[PATCH net-next v2 0/5] net: ipa: change GSI firmware load specification

[PATCH net-next v2 0/5] net: ipa: change GSI firmware load specification

[Alex Elder]

Version 2 of this series modifies the first patch only.  One section
in the description is reworded, and the example now consistenly
describes the SC7180 SoC, both as suggested by Krzysztof.

Currently, GSI firmware must be loaded for IPA before it can be
used--either by the modem, or by the AP.  New hardware supports a
third option, with the bootloader taking responsibility for loading
GSI firmware.  In that case, neither the AP nor the modem needs to
do that.

The first patch in this series deprecates the "modem-init" Device
Tree property in the IPA binding, using a new "qcom,gsi-loader"
property instead.  The second and third implement logic in the code
to support either the "old" or the "new" way of specifying how GSI
firmware is loaded.

The last two patches implement a new value for the "qcom,gsi-loader"
property.  If the value is "skip", neither the AP nor modem needs to
load the GSI firmware.  The first of these patches implements the
change in the IPA binding; the second implements it in the code.

					-Alex

Alex Elder (5):
  dt-bindings: net: qcom,ipa: deprecate modem-init
  net: ipa: encapsulate decision about firmware load
  net: ipa: introduce "qcom,gsi-loader" property
  dt-bindings: net: qcom,ipa: support skipping GSI firmware load
  net: ipa: permit GSI firmware loading to be skipped

 .../devicetree/bindings/net/qcom,ipa.yaml     | 78 +++++++++++----
 drivers/net/ipa/ipa_main.c                    | 95 +++++++++++++++----
 2 files changed, 135 insertions(+), 38 deletions(-)

-- 
2.34.1

[PATCH net-next v2 1/5] dt-bindings: net: qcom,ipa: deprecate modem-init

[Alex Elder]

GSI firmware for IPA must be loaded during initialization, either by
the AP or by the modem.  The loader is currently specified based on
whether the Boolean modem-init property is present.

Instead, use a new property with an enumerated value to indicate
explicitly how GSI firmware gets loaded.  With this in place, a
third approach can be added in an upcoming patch.

The new qcom,gsi-loader property has two defined values:
  - self:   The AP loads GSI firmware
  - modem:  The modem loads GSI firmware
The modem-init property must still be supported, but is now marked
deprecated.

Update the example so it represents the SC7180 SoC, and provide
examples for the qcom,gsi-loader, memory-region, and firmware-name
properties.

Signed-off-by: Alex Elder <elder@linaro.org>
---
v2:  Updated description, switched example completely to SC7180.

 .../devicetree/bindings/net/qcom,ipa.yaml     | 76 ++++++++++++++-----
 1 file changed, 55 insertions(+), 21 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/qcom,ipa.yaml b/Documentation/devicetree/bindings/net/qcom,ipa.yaml
index e752b76192df0..d0f34763b9383 100644
--- a/Documentation/devicetree/bindings/net/qcom,ipa.yaml
+++ b/Documentation/devicetree/bindings/net/qcom,ipa.yaml
@@ -124,19 +124,29 @@ properties:
       - const: ipa-clock-enabled-valid
       - const: ipa-clock-enabled
 
+  qcom,gsi-loader:
+    enum:
+      - self
+      - modem
+    description:
+      Indicates how GSI firmware should be loaded.  If the AP loads
+      and validates GSI firmware, this property has value "self".
+      If the modem does this, this property has value "modem".
+
   modem-init:
+    deprecated: true
     type: boolean
     description:
-      If present, it indicates that the modem is responsible for
-      performing early IPA initialization, including loading and
-      validating firwmare used by the GSI.
+      This is the older (deprecated) way of indicating how GSI firmware
+      should be loaded.  If present, the modem loads GSI firmware; if
+      absent, the AP loads GSI firmware.
 
   memory-region:
     maxItems: 1
     description:
       If present, a phandle for a reserved memory area that holds
       the firmware passed to Trust Zone for authentication.  Required
-      when Trust Zone (not the modem) performs early initialization.
+      when the AP (not the modem) performs early initialization.
 
   firmware-name:
     $ref: /schemas/types.yaml#/definitions/string
@@ -155,15 +165,36 @@ required:
   - interconnects
   - qcom,smem-states
 
