[PATCH v3] firmware: qcom: scm: Peripheral Authentication Service

[Bjorn Andersson]

This adds the Peripheral Authentication Service (PAS) interface to the
Qualcomm SCM interface. The API is used to authenticate and boot a range
of external processors in various Qualcomm platforms.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>
---
Depends on Andy's platformization of the scm code.

Changes since v2:
- Attached the dma allocation in init_image to the scm dev
- Requesting scm clocks
- Fixed some more big endian stuff
- Added stubs for ARM64

Changes since v1:
- Big endian compatibility

 drivers/firmware/qcom_scm-32.c |  82 +++++++++++++++++++++++++
 drivers/firmware/qcom_scm-64.c |  25 ++++++++
 drivers/firmware/qcom_scm.c    | 136 +++++++++++++++++++++++++++++++++++++++++
 drivers/firmware/qcom_scm.h    |  12 ++++
 include/linux/qcom_scm.h       |   6 ++
 5 files changed, 261 insertions(+)

diff --git a/drivers/firmware/qcom_scm-32.c b/drivers/firmware/qcom_scm-32.c
index 29e6850665eb..e9c306bcd371 100644
--- a/drivers/firmware/qcom_scm-32.c
+++ b/drivers/firmware/qcom_scm-32.c
@@ -499,3 +499,85 @@ int __qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp)
 	return qcom_scm_call(QCOM_SCM_SVC_HDCP, QCOM_SCM_CMD_HDCP,
 		req, req_cnt * sizeof(*req), resp, sizeof(*resp));
 }
+
+bool __qcom_scm_pas_supported(u32 peripheral)
+{
+	__le32 out;
+	__le32 in;
+	int ret;
+
+	in = cpu_to_le32(peripheral);
+	ret = qcom_scm_call(QCOM_SCM_SVC_PIL, QCOM_SCM_PAS_IS_SUPPORTED_CMD,
+			    &in, sizeof(in),
+			    &out, sizeof(out));
+
+	return ret ? false : !!out;
+}
+
+int __qcom_scm_pas_init_image(u32 peripheral, dma_addr_t metadata_phys)
+{
+	__le32 scm_ret;
+	int ret;
+	struct {
+		__le32 proc;
+		__le32 image_addr;
+	} request;
+
+	request.proc = cpu_to_le32(peripheral);
+	request.image_addr = cpu_to_le32(metadata_phys);
+
+	ret = qcom_scm_call(QCOM_SCM_SVC_PIL, QCOM_SCM_PAS_INIT_IMAGE_CMD,
+			    &request, sizeof(request),
+			    &scm_ret, sizeof(scm_ret));
+
+	return ret ? : le32_to_cpu(scm_ret);
+}
+
+int __qcom_scm_pas_mem_setup(u32 peripheral, phys_addr_t addr, phys_addr_t size)
+{
+	__le32 scm_ret;
+	int ret;
+	struct {
+		__le32 proc;
+		__le32 addr;
+		__le32 len;
+	} request;
+
+	request.proc = cpu_to_le32(peripheral);
+	request.addr = cpu_to_le32(addr);
+	request.len = cpu_to_le32(size);
+
+	ret = qcom_scm_call(QCOM_SCM_SVC_PIL, QCOM_SCM_PAS_MEM_SETUP_CMD,
+			    &request, sizeof(request),
+			    &scm_ret, sizeof(scm_ret));
+
+	return ret ? : le32_to_cpu(scm_ret);
+}
+
+int __qcom_scm_pas_auth_and_reset(u32 peripheral)
+{
+	__le32 out;
+	__le32 in;
+	int ret;
+
+	in = cpu_to_le32(peripheral);
+	ret = qcom_scm_call(QCOM_SCM_SVC_PIL, QCOM_SCM_PAS_AUTH_AND_RESET_CMD,
+			    &in, sizeof(in),
+			    &out, sizeof(out));
+
+	return ret ? : le32_to_cpu(out);
+}
+
+int __qcom_scm_pas_shutdown(u32 peripheral)
+{
+	__le32 out;
+	__le32 in;
+	int ret;
+
+	in = cpu_to_le32(peripheral);
+	ret = qcom_scm_call(QCOM_SCM_SVC_PIL, QCOM_SCM_PAS_SHUTDOWN_CMD,
+			    &in, sizeof(in),
+			    &out, sizeof(out));
+
+	return ret ? : le32_to_cpu(out);
+}
diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c
index bb6555f6d63b..e64fd927e5ae 100644
--- a/drivers/firmware/qcom_scm-64.c
+++ b/drivers/firmware/qcom_scm-64.c
@@ -61,3 +61,28 @@ int __qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp)
 {
 	return -ENOTSUPP;
 }
+
+bool __qcom_scm_pas_supported(u32 peripheral)
+{
+	return false;
+}
+
+int __qcom_scm_pas_init_image(u32 peripheral, dma_addr_t metadata_phys)
+{
+	return -ENOTSUPP;
+}
+
+int __qcom_scm_pas_mem_setup(u32 peripheral, phys_addr_t addr, phys_addr_t size)
+{
+	return -ENOTSUPP;
+}
+
+int __qcom_scm_pas_auth_and_reset(u32 peripheral)
+{
+	return -ENOTSUPP;
+}
+
+int __qcom_scm_pas_shutdown(u32 peripheral)
+{
+	return -ENOTSUPP;
+}
diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index 5dd05142069d..118df0ae242b 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -20,6 +20,7 @@
 #include <linux/platform_device.h>
 #include <linux/cpumask.h>
 #include <linux/export.h>
+#include <linux/dma-mapping.h>
 #include <linux/types.h>
 #include <linux/qcom_scm.h>
 #include <linux/of.h>
@@ -28,6 +29,7 @@
 #include "qcom_scm.h"
 
