[2/6] bus: mhi: add support to allocate rddm memory during crash time

diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c
index ca842facf820..1a918e340424 100644
--- a/drivers/bus/mhi/host/boot.c
+++ b/drivers/bus/mhi/host/boot.c
@@ -35,6 +35,16 @@  int mhi_rddm_prepare(struct mhi_controller *mhi_cntrl,
 		bhi_vec->size = mhi_buf->len;
 	}
 
+	if (!mhi_cntrl->rddm_prealloc) {
+		mhi_buf->dma_addr = dma_map_single(mhi_cntrl->cntrl_dev,
+						   mhi_buf->buf, mhi_buf->len,
+						   DMA_TO_DEVICE);
+		if (dma_mapping_error(mhi_cntrl->cntrl_dev, mhi_buf->dma_addr)) {
+			dev_err(dev, "dma mapping failed\n");
+			return -ENOMEM;
+		}
+	}
+
 	dev_dbg(dev, "BHIe programming for RDDM\n");
 
 	mhi_write_reg(mhi_cntrl, base, BHIE_RXVECADDR_HIGH_OFFS,
@@ -158,10 +168,35 @@  int mhi_download_rddm_image(struct mhi_controller *mhi_cntrl, bool in_panic)
 {
 	void __iomem *base = mhi_cntrl->bhie;
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
+	struct mhi_buf *mhi_buf = NULL;
 	u32 rx_status;
+	int ret;
 
-	if (in_panic)
-		return __mhi_download_rddm_in_panic(mhi_cntrl);
+	/*
+	 * Allocate RDDM table if specified, this table is for debugging purpose
+	 */
+	if (!mhi_cntrl->rddm_prealloc && mhi_cntrl->rddm_size) {
+		ret = mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->rddm_image,
+					   mhi_cntrl->rddm_size, IMG_TYPE_RDDM);
+		if (ret) {
+			dev_err(dev, "Failed to allocate RDDM table memory\n");
+			return ret;
+		}
+
+		/* setup the RX vector table */
+		ret = mhi_rddm_prepare(mhi_cntrl, mhi_cntrl->rddm_image);
+		if (ret) {
+			dev_err(dev, "Failed to prepare RDDM\n");
+			mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->rddm_image,
+					    IMG_TYPE_RDDM);
+			return ret;
+		}
+	}
+
+	if (in_panic) {
+		ret = __mhi_download_rddm_in_panic(mhi_cntrl);
+		goto out;
+	}
 
 	dev_dbg(dev, "Waiting for RDDM image download via BHIe\n");
 
@@ -173,7 +208,16 @@  int mhi_download_rddm_image(struct mhi_controller *mhi_cntrl, bool in_panic)
 					      &rx_status) || rx_status,
 			   msecs_to_jiffies(mhi_cntrl->timeout_ms));
 
-	return (rx_status == BHIE_RXVECSTATUS_STATUS_XFER_COMPL) ? 0 : -EIO;
+	ret = (rx_status == BHIE_RXVECSTATUS_STATUS_XFER_COMPL) ? 0 : -EIO;
+
+out:
+	mhi_buf = &mhi_cntrl->rddm_image->mhi_buf[mhi_cntrl->rddm_image->entries - 1];
+
+	if (!mhi_cntrl->rddm_prealloc)
+		dma_unmap_single(mhi_cntrl->cntrl_dev, mhi_buf->dma_addr,
+				 mhi_buf->len, DMA_TO_DEVICE);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(mhi_download_rddm_image);
 
@@ -297,14 +341,25 @@  static int mhi_fw_load_bhi(struct mhi_controller *mhi_cntrl,
 }
 
 void mhi_free_bhie_table(struct mhi_controller *mhi_cntrl,
-			 struct image_info *image_info)
+			 struct image_info *image_info,
+			 enum image_type img_type)
 {
 	int i;
 	struct mhi_buf *mhi_buf = image_info->mhi_buf;
 