-# If modem-init is not present, the AP loads GSI firmware, and
-# memory-region must be specified
-if:
-  not:
-    required:
-      - modem-init
-then:
-  required:
-    - memory-region
+allOf:
+  # If qcom,gsi-loader is present, modem-init must not be present
+  - if:
+      required:
+        - qcom,gsi-loader
+    then:
+      properties:
+        modem-init: false
+
+      # If qcom,gsi-loader is "self", the AP loads GSI firmware, and
+      # memory-region must be specified
+      if:
+        properties:
+          qcom,gsi-loader:
+            contains:
+              const: self
+      then:
+        required:
+          - memory-region
+    else:
+      # If qcom,gsi-loader is not present, we use deprecated behavior.
+      # If modem-init is not present, the AP loads GSI firmware, and
+      # memory-region must be specified.
+      if:
+        not:
+          required:
+            - modem-init
+      then:
+        required:
+          - memory-region
 
 additionalProperties: false
 
@@ -194,14 +225,17 @@ examples:
         };
 
         ipa@1e40000 {
-                compatible = "qcom,sdm845-ipa";
+                compatible = "qcom,sc7180-ipa";
 
-                modem-init;
+                qcom,gsi-loader = "self";
+                memory-region = <&ipa_fw_mem>;
+                firmware-name = "qcom/sc7180-trogdor/modem/modem.mdt";
 
-                iommus = <&apps_smmu 0x720 0x3>;
+                iommus = <&apps_smmu 0x440 0x0>,
+                         <&apps_smmu 0x442 0x0>;
                 reg = <0x1e40000 0x7000>,
-                        <0x1e47000 0x2000>,
-                        <0x1e04000 0x2c000>;
+                      <0x1e47000 0x2000>,
+                      <0x1e04000 0x2c000>;
                 reg-names = "ipa-reg",
                             "ipa-shared",
                             "gsi";
@@ -219,9 +253,9 @@ examples:
                 clock-names = "core";
 
                 interconnects =
-                        <&rsc_hlos MASTER_IPA &rsc_hlos SLAVE_EBI1>,
-                        <&rsc_hlos MASTER_IPA &rsc_hlos SLAVE_IMEM>,
-                        <&rsc_hlos MASTER_APPSS_PROC &rsc_hlos SLAVE_IPA_CFG>;
+                        <&aggre2_noc MASTER_IPA 0 &mc_virt SLAVE_EBI1 0>,
+                        <&aggre2_noc MASTER_IPA 0 &system_noc SLAVE_IMEM 0>,
+                        <&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_IPA_CFG 0>;
                 interconnect-names = "memory",
                                      "imem",
                                      "config";
-- 
2.34.1

[PATCH net-next v2 2/5] net: ipa: encapsulate decision about firmware load

[Alex Elder]

The GSI layer used for IPA requires firmware to be loaded.

Currently either the AP or the modem loads the firmware,
distinguished by whether the "modem-init" Device Tree
property is defined.

Some newer systems implement a third option.  In preparation for
that, encapsulate the code that determines how the GSI firmware
gets loaded in a new function, ipa_firmware_loader().

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_main.c | 39 ++++++++++++++++++++++++++++++--------
 1 file changed, 31 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c
index ebb6c9b311eb9..9e43b79d233e9 100644
--- a/drivers/net/ipa/ipa_main.c
+++ b/drivers/net/ipa/ipa_main.c
@@ -81,6 +81,19 @@
 /* Divider for 19.2 MHz crystal oscillator clock to get common timer clock */
 #define IPA_XO_CLOCK_DIVIDER	192	/* 1 is subtracted where used */
 
+/**
+ * enum ipa_firmware_loader: How GSI firmware gets loaded
+ *
+ * @IPA_LOADER_DEFER:		System not ready; try again later
+ * @IPA_LOADER_SELF:		AP loads GSI firmware
+ * @IPA_LOADER_MODEM:		Modem loads GSI firmware, signals when done
+ */
+enum ipa_firmware_loader {
+	IPA_LOADER_DEFER,
+	IPA_LOADER_SELF,
+	IPA_LOADER_MODEM,
+};
+
 /**
  * ipa_setup() - Set up IPA hardware
  * @ipa:	IPA pointer
@@ -696,6 +709,18 @@ static void ipa_validate_build(void)
 	BUILD_BUG_ON(!ipa_aggr_granularity_val(IPA_AGGR_GRANULARITY));
 }
 
