[PATCH v3 03/20] vmw_balloon: merge send_lock and send_unlock path

From: Nadav Amit
Date: Wed Sep 26 2018 - 15:15:13 EST


The lock and unlock code paths are very similar, so avoid the duplicate
code by merging them together.

Reviewed-by: Xavier Deguillard <xdeguillard@xxxxxxxxxx>
Signed-off-by: Nadav Amit <namit@xxxxxxxxxx>
---
drivers/misc/vmw_balloon.c | 62 +++++++++++++-------------------------
1 file changed, 21 insertions(+), 41 deletions(-)

diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c
index 2ed4875319c8..5e5f61f207f4 100644
--- a/drivers/misc/vmw_balloon.c
+++ b/drivers/misc/vmw_balloon.c
@@ -420,16 +420,18 @@ static bool vmballoon_send_get_target(struct vmballoon *b)
* check the return value and maybe submit a different page.
*/
static int vmballoon_send_lock_page(struct vmballoon *b, unsigned long pfn,
- unsigned int *hv_status)
+ unsigned int *hv_status, bool lock)
{
- unsigned long status;
+ unsigned long status, cmd;
u32 pfn32;

pfn32 = (u32)pfn;
if (pfn32 != pfn)
return -EINVAL;

- *hv_status = status = vmballoon_cmd(b, VMW_BALLOON_CMD_LOCK, pfn, 0);
+ cmd = lock ? VMW_BALLOON_CMD_LOCK : VMW_BALLOON_CMD_UNLOCK;
+
+ *hv_status = status = vmballoon_cmd(b, cmd, pfn, 0);

if (status == VMW_BALLOON_SUCCESS)
return 0;
@@ -438,13 +440,18 @@ static int vmballoon_send_lock_page(struct vmballoon *b, unsigned long pfn,
}

static int vmballoon_send_batched_lock(struct vmballoon *b,
- unsigned int num_pages, bool is_2m_pages)
+ unsigned int num_pages, bool is_2m_pages,
+ bool lock)
{
unsigned long pfn = PHYS_PFN(virt_to_phys(b->batch_page));
unsigned long status, cmd;

- cmd = is_2m_pages ? VMW_BALLOON_CMD_BATCHED_2M_LOCK :
- VMW_BALLOON_CMD_BATCHED_LOCK;
+ if (lock)
+ cmd = is_2m_pages ? VMW_BALLOON_CMD_BATCHED_2M_LOCK :
+ VMW_BALLOON_CMD_BATCHED_LOCK;
+ else
+ cmd = is_2m_pages ? VMW_BALLOON_CMD_BATCHED_2M_UNLOCK :
+ VMW_BALLOON_CMD_BATCHED_UNLOCK;

status = vmballoon_cmd(b, cmd, pfn, num_pages);

@@ -454,37 +461,6 @@ static int vmballoon_send_batched_lock(struct vmballoon *b,
return 1;
}

-/*
- * Notify the host that guest intends to release given page back into
- * the pool of available (to the guest) pages.
- */
-static bool vmballoon_send_unlock_page(struct vmballoon *b, unsigned long pfn)
-{
- unsigned long status;
- u32 pfn32;
-
- pfn32 = (u32)pfn;
- if (pfn32 != pfn)
- return false;
-
- status = vmballoon_cmd(b, VMW_BALLOON_CMD_UNLOCK, pfn, 0);
- return status == VMW_BALLOON_SUCCESS;
-}
-
-static bool vmballoon_send_batched_unlock(struct vmballoon *b,
- unsigned int num_pages, bool is_2m_pages)
-{
- unsigned long pfn = PHYS_PFN(virt_to_phys(b->batch_page));
- unsigned long status, cmd;
-
- cmd = is_2m_pages ? VMW_BALLOON_CMD_BATCHED_2M_UNLOCK :
- VMW_BALLOON_CMD_BATCHED_UNLOCK;
-
- status = vmballoon_cmd(b, cmd, pfn, num_pages);
-
- return status == VMW_BALLOON_SUCCESS;
-}
-
static struct page *vmballoon_alloc_page(gfp_t flags, bool is_2m_page)
{
if (is_2m_page)
@@ -546,7 +522,8 @@ static int vmballoon_lock_page(struct vmballoon *b, unsigned int num_pages,

/* is_2m_pages can never happen as 2m pages support implies batching */

- locked = vmballoon_send_lock_page(b, page_to_pfn(page), &hv_status);
+ locked = vmballoon_send_lock_page(b, page_to_pfn(page), &hv_status,
+ true);

if (locked) {
STATS_INC(b->stats.refused_alloc[false]);
@@ -587,7 +564,7 @@ static int vmballoon_lock_batched_page(struct vmballoon *b,
int locked, i;
u16 size_per_page = vmballoon_page_size(is_2m_pages);

- locked = vmballoon_send_batched_lock(b, num_pages, is_2m_pages);
+ locked = vmballoon_send_batched_lock(b, num_pages, is_2m_pages, true);

if (locked > 0) {
for (i = 0; i < num_pages; i++) {
@@ -645,10 +622,12 @@ static int vmballoon_unlock_page(struct vmballoon *b, unsigned int num_pages,
{
struct page *page = b->page;
struct vmballoon_page_size *page_size = &b->page_sizes[false];
+ unsigned int hv_status;

/* is_2m_pages can never happen as 2m pages support implies batching */

- if (!vmballoon_send_unlock_page(b, page_to_pfn(page))) {
+ if (!vmballoon_send_lock_page(b, page_to_pfn(page), &hv_status,
+ false)) {
list_add(&page->lru, &page_size->pages);
return -EIO;
}
@@ -670,7 +649,8 @@ static int vmballoon_unlock_batched_page(struct vmballoon *b,
bool hv_success;
u16 size_per_page = vmballoon_page_size(is_2m_pages);

- hv_success = vmballoon_send_batched_unlock(b, num_pages, is_2m_pages);
+ hv_success = vmballoon_send_batched_lock(b, num_pages, is_2m_pages,
+ false);

if (!hv_success)
ret = -EIO;
--
2.17.1