[PATCH v6 0/6] imx8mp: add support for the IMX AIPSTZ bridge

[PATCH v6 0/6] imx8mp: add support for the IMX AIPSTZ bridge

[Laurentiu Mihalcea]

From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

The AIPSTZ bridge offers some security-related configurations which can
be used to restrict master access to certain peripherals on the bridge.

Normally, this could be done from a secure environment such as ATF before
Linux boots but the configuration of AIPSTZ5 is lost each time the power
domain is powered off and then powered on. Because of this, it has to be
configured each time the power domain is turned on and before any master
tries to access the peripherals (e.g: AP, CM7, DSP, on i.MX8MP).

The child-parent relationship between the bridge and its peripherals
should guarantee that the bridge is configured before the AP attempts
to access the IPs.

Other masters should use the 'access-controllers' property to enforce
a dependency between their device and the bridge device (see the DSP,
for example).

The initial version of the series can be found at [1]. The new version
should provide better management of the device dependencies.

[1]: https://lore.kernel.org/linux-arm-kernel/20241119130726.2761726-1-daniel.baluta@nxp.com/

---
Changes in v6:
* drop the 'IMX8MP_AIPSTZ_HIFI4_T_RW_PL' macro. Its whole point was to
help with making the DTS more readable but if it makes it look worse
then there's no point in keeping it.
* use consumer ID as first AC cell and consumer type as the second cell.
Better to go with a format that more people are used to as long as it
still makes sense.
* pick up Rob's R-b
* link to v5: https://lore.kernel.org/lkml/20250408154236.49421-1-laurentiumihalcea111@gmail.com/

Changes in v5:
* merge imx-aipstz.h into imx8mp-aipstz.h. imx-aipstz.h is
currently only used in the DTS so it can't be added as a binding.
* place 'ranges' property just after 'reg' in the binding DT example
as Frank suggested.
* use the  (1 << x) notation for the configuration bits. Previously,
hex values were used which didn't make it very clear that the
configuration options are bits.
* shorten the description of the bridge's AC cells.
* shorten the message of the commit introducing the bridge's binding.
* pick up some more R-b's on patches that remained untouched since V4.
* link to v4: https://lore.kernel.org/lkml/20250401154404.45932-1-laurentiumihalcea111@gmail.com/

Changes in v4:
* AIPS5 node now only contains a single memory region: that of the AC
(just like in V2). 'reg-names' property is dropped.
* AIPS5 node now uses 'ranges' property to restrict the size of the bus
(1:1 mapping)
* change the number of AC cells from 0 to 3
* add binding headers
* link to v3: https://lore.kernel.org/lkml/20250324162556.30972-1-laurentiumihalcea111@gmail.com/

Changes in v3:
* make '#address-cells' and '#size-cells' constants and equal to 1 in the
binding. The bus is 32-bit.
* add child node in the example DT snippet.
* the 'aips5' DT node now contains 2 memory regions: that of the
peripherals accessible via this bridge and that of the access controller.
* link to v2: https://lore.kernel.org/lkml/20250226165314.34205-1-laurentiumihalcea111@gmail.com/

Changes in v2:
* adress Frank Li's comments
* pick up some A-b/R-b's
* don't use "simple-bus" as the second compatible. As per Krzysztof's
comment, AIPSTZ is not a "simple-bus".
* link to v1: https://lore.kernel.org/lkml/20250221191909.31874-1-laurentiumihalcea111@gmail.com/
---

Laurentiu Mihalcea (6):
  dt-bindings: bus: document the IMX AIPSTZ bridge
  dt-bindings: dsp: fsl,dsp: document 'access-controllers' property
  bus: add driver for IMX AIPSTZ bridge
  arm64: dts: imx8mp: convert 'aips5' to 'aipstz5'
  arm64: dts: imx8mp: add aipstz-related definitions
  arm64: dts: imx8mp: make 'dsp' node depend on 'aips5'

 .../bindings/bus/fsl,imx8mp-aipstz.yaml       | 104 ++++++++++++++++++
 .../devicetree/bindings/dsp/fsl,dsp.yaml      |   3 +
 arch/arm64/boot/dts/freescale/imx8mp-aipstz.h |  33 ++++++
 arch/arm64/boot/dts/freescale/imx8mp.dtsi     |  16 ++-
 drivers/bus/Kconfig                           |   6 +
 drivers/bus/Makefile                          |   1 +
 drivers/bus/imx-aipstz.c                      |  92 ++++++++++++++++
 7 files changed, 251 insertions(+), 4 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/bus/fsl,imx8mp-aipstz.yaml
 create mode 100644 arch/arm64/boot/dts/freescale/imx8mp-aipstz.h
 create mode 100644 drivers/bus/imx-aipstz.c

-- 
2.34.1

[PATCH v6 1/6] dt-bindings: bus: document the IMX AIPSTZ bridge

[Laurentiu Mihalcea]

From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

Add documentation for IMX AIPSTZ bridge.

