drm/panfrost: Use u64 for size in lock_region

commit a77b588 upstream.

Mali virtual addresses are 48-bit. Use a u64 instead of size_t to ensure
we can express the "lock everything" condition as ~0ULL without
overflow. This code was silently broken on any platform where a size_t
is less than 48-bits; in particular, it was broken on 32-bit armv7
platforms which remain in use with panfrost. (Mainly RK3288)

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Suggested-by: Rob Herring <robh@kernel.org>
Tested-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Fixes: f3ba912 ("drm/panfrost: Add initial panfrost driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210824173028.7528-3-alyssa.rosenzweig@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/gpu/drm/panfrost/panfrost_mmu.c

@@ -55,7 +55,7 @@ static int write_cmd(struct panfrost_device *pfdev, u32 as_nr, u32 cmd)
 }
 
 static void lock_region(struct panfrost_device *pfdev, u32 as_nr,
-			u64 iova, size_t size)
+			u64 iova, u64 size)
 {
 	u8 region_width;
 	u64 region = iova & PAGE_MASK;
@@ -75,7 +75,7 @@ static void lock_region(struct panfrost_device *pfdev, u32 as_nr,
 
 
 static int mmu_hw_do_operation_locked(struct panfrost_device *pfdev, int as_nr,
-				      u64 iova, size_t size, u32 op)
+				      u64 iova, u64 size, u32 op)
 {
 	if (as_nr < 0)
 		return 0;
@@ -92,7 +92,7 @@ static int mmu_hw_do_operation_locked(struct panfrost_device *pfdev, int as_nr,
 
 static int mmu_hw_do_operation(struct panfrost_device *pfdev,
 			       struct panfrost_mmu *mmu,
-			       u64 iova, size_t size, u32 op)
+			       u64 iova, u64 size, u32 op)
 {
 	int ret;
 
@@ -109,7 +109,7 @@ static void panfrost_mmu_enable(struct panfrost_device *pfdev, struct panfrost_m
 	u64 transtab = cfg->arm_mali_lpae_cfg.transtab;
 	u64 memattr = cfg->arm_mali_lpae_cfg.memattr;
 
-	mmu_hw_do_operation_locked(pfdev, as_nr, 0, ~0UL, AS_COMMAND_FLUSH_MEM);
+	mmu_hw_do_operation_locked(pfdev, as_nr, 0, ~0ULL, AS_COMMAND_FLUSH_MEM);
 
 	mmu_write(pfdev, AS_TRANSTAB_LO(as_nr), transtab & 0xffffffffUL);
 	mmu_write(pfdev, AS_TRANSTAB_HI(as_nr), transtab >> 32);
@@ -125,7 +125,7 @@ static void panfrost_mmu_enable(struct panfrost_device *pfdev, struct panfrost_m
 
 static void panfrost_mmu_disable(struct panfrost_device *pfdev, u32 as_nr)
 {
-	mmu_hw_do_operation_locked(pfdev, as_nr, 0, ~0UL, AS_COMMAND_FLUSH_MEM);
+	mmu_hw_do_operation_locked(pfdev, as_nr, 0, ~0ULL, AS_COMMAND_FLUSH_MEM);
 
 	mmu_write(pfdev, AS_TRANSTAB_LO(as_nr), 0);
 	mmu_write(pfdev, AS_TRANSTAB_HI(as_nr), 0);
@@ -225,7 +225,7 @@ static size_t get_pgsize(u64 addr, size_t size)
 
 static void panfrost_mmu_flush_range(struct panfrost_device *pfdev,
 				     struct panfrost_mmu *mmu,
-				     u64 iova, size_t size)
+				     u64 iova, u64 size)
 {
 	if (mmu->as < 0)
 		return;