* [PATCH v3 0/5] Expose RPi4's bootloader configuration
@ 2021-01-12 14:23 ` Nicolas Saenz Julienne
0 siblings, 0 replies; 18+ messages in thread
From: Nicolas Saenz Julienne @ 2021-01-12 14:23 UTC (permalink / raw)
To: srinivas.kandagatla, linux-kernel
Cc: devicetree, tim.gover, catalin.marinas, linux, robh+dt,
bcm-kernel-feedback-list, linux-arm-kernel, will, phil,
nsaenzjulienne, linux-rpi-kernel
Soon to be released versions of RPi4's firmware will take of care
passing their bootloader's configuration[1] to the OS by copying it into
memory and creating a reserved memory node in the board's DT. By
modeling this reserved memory node as an nvmem device using
'nvmem-rmem', which this series introduces, user-space applications will
be able to query this information through nvmem's sysfs interface.
An alternative approach, less nice IMO, would be to create a
platform-specific 'soc' driver.
Regards,
Nicolas
[1] https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2711_bootloader_config.md
---
Changes since v2:
- Fix DT bingins
Changes since v1:
- Avoid the reserved-memory indirection by integrating the nvmem driver
into the reserved memory node.
Nicolas Saenz Julienne (5):
dt-bindings: nvmem: Add bindings for rmem driver
nvmem: Add driver to expose reserved memory as nvmem
ARM: dts: bcm2711: Add reserved memory template to hold firmware
configuration
arm64: defconfig: Enable nvmem's rmem driver
ARM: multi_v7_defconfig: Enable nvmem's rmem driver
.../devicetree/bindings/nvmem/rmem.yaml | 49 ++++++++++
arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 17 ++++
arch/arm/configs/multi_v7_defconfig | 1 +
arch/arm64/configs/defconfig | 1 +
drivers/nvmem/Kconfig | 8 ++
drivers/nvmem/Makefile | 2 +
drivers/nvmem/rmem.c | 97 +++++++++++++++++++
drivers/of/platform.c | 1 +
8 files changed, 176 insertions(+)
create mode 100644 Documentation/devicetree/bindings/nvmem/rmem.yaml
create mode 100644 drivers/nvmem/rmem.c
--
2.29.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v3 1/5] dt-bindings: nvmem: Add bindings for rmem driver
2021-01-12 14:23 ` Nicolas Saenz Julienne
@ 2021-01-12 14:23 ` Nicolas Saenz Julienne
-1 siblings, 0 replies; 18+ messages in thread
From: Nicolas Saenz Julienne @ 2021-01-12 14:23 UTC (permalink / raw)
To: srinivas.kandagatla, linux-kernel, Saenz Julienne
Cc: linux-arm-kernel, linux, catalin.marinas, will, devicetree,
linux-rpi-kernel, robh+dt, bcm-kernel-feedback-list, tim.gover,
phil
Firmware/co-processors might use reserved memory areas in order to pass
data stemming from an nvmem device otherwise non accessible to Linux.
For example an EEPROM memory only physically accessible to firmware, or
data only accessible early at boot time.
Introduce the dt-bindings to nvmem's rmem.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
Changes since v2:
- Run yamllint and fix indentation issues
Changes since v1:
- Update schema to new driver design
.../devicetree/bindings/nvmem/rmem.yaml | 49 +++++++++++++++++++
1 file changed, 49 insertions(+)
create mode 100644 Documentation/devicetree/bindings/nvmem/rmem.yaml
diff --git a/Documentation/devicetree/bindings/nvmem/rmem.yaml b/Documentation/devicetree/bindings/nvmem/rmem.yaml
new file mode 100644
index 000000000000..1d85a0a30846
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/rmem.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/nvmem/rmem.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Reserved Memory Based nvmem Device
+
+maintainers:
+ - Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+
+allOf:
+ - $ref: "nvmem.yaml#"
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - raspberrypi,bootloader-config
+ - const: nvmem-rmem
+
+ no-map:
+ $ref: /schemas/types.yaml#/definitions/flag
+ description:
+ Avoid creating a virtual mapping of the region as part of the OS'
+ standard mapping of system memory.
+
+required:
+ - compatible
+ - no-map
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ reserved-memory {
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ blconfig: nvram@10000000 {
+ compatible = "raspberrypi,bootloader-config", "nvmem-rmem";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ reg = <0x10000000 0x1000>;
+ no-map;
+ };
+ };
+
+...