Co-developed-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
---
 .../bindings/bus/fsl,imx8mp-aipstz.yaml       | 104 ++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/fsl,imx8mp-aipstz.yaml

diff --git a/Documentation/devicetree/bindings/bus/fsl,imx8mp-aipstz.yaml b/Documentation/devicetree/bindings/bus/fsl,imx8mp-aipstz.yaml
new file mode 100644
index 000000000000..993293ebc4d3
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/fsl,imx8mp-aipstz.yaml
@@ -0,0 +1,104 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/bus/fsl,imx8mp-aipstz.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Secure AHB to IP Slave bus (AIPSTZ) bridge
+
+description:
+  The secure AIPS bridge (AIPSTZ) acts as a bridge for AHB masters issuing
+  transactions to IP Slave peripherals. Additionally, this module offers access
+  control configurations meant to restrict which peripherals a master can
+  access.
+
+maintainers:
+  - Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
+
+properties:
+  compatible:
+    const: fsl,imx8mp-aipstz
+
+  reg:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 1
+
+  "#access-controller-cells":
+    const: 3
+    description:
+      First cell - consumer ID
+      Second cell - consumer type (master or peripheral)
+      Third cell - configuration value
+
+  ranges: true
+
+# borrowed from simple-bus.yaml, no additional requirements for children
+patternProperties:
+  "@(0|[1-9a-f][0-9a-f]*)$":
+    type: object
+    additionalProperties: true
+    properties:
+      reg:
+        items:
+          minItems: 2
+          maxItems: 4
+        minItems: 1
+        maxItems: 1024
+      ranges:
+        oneOf:
+          - items:
+              minItems: 3
+              maxItems: 7
+            minItems: 1
+            maxItems: 1024
+          - $ref: /schemas/types.yaml#/definitions/flag
+    anyOf:
+      - required:
+          - reg
+      - required:
+          - ranges
+
+required:
+  - compatible
+  - reg
+  - power-domains
+  - "#address-cells"
+  - "#size-cells"
+  - "#access-controller-cells"
+  - ranges
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/imx8mp-clock.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    bus@30df0000 {
+        compatible = "fsl,imx8mp-aipstz";
+        reg = <0x30df0000 0x10000>;
+        ranges = <0x30c00000 0x30c00000 0x400000>;
+        power-domains = <&pgc_audio>;
+        #address-cells = <1>;
+        #size-cells = <1>;
+        #access-controller-cells = <3>;
+
+        dma-controller@30e00000 {
+            compatible = "fsl,imx8mp-sdma", "fsl,imx8mq-sdma";
+            reg = <0x30e00000 0x10000>;
+            #dma-cells = <3>;
+            clocks = <&audio_blk_ctrl IMX8MP_CLK_AUDIOMIX_SDMA3_ROOT>,
+                     <&clk IMX8MP_CLK_AUDIO_ROOT>;
+            clock-names = "ipg", "ahb";
+            interrupts = <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>;
+            fsl,sdma-ram-script-name = "imx/sdma/sdma-imx7d.bin";
+        };
+    };
-- 
2.34.1

[PATCH v6 2/6] dt-bindings: dsp: fsl,dsp: document 'access-controllers' property

[Laurentiu Mihalcea]

From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

Some DSP instances may have their access to certain peripherals
conditioned by a bus access controller such as the one from the
AIPSTZ bridge.

Add the optional 'access-controllers' property, which may be used
in such cases.

Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
---
 Documentation/devicetree/bindings/dsp/fsl,dsp.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml b/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml
index b8693e4b4b0d..e610b7636a08 100644
--- a/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml
+++ b/Documentation/devicetree/bindings/dsp/fsl,dsp.yaml
@@ -91,6 +91,9 @@ properties:
       - const: runstall
       - const: softreset
 
+  access-controllers:
+    maxItems: 1
+
 required:
   - compatible
   - reg
-- 
2.34.1

[PATCH v6 3/6] bus: add driver for IMX AIPSTZ bridge

[Laurentiu Mihalcea]

From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

The secure AHB to IP Slave (AIPSTZ) bus bridge provides access control
configurations meant to restrict access to certain peripherals.
Some of the configurations include:

	1) Marking masters as trusted for R/W. Based on this
	(and the configuration of the accessed peripheral), the bridge
	may choose to abort the R/W transactions issued by certain
	masters.

	2) Allowing/disallowing write accesses to peripherals.

Add driver for this IP. Since there's currently no framework for
access controllers (and since there's currently no need for having
flexibility w.r.t the configurations) all this driver does is it
applies a relaxed, "default" configuration, in which all masters
are trusted for R/W.

