[PATCH 1/3 v4] mmc: block: Anonymize the drv op data pointer

[PATCH 1/3 v4] mmc: block: Anonymize the drv op data pointer

[Linus Walleij]

We have a data pointer for the ioctl() data, but we need to
pass other data along with the DRV_OP:s, so make this a
void * so it can be reused.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v3->v4:
- No changes just resending
ChangeLog v2->v3:
- No changes just resending
---
 drivers/mmc/core/block.c | 8 +++++---
 drivers/mmc/core/queue.h | 2 +-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 3c7efbdc8591..d410f578b8df 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -598,7 +598,7 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev,
 		__GFP_RECLAIM);
 	idatas[0] = idata;
 	req_to_mmc_queue_req(req)->drv_op = MMC_DRV_OP_IOCTL;
-	req_to_mmc_queue_req(req)->idata = idatas;
+	req_to_mmc_queue_req(req)->drv_op_data = idatas;
 	req_to_mmc_queue_req(req)->ioc_count = 1;
 	blk_execute_rq(mq->queue, NULL, req, 0);
 	ioc_err = req_to_mmc_queue_req(req)->drv_op_result;
@@ -674,7 +674,7 @@ static int mmc_blk_ioctl_multi_cmd(struct block_device *bdev,
 		idata[0]->ic.write_flag ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN,
 		__GFP_RECLAIM);
 	req_to_mmc_queue_req(req)->drv_op = MMC_DRV_OP_IOCTL;
-	req_to_mmc_queue_req(req)->idata = idata;
+	req_to_mmc_queue_req(req)->drv_op_data = idata;
 	req_to_mmc_queue_req(req)->ioc_count = num_of_cmds;
 	blk_execute_rq(mq->queue, NULL, req, 0);
 	ioc_err = req_to_mmc_queue_req(req)->drv_op_result;
@@ -1175,6 +1175,7 @@ static void mmc_blk_issue_drv_op(struct mmc_queue *mq, struct request *req)
 	struct mmc_queue_req *mq_rq;
 	struct mmc_card *card = mq->card;
 	struct mmc_blk_data *md = mq->blkdata;
+	struct mmc_blk_ioc_data **idata;
 	int ret;
 	int i;
 
@@ -1182,8 +1183,9 @@ static void mmc_blk_issue_drv_op(struct mmc_queue *mq, struct request *req)
 
 	switch (mq_rq->drv_op) {
 	case MMC_DRV_OP_IOCTL:
+		idata = mq_rq->drv_op_data;
 		for (i = 0; i < mq_rq->ioc_count; i++) {
-			ret = __mmc_blk_ioctl_cmd(card, md, mq_rq->idata[i]);
+			ret = __mmc_blk_ioctl_cmd(card, md, idata[i]);
 			if (ret)
 				break;
 		}
diff --git a/drivers/mmc/core/queue.h b/drivers/mmc/core/queue.h
index 361b46408e0f..cf26a15a64bf 100644
--- a/drivers/mmc/core/queue.h
+++ b/drivers/mmc/core/queue.h
@@ -51,7 +51,7 @@ struct mmc_queue_req {
 	struct mmc_async_req	areq;
 	enum mmc_drv_op		drv_op;
 	int			drv_op_result;
-	struct mmc_blk_ioc_data	**idata;
+	void			*drv_op_data;
 	unsigned int		ioc_count;
 };
 
-- 
2.9.4

[PATCH 2/3 v4] mmc: ops: export mmc_get_status()

[Linus Walleij]

This function retrieves the status of the card with the default
number of retries. Since the block layer wants to use this, and
since the block layer is a loadable kernel module, we need to
export this symbol.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v3->v4:
- No changes just resending
ChangeLog v2->v3:
- New patch to fix a build error, enumerating v3 to keep it
  together with the other patches.
---
 drivers/mmc/core/mmc_ops.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 5f7c5920231a..b56fa822ab6b 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -83,6 +83,7 @@ int mmc_send_status(struct mmc_card *card, u32 *status)
 {
 	return __mmc_send_status(card, status, MMC_CMD_RETRIES);
 }
+EXPORT_SYMBOL_GPL(mmc_send_status);
 
 static int _mmc_select_card(struct mmc_host *host, struct mmc_card *card)
 {
-- 
2.9.4

[PATCH 3/3 v4] mmc: debugfs: Move block debugfs into block module

[Linus Walleij]

If we don't have the block layer enabled, we do not present card
status and extcsd in the debugfs.