--
2.29.2
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH v3 1/5] dt-bindings: nvmem: Add bindings for rmem driver
@ 2021-01-12 14:23 ` Nicolas Saenz Julienne
0 siblings, 0 replies; 18+ messages in thread
From: Nicolas Saenz Julienne @ 2021-01-12 14:23 UTC (permalink / raw)
To: srinivas.kandagatla, linux-kernel, Saenz Julienne
Cc: devicetree, tim.gover, catalin.marinas, linux, robh+dt,
bcm-kernel-feedback-list, linux-rpi-kernel, will, phil,
linux-arm-kernel
Firmware/co-processors might use reserved memory areas in order to pass
data stemming from an nvmem device otherwise non accessible to Linux.
For example an EEPROM memory only physically accessible to firmware, or
data only accessible early at boot time.
Introduce the dt-bindings to nvmem's rmem.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
Changes since v2:
- Run yamllint and fix indentation issues
Changes since v1:
- Update schema to new driver design
.../devicetree/bindings/nvmem/rmem.yaml | 49 +++++++++++++++++++
1 file changed, 49 insertions(+)
create mode 100644 Documentation/devicetree/bindings/nvmem/rmem.yaml
diff --git a/Documentation/devicetree/bindings/nvmem/rmem.yaml b/Documentation/devicetree/bindings/nvmem/rmem.yaml
new file mode 100644
index 000000000000..1d85a0a30846
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/rmem.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/nvmem/rmem.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Reserved Memory Based nvmem Device
+
+maintainers:
+ - Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+
+allOf:
+ - $ref: "nvmem.yaml#"
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - raspberrypi,bootloader-config
+ - const: nvmem-rmem
+
+ no-map:
+ $ref: /schemas/types.yaml#/definitions/flag
+ description:
+ Avoid creating a virtual mapping of the region as part of the OS'
+ standard mapping of system memory.
+
+required:
+ - compatible
+ - no-map
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ reserved-memory {
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ blconfig: nvram@10000000 {
+ compatible = "raspberrypi,bootloader-config", "nvmem-rmem";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ reg = <0x10000000 0x1000>;
+ no-map;
+ };
+ };
+
+...
--
2.29.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 18+ messages in thread
* Re: [PATCH v3 1/5] dt-bindings: nvmem: Add bindings for rmem driver
2021-01-12 14:23 ` Nicolas Saenz Julienne
@ 2021-01-14 20:17 ` Rob Herring
-1 siblings, 0 replies; 18+ messages in thread
From: Rob Herring @ 2021-01-14 20:17 UTC (permalink / raw)
To: Nicolas Saenz Julienne
Cc: tim.gover, srinivas.kandagatla, linux-arm-kernel, robh+dt,
bcm-kernel-feedback-list, phil, linux-kernel, linux-rpi-kernel,
linux, devicetree, catalin.marinas, will
On Tue, 12 Jan 2021 15:23:38 +0100, Nicolas Saenz Julienne wrote:
> Firmware/co-processors might use reserved memory areas in order to pass
> data stemming from an nvmem device otherwise non accessible to Linux.
> For example an EEPROM memory only physically accessible to firmware, or
> data only accessible early at boot time.
>
> Introduce the dt-bindings to nvmem's rmem.
>
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
>
> ---
>
> Changes since v2:
> - Run yamllint and fix indentation issues
>
> Changes since v1:
> - Update schema to new driver design
>
> .../devicetree/bindings/nvmem/rmem.yaml | 49 +++++++++++++++++++
> 1 file changed, 49 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/nvmem/rmem.yaml
>
Reviewed-by: Rob Herring <robh@kernel.org>
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v3 1/5] dt-bindings: nvmem: Add bindings for rmem driver
@ 2021-01-14 20:17 ` Rob Herring
0 siblings, 0 replies; 18+ messages in thread
From: Rob Herring @ 2021-01-14 20:17 UTC (permalink / raw)
To: Nicolas Saenz Julienne
Cc: devicetree, tim.gover, catalin.marinas, linux-kernel, linux,
robh+dt, bcm-kernel-feedback-list, linux-rpi-kernel,
srinivas.kandagatla, will, phil, linux-arm-kernel
On Tue, 12 Jan 2021 15:23:38 +0100, Nicolas Saenz Julienne wrote:
> Firmware/co-processors might use reserved memory areas in order to pass
> data stemming from an nvmem device otherwise non accessible to Linux.
> For example an EEPROM memory only physically accessible to firmware, or
> data only accessible early at boot time.
>
> Introduce the dt-bindings to nvmem's rmem.
