[PATCH v4 13/18] coresight tmc etr: Detect address width at runtime

From: Suzuki K Poulose
Date: Tue Jul 18 2017 - 05:54:34 EST


TMC in Coresight SoC-600 advertises the AXI address width
in the device configuration register.

Bit 16 - AXIAW_VALID
0 - AXI Address Width not valid
1 - Valid AXI Address width in Bits[23-17]

Bits [23-17] - AXIAW. If AXIAW_VALID = b01 then
0x20 - 32bit AXI address bus
0x28 - 40bit AXI address bus
0x2c - 44bit AXI address bus
0x30 - 48bit AXI address bus
0x34 - 52bit AXI address bus

Use the address bits from the device configuration register, if
available. Otherwise, default to 40bit.

Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Cc: Robin Murphy <robin.murphy@xxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
---
drivers/hwtracing/coresight/coresight-tmc.c | 26 +++++++++++++++++++++++---
drivers/hwtracing/coresight/coresight-tmc.h | 4 ++++
2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc.c b/drivers/hwtracing/coresight/coresight-tmc.c
index a1de265..32e88ec 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.c
+++ b/drivers/hwtracing/coresight/coresight-tmc.c
@@ -301,16 +301,36 @@ const struct attribute_group *coresight_tmc_groups[] = {
static int tmc_etr_setup_caps(struct tmc_drvdata *drvdata,
u32 devid, void *dev_caps)
{
+ u32 dma_mask = 0;
+
/* Set the unadvertised capabilities */
tmc_etr_init_caps(drvdata, (u32)(unsigned long)dev_caps);

if (!(devid & TMC_DEVID_NOSCAT))
tmc_etr_set_cap(drvdata, TMC_ETR_SG);
+
+ /* Check if the AXI address width is available */
+ if (devid & TMC_DEVID_AXIAW_VALID)
+ dma_mask = ((devid >> TMC_DEVID_AXIAW_SHIFT) &
+ TMC_DEVID_AXIAW_MASK);
+
/*
- * ETR configuration uses a 40-bit AXI master in place of
- * the embedded SRAM of ETB/ETF.
+ * Unless specified in the device configuration, ETR uses a 40-bit
+ * AXI master in place of the embedded SRAM of ETB/ETF.
*/
- return dma_set_mask_and_coherent(drvdata->dev, DMA_BIT_MASK(40));
+ switch (dma_mask) {
+ case 32:
+ case 40:
+ case 44:
+ case 48:
+ case 52:
+ dev_info(drvdata->dev, "Detected dma mask %dbits\n", dma_mask);
+ break;
+ default:
+ dma_mask = 40;
+ }
+
+ return dma_set_mask_and_coherent(drvdata->dev, DMA_BIT_MASK(dma_mask));
}

static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 23dfbf3..3e94b4b 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -72,6 +72,10 @@

#define TMC_DEVID_NOSCAT BIT(24)

+#define TMC_DEVID_AXIAW_VALID BIT(16)
+#define TMC_DEVID_AXIAW_SHIFT 17
+#define TMC_DEVID_AXIAW_MASK 0x7f
+
enum tmc_config_type {
TMC_CONFIG_TYPE_ETB,
TMC_CONFIG_TYPE_ETR,
--
2.7.5