Linux-mediatek Archive on lore.kernel.org
 help / color / Atom feed
* (no subject)
@ 2020-10-15  3:20 Neal Liu
  2020-10-15  3:20 ` [PATCH v8 1/2] dt-bindings: devapc: add bindings for mtk-devapc Neal Liu
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Neal Liu @ 2020-10-15  3:20 UTC (permalink / raw)
  To: Rob Herring, Matthias Brugger, Chun-Kuang Hu
  Cc: devicetree, wsd_upstream, lkml, linux-mediatek, Neal Liu,
	linux-arm-kernel

These patch series introduce a MediaTek MT6779 devapc driver.

MediaTek bus fabric provides TrustZone security support and data protection to prevent slaves from being accessed by unexpected masters.
The security violation is logged and sent to the processor for further analysis or countermeasures.

Any occurrence of security violation would raise an interrupt, and it will be handled by mtk-devapc driver.
The violation information is printed in order to find the murderer.

changes since v7:
- fix VIO_MOD_TO_REG_IND calculation wrong problem.
- revise parameter type of ISR.

changes since v6:
- remove unnecessary mask/unmask module irq during ISR.

changes since v5:
- remove redundant write reg operation.
- use static variable of vio_dbgs instead.
- add stop_devapc() if driver is removed.

changes since v4:
- refactor data structure.
- merge two simple functions into one.
- refactor register setting to prevent too many function call overhead.

changes since v3:
- revise violation handling flow to make it more easily to understand
  hardware behavior.
- add more comments to understand how hardware works.

changes since v2:
- pass platform info through DT data.
- remove unnecessary function.
- remove slave_type because it always equals to 1 in current support SoC.
- use vio_idx_num instread of list all devices' index.
- add more comments to describe hardware behavior.

changes since v1:
- move SoC specific part to DT data.
- remove unnecessary boundary check.
- remove unnecessary data type declaration.
- use read_poll_timeout() instread of for loop polling.
- revise coding style elegantly.


*** BLURB HERE ***

Neal Liu (2):
  dt-bindings: devapc: add bindings for mtk-devapc
  soc: mediatek: add mt6779 devapc driver

 .../bindings/soc/mediatek/devapc.yaml         |  58 ++++
 drivers/soc/mediatek/Kconfig                  |   9 +
 drivers/soc/mediatek/Makefile                 |   1 +
 drivers/soc/mediatek/mtk-devapc.c             | 308 ++++++++++++++++++
 4 files changed, 376 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/mediatek/devapc.yaml
 create mode 100644 drivers/soc/mediatek/mtk-devapc.c

-- 
2.18.0
_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v8 1/2] dt-bindings: devapc: add bindings for mtk-devapc
  2020-10-15  3:20 Neal Liu
@ 2020-10-15  3:20 ` Neal Liu
  2020-10-15  3:20 ` [PATCH v8 2/2] soc: mediatek: add mt6779 devapc driver Neal Liu
  2020-10-15  3:24 ` [PATCH v8] Add MediaTek MT6779 " Neal Liu
  2 siblings, 0 replies; 4+ messages in thread
From: Neal Liu @ 2020-10-15  3:20 UTC (permalink / raw)
  To: Rob Herring, Matthias Brugger, Chun-Kuang Hu
  Cc: devicetree, wsd_upstream, lkml, linux-mediatek, Neal Liu,
	linux-arm-kernel

Add bindings for mtk-devapc.

Signed-off-by: Neal Liu <neal.liu@mediatek.com>
---
 .../devicetree/bindings/soc/mediatek/devapc.yaml   |   58 ++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/mediatek/devapc.yaml