Note that some instances of this IP (e.g: AIPSTZ5 on i.MX8MP) may be tied
to a power domain and may lose their configuration when the domain is
powered off. This is why the configuration has to be restored when the
domain is powered on.

Co-developed-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
---
 drivers/bus/Kconfig      |  6 +++
 drivers/bus/Makefile     |  1 +
 drivers/bus/imx-aipstz.c | 92 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 99 insertions(+)
 create mode 100644 drivers/bus/imx-aipstz.c

diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index ff669a8ccad9..fe7600283e70 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -87,6 +87,12 @@ config HISILICON_LPC
 	  Driver to enable I/O access to devices attached to the Low Pin
 	  Count bus on the HiSilicon Hip06/7 SoC.
 
+config IMX_AIPSTZ
+	tristate "Support for IMX Secure AHB to IP Slave bus (AIPSTZ) bridge"
+	depends on ARCH_MXC
+	help
+	  Enable support for IMX AIPSTZ bridge.
+
 config IMX_WEIM
 	bool "Freescale EIM DRIVER"
 	depends on ARCH_MXC || COMPILE_TEST
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index cddd4984d6af..8e693fe8a03a 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_FSL_MC_BUS)	+= fsl-mc/
 
 obj-$(CONFIG_BT1_APB)		+= bt1-apb.o
 obj-$(CONFIG_BT1_AXI)		+= bt1-axi.o
+obj-$(CONFIG_IMX_AIPSTZ)	+= imx-aipstz.o
 obj-$(CONFIG_IMX_WEIM)		+= imx-weim.o
 obj-$(CONFIG_INTEL_IXP4XX_EB)	+= intel-ixp4xx-eb.o
 obj-$(CONFIG_MIPS_CDMM)		+= mips_cdmm.o
diff --git a/drivers/bus/imx-aipstz.c b/drivers/bus/imx-aipstz.c
new file mode 100644
index 000000000000..44db40dae71b
--- /dev/null
+++ b/drivers/bus/imx-aipstz.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2025 NXP
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+
+#define IMX_AIPSTZ_MPR0 0x0
+
+struct imx_aipstz_config {
+	u32 mpr0;
+};
+
+static void imx_aipstz_apply_default(void __iomem *base,
+				     const struct imx_aipstz_config *default_cfg)
+{
+	writel(default_cfg->mpr0, base + IMX_AIPSTZ_MPR0);
+}
+
+static int imx_aipstz_probe(struct platform_device *pdev)
+{
+	const struct imx_aipstz_config *default_cfg;
+	void __iomem *base;
+
+	base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
+	if (IS_ERR(base))
+		return dev_err_probe(&pdev->dev, -ENOMEM,
+				     "failed to get/ioremap AC memory\n");
+
+	default_cfg = of_device_get_match_data(&pdev->dev);
+
+	imx_aipstz_apply_default(base, default_cfg);
+
+	dev_set_drvdata(&pdev->dev, base);
+
+	pm_runtime_set_active(&pdev->dev);
+	devm_pm_runtime_enable(&pdev->dev);
+
+	return devm_of_platform_populate(&pdev->dev);
+}
+
+static int imx_aipstz_runtime_resume(struct device *dev)
+{
+	const struct imx_aipstz_config *default_cfg;
+	void __iomem *base;
+
+	base = dev_get_drvdata(dev);
+	default_cfg = of_device_get_match_data(dev);
+
+	/* restore potentially lost configuration during domain power-off */
+	imx_aipstz_apply_default(base, default_cfg);
+
+	return 0;
+}
+
+static const struct dev_pm_ops imx_aipstz_pm_ops = {
+	RUNTIME_PM_OPS(NULL, imx_aipstz_runtime_resume, NULL)
+	SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
+};
+
+/*
+ * following configuration is equivalent to:
+ *	masters 0-7 => trusted for R/W + use AHB's HPROT[1] to det. privilege
+ */
+static const struct imx_aipstz_config imx8mp_aipstz_default_cfg = {
+	.mpr0 = 0x77777777,
+};
+
+static const struct of_device_id imx_aipstz_of_ids[] = {
+	{ .compatible = "fsl,imx8mp-aipstz", .data = &imx8mp_aipstz_default_cfg },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, imx_aipstz_of_ids);
+
+static struct platform_driver imx_aipstz_of_driver = {
+	.probe = imx_aipstz_probe,
+	.driver = {
+		.name = "imx-aipstz",
+		.of_match_table = imx_aipstz_of_ids,
+		.pm = pm_ptr(&imx_aipstz_pm_ops),
+	},
+};
+module_platform_driver(imx_aipstz_of_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("IMX secure AHB to IP Slave bus (AIPSTZ) bridge driver");
+MODULE_AUTHOR("Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>");
-- 
2.34.1

[PATCH v6 4/6] arm64: dts: imx8mp: convert 'aips5' to 'aipstz5'

[Laurentiu Mihalcea]

From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

AIPS5 is actually AIPSTZ5 as it offers some security-related
configurations. Since these configurations need to be applied before
accessing any of the peripherals on the bus, it's better to make AIPSTZ5
be their parent instead of keeping AIPS5 and adding a child node for
AIPSTZ5. Also, because of the security configurations, the address space
of the bus has to be changed to that of the configuration registers.

