diff options
author | Nadav Amit <namit@vmware.com> | 2018-09-20 10:30:10 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-25 20:11:42 +0200 |
commit | 6c94875799eaf99bfdbb0efce21d75e1c56e96d5 (patch) | |
tree | d0b4a73641c092ebcd50fb1ae01ac9c0592bbfa8 /drivers | |
parent | 4c9a7d6a771d6e9038049a49e26b350a6ee4ffd2 (diff) | |
download | linux-6c94875799eaf99bfdbb0efce21d75e1c56e96d5.tar.bz2 |
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: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/misc/vmw_balloon.c | 81 |
1 files changed, 30 insertions, 51 deletions
diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c index 5e5f61f207f4..7af70fc988b9 100644 --- a/drivers/misc/vmw_balloon.c +++ b/drivers/misc/vmw_balloon.c @@ -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 |