diff --git a/Documentation/devicetree/bindings/soc/mediatek/devapc.yaml b/Documentation/devicetree/bindings/soc/mediatek/devapc.yaml
new file mode 100644
index 0000000..6c763f8
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/mediatek/devapc.yaml
@@ -0,0 +1,58 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# # Copyright 2020 MediaTek Inc.
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/soc/mediatek/devapc.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: MediaTek Device Access Permission Control driver
+
+description: |
+  MediaTek bus fabric provides TrustZone security support and data
+  protection to prevent slaves from being accessed by unexpected masters.
+  The security violation is logged and sent to the processor for further
+  analysis and countermeasures.
+
+maintainers:
+  - Neal Liu <neal.liu@mediatek.com>
+
+properties:
+  compatible:
+    enum:
+      - mediatek,mt6779-devapc
+
+  reg:
+    description: The base address of devapc register bank
+    maxItems: 1
+
+  interrupts:
+    description: A single interrupt specifier
+    maxItems: 1
+
+  clocks:
+    description: Contains module clock source and clock names
+    maxItems: 1
+
+  clock-names:
+    description: Names of the clocks list in clocks property
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/mt6779-clk.h>
+
+    devapc: devapc@10207000 {
+      compatible = "mediatek,mt6779-devapc";
+      reg = <0x10207000 0x1000>;
+      interrupts = <GIC_SPI 168 IRQ_TYPE_LEVEL_LOW>;
+      clocks = <&infracfg_ao CLK_INFRA_DEVICE_APC>;
+      clock-names = "devapc-infra-clock";
+    };
-- 
1.7.9.5
_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v8 2/2] soc: mediatek: add mt6779 devapc driver
  2020-10-15  3:20 Neal Liu
  2020-10-15  3:20 ` [PATCH v8 1/2] dt-bindings: devapc: add bindings for mtk-devapc Neal Liu
@ 2020-10-15  3:20 ` Neal Liu
  2020-10-15  3:24 ` [PATCH v8] Add MediaTek MT6779 " Neal Liu
  2 siblings, 0 replies; 4+ messages in thread
From: Neal Liu @ 2020-10-15  3:20 UTC (permalink / raw)
  To: Rob Herring, Matthias Brugger, Chun-Kuang Hu
  Cc: devicetree, wsd_upstream, lkml, linux-mediatek, Neal Liu,
	linux-arm-kernel

MediaTek bus fabric provides TrustZone security support and data
protection to prevent slaves from being accessed by unexpected
masters.
The security violation is logged and sent to the processor for
further analysis or countermeasures.

Any occurrence of security violation would raise an interrupt, and
it will be handled by mtk-devapc driver. The violation
information is printed in order to find the murderer.

Signed-off-by: Neal Liu <neal.liu@mediatek.com>
---
 drivers/soc/mediatek/Kconfig      |    9 ++
 drivers/soc/mediatek/Makefile     |    1 +
 drivers/soc/mediatek/mtk-devapc.c |  308 +++++++++++++++++++++++++++++++++++++
 3 files changed, 318 insertions(+)
 create mode 100644 drivers/soc/mediatek/mtk-devapc.c

diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
index 59a56cd..1177c98 100644
--- a/drivers/soc/mediatek/Kconfig
+++ b/drivers/soc/mediatek/Kconfig
@@ -17,6 +17,15 @@ config MTK_CMDQ
 	  time limitation, such as updating display configuration during the
 	  vblank.
 
