Commit dd11c7de authored by Karunika Choo's avatar Karunika Choo Committed by Steven Price
Browse files

drm/panthor: Make MMU cache maintenance use FLUSH_CACHES command 



As the FLUSH_MEM and FLUSH_PT MMU_AS commands are deprecated in GPUs
from Mali-Gx20 onwards, this patch adds support for performing cache
maintenance via the FLUSH_CACHES command in GPU_COMMAND in place of
FLUSH_MEM and FLUSH_PT commands.

Mali-Gx10 and Mali-Gx15 GPUs also has support for the FLUSH_CACHES
command and will also use this by default going forward.

Reviewed-by: default avatarSteven Price <steven.price@arm.com>
Reviewed-by: default avatarChia-I Wu <olvaffe@gmail.com>
Reviewed-by: default avatarLiviu Dudau <liviu.dudau@arm.com>
Signed-off-by: default avatarKarunika Choo <karunika.choo@arm.com>
Signed-off-by: default avatarSteven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20250807162633.3666310-7-karunika.choo@arm.com
parent e322a484

drivers/gpu/drm/panthor/panthor_mmu.c

+33 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 


#include "panthor_device.h"

#include "panthor_gem.h"

#include "panthor_gpu.h"

#include "panthor_heap.h"

#include "panthor_mmu.h"

#include "panthor_regs.h"
@@ -568,6 +569,35 @@ static void lock_region(struct panthor_device *ptdev, u32 as_nr, 
	write_cmd(ptdev, as_nr, AS_COMMAND_LOCK);

}



static int mmu_hw_do_flush_on_gpu_ctrl(struct panthor_device *ptdev, int as_nr,

				       u32 op)

{

	const u32 l2_flush_op = CACHE_CLEAN | CACHE_INV;

	u32 lsc_flush_op = 0;

	int ret;



	if (op == AS_COMMAND_FLUSH_MEM)

		lsc_flush_op = CACHE_CLEAN | CACHE_INV;



	ret = wait_ready(ptdev, as_nr);

	if (ret)

		return ret;



	ret = panthor_gpu_flush_caches(ptdev, l2_flush_op, lsc_flush_op, 0);

	if (ret)

		return ret;



	/*

	 * Explicitly unlock the region as the AS is not unlocked automatically

	 * 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);

}



static int mmu_hw_do_operation_locked(struct panthor_device *ptdev, int as_nr,

				      u64 iova, u64 size, u32 op)

{
@@ -585,6 +615,9 @@ static int mmu_hw_do_operation_locked(struct panthor_device *ptdev, int as_nr, 
	if (op != AS_COMMAND_UNLOCK)

		lock_region(ptdev, as_nr, iova, size);



	if (op == AS_COMMAND_FLUSH_MEM || op == AS_COMMAND_FLUSH_PT)

		return mmu_hw_do_flush_on_gpu_ctrl(ptdev, as_nr, op);



	/* Run the MMU operation */

	write_cmd(ptdev, as_nr, op);