Finally, since AIPSTZ5 belongs to the AUDIOMIX power domain, add the
missing 'power-domains' property. The domain needs to be powered on before
attempting to configure the security-related registers.

The DT node name is not changed to avoid potential issues with DTs in
which this node is referenced.

Co-developed-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
---
 arch/arm64/boot/dts/freescale/imx8mp.dtsi | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/boot/dts/freescale/imx8mp.dtsi b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
index ce6793b2d57e..aa7940c65f2d 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
@@ -1399,12 +1399,14 @@ eqos: ethernet@30bf0000 {
 			};
 		};
 
-		aips5: bus@30c00000 {
-			compatible = "fsl,aips-bus", "simple-bus";
-			reg = <0x30c00000 0x400000>;
+		aips5: bus@30df0000 {
+			compatible = "fsl,imx8mp-aipstz";
+			reg = <0x30df0000 0x10000>;
+			power-domains = <&pgc_audio>;
 			#address-cells = <1>;
 			#size-cells = <1>;
-			ranges;
+			#access-controller-cells = <3>;
+			ranges = <0x30c00000 0x30c00000 0x400000>;
 
 			spba-bus@30c00000 {
 				compatible = "fsl,spba-bus", "simple-bus";
-- 
2.34.1

[PATCH v6 5/6] arm64: dts: imx8mp: add aipstz-related definitions

[Laurentiu Mihalcea]

From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

Add header file with AIPSTZ-related definitions: consumer types,
master/peripheral configuration bits, and master ID definitions.

Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
---
 arch/arm64/boot/dts/freescale/imx8mp-aipstz.h | 33 +++++++++++++++++++
 arch/arm64/boot/dts/freescale/imx8mp.dtsi     |  1 +
 2 files changed, 34 insertions(+)
 create mode 100644 arch/arm64/boot/dts/freescale/imx8mp-aipstz.h

diff --git a/arch/arm64/boot/dts/freescale/imx8mp-aipstz.h b/arch/arm64/boot/dts/freescale/imx8mp-aipstz.h
new file mode 100644
index 000000000000..b5bfcbcf38b8
--- /dev/null
+++ b/arch/arm64/boot/dts/freescale/imx8mp-aipstz.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR MIT) */
+/*
+ * Copyright 2025 NXP
+ */
+
+#ifndef __IMX8MP_AIPSTZ_H
+#define __IMX8MP_AIPSTZ_H
+
+/* consumer type - master or peripheral */
+#define IMX8MP_AIPSTZ_MASTER 0x0
+#define IMX8MP_AIPSTZ_PERIPH 0x1
+
+/* master configuration options */
+#define IMX8MP_AIPSTZ_MPL (1 << 0)
+#define IMX8MP_AIPSTZ_MTW (1 << 1)
+#define IMX8MP_AIPSTZ_MTR (1 << 2)
+#define IMX8MP_AIPSTZ_MBW (1 << 3)
+
+/* peripheral configuration options */
+#define IMX8MP_AIPSTZ_TP (1 << 0)
+#define IMX8MP_AIPSTZ_WP (1 << 1)
+#define IMX8MP_AIPSTZ_SP (1 << 2)
+#define IMX8MP_AIPSTZ_BW (1 << 3)
+
+/* master ID definitions */
+#define IMX8MP_AIPSTZ_EDMA 0 /* AUDIOMIX EDMA */
+#define IMX8MP_AIPSTZ_CA53 1 /* Cortex-A53 cluster */
+#define IMX8MP_AIPSTZ_SDMA2 3 /* AUDIOMIX SDMA2 */
+#define IMX8MP_AIPSTZ_SDMA3 3 /* AUDIOMIX SDMA3 */
+#define IMX8MP_AIPSTZ_HIFI4 5 /* HIFI4 DSP */
+#define IMX8MP_AIPSTZ_CM7 6 /* Cortex-M7 */
+
+#endif /* __IMX8MP_AIPSTZ_H */
diff --git a/arch/arm64/boot/dts/freescale/imx8mp.dtsi b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
index aa7940c65f2d..ebbc99f9ceba 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
@@ -12,6 +12,7 @@
 #include <dt-bindings/interrupt-controller/arm-gic.h>
 #include <dt-bindings/thermal/thermal.h>
 
+#include "imx8mp-aipstz.h"
 #include "imx8mp-pinfunc.h"
 
 / {
-- 
2.34.1

[PATCH v6 6/6] arm64: dts: imx8mp: make 'dsp' node depend on 'aips5'

[Laurentiu Mihalcea]

From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

The DSP needs to access peripherals on AIPSTZ5 (to communicate with
the AP using AUDIOMIX MU, for instance). To do so, the security-related
registers of the bridge have to be configured before the DSP is started.
Enforce a dependency on AIPSTZ5 by adding the 'access-controllers'
property to the 'dsp' node.

Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
---
 arch/arm64/boot/dts/freescale/imx8mp.dtsi | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mp.dtsi b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
index ebbc99f9ceba..d0d24fe92c3e 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
@@ -2425,6 +2425,11 @@ dsp: dsp@3b6e8000 {
 			mboxes = <&mu2 2 0>, <&mu2 2 1>,
 				<&mu2 3 0>, <&mu2 3 1>;
 			memory-region = <&dsp_reserved>;
+			access-controllers = <&aips5
+				IMX8MP_AIPSTZ_HIFI4
+				IMX8MP_AIPSTZ_MASTER
+				(IMX8MP_AIPSTZ_MPL | IMX8MP_AIPSTZ_MTW | IMX8MP_AIPSTZ_MTR)
+			>;
 			status = "disabled";
 		};
 	};
-- 
2.34.1

Re: [PATCH v6 0/6] imx8mp: add support for the IMX AIPSTZ bridge

[Daniel Baluta]

Hi Shawn,

Gentle ping.

On Tue, Apr 15, 2025 at 8:21 PM Laurentiu Mihalcea
<laurentiumihalcea111@gmail.com> wrote:
>
> From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
>
> The AIPSTZ bridge offers some security-related configurations which can
> be used to restrict master access to certain peripherals on the bridge.
>
> Normally, this could be done from a secure environment such as ATF before
> Linux boots but the configuration of AIPSTZ5 is lost each time the power
> domain is powered off and then powered on. Because of this, it has to be
> configured each time the power domain is turned on and before any master
> tries to access the peripherals (e.g: AP, CM7, DSP, on i.MX8MP).
>
> The child-parent relationship between the bridge and its peripherals
> should guarantee that the bridge is configured before the AP attempts
> to access the IPs.
>
> Other masters should use the 'access-controllers' property to enforce
> a dependency between their device and the bridge device (see the DSP,
> for example).
>
> The initial version of the series can be found at [1]. The new version
> should provide better management of the device dependencies.
>
> [1]: https://lore.kernel.org/linux-arm-kernel/20241119130726.2761726-1-daniel.baluta@nxp.com/
>
> ---
> Changes in v6:
> * drop the 'IMX8MP_AIPSTZ_HIFI4_T_RW_PL' macro. Its whole point was to
> help with making the DTS more readable but if it makes it look worse
> then there's no point in keeping it.
> * use consumer ID as first AC cell and consumer type as the second cell.
> Better to go with a format that more people are used to as long as it
> still makes sense.
> * pick up Rob's R-b
> * link to v5: https://lore.kernel.org/lkml/20250408154236.49421-1-laurentiumihalcea111@gmail.com/
>
> Changes in v5:
> * merge imx-aipstz.h into imx8mp-aipstz.h. imx-aipstz.h is
> currently only used in the DTS so it can't be added as a binding.
> * place 'ranges' property just after 'reg' in the binding DT example
> as Frank suggested.
> * use the  (1 << x) notation for the configuration bits. Previously,
> hex values were used which didn't make it very clear that the
> configuration options are bits.
> * shorten the description of the bridge's AC cells.
> * shorten the message of the commit introducing the bridge's binding.
> * pick up some more R-b's on patches that remained untouched since V4.
> * link to v4: https://lore.kernel.org/lkml/20250401154404.45932-1-laurentiumihalcea111@gmail.com/
>
> Changes in v4:
> * AIPS5 node now only contains a single memory region: that of the AC
> (just like in V2). 'reg-names' property is dropped.
> * AIPS5 node now uses 'ranges' property to restrict the size of the bus
> (1:1 mapping)
> * change the number of AC cells from 0 to 3
> * add binding headers
> * link to v3: https://lore.kernel.org/lkml/20250324162556.30972-1-laurentiumihalcea111@gmail.com/
>
> Changes in v3:
> * make '#address-cells' and '#size-cells' constants and equal to 1 in the
> binding. The bus is 32-bit.
> * add child node in the example DT snippet.
> * the 'aips5' DT node now contains 2 memory regions: that of the
> peripherals accessible via this bridge and that of the access controller.
> * link to v2: https://lore.kernel.org/lkml/20250226165314.34205-1-laurentiumihalcea111@gmail.com/
>
> Changes in v2:
> * adress Frank Li's comments
> * pick up some A-b/R-b's
> * don't use "simple-bus" as the second compatible. As per Krzysztof's
> comment, AIPSTZ is not a "simple-bus".
> * link to v1: https://lore.kernel.org/lkml/20250221191909.31874-1-laurentiumihalcea111@gmail.com/
> ---
>
> Laurentiu Mihalcea (6):
>   dt-bindings: bus: document the IMX AIPSTZ bridge
>   dt-bindings: dsp: fsl,dsp: document 'access-controllers' property
>   bus: add driver for IMX AIPSTZ bridge
>   arm64: dts: imx8mp: convert 'aips5' to 'aipstz5'
>   arm64: dts: imx8mp: add aipstz-related definitions
>   arm64: dts: imx8mp: make 'dsp' node depend on 'aips5'
>
>  .../bindings/bus/fsl,imx8mp-aipstz.yaml       | 104 ++++++++++++++++++
>  .../devicetree/bindings/dsp/fsl,dsp.yaml      |   3 +
>  arch/arm64/boot/dts/freescale/imx8mp-aipstz.h |  33 ++++++
>  arch/arm64/boot/dts/freescale/imx8mp.dtsi     |  16 ++-
>  drivers/bus/Kconfig                           |   6 +
>  drivers/bus/Makefile                          |   1 +
>  drivers/bus/imx-aipstz.c                      |  92 ++++++++++++++++
>  7 files changed, 251 insertions(+), 4 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/bus/fsl,imx8mp-aipstz.yaml
>  create mode 100644 arch/arm64/boot/dts/freescale/imx8mp-aipstz.h
>  create mode 100644 drivers/bus/imx-aipstz.c
>
> --
> 2.34.1
>
>