>
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
>
> ---
>
> Changes since v2:
> - Run yamllint and fix indentation issues
>
> Changes since v1:
> - Update schema to new driver design
>
> .../devicetree/bindings/nvmem/rmem.yaml | 49 +++++++++++++++++++
> 1 file changed, 49 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/nvmem/rmem.yaml
>
Reviewed-by: Rob Herring <robh@kernel.org>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v3 2/5] nvmem: Add driver to expose reserved memory as nvmem
2021-01-12 14:23 ` Nicolas Saenz Julienne
@ 2021-01-12 14:23 ` Nicolas Saenz Julienne
-1 siblings, 0 replies; 18+ messages in thread
From: Nicolas Saenz Julienne @ 2021-01-12 14:23 UTC (permalink / raw)
To: srinivas.kandagatla, linux-kernel, Rob Herring, Frank Rowand
Cc: linux-arm-kernel, linux, nsaenzjulienne, catalin.marinas, will,
devicetree, linux-rpi-kernel, bcm-kernel-feedback-list,
tim.gover, phil, Rob Herring
Firmware/co-processors might use reserved memory areas in order to pass
data stemming from an nvmem device otherwise non accessible to Linux.
For example an EEPROM memory only physically accessible to firmware, or
data only accessible early at boot time.
In order to expose this data to other drivers and user-space, the driver
models the reserved memory area as an nvmem device.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Tested-by: Tim Gover <tim.gover@raspberrypi.com>
---
Changes since v1:
- Remove reserved memory phandle indirection by directly creating a
platform device from the reserved memory DT node
- Only map memory upon reading it to avoid corruption
- Small cosmetic cleanups
drivers/nvmem/Kconfig | 8 ++++
drivers/nvmem/Makefile | 2 +
drivers/nvmem/rmem.c | 97 ++++++++++++++++++++++++++++++++++++++++++
drivers/of/platform.c | 1 +
4 files changed, 108 insertions(+)
create mode 100644 drivers/nvmem/rmem.c
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 954d3b4a52ab..fecc19b884bf 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -270,4 +270,12 @@ config SPRD_EFUSE
This driver can also be built as a module. If so, the module
will be called nvmem-sprd-efuse.
+config NVMEM_RMEM
+ tristate "Reserved Memory Based Driver Support"
+ help
+ This drivers maps reserved memory into an nvmem device. It might be
+ useful to expose information left by firmware in memory.
+
+ This driver can also be built as a module. If so, the module
+ will be called nvmem-rmem.
endif
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index a7c377218341..5376b8e0dae5 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -55,3 +55,5 @@ obj-$(CONFIG_NVMEM_ZYNQMP) += nvmem_zynqmp_nvmem.o
nvmem_zynqmp_nvmem-y := zynqmp_nvmem.o
obj-$(CONFIG_SPRD_EFUSE) += nvmem_sprd_efuse.o
nvmem_sprd_efuse-y := sprd-efuse.o
+obj-$(CONFIG_NVMEM_RMEM) += nvmem-rmem.o
+nvmem-rmem-y := rmem.o
diff --git a/drivers/nvmem/rmem.c b/drivers/nvmem/rmem.c
new file mode 100644
index 000000000000..b11c3c974b3d
--- /dev/null
+++ b/drivers/nvmem/rmem.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/platform_device.h>
+
+struct rmem {
+ struct device *dev;
+ struct nvmem_device *nvmem;
+ struct reserved_mem *mem;
+
+ phys_addr_t size;
+};
+
+static int rmem_read(void *context, unsigned int offset,
+ void *val, size_t bytes)
+{
+ struct rmem *priv = context;
+ size_t available = priv->mem->size;
+ loff_t off = offset;
+ void *addr;
+ int count;
+
+ /*
+ * Only map the reserved memory at this point to avoid potential rogue
+ * kernel threads inadvertently modifying it. Based on the current
+ * uses-cases for this driver, the performance hit isn't a concern.
+ * Nor is likely to be, given the nature of the subsystem. Most nvmem
+ * devices operate over slow buses to begin with.
+ *
+ * An alternative would be setting the memory as RO, set_memory_ro(),
+ * but as of Dec 2020 this isn't possible on arm64.
