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Add a rman_reserve_resource_bound() function that takes an additional

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argument specifying the boundary for the resource allocation.
Use ulmin()/ulmax() instead of min()/max() in some places to correctly
deal with the u_long resource range specifications.
This commit is contained in:
Thomas Moestl 2001-12-21 21:40:55 +00:00
parent 70527a680b
commit 13fb665772
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=88372
2 changed files with 38 additions and 11 deletions
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46
sys/kern/subr_rman.c
View File

@ -175,12 +175,13 @@ rman_fini(struct rman *rm)
}
struct resource *
rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count,
u_int flags, struct device *dev)
rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end,
u_long count, u_long bound, u_int flags,
struct device *dev)
{
u_int want_activate;
struct resource *r, *s, *rv;
u_long rstart, rend;
u_long rstart, rend, amask, bmask;
rv = 0;
@ -202,6 +203,9 @@ rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count,
goto out;
}
amask = (1ul << RF_ALIGNMENT(flags)) - 1;
/* If bound is 0, bmask will also be 0 */
bmask = ~(bound - 1);
/*
* First try to find an acceptable totally-unshared region.
*/
@ -215,10 +219,19 @@ rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count,
DPRINTF(("region is allocated\n"));
continue;
}
rstart = max(s->r_start, start);
rstart = (rstart + ((1ul << RF_ALIGNMENT(flags))) - 1) &
~((1ul << RF_ALIGNMENT(flags)) - 1);
rend = min(s->r_end, max(rstart + count, end));
rstart = ulmax(s->r_start, start);
/*
* Try to find a region by adjusting to boundary and alignment
* until both conditions are satisfied. This is not an optimal
* algorithm, but in most cases it isn't really bad, either.
*/
do {
rstart = (rstart + amask) & ~amask;
if (((rstart ^ (rstart + count)) & bmask) != 0)
rstart += bound - (rstart & ~bmask);
} while ((rstart & amask) != 0 && rstart < end &&
rstart < s->r_end);
rend = ulmin(s->r_end, ulmax(rstart + count, end));
DPRINTF(("truncated region: [%#lx, %#lx]; size %#lx (requested %#lx)\n",
rstart, rend, (rend - rstart + 1), count));
@ -313,10 +326,12 @@ rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count,
break;
if ((s->r_flags & flags) != flags)
continue;
rstart = max(s->r_start, start);
rend = min(s->r_end, max(start + count, end));
rstart = ulmax(s->r_start, start);
rend = ulmin(s->r_end, ulmax(start + count, end));
if (s->r_start >= start && s->r_end <= end
&& (s->r_end - s->r_start + 1) == count) {
&& (s->r_end - s->r_start + 1) == count &&
(s->r_start & amask) == 0 &&
((s->r_start ^ s->r_end) & bmask) == 0) {
rv = malloc(sizeof *rv, M_RMAN, M_NOWAIT | M_ZERO);
if (rv == 0)
goto out;
@ -368,6 +383,15 @@ rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count,
return (rv);
}
struct resource *
rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count,
u_int flags, struct device *dev)
{
return (rman_reserve_resource_bound(rm, start, end, count, 0, flags,
dev));
}
static int
int_rman_activate_resource(struct rman *rm, struct resource *r,
struct resource **whohas)
@ -575,7 +599,7 @@ rman_make_alignment_flags(uint32_t size)
* Find the hightest bit set, and add one if more than one bit
* set. We're effectively computing the ceil(log2(size)) here.
*/
for (i = 32; i > 0; i--)
for (i = 31; i > 0; i--)
if ((1 << i) & size)
break;
if (~(1 << i) & size)

3
sys/sys/rman.h
View File

@ -126,6 +126,9 @@ int rman_release_resource(struct resource *r);
struct resource *rman_reserve_resource(struct rman *rm, u_long start,
u_long end, u_long count,
u_int flags, struct device *dev);
struct resource *rman_reserve_resource_bound(struct rman *rm, u_long start,
u_long end, u_long count, u_long bound,
u_int flags, struct device *dev);
uint32_t rman_make_alignment_flags(uint32_t size);
#define rman_get_start(r) ((r)->r_start)