+config MTK_DEVAPC
+	tristate "Mediatek Device APC Support"
+	help
+	  Say yes here to enable support for Mediatek Device APC driver.
+	  This driver is mainly used to handle the violation which catches
+	  unexpected transaction.
+	  The violation information is logged for further analysis or
+	  countermeasures.
+
 config MTK_INFRACFG
 	bool "MediaTek INFRACFG Support"
 	select REGMAP
diff --git a/drivers/soc/mediatek/Makefile b/drivers/soc/mediatek/Makefile
index 01f9f87..abfd4ba 100644
--- a/drivers/soc/mediatek/Makefile
+++ b/drivers/soc/mediatek/Makefile
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_MTK_CMDQ) += mtk-cmdq-helper.o
+obj-$(CONFIG_MTK_DEVAPC) += mtk-devapc.o
 obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o
 obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
 obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
diff --git a/drivers/soc/mediatek/mtk-devapc.c b/drivers/soc/mediatek/mtk-devapc.c
new file mode 100644
index 0000000..f1cea04
--- /dev/null
+++ b/drivers/soc/mediatek/mtk-devapc.c
@@ -0,0 +1,308 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 MediaTek Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+
+#define VIO_MOD_TO_REG_IND(m)	((m) / 32)
+#define VIO_MOD_TO_REG_OFF(m)	((m) % 32)
+
+struct mtk_devapc_vio_dbgs {
+	union {
+		u32 vio_dbg0;
+		struct {
+			u32 mstid:16;
+			u32 dmnid:6;
+			u32 vio_w:1;
+			u32 vio_r:1;
+			u32 addr_h:4;
+			u32 resv:4;
+		} dbg0_bits;
+	};
+
+	u32 vio_dbg1;
+};
+
+struct mtk_devapc_data {
+	/* numbers of violation index */
+	u32 vio_idx_num;
+
+	/* reg offset */
+	u32 vio_mask_offset;
+	u32 vio_sta_offset;
+	u32 vio_dbg0_offset;
+	u32 vio_dbg1_offset;
+	u32 apc_con_offset;
+	u32 vio_shift_sta_offset;
+	u32 vio_shift_sel_offset;
+	u32 vio_shift_con_offset;
+};
+
+struct mtk_devapc_context {
+	struct device *dev;
+	void __iomem *infra_base;
+	struct clk *infra_clk;
+	const struct mtk_devapc_data *data;
+};
+
+static void clear_vio_status(struct mtk_devapc_context *ctx)
+{
+	void __iomem *reg;
+	int i;
+
+	reg = ctx->infra_base + ctx->data->vio_sta_offset;
+
+	for (i = 0; i < VIO_MOD_TO_REG_IND(ctx->data->vio_idx_num) - 1; i++)
+		writel(GENMASK(31, 0), reg + 4 * i);
+
+	writel(GENMASK(VIO_MOD_TO_REG_OFF(ctx->data->vio_idx_num) - 1, 0),
+	       reg + 4 * i);
+}
+
+static void mask_module_irq(struct mtk_devapc_context *ctx, bool mask)
+{
+	void __iomem *reg;
+	u32 val;
+	int i;
+
+	reg = ctx->infra_base + ctx->data->vio_mask_offset;
+
+	if (mask)
+		val = GENMASK(31, 0);
+	else
+		val = 0;
+
+	for (i = 0; i < VIO_MOD_TO_REG_IND(ctx->data->vio_idx_num) - 1; i++)
+		writel(val, reg + 4 * i);
+
+	val = readl(reg + 4 * i);
+	if (mask)
+		val |= GENMASK(VIO_MOD_TO_REG_OFF(ctx->data->vio_idx_num) - 1,
+			       0);
+	else
+		val &= ~GENMASK(VIO_MOD_TO_REG_OFF(ctx->data->vio_idx_num) - 1,
+				0);
+
+	writel(val, reg + 4 * i);
+}
+
+#define PHY_DEVAPC_TIMEOUT	0x10000
+
+/*
+ * devapc_sync_vio_dbg - do "shift" mechansim" to get full violation information.
+ *                       shift mechanism is depends on devapc hardware design.
+ *                       Mediatek devapc set multiple slaves as a group.
+ *                       When violation is triggered, violation info is kept
+ *                       inside devapc hardware.
+ *                       Driver should do shift mechansim to sync full violation
+ *                       info to VIO_DBGs registers.
+ *
+ */
+static int devapc_sync_vio_dbg(struct mtk_devapc_context *ctx)
+{
+	void __iomem *pd_vio_shift_sta_reg;
+	void __iomem *pd_vio_shift_sel_reg;
+	void __iomem *pd_vio_shift_con_reg;
+	int min_shift_group;
+	int ret;
+	u32 val;
+
+	pd_vio_shift_sta_reg = ctx->infra_base +
+			       ctx->data->vio_shift_sta_offset;
+	pd_vio_shift_sel_reg = ctx->infra_base +
+			       ctx->data->vio_shift_sel_offset;
+	pd_vio_shift_con_reg = ctx->infra_base +
+			       ctx->data->vio_shift_con_offset;
+
+	/* Find the minimum shift group which has violation */
+	val = readl(pd_vio_shift_sta_reg);
+	if (!val)
+		return false;
+
+	min_shift_group = __ffs(val);
+
+	/* Assign the group to sync */
+	writel(0x1 << min_shift_group, pd_vio_shift_sel_reg);
+
+	/* Start syncing */
+	writel(0x1, pd_vio_shift_con_reg);
+
+	ret = readl_poll_timeout(pd_vio_shift_con_reg, val, val == 0x3, 0,
+				 PHY_DEVAPC_TIMEOUT);
+	if (ret) {
+		dev_err(ctx->dev, "%s: Shift violation info failed\n", __func__);
+		return false;
+	}
+
+	/* Stop syncing */
+	writel(0x0, pd_vio_shift_con_reg);