+ */
+ addr = memremap(priv->mem->base, available, MEMREMAP_WB);
+ if (IS_ERR(addr)) {
+ dev_err(priv->dev, "Failed to remap memory region\n");
+ return PTR_ERR(addr);
+ }
+
+ count = memory_read_from_buffer(val, bytes, &off, addr, available);
+
+ memunmap(addr);
+
+ return count;
+}
+
+static int rmem_probe(struct platform_device *pdev)
+{
+ struct nvmem_config config = { };
+ struct device *dev = &pdev->dev;
+ struct reserved_mem *mem;
+ struct rmem *priv;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ priv->dev = dev;
+
+ mem = of_reserved_mem_lookup(dev->of_node);
+ if (!mem) {
+ dev_err(dev, "Failed to lookup reserved memory\n");
+ return -EINVAL;
+ }
+ priv->mem = mem;
+
+ config.dev = dev;
+ config.priv = priv;
+ config.name = "rmem";
+ config.size = mem->size;
+ config.reg_read = rmem_read;
+
+ return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &config));
+}
+
+static const struct of_device_id rmem_match[] = {
+ { .compatible = "nvmem-rmem", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, rmem_match);
+
+static struct platform_driver rmem_driver = {
+ .probe = rmem_probe,
+ .driver = {
+ .name = "rmem",
+ .of_match_table = rmem_match,
+ },
+};
+module_platform_driver(rmem_driver);
+
+MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de>");
+MODULE_DESCRIPTION("Reserved Memory Based nvmem Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 79bd5f5a1bf1..6699cdbe58b6 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -511,6 +511,7 @@ static const struct of_device_id reserved_mem_matches[] = {
{ .compatible = "qcom,rmtfs-mem" },
{ .compatible = "qcom,cmd-db" },
{ .compatible = "ramoops" },
+ { .compatible = "nvmem-rmem" },
{}
};
--
2.29.2
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH v3 2/5] nvmem: Add driver to expose reserved memory as nvmem
@ 2021-01-12 14:23 ` Nicolas Saenz Julienne
0 siblings, 0 replies; 18+ messages in thread
From: Nicolas Saenz Julienne @ 2021-01-12 14:23 UTC (permalink / raw)
To: srinivas.kandagatla, linux-kernel, Rob Herring, Frank Rowand
Cc: devicetree, tim.gover, catalin.marinas, linux,
bcm-kernel-feedback-list, linux-arm-kernel, will, phil,
nsaenzjulienne, linux-rpi-kernel
Firmware/co-processors might use reserved memory areas in order to pass
data stemming from an nvmem device otherwise non accessible to Linux.
For example an EEPROM memory only physically accessible to firmware, or
data only accessible early at boot time.
In order to expose this data to other drivers and user-space, the driver
models the reserved memory area as an nvmem device.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Tested-by: Tim Gover <tim.gover@raspberrypi.com>
---
Changes since v1:
- Remove reserved memory phandle indirection by directly creating a
platform device from the reserved memory DT node
- Only map memory upon reading it to avoid corruption
- Small cosmetic cleanups
drivers/nvmem/Kconfig | 8 ++++
drivers/nvmem/Makefile | 2 +
drivers/nvmem/rmem.c | 97 ++++++++++++++++++++++++++++++++++++++++++
drivers/of/platform.c | 1 +
4 files changed, 108 insertions(+)
create mode 100644 drivers/nvmem/rmem.c
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 954d3b4a52ab..fecc19b884bf 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -270,4 +270,12 @@ config SPRD_EFUSE
This driver can also be built as a module. If so, the module
will be called nvmem-sprd-efuse.
+config NVMEM_RMEM
+ tristate "Reserved Memory Based Driver Support"
+ help
+ This drivers maps reserved memory into an nvmem device. It might be
+ useful to expose information left by firmware in memory.
+
+ This driver can also be built as a module. If so, the module
+ will be called nvmem-rmem.
endif
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index a7c377218341..5376b8e0dae5 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -55,3 +55,5 @@ obj-$(CONFIG_NVMEM_ZYNQMP) += nvmem_zynqmp_nvmem.o
nvmem_zynqmp_nvmem-y := zynqmp_nvmem.o
obj-$(CONFIG_SPRD_EFUSE) += nvmem_sprd_efuse.o
nvmem_sprd_efuse-y := sprd-efuse.o
+obj-$(CONFIG_NVMEM_RMEM) += nvmem-rmem.o
+nvmem-rmem-y := rmem.o
diff --git a/drivers/nvmem/rmem.c b/drivers/nvmem/rmem.c
new file mode 100644
index 000000000000..b11c3c974b3d
--- /dev/null
+++ b/drivers/nvmem/rmem.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/platform_device.h>
+
+struct rmem {
+ struct device *dev;
+ struct nvmem_device *nvmem;
+ struct reserved_mem *mem;
+
+ phys_addr_t size;
+};
+
+static int rmem_read(void *context, unsigned int offset,
+ void *val, size_t bytes)
+{
+ struct rmem *priv = context;
+ size_t available = priv->mem->size;
+ loff_t off = offset;
+ void *addr;
+ int count;
+
+ /*
+ * Only map the reserved memory at this point to avoid potential rogue
+ * kernel threads inadvertently modifying it. Based on the current
+ * uses-cases for this driver, the performance hit isn't a concern.
+ * Nor is likely to be, given the nature of the subsystem. Most nvmem
+ * devices operate over slow buses to begin with.
+ *
+ * An alternative would be setting the memory as RO, set_memory_ro(),
+ * but as of Dec 2020 this isn't possible on arm64.
