CoreSight STM device allows direct mapping of the channel regions to userspace for zero-copy writing. To support this ability, the STM freamwork has provided a hook 'mmio_addr', this patch just implemented this hook for CoreSight STM.
This patch also added an item into 'channel_space' to save the start physical address of channel region which mmap operation needs to know.
Signed-off-by: Chunyan Zhang zhang.chunyan@linaro.org --- drivers/hwtracing/coresight/coresight-stm.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c index 73be58a..4e70478 100644 --- a/drivers/hwtracing/coresight/coresight-stm.c +++ b/drivers/hwtracing/coresight/coresight-stm.c @@ -109,6 +109,7 @@ module_param_named( */ struct channel_space { void __iomem *base; + phys_addr_t phys; unsigned long *guaranteed; };
@@ -356,6 +357,23 @@ static void stm_generic_unlink(struct stm_data *stm_data, stm_disable(drvdata->csdev); }
+static phys_addr_t +stm_mmio_addr(struct stm_data *stm_data, unsigned int master, + unsigned int channel, unsigned int nr_chans) +{ + struct stm_drvdata *drvdata = container_of(stm_data, + struct stm_drvdata, stm); + phys_addr_t addr; + + addr = drvdata->chs.phys + channel * BYTES_PER_CHANNEL; + + if (offset_in_page(addr) || + offset_in_page(nr_chans * BYTES_PER_CHANNEL)) + return 0; + + return addr; +} + static long stm_generic_set_options(struct stm_data *stm_data, unsigned int master, unsigned int channel, @@ -761,7 +779,9 @@ static void stm_init_generic_data(struct stm_drvdata *drvdata) drvdata->stm.sw_end = 1; drvdata->stm.hw_override = true; drvdata->stm.sw_nchannels = drvdata->numsp; + drvdata->stm.sw_mmiosz = BYTES_PER_CHANNEL; drvdata->stm.packet = stm_generic_packet; + drvdata->stm.mmio_addr = stm_mmio_addr; drvdata->stm.link = stm_generic_link; drvdata->stm.unlink = stm_generic_unlink; drvdata->stm.set_options = stm_generic_set_options; @@ -808,6 +828,7 @@ static int stm_probe(struct amba_device *adev, const struct amba_id *id) ret = stm_get_resource_byname(np, "stm-stimulus-base", &ch_res); if (ret) return ret; + drvdata->chs.phys = ch_res.start;
base = devm_ioremap_resource(dev, &ch_res); if (IS_ERR(base))