Re: [PATCH v6 3/6] bus: add driver for IMX AIPSTZ bridge

[Shawn Guo]

On Tue, Apr 15, 2025 at 01:19:16PM -0400, Laurentiu Mihalcea wrote:
> From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
> 
> The secure AHB to IP Slave (AIPSTZ) bus bridge provides access control
> configurations meant to restrict access to certain peripherals.
> Some of the configurations include:
> 
> 	1) Marking masters as trusted for R/W. Based on this
> 	(and the configuration of the accessed peripheral), the bridge
> 	may choose to abort the R/W transactions issued by certain
> 	masters.
> 
> 	2) Allowing/disallowing write accesses to peripherals.
> 
> Add driver for this IP. Since there's currently no framework for
> access controllers (and since there's currently no need for having
> flexibility w.r.t the configurations) all this driver does is it
> applies a relaxed, "default" configuration, in which all masters
> are trusted for R/W.
> 
> Note that some instances of this IP (e.g: AIPSTZ5 on i.MX8MP) may be tied
> to a power domain and may lose their configuration when the domain is
> powered off. This is why the configuration has to be restored when the
> domain is powered on.
> 
> Co-developed-by: Daniel Baluta <daniel.baluta@nxp.com>
> Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
> Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
> ---
>  drivers/bus/Kconfig      |  6 +++
>  drivers/bus/Makefile     |  1 +
>  drivers/bus/imx-aipstz.c | 92 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 99 insertions(+)
>  create mode 100644 drivers/bus/imx-aipstz.c
> 
> diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
> index ff669a8ccad9..fe7600283e70 100644
> --- a/drivers/bus/Kconfig
> +++ b/drivers/bus/Kconfig
> @@ -87,6 +87,12 @@ config HISILICON_LPC
>  	  Driver to enable I/O access to devices attached to the Low Pin
>  	  Count bus on the HiSilicon Hip06/7 SoC.
>  
> +config IMX_AIPSTZ
> +	tristate "Support for IMX Secure AHB to IP Slave bus (AIPSTZ) bridge"
> +	depends on ARCH_MXC
> +	help
> +	  Enable support for IMX AIPSTZ bridge.
> +
>  config IMX_WEIM
>  	bool "Freescale EIM DRIVER"
>  	depends on ARCH_MXC || COMPILE_TEST
> diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
> index cddd4984d6af..8e693fe8a03a 100644
> --- a/drivers/bus/Makefile
> +++ b/drivers/bus/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_FSL_MC_BUS)	+= fsl-mc/
>  
>  obj-$(CONFIG_BT1_APB)		+= bt1-apb.o
>  obj-$(CONFIG_BT1_AXI)		+= bt1-axi.o
> +obj-$(CONFIG_IMX_AIPSTZ)	+= imx-aipstz.o
>  obj-$(CONFIG_IMX_WEIM)		+= imx-weim.o
>  obj-$(CONFIG_INTEL_IXP4XX_EB)	+= intel-ixp4xx-eb.o
>  obj-$(CONFIG_MIPS_CDMM)		+= mips_cdmm.o
> diff --git a/drivers/bus/imx-aipstz.c b/drivers/bus/imx-aipstz.c
> new file mode 100644
> index 000000000000..44db40dae71b
> --- /dev/null
> +++ b/drivers/bus/imx-aipstz.c
> @@ -0,0 +1,92 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2025 NXP
> + */
> +
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +
> +#define IMX_AIPSTZ_MPR0 0x0
> +
> +struct imx_aipstz_config {
> +	u32 mpr0;
> +};

