lkml.org 
[lkml]   [2017]   [Sep]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3/4] xen: add grant interface version dependent constants to gnttab_ops
Date
Instead of having multiple variables with constants like
grant_table_version or grefs_per_grant_frame add those to struct
gnttab_ops and access them just via the gnttab_interface pointer.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
drivers/xen/grant-table.c | 73 ++++++++++++++++++++++++++++-------------------
1 file changed, 43 insertions(+), 30 deletions(-)

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 02451a696cc5..573af785c425 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -78,6 +78,14 @@ static union {
/*This is a structure of function pointers for grant table*/
struct gnttab_ops {
/*
+ * Version of the grant interface.
+ */
+ unsigned int version;
+ /*
+ * Grant refs per grant frame.
+ */
+ unsigned int grefs_per_grant_frame;
+ /*
* Mapping a list of frames for storing grant entries. Frames parameter
* is used to store grant table address when grant table being setup,
* nr_gframes is the number of frames to map grant table. Returning
@@ -146,9 +154,6 @@ static const struct gnttab_ops *gnttab_interface;
/* This reflects status of grant entries, so act as a global value. */
static grant_status_t *grstatus;

-static int grant_table_version;
-static int grefs_per_grant_frame;
-
static struct gnttab_free_callback *gnttab_free_callback_list;

static int gnttab_expand(unsigned int req_entries);
@@ -648,19 +653,26 @@ void gnttab_cancel_free_callback(struct gnttab_free_callback *callback)
}
EXPORT_SYMBOL_GPL(gnttab_cancel_free_callback);

+static unsigned int gnttab_frames(unsigned int frames, unsigned int align)
+{
+ return (frames * gnttab_interface->grefs_per_grant_frame + align - 1) /
+ align;
+}
+
static int grow_gnttab_list(unsigned int more_frames)
{
unsigned int new_nr_grant_frames, extra_entries, i;
unsigned int nr_glist_frames, new_nr_glist_frames;
+ unsigned int grefs_per_frame;

- BUG_ON(grefs_per_grant_frame == 0);
+ BUG_ON(gnttab_interface == NULL);
+ grefs_per_frame = gnttab_interface->grefs_per_grant_frame;

new_nr_grant_frames = nr_grant_frames + more_frames;
- extra_entries = more_frames * grefs_per_grant_frame;
+ extra_entries = more_frames * grefs_per_frame;

- nr_glist_frames = (nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP;
- new_nr_glist_frames =
- (new_nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP;
+ nr_glist_frames = gnttab_frames(nr_grant_frames, RPP);
+ new_nr_glist_frames = gnttab_frames(new_nr_grant_frames, RPP);
for (i = nr_glist_frames; i < new_nr_glist_frames; i++) {
gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_ATOMIC);
if (!gnttab_list[i])
@@ -668,12 +680,12 @@ static int grow_gnttab_list(unsigned int more_frames)
}


- for (i = grefs_per_grant_frame * nr_grant_frames;
- i < grefs_per_grant_frame * new_nr_grant_frames - 1; i++)
+ for (i = grefs_per_frame * nr_grant_frames;
+ i < grefs_per_frame * new_nr_grant_frames - 1; i++)
gnttab_entry(i) = i + 1;

gnttab_entry(i) = gnttab_free_head;
- gnttab_free_head = grefs_per_grant_frame * nr_grant_frames;
+ gnttab_free_head = grefs_per_frame * nr_grant_frames;
gnttab_free_count += extra_entries;

nr_grant_frames = new_nr_grant_frames;
@@ -1025,8 +1037,8 @@ EXPORT_SYMBOL_GPL(gnttab_unmap_refs_sync);

static unsigned int nr_status_frames(unsigned int nr_grant_frames)
{
- BUG_ON(grefs_per_grant_frame == 0);
- return (nr_grant_frames * grefs_per_grant_frame + SPP - 1) / SPP;
+ BUG_ON(gnttab_interface == NULL);
+ return gnttab_frames(nr_grant_frames, SPP);
}