+ */
+ addr = memremap(priv->mem->base, available, MEMREMAP_WB);
+ if (IS_ERR(addr)) {
+ dev_err(priv->dev, "Failed to remap memory region\n");
+ return PTR_ERR(addr);
+ }
+
+ count = memory_read_from_buffer(val, bytes, &off, addr, available);
+
+ memunmap(addr);
+
+ return count;
+}
+
+static int rmem_probe(struct platform_device *pdev)
+{
+ struct nvmem_config config = { };
+ struct device *dev = &pdev->dev;
+ struct reserved_mem *mem;
+ struct rmem *priv;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ priv->dev = dev;
+
+ mem = of_reserved_mem_lookup(dev->of_node);
+ if (!mem) {
+ dev_err(dev, "Failed to lookup reserved memory\n");
+ return -EINVAL;
+ }
+ priv->mem = mem;
+
+ config.dev = dev;
+ config.priv = priv;
+ config.name = "rmem";
+ config.size = mem->size;
+ config.reg_read = rmem_read;
+
+ return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &config));
+}
+
+static const struct of_device_id rmem_match[] = {
+ { .compatible = "nvmem-rmem", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, rmem_match);
+
+static struct platform_driver rmem_driver = {
+ .probe = rmem_probe,
+ .driver = {
+ .name = "rmem",
+ .of_match_table = rmem_match,
+ },
+};
+module_platform_driver(rmem_driver);
+
+MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de>");
+MODULE_DESCRIPTION("Reserved Memory Based nvmem Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 79bd5f5a1bf1..6699cdbe58b6 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -511,6 +511,7 @@ static const struct of_device_id reserved_mem_matches[] = {
{ .compatible = "qcom,rmtfs-mem" },
{ .compatible = "qcom,cmd-db" },
{ .compatible = "ramoops" },
+ { .compatible = "nvmem-rmem" },
{}
};
--
2.29.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH v3 3/5] ARM: dts: bcm2711: Add reserved memory template to hold firmware configuration
2021-01-12 14:23 ` Nicolas Saenz Julienne
@ 2021-01-12 14:23 ` Nicolas Saenz Julienne
-1 siblings, 0 replies; 18+ messages in thread
From: Nicolas Saenz Julienne @ 2021-01-12 14:23 UTC (permalink / raw)
To: srinivas.kandagatla, linux-kernel, Rob Herring, Nicolas Saenz Julienne
Cc: linux-arm-kernel, linux, catalin.marinas, will, devicetree,
linux-rpi-kernel, bcm-kernel-feedback-list, tim.gover, phil
RPi4's co-processor will copy the board's bootloader[1] configuration
into memory for the OS to consume. Specifically, for the bootloader
configuration and upgrade user-space routines to query it through
nvmem's sysfs interface.
Introduce a reserved-memory area template for the co-processor to edit
before booting the system so as for Linux not to overwrite that memory
and to expose it as an nvmem device.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Tim Gover <tim.gover@raspberrypi.com>
[1] https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2711_bootloader_config.md
---
Changes since v1:
- Introduce compatible string
- Change alias name to something more explicit
arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
index 403bacf986eb..3b4ab947492a 100644
--- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
+++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
@@ -25,6 +25,7 @@ aliases {
emmc2bus = &emmc2bus;
ethernet0 = &genet;
pcie0 = &pcie0;
+ blconfig = &blconfig;
};
leds {
@@ -218,6 +219,22 @@ &pwm1 {
status = "okay";
};
+&rmem {
+ /*
+ * RPi4's co-processor will copy the board's bootloader configuration
+ * into memory for the OS to consume. It'll also update this node with
+ * its placement information.
+ */
+ blconfig: nvram@0 {
+ compatible = "raspberrypi,bootloader-config", "nvmem-rmem";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ reg = <0x0 0x0 0x0>;
+ no-map;
+ status = "disabled";
+ };
+};
+
/* SDHCI is used to control the SDIO for wireless */
&sdhci {
#address-cells = <1>;
--
2.29.2
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH v3 3/5] ARM: dts: bcm2711: Add reserved memory template to hold firmware configuration
@ 2021-01-12 14:23 ` Nicolas Saenz Julienne
0 siblings, 0 replies; 18+ messages in thread
From: Nicolas Saenz Julienne @ 2021-01-12 14:23 UTC (permalink / raw)
To: srinivas.kandagatla, linux-kernel, Rob Herring, Nicolas Saenz Julienne
Cc: devicetree, tim.gover, catalin.marinas, linux,
bcm-kernel-feedback-list, linux-rpi-kernel, will, phil,
linux-arm-kernel
RPi4's co-processor will copy the board's bootloader[1] configuration
into memory for the OS to consume. Specifically, for the bootloader
configuration and upgrade user-space routines to query it through
nvmem's sysfs interface.
