[RFC PATCH v4 05/11] coco: guest: arm64: Refresh interface-report cache during device lock

["Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>]

Add support for RHI_DA_VDEV_GET_INTERFACE_REPORT and use it to refresh the
host-side cached interface report when a device is locked.

Implement rhi_update_vdev_interface_report_cache() with busy retry and
cookie-based CONTINUE handling for incomplete operations. Surface the flow
through cca_update_device_object_cache(), and call it from the lock path so
the interface report is fetched before lock succeeds.

On refresh failure, unwind by unlocking the device and returning the error.

Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
---
 arch/arm64/include/asm/rhi.h              |  2 ++
 drivers/virt/coco/arm-cca-guest/arm-cca.c |  6 ++++
 drivers/virt/coco/arm-cca-guest/rhi-da.c  | 44 +++++++++++++++++++++++
 drivers/virt/coco/arm-cca-guest/rhi-da.h  |  1 +
 drivers/virt/coco/arm-cca-guest/rsi-da.c  | 13 +++++++
 drivers/virt/coco/arm-cca-guest/rsi-da.h  |  1 +
 6 files changed, 67 insertions(+)

diff --git a/arch/arm64/include/asm/rhi.h b/arch/arm64/include/asm/rhi.h
index 88de2d9b34d1..15946fe64484 100644
--- a/arch/arm64/include/asm/rhi.h
+++ b/arch/arm64/include/asm/rhi.h
@@ -50,6 +50,8 @@ unsigned long rhi_get_ipa_change_alignment(void);
 
 #define RHI_DA_VDEV_CONTINUE		SMC_RHI_CALL(0x0051)
 
+#define RHI_DA_VDEV_GET_INTERFACE_REPORT SMC_RHI_CALL(0x0053)
+
 enum rhi_tdi_state {
 	RHI_DA_TDI_CONFIG_UNLOCKED,
 	RHI_DA_TDI_CONFIG_LOCKED,
diff --git a/drivers/virt/coco/arm-cca-guest/arm-cca.c b/drivers/virt/coco/arm-cca-guest/arm-cca.c
index d4880ca59fc5..411cbbaa5d26 100644
--- a/drivers/virt/coco/arm-cca-guest/arm-cca.c
+++ b/drivers/virt/coco/arm-cca-guest/arm-cca.c
@@ -215,6 +215,12 @@ static struct pci_tsm *cca_tsm_lock(struct tsm_dev *tsm_dev, struct pci_dev *pde
 	if (ret)
 		return ERR_PTR(ret);
 
+	ret = cca_update_device_object_cache(pdev, NULL);
+	if (ret) {
+		cca_device_unlock(pdev);
+		return ERR_PTR(ret);
+	}
+
 	return &no_free_ptr(cca_dsc)->pci.base_tsm;
 }
 
diff --git a/drivers/virt/coco/arm-cca-guest/rhi-da.c b/drivers/virt/coco/arm-cca-guest/rhi-da.c
index 5b48c8d6ebe3..5078136a4cc6 100644
--- a/drivers/virt/coco/arm-cca-guest/rhi-da.c
+++ b/drivers/virt/coco/arm-cca-guest/rhi-da.c
@@ -161,3 +161,47 @@ int rhi_vdev_set_tdi_state(struct pci_dev *pdev, enum rhi_tdi_state target_state
 
 	return ret;
 }
+
+static inline int rhi_vdev_get_interface_report(unsigned long vdev_id,
+		unsigned long *cookie)
+{
+	unsigned long ret;
+
+	struct rsi_host_call *rhi_call __free(kfree) =
+		kmalloc(sizeof(struct rsi_host_call), GFP_KERNEL);
+	if (!rhi_call)
+		return -ENOMEM;
+
+	rhi_call->imm = 0;
+	rhi_call->gprs[0] = RHI_DA_VDEV_GET_INTERFACE_REPORT;
+	rhi_call->gprs[1] = vdev_id;
+
+	ret = rsi_host_call(rhi_call);
+	if (ret != RSI_SUCCESS)
+		return -EIO;
+
+	*cookie = rhi_call->gprs[1];
+	return map_rhi_da_error(rhi_call->gprs[0]);
+}
+
+int rhi_update_vdev_interface_report_cache(struct pci_dev *pdev)
+{
+	int ret;
+	unsigned long cookie;
+	int vdev_id = rsi_vdev_id(pdev);
+
+	for (;;) {
+		ret = rhi_vdev_get_interface_report(vdev_id, &cookie);
+		if (ret != -EBUSY)
+			break;
+		cond_resched();
+	}
+
+	while (ret == RHI_DA_INCOMPLETE) {
+		if (should_abort_rhi_call_loop(vdev_id))
+			return -EINTR;
+		ret = rhi_vdev_continue(vdev_id, cookie);
+	}
+
+	return ret;
+}
diff --git a/drivers/virt/coco/arm-cca-guest/rhi-da.h b/drivers/virt/coco/arm-cca-guest/rhi-da.h
index 43c1cda8738d..8b7faf4d1c8a 100644
--- a/drivers/virt/coco/arm-cca-guest/rhi-da.h
+++ b/drivers/virt/coco/arm-cca-guest/rhi-da.h
@@ -11,4 +11,5 @@
 struct pci_dev;
 bool rhi_has_da_support(void);
 int rhi_vdev_set_tdi_state(struct pci_dev *pdev, enum rhi_tdi_state target_state);
+int rhi_update_vdev_interface_report_cache(struct pci_dev *pdev);
 #endif
diff --git a/drivers/virt/coco/arm-cca-guest/rsi-da.c b/drivers/virt/coco/arm-cca-guest/rsi-da.c
index 2c3017933fb0..6c78f0e2f3a1 100644
--- a/drivers/virt/coco/arm-cca-guest/rsi-da.c
+++ b/drivers/virt/coco/arm-cca-guest/rsi-da.c
@@ -32,3 +32,16 @@ int cca_device_unlock(struct pci_dev *pdev)
 	}
 	return 0;
 }
+
+int cca_update_device_object_cache(struct pci_dev *pdev, const u8 *nonce)
+{
+	int ret;
+
+	ret = rhi_update_vdev_interface_report_cache(pdev);
+	if (ret) {
+		pci_err(pdev, "failed to get interface report (%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
diff --git a/drivers/virt/coco/arm-cca-guest/rsi-da.h b/drivers/virt/coco/arm-cca-guest/rsi-da.h
index 06fcea95d888..dda8026a1c3f 100644
--- a/drivers/virt/coco/arm-cca-guest/rsi-da.h
+++ b/drivers/virt/coco/arm-cca-guest/rsi-da.h
@@ -34,5 +34,6 @@ static inline int rsi_vdev_id(struct pci_dev *pdev)
 
 int cca_device_lock(struct pci_dev *pdev);
 int cca_device_unlock(struct pci_dev *pdev);
+int cca_update_device_object_cache(struct pci_dev *pdev, const u8 *nonce);
 
 #endif
-- 
2.43.0