[PATCH 1/6] scsi: target: tcmu: Adjust names of variables and definitions

Bodo Stroesser
2021-03-24T19:29:58Z

From: Bodo Stroesser <bstroesser@ts.fujitsu.com>

Some definitions and members of struct tcmu_dev had misleading
names. Examples:
- ring_size was used for the size of mailbox + cmd ring +
data area
- CMDR_SIZE was used for size of mailbox + cmd ring

I added the new definition MB_CMDR_SIZE (mailbox + command ring),
changed CMDR_SIZE to hold the size of the command ring only and
replaced in struct tcmu_dev the member ring_size with mmap_pages,
because the member is now used in tcmu_mmap() only, where we need
page count, not size.

I also added the new struct tcmu_dev member 'cmdr' which is used
to replace some occurences of '(void *)mb + CMDR_OFF' with
'udev->cmdr' for better readability.

Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
---
drivers/target/target_core_user.c | 39 ++++++++++++++++++++++-----------------
1 file changed, 22 insertions(+), 17 deletions(-)

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index bdfc057f000c..35975dd75dde 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -60,8 +60,11 @@

#define TCMU_TIME_OUT (30 * MSEC_PER_SEC)

-/* For cmd area, the size is fixed 8MB */
-#define CMDR_SIZE (8 * 1024 * 1024)
+/* For mailbox plus cmd ring, the size is fixed 8MB */
+#define MB_CMDR_SIZE (8 * 1024 * 1024)
+/* Offset of cmd ring is size of mailbox */
+#define CMDR_OFF sizeof(struct tcmu_mailbox)
+#define CMDR_SIZE (MB_CMDR_SIZE - CMDR_OFF)

/*
* For data area, the block size is PAGE_SIZE and
@@ -126,8 +129,10 @@ struct tcmu_dev {

struct inode *inode;

- struct tcmu_mailbox *mb_addr;
uint64_t dev_size;
+
+ struct tcmu_mailbox *mb_addr;
+ void *cmdr;
u32 cmdr_size;
u32 cmdr_last_cleaned;
/* Offset of data area from start of mb */
@@ -135,7 +140,7 @@ struct tcmu_dev {
size_t data_off;
size_t data_size;
uint32_t max_blocks;
- size_t ring_size;
+ size_t mmap_pages;

struct mutex cmdr_lock;
struct list_head qfull_queue;
@@ -166,8 +171,6 @@ struct tcmu_dev {

#define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)

-#define CMDR_OFF sizeof(struct tcmu_mailbox)
-
struct tcmu_cmd {
struct se_cmd *se_cmd;
struct tcmu_dev *tcmu_dev;
@@ -941,7 +944,7 @@ static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size)
if (head_to_end(cmd_head, udev->cmdr_size) < cmd_size) {
size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);

- hdr = (void *) mb + CMDR_OFF + cmd_head;
+ hdr = udev->cmdr + cmd_head;
tcmu_hdr_set_op(&hdr->len_op, TCMU_OP_PAD);
tcmu_hdr_set_len(&hdr->len_op, pad_size);
hdr->cmd_id = 0; /* not used for PAD */
@@ -1065,7 +1068,7 @@ static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)

cmd_head = ring_insert_padding(udev, command_size);

- entry = (void *) mb + CMDR_OFF + cmd_head;
+ entry = udev->cmdr + cmd_head;
memset(entry, 0, command_size);
tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);

@@ -1157,7 +1160,7 @@ queue_tmr_ring(struct tcmu_dev *udev, struct tcmu_tmr *tmr)

cmd_head = ring_insert_padding(udev, cmd_size);

- entry = (void *)mb + CMDR_OFF + cmd_head;
+ entry = udev->cmdr + cmd_head;
memset(entry, 0, cmd_size);
tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_TMR);
tcmu_hdr_set_len(&entry->hdr.len_op, cmd_size);
@@ -1412,7 +1415,7 @@ static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)

while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {

- struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned;
+ struct tcmu_cmd_entry *entry = udev->cmdr + udev->cmdr_last_cleaned;

/*
* Flush max. up to end of cmd ring since current entry might
@@ -1851,7 +1854,7 @@ static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
vma->vm_private_data = udev;

/* Ensure the mmap is exactly the right size */
- if (vma_pages(vma) != (udev->ring_size >> PAGE_SHIFT))
+ if (vma_pages(vma) != udev->mmap_pages)
return -EINVAL;

tcmu_vma_open(vma);
@@ -2100,20 +2103,22 @@ static int tcmu_configure_device(struct se_device *dev)
goto err_bitmap_alloc;
}

- udev->mb_addr = vzalloc(CMDR_SIZE);
- if (!udev->mb_addr) {
+ mb = vzalloc(MB_CMDR_SIZE);
+ if (!mb) {
ret = -ENOMEM;
goto err_vzalloc;
}

/* mailbox fits in first part of CMDR space */
- udev->cmdr_size = CMDR_SIZE - CMDR_OFF;
- udev->data_off = CMDR_SIZE;
+ udev->mb_addr = mb;
+ udev->cmdr = (void *)mb + CMDR_OFF;
+ udev->cmdr_size = CMDR_SIZE;
+ udev->data_off = MB_CMDR_SIZE;
udev->data_size = udev->max_blocks * DATA_BLOCK_SIZE;
+ udev->mmap_pages = (udev->data_size + MB_CMDR_SIZE) >> PAGE_SHIFT;
udev->dbi_thresh = 0; /* Default in Idle state */

/* Initialise the mailbox of the ring buffer */
- mb = udev->mb_addr;
mb->version = TCMU_MAILBOX_VERSION;
mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC |
TCMU_MAILBOX_FLAG_CAP_READ_LEN |
@@ -2129,7 +2134,7 @@ static int tcmu_configure_device(struct se_device *dev)

info->mem[0].name = "tcm-user command & data buffer";
info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
- info->mem[0].size = udev->ring_size = udev->data_size + CMDR_SIZE;
+ info->mem[0].size = udev->data_size + MB_CMDR_SIZE;
info->mem[0].memtype = UIO_MEM_NONE;

info->irqcontrol = tcmu_irqcontrol;
--
2.12.3