+static enum ipa_firmware_loader ipa_firmware_loader(struct device *dev)
+{
+	if (of_property_read_bool(dev->of_node, "modem-init"))
+		return IPA_LOADER_MODEM;
+
+	/* We need Trust Zone to load firmware; make sure it's available */
+	if (qcom_scm_is_available())
+		return IPA_LOADER_SELF;
+
+	return IPA_LOADER_DEFER;
+}
+
 /**
  * ipa_probe() - IPA platform driver probe function
  * @pdev:	Platform device pointer
@@ -722,9 +747,9 @@ static void ipa_validate_build(void)
 static int ipa_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	enum ipa_firmware_loader loader;
 	const struct ipa_data *data;
 	struct ipa_power *power;
-	bool modem_init;
 	struct ipa *ipa;
 	int ret;
 
@@ -747,11 +772,9 @@ static int ipa_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	/* If we need Trust Zone, make sure it's available */
-	modem_init = of_property_read_bool(dev->of_node, "modem-init");
-	if (!modem_init)
-		if (!qcom_scm_is_available())
-			return -EPROBE_DEFER;
+	loader = ipa_firmware_loader(dev);
+	if (loader == IPA_LOADER_DEFER)
+		return -EPROBE_DEFER;
 
 	/* The clock and interconnects might not be ready when we're
 	 * probed, so might return -EPROBE_DEFER.
@@ -796,7 +819,7 @@ static int ipa_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_endpoint_exit;
 
-	ret = ipa_smp2p_init(ipa, modem_init);
+	ret = ipa_smp2p_init(ipa, loader == IPA_LOADER_MODEM);
 	if (ret)
 		goto err_table_exit;
 
@@ -815,7 +838,7 @@ static int ipa_probe(struct platform_device *pdev)
 	 * call to ipa_setup() when it has finished.  In that case we're
 	 * done here.
 	 */
-	if (modem_init)
+	if (loader == IPA_LOADER_MODEM)
 		goto done;
 
 	/* Otherwise we need to load the firmware and have Trust Zone validate
-- 
2.34.1

[PATCH net-next v2 3/5] net: ipa: introduce "qcom,gsi-loader" property

[Alex Elder]

Introduce a new way of specifying how the GSI firmware gets loaded
for IPA.  Currently, this is indicated by the presence or absence of
the Boolean "modem-init" Device Tree property.  The new property
must have a value--either "self" or "modem"--which indicates whether
the AP or modem is the GSI firmware loader, respectively.

For legacy systems, the new property will not exist, and the
"modem-init" property will be used.  For newer systems, the
"qcom,gsi-loader" property *must* exist, and must have one of the
two prescribed values.  It is an error to have both properties
defined, and it is an error for the new property to have an
unrecognized value.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_main.c | 44 ++++++++++++++++++++++++++++++++------
 1 file changed, 37 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c
index 9e43b79d233e9..214e524dce795 100644
--- a/drivers/net/ipa/ipa_main.c
+++ b/drivers/net/ipa/ipa_main.c
@@ -87,11 +87,13 @@
  * @IPA_LOADER_DEFER:		System not ready; try again later
  * @IPA_LOADER_SELF:		AP loads GSI firmware
  * @IPA_LOADER_MODEM:		Modem loads GSI firmware, signals when done
+ * @IPA_LOADER_INVALID:	GSI firmware loader specification is invalid
  */
 enum ipa_firmware_loader {
 	IPA_LOADER_DEFER,
 	IPA_LOADER_SELF,
 	IPA_LOADER_MODEM,
+	IPA_LOADER_INVALID,
 };
 