Introduce a reserved-memory area template for the co-processor to edit
before booting the system so as for Linux not to overwrite that memory
and to expose it as an nvmem device.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Tim Gover <tim.gover@raspberrypi.com>
[1] https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2711_bootloader_config.md
---
Changes since v1:
- Introduce compatible string
- Change alias name to something more explicit
arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
index 403bacf986eb..3b4ab947492a 100644
--- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
+++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
@@ -25,6 +25,7 @@ aliases {
emmc2bus = &emmc2bus;
ethernet0 = &genet;
pcie0 = &pcie0;
+ blconfig = &blconfig;
};
leds {
@@ -218,6 +219,22 @@ &pwm1 {
status = "okay";
};
+&rmem {
+ /*
+ * RPi4's co-processor will copy the board's bootloader configuration
+ * into memory for the OS to consume. It'll also update this node with
+ * its placement information.
+ */
+ blconfig: nvram@0 {
+ compatible = "raspberrypi,bootloader-config", "nvmem-rmem";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ reg = <0x0 0x0 0x0>;
+ no-map;
+ status = "disabled";
+ };
+};
+
/* SDHCI is used to control the SDIO for wireless */
&sdhci {
#address-cells = <1>;
--
2.29.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH v3 4/5] arm64: defconfig: Enable nvmem's rmem driver
2021-01-12 14:23 ` Nicolas Saenz Julienne
@ 2021-01-12 14:23 ` Nicolas Saenz Julienne
-1 siblings, 0 replies; 18+ messages in thread
From: Nicolas Saenz Julienne @ 2021-01-12 14:23 UTC (permalink / raw)
To: srinivas.kandagatla, linux-kernel
Cc: linux-arm-kernel, linux, nsaenzjulienne, catalin.marinas, will,
devicetree, linux-rpi-kernel, robh+dt, bcm-kernel-feedback-list,
tim.gover, phil
It'll be used by the RPi4 family of boards to access its bootloader
configuration.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
arch/arm64/configs/defconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index 9957b6669eb1..81b2418f7f72 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -1077,6 +1077,7 @@ CONFIG_ROCKCHIP_EFUSE=y
CONFIG_NVMEM_SUNXI_SID=y
CONFIG_UNIPHIER_EFUSE=y
CONFIG_MESON_EFUSE=m
+CONFIG_NVMEM_RMEM=m
CONFIG_FPGA=y
CONFIG_FPGA_MGR_STRATIX10_SOC=m
CONFIG_FPGA_BRIDGE=m
--
2.29.2
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH v3 4/5] arm64: defconfig: Enable nvmem's rmem driver
@ 2021-01-12 14:23 ` Nicolas Saenz Julienne
0 siblings, 0 replies; 18+ messages in thread
From: Nicolas Saenz Julienne @ 2021-01-12 14:23 UTC (permalink / raw)
To: srinivas.kandagatla, linux-kernel
Cc: devicetree, tim.gover, catalin.marinas, linux, robh+dt,
bcm-kernel-feedback-list, linux-arm-kernel, will, phil,
nsaenzjulienne, linux-rpi-kernel
It'll be used by the RPi4 family of boards to access its bootloader
configuration.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
arch/arm64/configs/defconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index 9957b6669eb1..81b2418f7f72 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -1077,6 +1077,7 @@ CONFIG_ROCKCHIP_EFUSE=y
CONFIG_NVMEM_SUNXI_SID=y
CONFIG_UNIPHIER_EFUSE=y
CONFIG_MESON_EFUSE=m
+CONFIG_NVMEM_RMEM=m
CONFIG_FPGA=y
CONFIG_FPGA_MGR_STRATIX10_SOC=m
CONFIG_FPGA_BRIDGE=m
--
2.29.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH v3 5/5] ARM: multi_v7_defconfig: Enable nvmem's rmem driver
2021-01-12 14:23 ` Nicolas Saenz Julienne
@ 2021-01-12 14:23 ` Nicolas Saenz Julienne
-1 siblings, 0 replies; 18+ messages in thread
From: Nicolas Saenz Julienne @ 2021-01-12 14:23 UTC (permalink / raw)
To: srinivas.kandagatla, linux-kernel
Cc: linux-arm-kernel, linux, nsaenzjulienne, catalin.marinas, will,
devicetree, linux-rpi-kernel, robh+dt, bcm-kernel-feedback-list,
tim.gover, phil
It'll be used by the RPi4 family of boards to access its bootloader
configuration.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
arch/arm/configs/multi_v7_defconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index 6492a3601e7c..0914fa09af0c 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -1106,6 +1106,7 @@ CONFIG_ROCKCHIP_EFUSE=m
CONFIG_NVMEM_SUNXI_SID=y
CONFIG_NVMEM_VF610_OCOTP=y
CONFIG_MESON_MX_EFUSE=m