-	for (i = 0; i < image_info->entries; i++, mhi_buf++)
-		mhi_fw_free_coherent(mhi_cntrl, mhi_buf->len,
-				     mhi_buf->buf, mhi_buf->dma_addr);
+	for (i = 0; i < image_info->entries; i++, mhi_buf++) {
+		if (img_type == IMG_TYPE_RDDM && !mhi_cntrl->rddm_prealloc) {
+			if (i == (image_info->entries - 1))
+				dma_unmap_single(mhi_cntrl->cntrl_dev,
+						 mhi_buf->dma_addr,
+						 mhi_buf->len,
+						 DMA_FROM_DEVICE);
+			kfree(mhi_buf->buf);
+		} else {
+			mhi_fw_free_coherent(mhi_cntrl, mhi_buf->len,
+					     mhi_buf->buf, mhi_buf->dma_addr);
+		}
+	}
 
 	kfree(image_info->mhi_buf);
 	kfree(image_info);
@@ -312,21 +367,31 @@  void mhi_free_bhie_table(struct mhi_controller *mhi_cntrl,
 
 int mhi_alloc_bhie_table(struct mhi_controller *mhi_cntrl,
 			 struct image_info **image_info,
-			 size_t alloc_size)
+			 size_t alloc_size, enum image_type img_type)
 {
 	size_t seg_size = mhi_cntrl->seg_len;
-	int segments = DIV_ROUND_UP(alloc_size, seg_size) + 1;
+	int segments;
 	int i;
 	struct image_info *img_info;
 	struct mhi_buf *mhi_buf;
+	/* Masked __GFP_DIRECT_RECLAIM flag for non-interrupt context
+	 * to avoid rcu context sleep issue in kmalloc during kernel panic
+	 */
+	gfp_t gfp = (in_interrupt() ? GFP_ATOMIC :
+		((GFP_KERNEL | __GFP_NORETRY) & ~__GFP_DIRECT_RECLAIM));
+
+	if (img_type == IMG_TYPE_RDDM)
+		seg_size = mhi_cntrl->rddm_seg_len;
 
-	img_info = kzalloc(sizeof(*img_info), GFP_KERNEL);
+	segments = DIV_ROUND_UP(alloc_size, seg_size) + 1;
+
+	img_info = kzalloc(sizeof(*img_info), gfp);
 	if (!img_info)
 		return -ENOMEM;
 
 	/* Allocate memory for entries */
 	img_info->mhi_buf = kcalloc(segments, sizeof(*img_info->mhi_buf),
-				    GFP_KERNEL);
+				    gfp);
 	if (!img_info->mhi_buf)
 		goto error_alloc_mhi_buf;
 
@@ -340,11 +405,42 @@  int mhi_alloc_bhie_table(struct mhi_controller *mhi_cntrl,
 			vec_size = sizeof(struct bhi_vec_entry) * i;
 
 		mhi_buf->len = vec_size;
-		mhi_buf->buf = mhi_fw_alloc_coherent(mhi_cntrl, vec_size,
-						     &mhi_buf->dma_addr,
-						     GFP_KERNEL);
-		if (!mhi_buf->buf)
-			goto error_alloc_segment;
+
+		if (img_type == IMG_TYPE_RDDM && !mhi_cntrl->rddm_prealloc) {
+			/* Vector table is the last entry */
+			if (i == segments - 1) {
+				mhi_buf->buf = kzalloc(PAGE_ALIGN(vec_size),
+						       gfp);
+				if (!mhi_buf->buf)
+					goto error_alloc_segment;
+
+				/* Vector table entry will be dma_mapped during
+				 * rddm prepare with DMA_TO_DEVICE and unmapped
+				 * once the target completes the RDDM XFER.
+				 */
+				continue;
+			}
+			mhi_buf->buf = kmalloc(vec_size, gfp);
+			if (!mhi_buf->buf)
+				goto error_alloc_segment;
+
+			mhi_buf->dma_addr = dma_map_single(mhi_cntrl->cntrl_dev,
+							   mhi_buf->buf,
+							   vec_size,
+							   DMA_FROM_DEVICE);
+			if (dma_mapping_error(mhi_cntrl->cntrl_dev,
+					      mhi_buf->dma_addr)) {
+				kfree(mhi_buf->buf);
+				goto error_alloc_segment;
+			}
+		} else {
+			mhi_buf->buf = mhi_fw_alloc_coherent(mhi_cntrl,
+							     vec_size,
+							     &mhi_buf->dma_addr,
+							     GFP_KERNEL);
+			if (!mhi_buf->buf)
+				goto error_alloc_segment;
+		}
 	}
 