 /**
@@ -711,9 +713,37 @@ static void ipa_validate_build(void)
 
 static enum ipa_firmware_loader ipa_firmware_loader(struct device *dev)
 {
-	if (of_property_read_bool(dev->of_node, "modem-init"))
+	bool modem_init;
+	const char *str;
+	int ret;
+
+	/* Look up the old and new properties by name */
+	modem_init = of_property_read_bool(dev->of_node, "modem-init");
+	ret = of_property_read_string(dev->of_node, "qcom,gsi-loader", &str);
+
+	/* If the new property doesn't exist, it's legacy behavior */
+	if (ret == -EINVAL) {
+		if (modem_init)
+			return IPA_LOADER_MODEM;
+		goto out_self;
+	}
+
+	/* Any other error on the new property means it's poorly defined */
+	if (ret)
+		return IPA_LOADER_INVALID;
+
+	/* New property value exists; if old one does too, that's invalid */
+	if (modem_init)
+		return IPA_LOADER_INVALID;
+
+	/* Modem loads GSI firmware for "modem" */
+	if (!strcmp(str, "modem"))
 		return IPA_LOADER_MODEM;
 
+	/* Any value other than "self" is an error */
+	if (strcmp(str, "self"))
+		return IPA_LOADER_INVALID;
+out_self:
 	/* We need Trust Zone to load firmware; make sure it's available */
 	if (qcom_scm_is_available())
 		return IPA_LOADER_SELF;
@@ -773,6 +803,8 @@ static int ipa_probe(struct platform_device *pdev)
 	}
 
 	loader = ipa_firmware_loader(dev);
+	if (loader == IPA_LOADER_INVALID)
+		return -EINVAL;
 	if (loader == IPA_LOADER_DEFER)
 		return -EPROBE_DEFER;
 
@@ -834,20 +866,18 @@ static int ipa_probe(struct platform_device *pdev)
 
 	dev_info(dev, "IPA driver initialized");
 
-	/* If the modem is doing early initialization, it will trigger a
-	 * call to ipa_setup() when it has finished.  In that case we're
-	 * done here.
+	/* If the modem is loading GSI firmware, it will trigger a call to
+	 * ipa_setup() when it has finished.  In that case we're done here.
 	 */
 	if (loader == IPA_LOADER_MODEM)
 		goto done;
 
-	/* Otherwise we need to load the firmware and have Trust Zone validate
-	 * and install it.  If that succeeds we can proceed with setup.
-	 */
+	/* The AP is loading GSI firmware; do so now */
 	ret = ipa_firmware_load(dev);
 	if (ret)
 		goto err_deconfig;
 
+	/* GSI firmware is loaded; proceed to setup */
 	ret = ipa_setup(ipa);
 	if (ret)
 		goto err_deconfig;
-- 
2.34.1

[PATCH net-next v2 4/5] dt-bindings: net: qcom,ipa: support skipping GSI firmware load

[Alex Elder]

Add a new enumerated value to those defined for the qcom,gsi-loader
property.  If the qcom,gsi-loader is "skip", the GSI firmware will
already be loaded, so neither the AP nor modem is required to load
GSI firmware.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 Documentation/devicetree/bindings/net/qcom,ipa.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/qcom,ipa.yaml b/Documentation/devicetree/bindings/net/qcom,ipa.yaml
index d0f34763b9383..9e81b9ec7cfdd 100644
--- a/Documentation/devicetree/bindings/net/qcom,ipa.yaml
+++ b/Documentation/devicetree/bindings/net/qcom,ipa.yaml
@@ -128,10 +128,12 @@ properties:
     enum:
       - self
       - modem
+      - skip
     description:
       Indicates how GSI firmware should be loaded.  If the AP loads
       and validates GSI firmware, this property has value "self".
       If the modem does this, this property has value "modem".
+      Otherwise, "skip" means GSI firmware loading is not required.
 
   modem-init:
     deprecated: true
-- 
2.34.1

[PATCH net-next v2 5/5] net: ipa: permit GSI firmware loading to be skipped

[Alex Elder]

Define a new value "skip" for the "qcom,gsi-loader" Device Tree
property.  If used, it indicates that neither the AP nor the modem
need to load GSI firmware (because it has already been loaded--for
example by the boot loader).