 struct qcom_scm {
+	struct device *dev;
 	struct clk *core_clk;
 	struct clk *iface_clk;
 	struct clk *bus_clk;
@@ -152,6 +154,138 @@ int qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp)
 EXPORT_SYMBOL(qcom_scm_hdcp_req);
 
 /**
+ * qcom_scm_pas_supported() - Check if the peripheral authentication service is
+ *			      available for the given peripherial
+ * @peripheral:	peripheral id
+ *
+ * Returns true if PAS is supported for this peripheral, otherwise false.
+ */
+bool qcom_scm_pas_supported(u32 peripheral)
+{
+	int ret;
+
+	ret = __qcom_scm_is_call_available(QCOM_SCM_SVC_PIL,
+					   QCOM_SCM_PAS_IS_SUPPORTED_CMD);
+	if (ret <= 0)
+		return false;
+
+	return __qcom_scm_pas_supported(peripheral);
+}
+EXPORT_SYMBOL(qcom_scm_pas_supported);
+
+/**
+ * qcom_scm_pas_init_image() - Initialize peripheral authentication service
+ *			       state machine for a given peripheral, using the
+ *			       metadata
+ * @peripheral: peripheral id
+ * @metadata:	pointer to memory containing ELF header, program header table
+ *		and optional blob of data used for authenticating the metadata
+ *		and the rest of the firmware
+ * @size:	size of the metadata
+ *
+ * Returns 0 on success.
+ */
+int qcom_scm_pas_init_image(u32 peripheral, const void *metadata, size_t size)
+{
+	dma_addr_t mdata_phys;
+	void *mdata_buf;
+	int ret;
+
+	/*
+	 * During the scm call memory protection will be enabled for the meta
+	 * data blob, so make sure it's physically contiguous, 4K aligned and
+	 * non-cachable to avoid XPU violations.
+	 */
+	mdata_buf = dma_alloc_coherent(__scm->dev, size, &mdata_phys, GFP_KERNEL);
+	if (!mdata_buf) {
+		dev_err(__scm->dev, "Allocation of metadata buffer failed.\n");
+		return -ENOMEM;
+	}
+	memcpy(mdata_buf, metadata, size);
+
+	ret = qcom_scm_clk_enable();
+	if (ret)
+		goto free_metadata;
+
+	ret = __qcom_scm_pas_init_image(peripheral, mdata_phys);
+
+	qcom_scm_clk_disable();
+
+free_metadata:
+	dma_free_coherent(__scm->dev, size, mdata_buf, mdata_phys);
+
+	return ret;
+}
+EXPORT_SYMBOL(qcom_scm_pas_init_image);
+
+/**
+ * qcom_scm_pas_mem_setup() - Prepare the memory related to a given peripheral
+ *			      for firmware loading
+ * @peripheral:	peripheral id
+ * @addr:	start address of memory area to prepare
+ * @size:	size of the memory area to prepare
+ *
+ * Returns 0 on success.
+ */
+int qcom_scm_pas_mem_setup(u32 peripheral, phys_addr_t addr, phys_addr_t size)
+{
+	int ret;
+
+	ret = qcom_scm_clk_enable();
+	if (ret)
+		return ret;
+
+	ret = __qcom_scm_pas_mem_setup(peripheral, addr, size);
+	qcom_scm_clk_disable();
+
+	return ret;
+}
+EXPORT_SYMBOL(qcom_scm_pas_mem_setup);
+
+/**
+ * qcom_scm_pas_auth_and_reset() - Authenticate the given peripheral firmware
+ *				   and reset the remote processor
+ * @peripheral:	peripheral id
+ *
+ * Return 0 on success.
+ */
+int qcom_scm_pas_auth_and_reset(u32 peripheral)
+{
+	int ret;
+
+	ret = qcom_scm_clk_enable();
+	if (ret)
+		return ret;
+
+	ret = __qcom_scm_pas_auth_and_reset(peripheral);
+	qcom_scm_clk_disable();
+
+	return ret;
+}
+EXPORT_SYMBOL(qcom_scm_pas_auth_and_reset);
+
+/**
+ * qcom_scm_pas_shutdown() - Shut down the remote processor
+ * @peripheral: peripheral id
+ *
+ * Returns 0 on success.
+ */
+int qcom_scm_pas_shutdown(u32 peripheral)
+{
+	int ret;
+
+	ret = qcom_scm_clk_enable();
+	if (ret)
+		return ret;
+
+	ret = __qcom_scm_pas_shutdown(peripheral);
+	qcom_scm_clk_disable();
+
+	return ret;
+}
+EXPORT_SYMBOL(qcom_scm_pas_shutdown);
+
+/**
  * qcom_scm_is_available() - Checks if SCM is available
  */
 bool qcom_scm_is_available(void)
@@ -176,6 +310,8 @@ static int qcom_scm_probe(struct platform_device *pdev)
 	if (!scm)
 		return -ENOMEM;
 