 	img_info->bhi_vec = img_info->mhi_buf[segments - 1].buf;
@@ -354,9 +450,18 @@  int mhi_alloc_bhie_table(struct mhi_controller *mhi_cntrl,
 	return 0;
 
 error_alloc_segment:
-	for (--i, --mhi_buf; i >= 0; i--, mhi_buf--)
-		mhi_fw_free_coherent(mhi_cntrl, mhi_buf->len,
-				     mhi_buf->buf, mhi_buf->dma_addr);
+	for (--i, --mhi_buf; i >= 0; i--, mhi_buf--) {
+		if (img_type == IMG_TYPE_RDDM && !mhi_cntrl->rddm_prealloc) {
+			dma_unmap_single(mhi_cntrl->cntrl_dev,
+					 mhi_buf->dma_addr, mhi_buf->len,
+					 DMA_FROM_DEVICE);
+			kfree(mhi_buf->buf);
+
+		} else {
+			mhi_fw_free_coherent(mhi_cntrl, mhi_buf->len,
+					     mhi_buf->buf, mhi_buf->dma_addr);
+		}
+	}
 
 error_alloc_mhi_buf:
 	kfree(img_info);
@@ -485,7 +590,8 @@  void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
 	 * device transitioning into MHI READY state
 	 */
 	if (mhi_cntrl->fbc_download) {
-		ret = mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->fbc_image, fw_sz);
+		ret = mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->fbc_image, fw_sz,
+					   IMG_TYPE_FBC);
 		if (ret) {
 			release_firmware(firmware);
 			goto error_fw_load;
@@ -510,7 +616,8 @@  void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
 
 error_ready_state:
 	if (mhi_cntrl->fbc_download) {
-		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image);
+		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image,
+				    IMG_TYPE_FBC);
 		mhi_cntrl->fbc_image = NULL;
 	}
 
diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
index c1e1412c43e2..8a47c3354560 100644
--- a/drivers/bus/mhi/host/init.c
+++ b/drivers/bus/mhi/host/init.c
@@ -1058,6 +1058,9 @@  int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 		mhi_cntrl->unmap_single = mhi_unmap_single_no_bb;
 	}
 
+	mhi_cntrl->rddm_prealloc = true;
+	mhi_cntrl->rddm_seg_len = mhi_cntrl->seg_len;
+
 	mhi_cntrl->index = ida_alloc(&mhi_controller_ida, GFP_KERNEL);
 	if (mhi_cntrl->index < 0) {
 		ret = mhi_cntrl->index;
@@ -1224,14 +1227,18 @@  int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
 		/*
 		 * Allocate RDDM table for debugging purpose if specified
 		 */
-		mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->rddm_image,
-				     mhi_cntrl->rddm_size);
+		if (mhi_cntrl->rddm_prealloc)
+			mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->rddm_image,
+					     mhi_cntrl->rddm_size,
+					     IMG_TYPE_RDDM);
+
 		if (mhi_cntrl->rddm_image) {
 			ret = mhi_rddm_prepare(mhi_cntrl,
 					       mhi_cntrl->rddm_image);
 			if (ret) {
 				mhi_free_bhie_table(mhi_cntrl,
-						    mhi_cntrl->rddm_image);
+						    mhi_cntrl->rddm_image,
+						    IMG_TYPE_RDDM);
 				goto error_reg_offset;
 			}
 		}
@@ -1254,12 +1261,14 @@  EXPORT_SYMBOL_GPL(mhi_prepare_for_power_up);
 void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl)
 {
 	if (mhi_cntrl->fbc_image) {
-		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image);
+		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image,
+				    IMG_TYPE_FBC);
 		mhi_cntrl->fbc_image = NULL;
 	}
 