+
+	/* Write clear */
+	writel(0x1 << min_shift_group, pd_vio_shift_sta_reg);
+
+	return true;
+}
+
+/*
+ * devapc_extract_vio_dbg - extract full violation information after doing
+ *                          shift mechanism.
+ */
+static void devapc_extract_vio_dbg(struct mtk_devapc_context *ctx)
+{
+	struct mtk_devapc_vio_dbgs vio_dbgs;
+	void __iomem *vio_dbg0_reg;
+	void __iomem *vio_dbg1_reg;
+
+	vio_dbg0_reg = ctx->infra_base + ctx->data->vio_dbg0_offset;
+	vio_dbg1_reg = ctx->infra_base + ctx->data->vio_dbg1_offset;
+
+	vio_dbgs.vio_dbg0 = readl(vio_dbg0_reg);
+	vio_dbgs.vio_dbg1 = readl(vio_dbg1_reg);
+
+	/* Print violation information */
+	if (vio_dbgs.dbg0_bits.vio_w)
+		dev_info(ctx->dev, "Write Violation\n");
+	else if (vio_dbgs.dbg0_bits.vio_r)
+		dev_info(ctx->dev, "Read Violation\n");
+
+	dev_info(ctx->dev, "Bus ID:0x%x, Dom ID:0x%x, Vio Addr:0x%x\n",
+		 vio_dbgs.dbg0_bits.mstid, vio_dbgs.dbg0_bits.dmnid,
+		 vio_dbgs.vio_dbg1);
+}
+
+/*
+ * devapc_violation_irq - the devapc Interrupt Service Routine (ISR) will dump
+ *                        violation information including which master violates
+ *                        access slave.
+ */
+static irqreturn_t devapc_violation_irq(int irq_number, void *data)
+{
+	struct mtk_devapc_context *ctx = data;
+
+	while (devapc_sync_vio_dbg(ctx))
+		devapc_extract_vio_dbg(ctx);
+
+	clear_vio_status(ctx);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * start_devapc - unmask slave's irq to start receiving devapc violation.
+ */
+static void start_devapc(struct mtk_devapc_context *ctx)
+{
+	writel(BIT(31), ctx->infra_base + ctx->data->apc_con_offset);
+
+	mask_module_irq(ctx, false);
+}
+
+/*
+ * stop_devapc - mask slave's irq to stop service.
+ */
+static void stop_devapc(struct mtk_devapc_context *ctx)
+{
+	mask_module_irq(ctx, true);
+
+	writel(BIT(2), ctx->infra_base + ctx->data->apc_con_offset);
+}
+
+static const struct mtk_devapc_data devapc_mt6779 = {
+	.vio_idx_num = 511,
+	.vio_mask_offset = 0x0,
+	.vio_sta_offset = 0x400,
+	.vio_dbg0_offset = 0x900,
+	.vio_dbg1_offset = 0x904,
+	.apc_con_offset = 0xF00,
+	.vio_shift_sta_offset = 0xF10,
+	.vio_shift_sel_offset = 0xF14,
+	.vio_shift_con_offset = 0xF20,
+};
+
+static const struct of_device_id mtk_devapc_dt_match[] = {
+	{
+		.compatible = "mediatek,mt6779-devapc",
+		.data = &devapc_mt6779,
+	}, {
+	},
+};
+
+static int mtk_devapc_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct mtk_devapc_context *ctx;
+	u32 devapc_irq;
+	int ret;
+
+	if (IS_ERR(node))
+		return -ENODEV;
+
+	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->data = of_device_get_match_data(&pdev->dev);
+	ctx->dev = &pdev->dev;
+
+	ctx->infra_base = of_iomap(node, 0);
+	if (!ctx->infra_base)
+		return -EINVAL;
+
+	devapc_irq = irq_of_parse_and_map(node, 0);
+	if (!devapc_irq)
+		return -EINVAL;
+
+	ctx->infra_clk = devm_clk_get(&pdev->dev, "devapc-infra-clock");
+	if (IS_ERR(ctx->infra_clk))
+		return -EINVAL;
+
+	if (clk_prepare_enable(ctx->infra_clk))
+		return -EINVAL;
+
+	ret = devm_request_irq(&pdev->dev, devapc_irq, devapc_violation_irq,
+			       IRQF_TRIGGER_NONE, "devapc", ctx);
+	if (ret) {
+		clk_disable_unprepare(ctx->infra_clk);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, ctx);
+
+	start_devapc(ctx);
+
+	return 0;
+}
+
+static int mtk_devapc_remove(struct platform_device *pdev)
+{
+	struct mtk_devapc_context *ctx = platform_get_drvdata(pdev);
+
+	stop_devapc(ctx);
+
+	clk_disable_unprepare(ctx->infra_clk);
+
+	return 0;
+}
+
+static struct platform_driver mtk_devapc_driver = {
+	.probe = mtk_devapc_probe,
+	.remove = mtk_devapc_remove,
+	.driver = {
+		.name = "mtk-devapc",
+		.of_match_table = mtk_devapc_dt_match,
+	},
+};
+
+module_platform_driver(mtk_devapc_driver);
+
+MODULE_DESCRIPTION("Mediatek Device APC Driver");
+MODULE_AUTHOR("Neal Liu <neal.liu@mediatek.com>");
+MODULE_LICENSE("GPL");
-- 
1.7.9.5
_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v8] Add MediaTek MT6779 devapc driver
  2020-10-15  3:20 Neal Liu
  2020-10-15  3:20 ` [PATCH v8 1/2] dt-bindings: devapc: add bindings for mtk-devapc Neal Liu
  2020-10-15  3:20 ` [PATCH v8 2/2] soc: mediatek: add mt6779 devapc driver Neal Liu
@ 2020-10-15  3:24 ` Neal Liu
  2 siblings, 0 replies; 4+ messages in thread
From: Neal Liu @ 2020-10-15  3:24 UTC (permalink / raw)
  To: Rob Herring, Chun-Kuang Hu, Matthias Brugger
  Cc: devicetree, wsd_upstream, lkml, linux-mediatek, Neal Liu,
	linux-arm-kernel

