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From: Sumit Gupta <sumitg@nvidia.com>
To: <krzysztof.kozlowski@linaro.org>, <robh@kernel.org>,
	<conor+dt@kernel.org>, <maz@kernel.org>, <mark.rutland@arm.com>,
	<treding@nvidia.com>, <jonathanh@nvidia.com>
Cc: <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<linux-tegra@vger.kernel.org>, <amhetre@nvidia.com>,
	<bbasu@nvidia.com>, <sumitg@nvidia.com>
Subject: [Patch v3 2/2] memory: tegra: make sid and broadcast regions optional
Date: Fri, 12 Apr 2024 18:35:40 +0530	[thread overview]
Message-ID: <20240412130540.28447-3-sumitg@nvidia.com> (raw)
In-Reply-To: <20240412130540.28447-1-sumitg@nvidia.com>

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 <sumitg@nvidia.com>
---
 drivers/memory/tegra/mc.c       |  9 ++++++++-
 drivers/memory/tegra/mc.h       | 22 ++++++++++++----------
 drivers/memory/tegra/tegra186.c | 25 +++++++++++++------------
 3 files changed, 33 insertions(+), 23 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..7e7bd3e09cdc 100644
--- a/drivers/memory/tegra/mc.h
+++ b/drivers/memory/tegra/mc.h
@@ -112,25 +112,27 @@ 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);
+	} else if (mc->ch_regs) {
+		return readl_relaxed(mc->ch_regs[ch] + offset);
+	}
 
-	return readl_relaxed(mc->ch_regs[ch] + offset);
+	return 0;
 }
 
 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 if (mc->ch_regs) {
 		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..716582255eeb 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];
+	char name[14];
 	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),
@@ -55,7 +51,6 @@ static int tegra186_mc_probe(struct tegra_mc *mc)
 			return PTR_ERR(mc->ch_regs[i]);
 	}
 
-populate:
 	err = of_platform_populate(mc->dev->of_node, NULL, NULL, mc->dev);
 	if (err < 0)
 		return err;
@@ -121,6 +116,9 @@ 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 +144,9 @@ 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


  parent reply	other threads:[~2024-04-12 13:06 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-12 13:05 [Patch v3 0/2] memory: tegra: Skip restricted register access from Guest Sumit Gupta
2024-04-12 13:05 ` [Patch v3 1/2] dt-bindings: make sid and broadcast reg optional Sumit Gupta
2024-04-22  7:02   ` Krzysztof Kozlowski
2024-04-24 16:26     ` Thierry Reding
2024-04-24 17:04       ` Thierry Reding
2024-04-25  7:52         ` Krzysztof Kozlowski
2024-04-25  9:39           ` Thierry Reding
2024-04-25  9:45             ` Krzysztof Kozlowski
2024-04-25 15:03               ` Thierry Reding
2024-04-25 15:16                 ` Krzysztof Kozlowski
2024-04-25 15:51                   ` Thierry Reding
2024-04-25  7:51       ` Krzysztof Kozlowski
2024-04-25  7:52   ` Krzysztof Kozlowski
2024-04-12 13:05 ` Sumit Gupta [this message]
2024-04-22  7:12   ` [Patch v3 2/2] memory: tegra: make sid and broadcast regions optional Krzysztof Kozlowski
2024-04-22 14:36     ` Sumit Gupta
2024-04-23 14:41       ` Krzysztof Kozlowski
2024-04-23 19:46         ` Sumit Gupta
2024-04-24  4:09           ` Krzysztof Kozlowski
2024-04-24  5:27             ` Sumit Gupta
2024-04-24  5:44               ` Krzysztof Kozlowski
2024-04-24  6:27                 ` Sumit Gupta

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