ANDROID: scsi: ufs: Make CONFIG_SCSI_UFS_HPB compatible with the GKI

Move the ufshpb_dev member into a new structure such that enabling HPB
does not affect the layout of other members of struct ufs_hba. This change
does not affect the ABI since UFS HPB support is currently disabled.

The only function that allocates a struct ufs_hba instance is
ufshcd_alloc_host() and that function allocates struct ufs_hba dynamically.
Modify that function such that it also allocates memory for the HPB data if
necessary.

Bug: 194163838
Bug: 195507090
Test: Built the kernel with this patch applied and installed it on an Android device.
Change-Id: Ia4c5ba07ae343576373ec116553c5fdee8f75a94
Signed-off-by: Bart Van Assche <bvanassche@google.com>

drivers/scsi/ufs/ufshcd.c

@@ -9313,7 +9313,7 @@ int ufshcd_alloc_host(struct device *dev, struct ufs_hba **hba_handle)
 	}
 
 	host = scsi_host_alloc(&ufshcd_driver_template,
-				sizeof(struct ufs_hba));
+			       sizeof(struct ufs_hba_with_hpb));
 	if (!host) {
 		dev_err(dev, "scsi_host_alloc failed\n");
 		err = -ENOMEM;

drivers/scsi/ufs/ufshcd.h

@@ -912,7 +912,8 @@ struct ufs_hba {
 	bool wb_enabled;
 	struct delayed_work rpm_dev_flush_recheck_work;
 
-#ifdef CONFIG_SCSI_UFS_HPB
+#if 0
+	/* This has been moved into struct ufs_hba_with_hpb. */
 	struct ufshpb_dev_info ufshpb_dev;
 #endif
 
@@ -934,6 +935,17 @@ struct ufs_hba {
 	ANDROID_KABI_RESERVE(4);
 };
 
+/*
+ * Compared to the upstream equivalent, @hpb_dev has been moved from struct
+ * ufs_hba into struct ufs_hba_with_hpb to satisfy the Android ABI checks.
+ */
+struct ufs_hba_with_hpb {
+	struct ufs_hba hba;
+#ifdef CONFIG_SCSI_UFS_HPB
+	struct ufshpb_dev_info hpb_dev;
+#endif
+};
+
 /* Returns true if clocks can be gated. Otherwise false */
 static inline bool ufshcd_is_clkgating_allowed(struct ufs_hba *hba)
 {

drivers/scsi/ufs/ufshpb.c

@@ -35,15 +35,20 @@ static struct workqueue_struct *ufshpb_wq;
 static void ufshpb_update_active_info(struct ufshpb_lu *hpb, int rgn_idx,
 				      int srgn_idx);
 
+static inline struct ufshpb_dev_info *ufs_hba_to_hpb(struct ufs_hba *hba)
+{
+	return &container_of(hba, struct ufs_hba_with_hpb, hba)->hpb_dev;
+}
+
 bool ufshpb_is_allowed(struct ufs_hba *hba)
 {
-	return !(hba->ufshpb_dev.hpb_disabled);
+	return !(ufs_hba_to_hpb(hba)->hpb_disabled);
 }
 
 /* HPB version 1.0 is called as legacy version. */
 bool ufshpb_is_legacy(struct ufs_hba *hba)
 {
-	return hba->ufshpb_dev.is_legacy;
+	return ufs_hba_to_hpb(hba)->is_legacy;
 }
 
 static struct ufshpb_lu *ufshpb_get_hpb_data(struct scsi_device *sdev)
@@ -2743,8 +2748,7 @@ void ufshpb_init_hpb_lu(struct ufs_hba *hba, struct scsi_device *sdev)
 	if (ret)
 		goto out;
 
-	hpb = ufshpb_alloc_hpb_lu(hba, sdev, &hba->ufshpb_dev,
+	hpb = ufshpb_alloc_hpb_lu(hba, sdev, ufs_hba_to_hpb(hba), &hpb_lu_info);
-				  &hpb_lu_info);
 	if (!hpb)
 		goto out;
 
@@ -2753,7 +2757,7 @@ void ufshpb_init_hpb_lu(struct ufs_hba *hba, struct scsi_device *sdev)
 
 out:
 	/* All LUs are initialized */
-	if (atomic_dec_and_test(&hba->ufshpb_dev.slave_conf_cnt))
+	if (atomic_dec_and_test(&ufs_hba_to_hpb(hba)->slave_conf_cnt))
 		ufshpb_hpb_lu_prepared(hba);
 }
 
@@ -2810,7 +2814,7 @@ release_mctx_cache:
 
 void ufshpb_get_geo_info(struct ufs_hba *hba, u8 *geo_buf)
 {
-	struct ufshpb_dev_info *hpb_info = &hba->ufshpb_dev;
+	struct ufshpb_dev_info *hpb_info = ufs_hba_to_hpb(hba);
 	int max_active_rgns = 0;
 	int hpb_num_lu;
 
@@ -2836,7 +2840,7 @@ void ufshpb_get_geo_info(struct ufs_hba *hba, u8 *geo_buf)
 
 void ufshpb_get_dev_info(struct ufs_hba *hba, u8 *desc_buf)
 {
-	struct ufshpb_dev_info *hpb_dev_info = &hba->ufshpb_dev;
+	struct ufshpb_dev_info *hpb_dev_info = ufs_hba_to_hpb(hba);
 	int version, ret;
 	u32 max_hpb_single_cmd = HPB_MULTI_CHUNK_LOW;
 
@@ -2873,7 +2877,7 @@ void ufshpb_get_dev_info(struct ufs_hba *hba, u8 *desc_buf)
 
 void ufshpb_init(struct ufs_hba *hba)
 {
-	struct ufshpb_dev_info *hpb_dev_info = &hba->ufshpb_dev;
+	struct ufshpb_dev_info *hpb_dev_info = ufs_hba_to_hpb(hba);
 	int try;
 	int ret;