[PATCH v5 18/19] coresight tmc: Add support for Coresight SoC 600 TMC

On 24/07/17 18:12, Mathieu Poirier wrote:

On 20 July 2017 at 04:17, Suzuki K Poulose [off-list ref] wrote:

quoted

The coresight SoC 600 supports ETR save-restore which allows us
to restore a trace session by retaining the RRP/RWP/STS.Full values
when the TMC leaves the Disabled state. However, the TMC doesn't
have a scatter-gather unit in built.

Also, TMCs have different PIDs in different configurations (ETF,
ETB & ETR), unlike the previous generation.

While the DEVID exposes some of the features/changes in the TMC,
it doesn't explicitly advertises the new save-restore feature
as described above.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 drivers/hwtracing/coresight/coresight-tmc.c | 16 ++++++++++++++++
 drivers/hwtracing/coresight/coresight-tmc.h |  4 ++++
 2 files changed, 20 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-tmc.c b/drivers/hwtracing/coresight/coresight-tmc.c
index c4a5dea..e754a3e 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.c
+++ b/drivers/hwtracing/coresight/coresight-tmc.c

@@ -442,6 +442,22 @@ static struct amba_id tmc_ids[] = {
                .id     = 0x000bb961,
                .mask   = 0x000fffff,
        },
+       {
+               /* Coresight SoC 600 TMC-ETR/ETS */
+               .id     = 0x000bb9e8,
+               .mask   = 0x000fffff,
+               .data   = (void *)(unsigned long)CORESIGHT_SOC_600_ETR_CAPS,

It the casting to unsigned long mandatory?

Yes. Given the ETR caps is u32, we don't want a trouble with
little/big endian switch. Also, it keeps the compiler happy when you
upsize an integer to a pointer directly.

e.g:

$ cat cast.c
int main(void)
{
	void *ptr;
	int a;
	ptr = (void *)a;
	return 0;
}

Compiler warns:

cc     cast.c   -o cast
cast.c: In function ?main?:
cast.c:5:8: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
   ptr = (void *)a;
         ^

Cheers
Suzuki