Would it be more future-proof to have something like this?

struct imx_aipstz_priv {
	__iomem *base;
	const struct imx_aipstz_config *default_cfg;
}; 

With imx_aipstz_priv being drvdata, it could be easily scaled to have
more data later if needed. 

Shawn

> +
> +static void imx_aipstz_apply_default(void __iomem *base,
> +				     const struct imx_aipstz_config *default_cfg)
> +{
> +	writel(default_cfg->mpr0, base + IMX_AIPSTZ_MPR0);
> +}
> +
> +static int imx_aipstz_probe(struct platform_device *pdev)
> +{
> +	const struct imx_aipstz_config *default_cfg;
> +	void __iomem *base;
> +
> +	base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
> +	if (IS_ERR(base))
> +		return dev_err_probe(&pdev->dev, -ENOMEM,
> +				     "failed to get/ioremap AC memory\n");
> +
> +	default_cfg = of_device_get_match_data(&pdev->dev);
> +
> +	imx_aipstz_apply_default(base, default_cfg);
> +
> +	dev_set_drvdata(&pdev->dev, base);
> +
> +	pm_runtime_set_active(&pdev->dev);
> +	devm_pm_runtime_enable(&pdev->dev);
> +
> +	return devm_of_platform_populate(&pdev->dev);
> +}
> +
> +static int imx_aipstz_runtime_resume(struct device *dev)
> +{
> +	const struct imx_aipstz_config *default_cfg;
> +	void __iomem *base;
> +
> +	base = dev_get_drvdata(dev);
> +	default_cfg = of_device_get_match_data(dev);
> +
> +	/* restore potentially lost configuration during domain power-off */
> +	imx_aipstz_apply_default(base, default_cfg);
> +
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops imx_aipstz_pm_ops = {
> +	RUNTIME_PM_OPS(NULL, imx_aipstz_runtime_resume, NULL)
> +	SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
> +};
> +
> +/*
> + * following configuration is equivalent to:
> + *	masters 0-7 => trusted for R/W + use AHB's HPROT[1] to det. privilege
> + */
> +static const struct imx_aipstz_config imx8mp_aipstz_default_cfg = {
> +	.mpr0 = 0x77777777,
> +};
> +
> +static const struct of_device_id imx_aipstz_of_ids[] = {
> +	{ .compatible = "fsl,imx8mp-aipstz", .data = &imx8mp_aipstz_default_cfg },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, imx_aipstz_of_ids);
> +
> +static struct platform_driver imx_aipstz_of_driver = {
> +	.probe = imx_aipstz_probe,
> +	.driver = {
> +		.name = "imx-aipstz",
> +		.of_match_table = imx_aipstz_of_ids,
> +		.pm = pm_ptr(&imx_aipstz_pm_ops),
> +	},
> +};
> +module_platform_driver(imx_aipstz_of_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("IMX secure AHB to IP Slave bus (AIPSTZ) bridge driver");
> +MODULE_AUTHOR("Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>");
> -- 
> 2.34.1
> 

Re: [PATCH v6 3/6] bus: add driver for IMX AIPSTZ bridge

[Shawn Guo]

On Tue, Apr 15, 2025 at 01:19:16PM -0400, Laurentiu Mihalcea wrote:
> Add driver for this IP. Since there's currently no framework for
> access controllers (and since there's currently no need for having
> flexibility w.r.t the configurations) all this driver does is it
> applies a relaxed, "default" configuration, in which all masters
> are trusted for R/W.

Just out of curiosity, is there any ongoing/planned effort about creating
a framework for access controllers at all?