Debugfs is not ABI, and maintaining files of no relevance for
non-block devices comes at a high maintenance cost if we shall
support it with the block layer compiled out.

The debugfs entries suffer from all the same starvation
issues as the other userspace things, under e.g. a heavy
dd operation.

The expected number of debugfs users utilizing these two
debugfs files is already low as there is an ioctl() to get the
same information using the mmc-tools, and of these few users
the expected number of people using it on SDIO or combo cards
are expected to be zero.

It is therefore logical to move this over to the block layer
when it is enabled, using the new custom requests and issue
it using the block request queue.

On the other hand it moves some debugfs code from debugfs.c
and into block.c.

Tested during heavy dd load by cat:in the status file.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v3->v4:
- Squash all the refactorings of these operations into a big
  commit simply moving all the debugfs over to the block layer
  and only creating the files from there.
- Avoid the whole middle-step of creating #if IS_ENABLED()
  that was required to move it stepwise from the debugfs file
  to the block file.
---
 drivers/mmc/core/block.c   | 143 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/mmc/core/debugfs.c |  89 ----------------------------
 drivers/mmc/core/queue.h   |   4 ++
 3 files changed, 147 insertions(+), 89 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index d410f578b8df..dbfbc76576ea 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -36,6 +36,7 @@
 #include <linux/compat.h>
 #include <linux/pm_runtime.h>
 #include <linux/idr.h>
+#include <linux/debugfs.h>
 
 #include <linux/mmc/ioctl.h>
 #include <linux/mmc/card.h>
@@ -1176,6 +1177,8 @@ static void mmc_blk_issue_drv_op(struct mmc_queue *mq, struct request *req)
 	struct mmc_card *card = mq->card;
 	struct mmc_blk_data *md = mq->blkdata;
 	struct mmc_blk_ioc_data **idata;
+	u8 **ext_csd;
+	u32 status;
 	int ret;
 	int i;
 
@@ -1205,6 +1208,15 @@ static void mmc_blk_issue_drv_op(struct mmc_queue *mq, struct request *req)
 			card->ext_csd.boot_ro_lock |=
 				EXT_CSD_BOOT_WP_B_PWR_WP_EN;
 		break;
+	case MMC_DRV_OP_GET_CARD_STATUS:
+		ret = mmc_send_status(card, &status);
+		if (!ret)
+			ret = status;
+		break;
+	case MMC_DRV_OP_GET_EXT_CSD:
+		ext_csd = mq_rq->drv_op_data;
+		ret = mmc_get_ext_csd(card, ext_csd);
+		break;
 	default:
 		pr_err("%s: unknown driver specific operation\n",
 		       md->disk->disk_name);
@@ -2236,6 +2248,134 @@ static int mmc_add_disk(struct mmc_blk_data *md)
 	return ret;
 }
 