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_main.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c
index 214e524dce795..8f20825675a1a 100644
--- a/drivers/net/ipa/ipa_main.c
+++ b/drivers/net/ipa/ipa_main.c
@@ -87,12 +87,14 @@
  * @IPA_LOADER_DEFER:		System not ready; try again later
  * @IPA_LOADER_SELF:		AP loads GSI firmware
  * @IPA_LOADER_MODEM:		Modem loads GSI firmware, signals when done
+ * @IPA_LOADER_SKIP:		Neither AP nor modem need to load GSI firmware
  * @IPA_LOADER_INVALID:	GSI firmware loader specification is invalid
  */
 enum ipa_firmware_loader {
 	IPA_LOADER_DEFER,
 	IPA_LOADER_SELF,
 	IPA_LOADER_MODEM,
+	IPA_LOADER_SKIP,
 	IPA_LOADER_INVALID,
 };
 
@@ -740,6 +742,10 @@ static enum ipa_firmware_loader ipa_firmware_loader(struct device *dev)
 	if (!strcmp(str, "modem"))
 		return IPA_LOADER_MODEM;
 
+	/* No GSI firmware load is needed for "skip" */
+	if (!strcmp(str, "skip"))
+		return IPA_LOADER_SKIP;
+
 	/* Any value other than "self" is an error */
 	if (strcmp(str, "self"))
 		return IPA_LOADER_INVALID;
@@ -872,10 +878,12 @@ static int ipa_probe(struct platform_device *pdev)
 	if (loader == IPA_LOADER_MODEM)
 		goto done;
 
-	/* The AP is loading GSI firmware; do so now */
-	ret = ipa_firmware_load(dev);
-	if (ret)
-		goto err_deconfig;
+	if (loader == IPA_LOADER_SELF) {
+		/* The AP is loading GSI firmware; do so now */
+		ret = ipa_firmware_load(dev);
+		if (ret)
+			goto err_deconfig;
+	} /* Otherwise loader == IPA_LOADER_SKIP */
 
 	/* GSI firmware is loaded; proceed to setup */
 	ret = ipa_setup(ipa);
-- 
2.34.1

Re: [PATCH net-next v2 4/5] dt-bindings: net: qcom,ipa: support skipping GSI firmware load

[Krzysztof Kozlowski]

On 15/11/2022 12:31, Alex Elder wrote:
> Add a new enumerated value to those defined for the qcom,gsi-loader
> property.  If the qcom,gsi-loader is "skip", the GSI firmware will
> already be loaded, so neither the AP nor modem is required to load
> GSI firmware.
> 
> Signed-off-by: Alex Elder <elder@linaro.org>
> ---

This is a friendly reminder during the review process.

It looks like you received a tag and forgot to add it.

If you do not know the process, here is a short explanation:
Please add Acked-by/Reviewed-by/Tested-by tags when posting new
versions. However, there's no need to repost patches *only* to add the
tags. The upstream maintainer will do that for acks received on the
version they apply.

https://elixir.bootlin.com/linux/v5.17/source/Documentation/process/submitting-patches.rst#L540

If a tag was not added on purpose, please state why and what changed.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

Re: [PATCH net-next v2 1/5] dt-bindings: net: qcom,ipa: deprecate modem-init

[Krzysztof Kozlowski]

On 15/11/2022 12:31, Alex Elder wrote:
> GSI firmware for IPA must be loaded during initialization, either by
> the AP or by the modem.  The loader is currently specified based on
> whether the Boolean modem-init property is present.
> 
> Instead, use a new property with an enumerated value to indicate
> explicitly how GSI firmware gets loaded.  With this in place, a
> third approach can be added in an upcoming patch.
> 
> The new qcom,gsi-loader property has two defined values:
>   - self:   The AP loads GSI firmware
>   - modem:  The modem loads GSI firmware
> The modem-init property must still be supported, but is now marked
> deprecated.
> 
> Update the example so it represents the SC7180 SoC, and provide
> examples for the qcom,gsi-loader, memory-region, and firmware-name
> properties.
> 
> Signed-off-by: Alex Elder <elder@linaro.org>
> ---


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>


Best regards,
Krzysztof

Re: [PATCH net-next v2 4/5] dt-bindings: net: qcom,ipa: support skipping GSI firmware load

[Alex Elder]

On 11/15/22 06:56, Krzysztof Kozlowski wrote:
> This is a friendly reminder during the review process.

Yes as soon as I saw your message I remembered that I'd forgotten
to add your reviewed-by tag.  I can send v3, but if the network
maintainers are willing they could generously add it for me.

					-Alex