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coresight: tmc-etr buf: Add TMC scatter gather mode backend 

Add the support for Scatter-Gather mode to the etr-buf layer.
Since we now have two different modes, we choose the backend
based on a set of conditions, documented in the code.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Suzuki K Poulose 2018-07-11 13:40:23 -06:00 committed by Greg Kroah-Hartman
parent 75f4e3619f
commit e8e3b77139
2 changed files with 111 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

114
drivers/hwtracing/coresight/coresight-tmc-etr.c
View File

@ -516,7 +516,7 @@ static void tmc_etr_sg_table_populate(struct etr_sg_table *etr_table)
* @size - Total size of the data buffer
* @pages - Optional list of page virtual address
*/
static struct etr_sg_table __maybe_unused *
static struct etr_sg_table *
tmc_init_etr_sg_table(struct device *dev, int node,
unsigned long size, void **pages)
{
@ -623,8 +623,86 @@ static const struct etr_buf_operations etr_flat_buf_ops = {
.get_data = tmc_etr_get_data_flat_buf,
};
/*
* tmc_etr_alloc_sg_buf: Allocate an SG buf @etr_buf. Setup the parameters
* appropriately.
*/
static int tmc_etr_alloc_sg_buf(struct tmc_drvdata *drvdata,
struct etr_buf *etr_buf, int node,
void **pages)
{
struct etr_sg_table *etr_table;
etr_table = tmc_init_etr_sg_table(drvdata->dev, node,
etr_buf->size, pages);
if (IS_ERR(etr_table))
return -ENOMEM;
etr_buf->hwaddr = etr_table->hwaddr;
etr_buf->mode = ETR_MODE_ETR_SG;
etr_buf->private = etr_table;
return 0;
}
static void tmc_etr_free_sg_buf(struct etr_buf *etr_buf)
{
struct etr_sg_table *etr_table = etr_buf->private;
if (etr_table) {
tmc_free_sg_table(etr_table->sg_table);
kfree(etr_table);
}
}
static ssize_t tmc_etr_get_data_sg_buf(struct etr_buf *etr_buf, u64 offset,
size_t len, char **bufpp)
{
struct etr_sg_table *etr_table = etr_buf->private;
return tmc_sg_table_get_data(etr_table->sg_table, offset, len, bufpp);
}
static void tmc_etr_sync_sg_buf(struct etr_buf *etr_buf, u64 rrp, u64 rwp)
{
long r_offset, w_offset;
struct etr_sg_table *etr_table = etr_buf->private;
struct tmc_sg_table *table = etr_table->sg_table;
/* Convert hw address to offset in the buffer */
r_offset = tmc_sg_get_data_page_offset(table, rrp);
if (r_offset < 0) {
dev_warn(table->dev,
"Unable to map RRP %llx to offset\n", rrp);
etr_buf->len = 0;
return;
}
w_offset = tmc_sg_get_data_page_offset(table, rwp);
if (w_offset < 0) {
dev_warn(table->dev,
"Unable to map RWP %llx to offset\n", rwp);
etr_buf->len = 0;
return;
}
etr_buf->offset = r_offset;
if (etr_buf->full)
etr_buf->len = etr_buf->size;
else
etr_buf->len = ((w_offset < r_offset) ? etr_buf->size : 0) +
w_offset - r_offset;
tmc_sg_table_sync_data_range(table, r_offset, etr_buf->len);
}
static const struct etr_buf_operations etr_sg_buf_ops = {
.alloc = tmc_etr_alloc_sg_buf,
.free = tmc_etr_free_sg_buf,
.sync = tmc_etr_sync_sg_buf,
.get_data = tmc_etr_get_data_sg_buf,
};
static const struct etr_buf_operations *etr_buf_ops[] = {
[ETR_MODE_FLAT] = &etr_flat_buf_ops,
[ETR_MODE_ETR_SG] = &etr_sg_buf_ops,
};
static inline int tmc_etr_mode_alloc_buf(int mode,
@ -636,6 +714,7 @@ static inline int tmc_etr_mode_alloc_buf(int mode,
switch (mode) {
case ETR_MODE_FLAT:
case ETR_MODE_ETR_SG:
rc = etr_buf_ops[mode]->alloc(drvdata, etr_buf, node, pages);
if (!rc)
etr_buf->ops = etr_buf_ops[mode];
@ -657,17 +736,38 @@ static struct etr_buf *tmc_alloc_etr_buf(struct tmc_drvdata *drvdata,
ssize_t size, int flags,
int node, void **pages)
{
int rc = 0;
int rc = -ENOMEM;
bool has_etr_sg, has_iommu;
struct etr_buf *etr_buf;
has_etr_sg = tmc_etr_has_cap(drvdata, TMC_ETR_SG);
has_iommu = iommu_get_domain_for_dev(drvdata->dev);
etr_buf = kzalloc(sizeof(*etr_buf), GFP_KERNEL);
if (!etr_buf)
return ERR_PTR(-ENOMEM);
etr_buf->size = size;
rc = tmc_etr_mode_alloc_buf(ETR_MODE_FLAT, drvdata,
etr_buf, node, pages);
/*
* If we have to use an existing list of pages, we cannot reliably
* use a contiguous DMA memory (even if we have an IOMMU). Otherwise,
* we use the contiguous DMA memory if at least one of the following
* conditions is true:
* a) The ETR cannot use Scatter-Gather.
* b) we have a backing IOMMU
* c) The requested memory size is smaller (< 1M).
*
* Fallback to available mechanisms.
*
*/
if (!pages &&
(!has_etr_sg || has_iommu || size < SZ_1M))
rc = tmc_etr_mode_alloc_buf(ETR_MODE_FLAT, drvdata,
etr_buf, node, pages);
if (rc && has_etr_sg)
rc = tmc_etr_mode_alloc_buf(ETR_MODE_ETR_SG, drvdata,
etr_buf, node, pages);
if (rc) {
kfree(etr_buf);
return ERR_PTR(rc);
@ -761,6 +861,12 @@ static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata)
axictl |= TMC_AXICTL_ARCACHE_OS;
}
if (etr_buf->mode == ETR_MODE_ETR_SG) {
if (WARN_ON(!tmc_etr_has_cap(drvdata, TMC_ETR_SG)))
return;
axictl |= TMC_AXICTL_SCT_GAT_MODE;
}
writel_relaxed(axictl, drvdata->base + TMC_AXICTL);
tmc_write_dba(drvdata, etr_buf->hwaddr);
/*

1
drivers/hwtracing/coresight/coresight-tmc.h
View File

@ -125,6 +125,7 @@ enum tmc_mem_intf_width {
enum etr_mode {
ETR_MODE_FLAT, /* Uses contiguous flat buffer */
ETR_MODE_ETR_SG, /* Uses in-built TMC ETR SG mechanism */
};
struct etr_buf_operations;