+#ifdef CONFIG_DEBUG_FS
+
+static int mmc_dbg_card_status_get(void *data, u64 *val)
+{
+	struct mmc_card *card = data;
+	struct mmc_blk_data *md = dev_get_drvdata(&card->dev);
+	struct mmc_queue *mq = &md->queue;
+	struct request *req;
+	int ret;
+
+	/* Ask the block layer about the card status */
+	req = blk_get_request(mq->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
+	req_to_mmc_queue_req(req)->drv_op = MMC_DRV_OP_GET_CARD_STATUS;
+	blk_execute_rq(mq->queue, NULL, req, 0);
+	ret = req_to_mmc_queue_req(req)->drv_op_result;
+	if (ret >= 0) {
+		*val = ret;
+		ret = 0;
+	}
+
+	return ret;
+}
+DEFINE_SIMPLE_ATTRIBUTE(mmc_dbg_card_status_fops, mmc_dbg_card_status_get,
+		NULL, "%08llx\n");
+
+/* That is two digits * 512 + 1 for newline */
+#define EXT_CSD_STR_LEN 1025
+
+static int mmc_ext_csd_open(struct inode *inode, struct file *filp)
+{
+	struct mmc_card *card = inode->i_private;
+	struct mmc_blk_data *md = dev_get_drvdata(&card->dev);
+	struct mmc_queue *mq = &md->queue;
+	struct request *req;
+	char *buf;
+	ssize_t n = 0;
+	u8 *ext_csd;
+	int err, i;
+
+	buf = kmalloc(EXT_CSD_STR_LEN + 1, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Ask the block layer for the EXT CSD */
+	req = blk_get_request(mq->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
+	req_to_mmc_queue_req(req)->drv_op = MMC_DRV_OP_GET_EXT_CSD;
+	req_to_mmc_queue_req(req)->drv_op_data = &ext_csd;
+	blk_execute_rq(mq->queue, NULL, req, 0);
+	err = req_to_mmc_queue_req(req)->drv_op_result;
+	if (err) {
+		pr_err("FAILED %d\n", err);
+		goto out_free;
+	}
+
+	for (i = 0; i < 512; i++)
+		n += sprintf(buf + n, "%02x", ext_csd[i]);
+	n += sprintf(buf + n, "\n");
+
+	if (n != EXT_CSD_STR_LEN) {
+		err = -EINVAL;
+		goto out_free;
+	}
+
+	filp->private_data = buf;
+	kfree(ext_csd);
+	return 0;
+
+out_free:
+	kfree(buf);
+	return err;
+}
+
+static ssize_t mmc_ext_csd_read(struct file *filp, char __user *ubuf,
+				size_t cnt, loff_t *ppos)
+{
+	char *buf = filp->private_data;
+
+	return simple_read_from_buffer(ubuf, cnt, ppos,
+				       buf, EXT_CSD_STR_LEN);
+}
+
+static int mmc_ext_csd_release(struct inode *inode, struct file *file)
+{
+	kfree(file->private_data);
+	return 0;
+}
+
+static const struct file_operations mmc_dbg_ext_csd_fops = {
+	.open		= mmc_ext_csd_open,
+	.read		= mmc_ext_csd_read,
+	.release	= mmc_ext_csd_release,
+	.llseek		= default_llseek,
+};
+
+static int mmc_blk_add_debugfs(struct mmc_card *card)
+{
+	struct dentry *root;
+
+	if (!card->debugfs_root)
+		return 0;
+
+	root = card->debugfs_root;
+
+	if (mmc_card_mmc(card) || mmc_card_sd(card)) {
+		if (!debugfs_create_file("status", S_IRUSR, root, card,
+					 &mmc_dbg_card_status_fops))
+			return -EIO;
+	}
+
+	if (mmc_card_mmc(card)) {
+		if (!debugfs_create_file("ext_csd", S_IRUSR, root, card,
+					 &mmc_dbg_ext_csd_fops))
+			return -EIO;
+	}
+
+	return 0;
+}
+
+
+#else
+
+static int mmc_blk_add_debugfs(struct mmc_card *card)
+{
+	return 0;
+}
+
+#endif /* CONFIG_DEBUG_FS */
+
 static int mmc_blk_probe(struct mmc_card *card)
 {
 	struct mmc_blk_data *md, *part_md;
@@ -2272,6 +2412,9 @@ static int mmc_blk_probe(struct mmc_card *card)
 			goto out;
 	}
 
+	/* Add two debugfs entries */
+	mmc_blk_add_debugfs(card);
+
 	pm_runtime_set_autosuspend_delay(&card->dev, 3000);
 	pm_runtime_use_autosuspend(&card->dev);
 
diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c
index a1fba5732d66..01e459a34f33 100644
--- a/drivers/mmc/core/debugfs.c
+++ b/drivers/mmc/core/debugfs.c
@@ -281,85 +281,6 @@ void mmc_remove_host_debugfs(struct mmc_host *host)
 	debugfs_remove_recursive(host->debugfs_root);
 }
 