+	scm->dev = &pdev->dev;
+
 	scm->core_clk = devm_clk_get(&pdev->dev, "core");
 	if (IS_ERR(scm->core_clk)) {
 		if (PTR_ERR(scm->core_clk) != -EPROBE_DEFER)
diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
index 2cce75c08b99..220d19c93cfc 100644
--- a/drivers/firmware/qcom_scm.h
+++ b/drivers/firmware/qcom_scm.h
@@ -36,6 +36,18 @@ extern int __qcom_scm_is_call_available(u32 svc_id, u32 cmd_id);
 extern int __qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt,
 		u32 *resp);
 
+#define QCOM_SCM_SVC_PIL		0x2
+#define QCOM_SCM_PAS_INIT_IMAGE_CMD	0x1
+#define QCOM_SCM_PAS_MEM_SETUP_CMD	0x2
+#define QCOM_SCM_PAS_AUTH_AND_RESET_CMD	0x5
+#define QCOM_SCM_PAS_SHUTDOWN_CMD	0x6
+#define QCOM_SCM_PAS_IS_SUPPORTED_CMD	0x7
+extern bool __qcom_scm_pas_supported(u32 peripheral);
+extern int  __qcom_scm_pas_init_image(u32 peripheral, dma_addr_t metadata_phys);
+extern int  __qcom_scm_pas_mem_setup(u32 peripheral, phys_addr_t addr, phys_addr_t size);
+extern int  __qcom_scm_pas_auth_and_reset(u32 peripheral);
+extern int  __qcom_scm_pas_shutdown(u32 peripheral);
+
 /* common error codes */
 #define QCOM_SCM_ENOMEM		-5
 #define QCOM_SCM_EOPNOTSUPP	-4
diff --git a/include/linux/qcom_scm.h b/include/linux/qcom_scm.h
index 6e7d5ec65838..46d41e44d432 100644
--- a/include/linux/qcom_scm.h
+++ b/include/linux/qcom_scm.h
@@ -27,6 +27,12 @@ extern bool qcom_scm_hdcp_available(void);
 extern int qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt,
 		u32 *resp);
 
+extern bool qcom_scm_pas_supported(u32 peripheral);
+extern int qcom_scm_pas_init_image(u32 peripheral, const void *metadata, size_t size);
+extern int qcom_scm_pas_mem_setup(u32 peripheral, phys_addr_t addr, phys_addr_t size);
+extern int qcom_scm_pas_auth_and_reset(u32 peripheral);
+extern int qcom_scm_pas_shutdown(u32 peripheral);
+
 #define QCOM_SCM_CPU_PWR_DOWN_L2_ON	0x0
 #define QCOM_SCM_CPU_PWR_DOWN_L2_OFF	0x1
 
-- 
1.8.2.2

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