthor_device *ptdev, u32 as_nr) return ret; } -static int write_cmd(struct panthor_device *ptdev, u32 as_nr, u32 cmd) +static int as_send_cmd_and_wait(struct panthor_device *ptdev, u32 as_nr, u32 cmd) { int status; /* write AS_COMMAND when MMU is ready to accept another command */ status = wait_ready(ptdev, as_nr); - if (!status) + if (!status) { gpu_write(ptdev, AS_COMMAND(as_nr), cmd); + status = wait_ready(ptdev, as_nr); + } return status; } -static void lock_region(struct panthor_device *ptdev, u32 as_nr, - u64 region_start, u64 size) +static int lock_region(struct panthor_device *ptdev, u32 as_nr, + u64 region_start, u64 size) { u8 region_width; u64 region; u64 region_end = region_start + size; if (!size) - return; + return 0; /* * The locked region is a naturally aligned power of 2 block encoded as @@ -567,7 +569,7 @@ static void lock_region(struct panthor_device *ptdev, u32 as_nr, /* Lock the region that needs to be updated */ gpu_write64(ptdev, AS_LOCKADDR(as_nr), region); - write_cmd(ptdev, as_nr, AS_COMMAND_LOCK); + return as_send_cmd_and_wait(ptdev, as_nr, AS_COMMAND_LOCK); } static int mmu_hw_do_operation_locked(struct panthor_device *ptdev, int as_nr, @@ -600,9 +602,7 @@ static int mmu_hw_do_operation_locked(struct panthor_device *ptdev, int as_nr, * power it up */ - lock_region(ptdev, as_nr, iova, size); - - ret = wait_ready(ptdev, as_nr); + ret = lock_region(ptdev, as_nr, iova, size); if (ret) return ret; @@ -615,10 +615,7 @@ static int mmu_hw_do_operation_locked(struct panthor_device *ptdev, int as_nr, * at the end of the GPU_CONTROL cache flush command, unlike * AS_COMMAND_FLUSH_MEM or AS_COMMAND_FLUSH_PT. */ - write_cmd(ptdev, as_nr, AS_COMMAND_UNLOCK); - - /* Wait for the unlock command to complete */ - return wait_ready(ptdev, as_nr); + return as_send_cmd_and_wait(ptdev, as_nr, AS_COMMAND_UNLOCK); } static int mmu_hw_do_operation(struct panthor_vm *vm, @@ -647,7 +644,7 @@ static int panthor_mmu_as_enable(struct panthor_device *ptdev, u32 as_nr, gpu_write64(ptdev, AS_MEMATTR(as_nr), memattr); gpu_write64(ptdev, AS_TRANSCFG(as_nr), transcfg); - return write_cmd(ptdev, as_nr, AS_COMMAND_UPDATE); + return as_send_cmd_and_wait(ptdev, as_nr, AS_COMMAND_UPDATE); } static int panthor_mmu_as_disable(struct panthor_device *ptdev, u32 as_nr) @@ -662,7 +659,7 @@ static int panthor_mmu_as_disable(struct panthor_device *ptdev, u32 as_nr) gpu_write64(ptdev, AS_MEMATTR(as_nr), 0); gpu_write64(ptdev, AS_TRANSCFG(as_nr), AS_TRANSCFG_ADRMODE_UNMAPPED); - return write_cmd(ptdev, as_nr, AS_COMMAND_UPDATE); + return as_send_cmd_and_wait(ptdev, as_nr, AS_COMMAND_UPDATE); } static u32 panthor_mmu_fault_mask(struct panthor_device *ptdev, u32 value) -- 2.51.1