-static int mmc_dbg_card_status_get(void *data, u64 *val)
-{
-	struct mmc_card	*card = data;
-	u32		status;
-	int		ret;
-
-	mmc_get_card(card);
-
-	ret = mmc_send_status(data, &status);
-	if (!ret)
-		*val = status;
-
-	mmc_put_card(card);
-
-	return ret;
-}
-DEFINE_SIMPLE_ATTRIBUTE(mmc_dbg_card_status_fops, mmc_dbg_card_status_get,
-		NULL, "%08llx\n");
-
-#define EXT_CSD_STR_LEN 1025
-
-static int mmc_ext_csd_open(struct inode *inode, struct file *filp)
-{
-	struct mmc_card *card = inode->i_private;
-	char *buf;
-	ssize_t n = 0;
-	u8 *ext_csd;
-	int err, i;
-
-	buf = kmalloc(EXT_CSD_STR_LEN + 1, GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-
-	mmc_get_card(card);
-	err = mmc_get_ext_csd(card, &ext_csd);
-	mmc_put_card(card);
-	if (err)
-		goto out_free;
-
-	for (i = 0; i < 512; i++)
-		n += sprintf(buf + n, "%02x", ext_csd[i]);
-	n += sprintf(buf + n, "\n");
-
-	if (n != EXT_CSD_STR_LEN) {
-		err = -EINVAL;
-		goto out_free;
-	}
-
-	filp->private_data = buf;
-	kfree(ext_csd);
-	return 0;
-
-out_free:
-	kfree(buf);
-	return err;
-}
-
-static ssize_t mmc_ext_csd_read(struct file *filp, char __user *ubuf,
-				size_t cnt, loff_t *ppos)
-{
-	char *buf = filp->private_data;
-
-	return simple_read_from_buffer(ubuf, cnt, ppos,
-				       buf, EXT_CSD_STR_LEN);
-}
-
-static int mmc_ext_csd_release(struct inode *inode, struct file *file)
-{
-	kfree(file->private_data);
-	return 0;
-}
-
-static const struct file_operations mmc_dbg_ext_csd_fops = {
-	.open		= mmc_ext_csd_open,
-	.read		= mmc_ext_csd_read,
-	.release	= mmc_ext_csd_release,
-	.llseek		= default_llseek,
-};
-
 void mmc_add_card_debugfs(struct mmc_card *card)
 {
 	struct mmc_host	*host = card->host;
@@ -382,16 +303,6 @@ void mmc_add_card_debugfs(struct mmc_card *card)
 	if (!debugfs_create_x32("state", S_IRUSR, root, &card->state))
 		goto err;
 
-	if (mmc_card_mmc(card) || mmc_card_sd(card))
-		if (!debugfs_create_file("status", S_IRUSR, root, card,
-					&mmc_dbg_card_status_fops))
-			goto err;
-
-	if (mmc_card_mmc(card))
-		if (!debugfs_create_file("ext_csd", S_IRUSR, root, card,
-					&mmc_dbg_ext_csd_fops))
-			goto err;
-
 	return;
 
 err:
diff --git a/drivers/mmc/core/queue.h b/drivers/mmc/core/queue.h
index cf26a15a64bf..04fc89360a7a 100644
--- a/drivers/mmc/core/queue.h
+++ b/drivers/mmc/core/queue.h
@@ -36,10 +36,14 @@ struct mmc_blk_request {
  * enum mmc_drv_op - enumerates the operations in the mmc_queue_req
  * @MMC_DRV_OP_IOCTL: ioctl operation
  * @MMC_DRV_OP_BOOT_WP: write protect boot partitions
+ * @MMC_DRV_OP_GET_CARD_STATUS: get card status
+ * @MMC_DRV_OP_GET_EXT_CSD: get the EXT CSD from an eMMC card
  */
 enum mmc_drv_op {
 	MMC_DRV_OP_IOCTL,
 	MMC_DRV_OP_BOOT_WP,
+	MMC_DRV_OP_GET_CARD_STATUS,
+	MMC_DRV_OP_GET_EXT_CSD,
 };
 
 struct mmc_queue_req {
-- 
2.9.4