[PATCH 3/4] iommu: dart: Write to all DART_T8020_STREAM_SELECT

Sven Peter
2023-01-28T11:11:56Z

We're about to add support for a DART variant that use more than 16
streams and requires writing to two separate stream select registers
when issuing TLB flushes.

Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
drivers/iommu/apple-dart.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
index 7d8b2b90cdb6..7579c97a9062 100644
--- a/drivers/iommu/apple-dart.c
+++ b/drivers/iommu/apple-dart.c
@@ -372,12 +372,14 @@ apple_dart_t8020_hw_stream_command(struct apple_dart_stream_map *stream_map,
u32 command)
{
unsigned long flags;
- int ret;
+ int ret, i;
u32 command_reg;

spin_lock_irqsave(&stream_map->dart->lock, flags);

- writel(stream_map->sidmap[0], stream_map->dart->regs + DART_T8020_STREAM_SELECT);
+ for (i = 0; i < BITS_TO_U32(stream_map->dart->num_streams); i++)
+ writel(stream_map->sidmap[i],
+ stream_map->dart->regs + DART_T8020_STREAM_SELECT + 4 * i);
writel(command, stream_map->dart->regs + DART_T8020_STREAM_COMMAND);

ret = readl_poll_timeout_atomic(
--
2.25.1