Shawn

Re: [PATCH v6 5/6] arm64: dts: imx8mp: add aipstz-related definitions

[Shawn Guo]

On Tue, Apr 15, 2025 at 01:19:18PM -0400, Laurentiu Mihalcea wrote:
> From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
> 
> Add header file with AIPSTZ-related definitions: consumer types,
> master/peripheral configuration bits, and master ID definitions.
> 
> Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
> ---
>  arch/arm64/boot/dts/freescale/imx8mp-aipstz.h | 33 +++++++++++++++++++
>  arch/arm64/boot/dts/freescale/imx8mp.dtsi     |  1 +
>  2 files changed, 34 insertions(+)
>  create mode 100644 arch/arm64/boot/dts/freescale/imx8mp-aipstz.h
> 
> diff --git a/arch/arm64/boot/dts/freescale/imx8mp-aipstz.h b/arch/arm64/boot/dts/freescale/imx8mp-aipstz.h
> new file mode 100644
> index 000000000000..b5bfcbcf38b8
> --- /dev/null
> +++ b/arch/arm64/boot/dts/freescale/imx8mp-aipstz.h
> @@ -0,0 +1,33 @@
> +/* SPDX-License-Identifier: (GPL-2.0-only OR MIT) */
> +/*
> + * Copyright 2025 NXP
> + */
> +
> +#ifndef __IMX8MP_AIPSTZ_H
> +#define __IMX8MP_AIPSTZ_H
> +
> +/* consumer type - master or peripheral */
> +#define IMX8MP_AIPSTZ_MASTER 0x0
> +#define IMX8MP_AIPSTZ_PERIPH 0x1
> +
> +/* master configuration options */
> +#define IMX8MP_AIPSTZ_MPL (1 << 0)
> +#define IMX8MP_AIPSTZ_MTW (1 << 1)
> +#define IMX8MP_AIPSTZ_MTR (1 << 2)
> +#define IMX8MP_AIPSTZ_MBW (1 << 3)
> +
> +/* peripheral configuration options */
> +#define IMX8MP_AIPSTZ_TP (1 << 0)
> +#define IMX8MP_AIPSTZ_WP (1 << 1)
> +#define IMX8MP_AIPSTZ_SP (1 << 2)
> +#define IMX8MP_AIPSTZ_BW (1 << 3)
> +
> +/* master ID definitions */
> +#define IMX8MP_AIPSTZ_EDMA 0 /* AUDIOMIX EDMA */
> +#define IMX8MP_AIPSTZ_CA53 1 /* Cortex-A53 cluster */
> +#define IMX8MP_AIPSTZ_SDMA2 3 /* AUDIOMIX SDMA2 */
> +#define IMX8MP_AIPSTZ_SDMA3 3 /* AUDIOMIX SDMA3 */
> +#define IMX8MP_AIPSTZ_HIFI4 5 /* HIFI4 DSP */
> +#define IMX8MP_AIPSTZ_CM7 6 /* Cortex-M7 */

Could we use tabs to align all these values vertically?

Shawn

> +
> +#endif /* __IMX8MP_AIPSTZ_H */
> diff --git a/arch/arm64/boot/dts/freescale/imx8mp.dtsi b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> index aa7940c65f2d..ebbc99f9ceba 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> @@ -12,6 +12,7 @@
>  #include <dt-bindings/interrupt-controller/arm-gic.h>
>  #include <dt-bindings/thermal/thermal.h>
>  
> +#include "imx8mp-aipstz.h"
>  #include "imx8mp-pinfunc.h"
>  
>  / {
> -- 
> 2.34.1
> 

Re: [PATCH v6 3/6] bus: add driver for IMX AIPSTZ bridge

[Peng Fan]

Hi Shawn,

On Mon, Jun 02, 2025 at 12:09:02PM +0800, Shawn Guo wrote:
>On Tue, Apr 15, 2025 at 01:19:16PM -0400, Laurentiu Mihalcea wrote:
>> Add driver for this IP. Since there's currently no framework for
>> access controllers (and since there's currently no need for having
>> flexibility w.r.t the configurations) all this driver does is it
>> applies a relaxed, "default" configuration, in which all masters
>> are trusted for R/W.
>
>Just out of curiosity, is there any ongoing/planned effort about creating
>a framework for access controllers at all?

I was planning to add a generic framework for access controller, mainly
for i.MX various parts for one SoC family. But I have not spent
much efforts on coding.

Regards,
Peng

>
>Shawn
>

Re: [PATCH v6 3/6] bus: add driver for IMX AIPSTZ bridge

[Laurentiu Mihalcea]

On 6/2/2025 7:09 AM, Shawn Guo wrote:
> On Tue, Apr 15, 2025 at 01:19:16PM -0400, Laurentiu Mihalcea wrote:
>> Add driver for this IP. Since there's currently no framework for
>> access controllers (and since there's currently no need for having
>> flexibility w.r.t the configurations) all this driver does is it
>> applies a relaxed, "default" configuration, in which all masters
>> are trusted for R/W.
> Just out of curiosity, is there any ongoing/planned effort about creating
> a framework for access controllers at all?

no plan ATM. Though, I would be interested in knowing if anyone else would benefit
from such an API? I know that STM also has some access controller-related drivers,
but I wonder if STM's drivers and the AIPSTZ are just some isolated cases in which
security-related configuration is done from EL1?