add subject

On Thu, 2020-10-15 at 11:20 +0800, Neal Liu wrote:
> These patch series introduce a MediaTek MT6779 devapc driver.
> 
> MediaTek bus fabric provides TrustZone security support and data protection to prevent slaves from being accessed by unexpected masters.
> The security violation is logged and sent to the processor for further analysis or countermeasures.
> 
> Any occurrence of security violation would raise an interrupt, and it will be handled by mtk-devapc driver.
> The violation information is printed in order to find the murderer.
> 
> changes since v7:
> - fix VIO_MOD_TO_REG_IND calculation wrong problem.
> - revise parameter type of ISR.
> 
> changes since v6:
> - remove unnecessary mask/unmask module irq during ISR.
> 
> changes since v5:
> - remove redundant write reg operation.
> - use static variable of vio_dbgs instead.
> - add stop_devapc() if driver is removed.
> 
> changes since v4:
> - refactor data structure.
> - merge two simple functions into one.
> - refactor register setting to prevent too many function call overhead.
> 
> changes since v3:
> - revise violation handling flow to make it more easily to understand
>   hardware behavior.
> - add more comments to understand how hardware works.
> 
> changes since v2:
> - pass platform info through DT data.
> - remove unnecessary function.
> - remove slave_type because it always equals to 1 in current support SoC.
> - use vio_idx_num instread of list all devices' index.
> - add more comments to describe hardware behavior.
> 
> changes since v1:
> - move SoC specific part to DT data.
> - remove unnecessary boundary check.
> - remove unnecessary data type declaration.
> - use read_poll_timeout() instread of for loop polling.
> - revise coding style elegantly.
> 
> 
> *** BLURB HERE ***
> 
> Neal Liu (2):
>   dt-bindings: devapc: add bindings for mtk-devapc
>   soc: mediatek: add mt6779 devapc driver
> 
>  .../bindings/soc/mediatek/devapc.yaml         |  58 ++++
>  drivers/soc/mediatek/Kconfig                  |   9 +
>  drivers/soc/mediatek/Makefile                 |   1 +
>  drivers/soc/mediatek/mtk-devapc.c             | 308 ++++++++++++++++++
>  4 files changed, 376 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/soc/mediatek/devapc.yaml
>  create mode 100644 drivers/soc/mediatek/mtk-devapc.c
> 

_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, back to index

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-10-15  3:20 Neal Liu
2020-10-15  3:20 ` [PATCH v8 1/2] dt-bindings: devapc: add bindings for mtk-devapc Neal Liu
2020-10-15  3:20 ` [PATCH v8 2/2] soc: mediatek: add mt6779 devapc driver Neal Liu
2020-10-15  3:24 ` [PATCH v8] Add MediaTek MT6779 " Neal Liu

Linux-mediatek Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mediatek/0 linux-mediatek/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mediatek linux-mediatek/ https://lore.kernel.org/linux-mediatek \
		linux-mediatek@lists.infradead.org
	public-inbox-index linux-mediatek

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-mediatek


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git