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Commit 6c948757 authored by Nadav Amit's avatar Nadav Amit Committed by Greg Kroah-Hartman
Browse files

vmw_balloon: simplifying batch access 



The use of accessors for batch entries complicates the code and makes it
less readable. Remove it an instead use bit-fields.

Reviewed-by: default avatarXavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: default avatarNadav Amit <namit@vmware.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4c9a7d6a

drivers/misc/vmw_balloon.c

+30 −51
Original line number Diff line number Diff line
@@ -121,24 +121,6 @@ enum vmwballoon_capabilities { 


#define VMW_BALLOON_SUCCESS_WITH_CAPABILITIES	(0x03000000)



/* Batch page description */



/*

 * Layout of a page in the batch page:

 *

 * +-------------+----------+--------+

 * |             |          |        |

 * | Page number | Reserved | Status |

 * |             |          |        |

 * +-------------+----------+--------+

 * 64  PAGE_SHIFT          6         0

 *

 * The reserved field should be set to 0.

 */

#define VMW_BALLOON_BATCH_MAX_PAGES	(PAGE_SIZE / sizeof(u64))

#define VMW_BALLOON_BATCH_STATUS_MASK	((1UL << 5) - 1)

#define VMW_BALLOON_BATCH_PAGE_MASK	(~((1UL << PAGE_SHIFT) - 1))



#define VMW_BALLOON_CMD_WITH_TARGET_MASK			\

	((1UL << VMW_BALLOON_CMD_GET_TARGET)		|	\

	 (1UL << VMW_BALLOON_CMD_LOCK)			|	\
@@ -161,27 +143,6 @@ static const char * const vmballoon_cmd_names[] = { 
	[VMW_BALLOON_CMD_VMCI_DOORBELL_SET]	= "doorbellSet"

};



struct vmballoon_batch_page {

	u64 pages[VMW_BALLOON_BATCH_MAX_PAGES];

};



static u64 vmballoon_batch_get_pa(struct vmballoon_batch_page *batch, int idx)

{

	return batch->pages[idx] & VMW_BALLOON_BATCH_PAGE_MASK;

}



static int vmballoon_batch_get_status(struct vmballoon_batch_page *batch,

				int idx)

{

	return (int)(batch->pages[idx] & VMW_BALLOON_BATCH_STATUS_MASK);

}



static void vmballoon_batch_set_pa(struct vmballoon_batch_page *batch, int idx,

				u64 pa)

{

	batch->pages[idx] = pa;

}



#ifdef CONFIG_DEBUG_FS

struct vmballoon_stats {

	unsigned int timer;
@@ -225,6 +186,19 @@ struct vmballoon_page_size { 
	unsigned int n_refused_pages;

};



/**

 * struct vmballoon_batch_entry - a batch entry for lock or unlock.

 *

 * @status: the status of the operation, which is written by the hypervisor.

 * @reserved: reserved for future use. Must be set to zero.

 * @pfn: the physical frame number of the page to be locked or unlocked.

 */

struct vmballoon_batch_entry {

	u64 status : 5;

	u64 reserved : PAGE_SHIFT - 5;

	u64 pfn : 52;

} __packed;



struct vmballoon {

	struct vmballoon_page_size page_sizes[VMW_BALLOON_NUM_PAGE_SIZES];
@@ -240,7 +214,14 @@ struct vmballoon { 


	unsigned long capabilities;



	struct vmballoon_batch_page *batch_page;

	/**

	 * @batch_page: pointer to communication batch page.

	 *

	 * When batching is used, batch_page points to a page, which holds up to

	 * %VMW_BALLOON_BATCH_MAX_PAGES entries for locking or unlocking.

	 */

	struct vmballoon_batch_entry *batch_page;



	unsigned int batch_max_pages;

	struct page *page;
@@ -568,8 +549,7 @@ static int vmballoon_lock_batched_page(struct vmballoon *b, 


	if (locked > 0) {

		for (i = 0; i < num_pages; i++) {

			u64 pa = vmballoon_batch_get_pa(b->batch_page, i);

			struct page *p = pfn_to_page(pa >> PAGE_SHIFT);

			struct page *p = pfn_to_page(b->batch_page[i].pfn);



			vmballoon_free_page(p, is_2m_pages);

		}
@@ -578,12 +558,11 @@ static int vmballoon_lock_batched_page(struct vmballoon *b, 
	}



	for (i = 0; i < num_pages; i++) {

		u64 pa = vmballoon_batch_get_pa(b->batch_page, i);

		struct page *p = pfn_to_page(pa >> PAGE_SHIFT);

		struct page *p = pfn_to_page(b->batch_page[i].pfn);

		struct vmballoon_page_size *page_size =

				&b->page_sizes[is_2m_pages];



		locked = vmballoon_batch_get_status(b->batch_page, i);

		locked = b->batch_page[i].status;



		switch (locked) {

		case VMW_BALLOON_SUCCESS:
@@ -656,12 +635,11 @@ static int vmballoon_unlock_batched_page(struct vmballoon *b, 
		ret = -EIO;



	for (i = 0; i < num_pages; i++) {

		u64 pa = vmballoon_batch_get_pa(b->batch_page, i);

		struct page *p = pfn_to_page(pa >> PAGE_SHIFT);

		struct page *p = pfn_to_page(b->batch_page[i].pfn);

		struct vmballoon_page_size *page_size =

				&b->page_sizes[is_2m_pages];



		locked = vmballoon_batch_get_status(b->batch_page, i);

		locked = b->batch_page[i].status;

		if (!hv_success || locked != VMW_BALLOON_SUCCESS) {

			/*

			 * That page wasn't successfully unlocked by the
@@ -710,8 +688,8 @@ static void vmballoon_add_page(struct vmballoon *b, int idx, struct page *p) 
static void vmballoon_add_batched_page(struct vmballoon *b, int idx,

				struct page *p)

{

	vmballoon_batch_set_pa(b->batch_page, idx,

			(u64)page_to_pfn(p) << PAGE_SHIFT);

	b->batch_page[idx] = (struct vmballoon_batch_entry)

					{ .pfn = page_to_pfn(p) };

}



/*
@@ -967,7 +945,8 @@ static void vmballoon_reset(struct vmballoon *b) 


	if ((b->capabilities & VMW_BALLOON_BATCHED_CMDS) != 0) {

		b->ops = &vmballoon_batched_ops;

		b->batch_max_pages = VMW_BALLOON_BATCH_MAX_PAGES;

		b->batch_max_pages = PAGE_SIZE / sizeof(struct

							vmballoon_batch_entry);

		if (!vmballoon_init_batching(b)) {

			/*

			 * We failed to initialize batching, inform the monitor