+CONFIG_NVMEM_RMEM=m
CONFIG_FSI=m
CONFIG_FSI_MASTER_GPIO=m
CONFIG_FSI_MASTER_HUB=m
--
2.29.2
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH v3 5/5] ARM: multi_v7_defconfig: Enable nvmem's rmem driver
@ 2021-01-12 14:23 ` Nicolas Saenz Julienne
0 siblings, 0 replies; 18+ messages in thread
From: Nicolas Saenz Julienne @ 2021-01-12 14:23 UTC (permalink / raw)
To: srinivas.kandagatla, linux-kernel
Cc: devicetree, tim.gover, catalin.marinas, linux, robh+dt,
bcm-kernel-feedback-list, linux-arm-kernel, will, phil,
nsaenzjulienne, linux-rpi-kernel
It'll be used by the RPi4 family of boards to access its bootloader
configuration.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
arch/arm/configs/multi_v7_defconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index 6492a3601e7c..0914fa09af0c 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -1106,6 +1106,7 @@ CONFIG_ROCKCHIP_EFUSE=m
CONFIG_NVMEM_SUNXI_SID=y
CONFIG_NVMEM_VF610_OCOTP=y
CONFIG_MESON_MX_EFUSE=m
+CONFIG_NVMEM_RMEM=m
CONFIG_FSI=m
CONFIG_FSI_MASTER_GPIO=m
CONFIG_FSI_MASTER_HUB=m
--
2.29.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 18+ messages in thread
* Re: [PATCH v3 0/5] Expose RPi4's bootloader configuration
2021-01-12 14:23 ` Nicolas Saenz Julienne
@ 2021-01-18 16:50 ` Srinivas Kandagatla
-1 siblings, 0 replies; 18+ messages in thread
From: Srinivas Kandagatla @ 2021-01-18 16:50 UTC (permalink / raw)
To: Nicolas Saenz Julienne, linux-kernel
Cc: linux-arm-kernel, linux, catalin.marinas, will, devicetree,
linux-rpi-kernel, robh+dt, bcm-kernel-feedback-list, tim.gover,
phil
On 12/01/2021 14:23, Nicolas Saenz Julienne wrote:
> Soon to be released versions of RPi4's firmware will take of care
> passing their bootloader's configuration[1] to the OS by copying it into
> memory and creating a reserved memory node in the board's DT. By
> modeling this reserved memory node as an nvmem device using
> 'nvmem-rmem', which this series introduces, user-space applications will
> be able to query this information through nvmem's sysfs interface.
>
> An alternative approach, less nice IMO, would be to create a
> platform-specific 'soc' driver.
>
> Regards,
> Nicolas
>
> [1] https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2711_bootloader_config.md
>
> ---
>
> Changes since v2:
> - Fix DT bingins
>
> Changes since v1:
> - Avoid the reserved-memory indirection by integrating the nvmem driver
> into the reserved memory node.
>
> Nicolas Saenz Julienne (5):
> dt-bindings: nvmem: Add bindings for rmem driver
> nvmem: Add driver to expose reserved memory as nvmem
> ARM: dts: bcm2711: Add reserved memory template to hold firmware
> configuration
> arm64: defconfig: Enable nvmem's rmem driver
> ARM: multi_v7_defconfig: Enable nvmem's rmem driver
>
Thanks Applied (1/5) and (2/5), rest of patches should go via arm-soc tree!
--srini
> .../devicetree/bindings/nvmem/rmem.yaml | 49 ++++++++++
> arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 17 ++++
> arch/arm/configs/multi_v7_defconfig | 1 +
> arch/arm64/configs/defconfig | 1 +
> drivers/nvmem/Kconfig | 8 ++
> drivers/nvmem/Makefile | 2 +
> drivers/nvmem/rmem.c | 97 +++++++++++++++++++
> drivers/of/platform.c | 1 +
> 8 files changed, 176 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/nvmem/rmem.yaml
> create mode 100644 drivers/nvmem/rmem.c
>
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v3 0/5] Expose RPi4's bootloader configuration
@ 2021-01-18 16:50 ` Srinivas Kandagatla
0 siblings, 0 replies; 18+ messages in thread
From: Srinivas Kandagatla @ 2021-01-18 16:50 UTC (permalink / raw)
To: Nicolas Saenz Julienne, linux-kernel
Cc: devicetree, tim.gover, catalin.marinas, linux, robh+dt,
bcm-kernel-feedback-list, linux-rpi-kernel, will, phil,
linux-arm-kernel
On 12/01/2021 14:23, Nicolas Saenz Julienne wrote:
> Soon to be released versions of RPi4's firmware will take of care
> passing their bootloader's configuration[1] to the OS by copying it into
> memory and creating a reserved memory node in the board's DT. By
> modeling this reserved memory node as an nvmem device using
> 'nvmem-rmem', which this series introduces, user-space applications will
> be able to query this information through nvmem's sysfs interface.