static int gnttab_map_frames_v1(xen_pfn_t *frames, unsigned int nr_gframes)
@@ -1154,6 +1166,9 @@ static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
}

static const struct gnttab_ops gnttab_v1_ops = {
+ .version = 1,
+ .grefs_per_grant_frame = XEN_PAGE_SIZE /
+ sizeof(struct grant_entry_v1),
.map_frames = gnttab_map_frames_v1,
.unmap_frames = gnttab_unmap_frames_v1,
.update_entry = gnttab_update_entry_v1,
@@ -1163,6 +1178,9 @@ static const struct gnttab_ops gnttab_v1_ops = {
};

static const struct gnttab_ops gnttab_v2_ops = {
+ .version = 2,
+ .grefs_per_grant_frame = XEN_PAGE_SIZE /
+ sizeof(union grant_entry_v2),
.map_frames = gnttab_map_frames_v2,
.unmap_frames = gnttab_unmap_frames_v2,
.update_entry = gnttab_update_entry_v2,
@@ -1179,18 +1197,12 @@ static void gnttab_request_version(void)
gsv.version = 1;

rc = HYPERVISOR_grant_table_op(GNTTABOP_set_version, &gsv, 1);
- if (rc == 0 && gsv.version == 2) {
- grant_table_version = 2;
- grefs_per_grant_frame = XEN_PAGE_SIZE /
- sizeof(union grant_entry_v2);
+ if (rc == 0 && gsv.version == 2)
gnttab_interface = &gnttab_v2_ops;
- } else {
- grant_table_version = 1;
- grefs_per_grant_frame = XEN_PAGE_SIZE /
- sizeof(struct grant_entry_v1);
+ else
gnttab_interface = &gnttab_v1_ops;
- }
- pr_info("Grant tables using version %d layout\n", grant_table_version);
+ pr_info("Grant tables using version %d layout\n",
+ gnttab_interface->version);
}

static int gnttab_setup(void)
@@ -1230,10 +1242,10 @@ static int gnttab_expand(unsigned int req_entries)
int rc;
unsigned int cur, extra;

- BUG_ON(grefs_per_grant_frame == 0);
+ BUG_ON(gnttab_interface == NULL);
cur = nr_grant_frames;
- extra = ((req_entries + (grefs_per_grant_frame-1)) /
- grefs_per_grant_frame);
+ extra = ((req_entries + gnttab_interface->grefs_per_grant_frame - 1) /
+ gnttab_interface->grefs_per_grant_frame);
if (cur + extra > gnttab_max_grant_frames()) {
pr_warn_ratelimited("xen/grant-table: max_grant_frames reached"
" cur=%u extra=%u limit=%u"
@@ -1265,16 +1277,16 @@ int gnttab_init(void)
/* Determine the maximum number of frames required for the
* grant reference free list on the current hypervisor.
*/
- BUG_ON(grefs_per_grant_frame == 0);
+ BUG_ON(gnttab_interface == NULL);
max_nr_glist_frames = (max_nr_grant_frames *
- grefs_per_grant_frame / RPP);
+ gnttab_interface->grefs_per_grant_frame / RPP);

gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *),
GFP_KERNEL);
if (gnttab_list == NULL)
return -ENOMEM;

- nr_glist_frames = (nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP;
+ nr_glist_frames = gnttab_frames(nr_grant_frames, RPP);
for (i = 0; i < nr_glist_frames; i++) {
gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL);
if (gnttab_list[i] == NULL) {
@@ -1293,7 +1305,8 @@ int gnttab_init(void)
goto ini_nomem;
}

- nr_init_grefs = nr_grant_frames * grefs_per_grant_frame;
+ nr_init_grefs = nr_grant_frames *
+ gnttab_interface->grefs_per_grant_frame;

for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++)
gnttab_entry(i) = i + 1;
--
2.12.3
\
 
 \ /
  Last update: 2017-09-08 18:05    [W:0.314 / U:5.288 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site