 	if (mhi_cntrl->rddm_image) {
-		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->rddm_image);
+		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->rddm_image,
+				    IMG_TYPE_RDDM);
 		mhi_cntrl->rddm_image = NULL;
 	}
 
diff --git a/drivers/bus/mhi/host/internal.h b/drivers/bus/mhi/host/internal.h
index 41ce100d87d2..c7946f81be38 100644
--- a/drivers/bus/mhi/host/internal.h
+++ b/drivers/bus/mhi/host/internal.h
@@ -176,6 +176,11 @@  enum mhi_er_type {
 	MHI_ER_TYPE_VALID = 0x1,
 };
 
+enum image_type {
+	IMG_TYPE_FBC,
+	IMG_TYPE_RDDM,
+};
+
 struct db_cfg {
 	bool reset_req;
 	bool db_mode;
@@ -314,9 +319,11 @@  int mhi_destroy_device(struct device *dev, void *data);
 void mhi_create_devices(struct mhi_controller *mhi_cntrl);
 
 int mhi_alloc_bhie_table(struct mhi_controller *mhi_cntrl,
-			 struct image_info **image_info, size_t alloc_size);
+			 struct image_info **image_info, size_t alloc_size,
+			 enum image_type img_type);
 void mhi_free_bhie_table(struct mhi_controller *mhi_cntrl,
-			 struct image_info *image_info);
+			 struct image_info *image_info,
+			 enum image_type img_type);
 
 /* Power management APIs */
 enum mhi_pm_state __must_check mhi_tryset_pm_state(
diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
index 4de75674f193..2f44f11fa5a6 100644
--- a/drivers/bus/mhi/host/main.c
+++ b/drivers/bus/mhi/host/main.c
@@ -503,13 +503,13 @@  irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv)
 	}
 	write_unlock_irq(&mhi_cntrl->pm_lock);
 
-	if (pm_state != MHI_PM_SYS_ERR_DETECT)
+	if (pm_state != MHI_PM_SYS_ERR_DETECT && ee != MHI_EE_RDDM)
 		goto exit_intvec;
 
 	switch (ee) {
 	case MHI_EE_RDDM:
 		/* proceed if power down is not already in progress */
-		if (mhi_cntrl->rddm_image && mhi_is_active(mhi_cntrl)) {
+		if (mhi_cntrl->rddm_size && mhi_is_active(mhi_cntrl)) {
 			mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_RDDM);
 			mhi_cntrl->ee = ee;
 			wake_up_all(&mhi_cntrl->state_event);
diff --git a/drivers/bus/mhi/host/pm.c b/drivers/bus/mhi/host/pm.c
index 11c0e751f223..68524e27e76c 100644
--- a/drivers/bus/mhi/host/pm.c
+++ b/drivers/bus/mhi/host/pm.c
@@ -767,7 +767,7 @@  void mhi_pm_sys_err_handler(struct mhi_controller *mhi_cntrl)
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 
 	/* skip if controller supports RDDM */
-	if (mhi_cntrl->rddm_image) {
+	if (mhi_cntrl->rddm_size) {
 		dev_dbg(dev, "Controller supports RDDM, skip SYS_ERROR\n");
 		return;
 	}
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index c788c12039b5..ce229a6a2b9a 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -452,6 +452,8 @@  struct mhi_controller {
 	struct device_node *cma_node;
 	phys_addr_t cma_base;
 	size_t cma_size;
+	bool rddm_prealloc;
+	u32 rddm_seg_len;
 };
 
 /**