>
> An alternative approach, less nice IMO, would be to create a
> platform-specific 'soc' driver.
>
> Regards,
> Nicolas
>
> [1] https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2711_bootloader_config.md
>
> ---
>
> Changes since v2:
> - Fix DT bingins
>
> Changes since v1:
> - Avoid the reserved-memory indirection by integrating the nvmem driver
> into the reserved memory node.
>
> Nicolas Saenz Julienne (5):
> dt-bindings: nvmem: Add bindings for rmem driver
> nvmem: Add driver to expose reserved memory as nvmem
> ARM: dts: bcm2711: Add reserved memory template to hold firmware
> configuration
> arm64: defconfig: Enable nvmem's rmem driver
> ARM: multi_v7_defconfig: Enable nvmem's rmem driver
>
Thanks Applied (1/5) and (2/5), rest of patches should go via arm-soc tree!
--srini
> .../devicetree/bindings/nvmem/rmem.yaml | 49 ++++++++++
> arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 17 ++++
> arch/arm/configs/multi_v7_defconfig | 1 +
> arch/arm64/configs/defconfig | 1 +
> drivers/nvmem/Kconfig | 8 ++
> drivers/nvmem/Makefile | 2 +
> drivers/nvmem/rmem.c | 97 +++++++++++++++++++
> drivers/of/platform.c | 1 +
> 8 files changed, 176 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/nvmem/rmem.yaml
> create mode 100644 drivers/nvmem/rmem.c
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v3 0/5] Expose RPi4's bootloader configuration
2021-01-12 14:23 ` Nicolas Saenz Julienne
@ 2021-01-25 21:04 ` Nicolas Saenz Julienne
-1 siblings, 0 replies; 18+ messages in thread
From: Nicolas Saenz Julienne @ 2021-01-25 21:04 UTC (permalink / raw)
To: srinivas.kandagatla, linux-kernel
Cc: devicetree, tim.gover, catalin.marinas, linux, robh+dt,
bcm-kernel-feedback-list, linux-arm-kernel, will, phil,
linux-rpi-kernel
[-- Attachment #1: Type: text/plain, Size: 786 bytes --]
On Tue, 2021-01-12 at 15:23 +0100, Nicolas Saenz Julienne wrote:
> Soon to be released versions of RPi4's firmware will take of care
> passing their bootloader's configuration[1] to the OS by copying it into
> memory and creating a reserved memory node in the board's DT. By
> modeling this reserved memory node as an nvmem device using
> 'nvmem-rmem', which this series introduces, user-space applications will
> be able to query this information through nvmem's sysfs interface.
>
> An alternative approach, less nice IMO, would be to create a
> platform-specific 'soc' driver.
>
> Regards,
> Nicolas
>
> [1] https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2711_bootloader_config.md
>
Applied patches #3 to #5 for next.
Regards,
Nicolas
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^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v3 0/5] Expose RPi4's bootloader configuration
@ 2021-01-25 21:04 ` Nicolas Saenz Julienne
0 siblings, 0 replies; 18+ messages in thread
From: Nicolas Saenz Julienne @ 2021-01-25 21:04 UTC (permalink / raw)
To: srinivas.kandagatla, linux-kernel
Cc: devicetree, tim.gover, catalin.marinas, linux, robh+dt,
bcm-kernel-feedback-list, linux-rpi-kernel, will, phil,
linux-arm-kernel
[-- Attachment #1.1: Type: text/plain, Size: 786 bytes --]
On Tue, 2021-01-12 at 15:23 +0100, Nicolas Saenz Julienne wrote:
> Soon to be released versions of RPi4's firmware will take of care
> passing their bootloader's configuration[1] to the OS by copying it into
> memory and creating a reserved memory node in the board's DT. By
> modeling this reserved memory node as an nvmem device using
> 'nvmem-rmem', which this series introduces, user-space applications will
> be able to query this information through nvmem's sysfs interface.
>
> An alternative approach, less nice IMO, would be to create a
> platform-specific 'soc' driver.
>
> Regards,
> Nicolas
>
> [1] https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2711_bootloader_config.md
>
Applied patches #3 to #5 for next.
Regards,
Nicolas
[-- Attachment #1.2: This is a digitally signed message part --]
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[-- Attachment #2: Type: text/plain, Size: 176 bytes --]
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 18+ messages in thread