MC SID and Broadbast channel register access is restricted for Guest VM.
But the Tegra MC driver is considering both these regions as mandatory
and causes error on access. Change that to consider both the regions as
optional in SoC's from Tegra186 onwards. Then skip access to the
restricted registers from Guest if its region is not present in Guest DT
and hence not mapped.
Previously, the solution in [1] was not accepted. Now, handled the
problem with this alternate solution.
---
v1[1] -> v2:
- consider broadcast channel registers also as restricted along with sid.
- make sid and broadcast regions optional and access if present in dt.
- update the yaml file.
Sumit Gupta (2):
dt-bindings: make sid and broadcast reg optional
memory: tegra: make sid and broadcast regions optional
.../nvidia,tegra186-mc.yaml | 18 +++++++--------
drivers/memory/tegra/mc.c | 9 +++++++-
drivers/memory/tegra/mc.h | 18 +++++++--------
drivers/memory/tegra/tegra186.c | 22 ++++++++++---------
4 files changed, 38 insertions(+), 29 deletions(-)
[1] https://lore.kernel.org/lkml/[email protected]/
--
2.17.1
MC SID and Broadbast channel register access is restricted for Guest VM.
In Tegra MC driver, consider both the regions as optional and skip
access to restricted registers from Guest if a region is not present
in Guest DT.
Signed-off-by: Sumit Gupta <[email protected]>
---
drivers/memory/tegra/mc.c | 9 ++++++++-
drivers/memory/tegra/mc.h | 18 +++++++++---------
drivers/memory/tegra/tegra186.c | 22 ++++++++++++----------
3 files changed, 29 insertions(+), 20 deletions(-)
diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index 224b488794e5..d819dab1b223 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -899,6 +899,7 @@ static void tegra_mc_num_channel_enabled(struct tegra_mc *mc)
static int tegra_mc_probe(struct platform_device *pdev)
{
+ struct resource *res;
struct tegra_mc *mc;
u64 mask;
int err;
@@ -923,7 +924,13 @@ static int tegra_mc_probe(struct platform_device *pdev)
/* length of MC tick in nanoseconds */
mc->tick = 30;
- mc->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (mc->soc->num_channels) {
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sid");
+ if (res)
+ mc->regs = devm_ioremap_resource(&pdev->dev, res);
+ } else {
+ mc->regs = devm_platform_ioremap_resource(pdev, 0);
+ }
if (IS_ERR(mc->regs))
return PTR_ERR(mc->regs);
diff --git a/drivers/memory/tegra/mc.h b/drivers/memory/tegra/mc.h
index c3f6655bec60..5cdb9451f364 100644
--- a/drivers/memory/tegra/mc.h
+++ b/drivers/memory/tegra/mc.h
@@ -112,11 +112,11 @@ icc_provider_to_tegra_mc(struct icc_provider *provider)
static inline u32 mc_ch_readl(const struct tegra_mc *mc, int ch,
unsigned long offset)
{
- if (!mc->bcast_ch_regs)
- return 0;
-
- if (ch == MC_BROADCAST_CHANNEL)
+ if (ch == MC_BROADCAST_CHANNEL) {
+ if (!mc->bcast_ch_regs)
+ return 0;
return readl_relaxed(mc->bcast_ch_regs + offset);
+ }
return readl_relaxed(mc->ch_regs[ch] + offset);
}
@@ -124,13 +124,13 @@ static inline u32 mc_ch_readl(const struct tegra_mc *mc, int ch,
static inline void mc_ch_writel(const struct tegra_mc *mc, int ch,
u32 value, unsigned long offset)
{
- if (!mc->bcast_ch_regs)
- return;
-
- if (ch == MC_BROADCAST_CHANNEL)
+ if (ch == MC_BROADCAST_CHANNEL) {
+ if (!mc->bcast_ch_regs)
+ return;
writel_relaxed(value, mc->bcast_ch_regs + offset);
- else
+ } else {
writel_relaxed(value, mc->ch_regs[ch] + offset);
+ }
}
static inline u32 mc_readl(const struct tegra_mc *mc, unsigned long offset)
diff --git a/drivers/memory/tegra/tegra186.c b/drivers/memory/tegra/tegra186.c
index 1b3183951bfe..7b5e9bd13ffd 100644
--- a/drivers/memory/tegra/tegra186.c
+++ b/drivers/memory/tegra/tegra186.c
@@ -26,20 +26,16 @@
static int tegra186_mc_probe(struct tegra_mc *mc)
{
struct platform_device *pdev = to_platform_device(mc->dev);
+ struct resource *res;
unsigned int i;
char name[8];
int err;
- mc->bcast_ch_regs = devm_platform_ioremap_resource_byname(pdev, "broadcast");
- if (IS_ERR(mc->bcast_ch_regs)) {
- if (PTR_ERR(mc->bcast_ch_regs) == -EINVAL) {
- dev_warn(&pdev->dev,
- "Broadcast channel is missing, please update your device-tree\n");
- mc->bcast_ch_regs = NULL;
- goto populate;
- }
-
- return PTR_ERR(mc->bcast_ch_regs);
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "broadcast");
+ if (res) {
+ mc->bcast_ch_regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(mc->bcast_ch_regs))
+ return PTR_ERR(mc->bcast_ch_regs);
}
mc->ch_regs = devm_kcalloc(mc->dev, mc->soc->num_channels, sizeof(*mc->ch_regs),
@@ -121,6 +117,9 @@ static int tegra186_mc_probe_device(struct tegra_mc *mc, struct device *dev)
if (!tegra_dev_iommu_get_stream_id(dev, &sid))
return 0;
+ if (!mc->regs)
+ return 0;
+
while (!of_parse_phandle_with_args(dev->of_node, "interconnects", "#interconnect-cells",
index, &args)) {
if (args.np == mc->dev->of_node && args.args_count != 0) {
@@ -146,6 +145,9 @@ static int tegra186_mc_resume(struct tegra_mc *mc)
#if IS_ENABLED(CONFIG_IOMMU_API)
unsigned int i;
+ if (!mc->regs)
+ return 0;
+
for (i = 0; i < mc->soc->num_clients; i++) {
const struct tegra_mc_client *client = &mc->soc->clients[i];
--
2.17.1