[PATCH 09/15] pcmcia: rsrc_nonstatic io memory probe improvements
Dominik Brodowski
linux at dominikbrodowski.net
Wed Jan 6 06:46:20 EST 2010
Add a lot of documentation to the rsrc_nonstatic io memory probe
functions. Also, add a first memory probe call -- just checking
whether request_resource() succeeds -- upon adding of resources.
Signed-off-by: Dominik Brodowski <linux at dominikbrodowski.net>
---
drivers/pcmcia/rsrc_nonstatic.c | 174 +++++++++++++++++++++++++-------------
1 files changed, 114 insertions(+), 60 deletions(-)
diff --git a/drivers/pcmcia/rsrc_nonstatic.c b/drivers/pcmcia/rsrc_nonstatic.c
index b886385..120d5ad 100644
--- a/drivers/pcmcia/rsrc_nonstatic.c
+++ b/drivers/pcmcia/rsrc_nonstatic.c
@@ -264,18 +264,15 @@ static void do_io_probe(struct pcmcia_socket *s, unsigned int base,
}
#endif
-/*======================================================================
-
- This is tricky... when we set up CIS memory, we try to validate
- the memory window space allocations.
-
-======================================================================*/
+/*======================================================================*/
-/* Validation function for cards with a valid CIS */
+/**
+ * readable() - iomem validation function for cards with a valid CIS
+ */
static int readable(struct pcmcia_socket *s, struct resource *res,
unsigned int *count)
{
- int ret = -1;
+ int ret = -EINVAL;
s->cis_mem.res = res;
s->cis_virt = ioremap(res->start, s->map_size);
@@ -286,13 +283,16 @@ static int readable(struct pcmcia_socket *s, struct resource *res,
s->cis_virt = NULL;
}
s->cis_mem.res = NULL;
- if ((ret != 0) || (*count == 0))
- return 0;
- return 1;
+ if ((ret) || (*count == 0))
+ return -EINVAL;
+ return 0;
}
-/* Validation function for simple memory cards */
-static int checksum(struct pcmcia_socket *s, struct resource *res)
+/**
+ * checksum() - iomem validation function for simple memory cards
+ */
+static int checksum(struct pcmcia_socket *s, struct resource *res,
+ unsigned int *value)
{
pccard_mem_map map;
int i, a = 0, b = -1, d;
@@ -320,61 +320,83 @@ static int checksum(struct pcmcia_socket *s, struct resource *res)
iounmap(virt);
}
- return (b == -1) ? -1 : (a>>1);
-}
-
-static int
-cis_readable(struct pcmcia_socket *s, unsigned long base, unsigned long size)
-{
- struct resource *res1, *res2;
- unsigned int info1, info2;
- int ret = 0;
-
- res1 = claim_region(s, base, size/2, IORESOURCE_MEM, "PCMCIA memprobe");
- res2 = claim_region(s, base + size/2, size/2, IORESOURCE_MEM,
- "PCMCIA memprobe");
-
- if (res1 && res2) {
- ret = readable(s, res1, &info1);
- ret += readable(s, res2, &info2);
- }
+ if (b == -1)
+ return -EINVAL;
- free_region(res2);
- free_region(res1);
+ *value = a;
- return (ret == 2) && (info1 == info2);
+ return 0;
}
-static int
-checksum_match(struct pcmcia_socket *s, unsigned long base, unsigned long size)
+/**
+ * do_validate_mem() - low level validate a memory region for PCMCIA use
+ * @s: PCMCIA socket to validate
+ * @base: start address of resource to check
+ * @size: size of resource to check
+ * @validate: validation function to use
+ *
+ * do_validate_mem() splits up the memory region which is to be checked
+ * into two parts. Both are passed to the @validate() function. If
+ * @validate() returns non-zero, or the value parameter to @validate()
+ * is zero, or the value parameter is different between both calls,
+ * the check fails, and -EINVAL is returned. Else, 0 is returned.
+ */
+static int do_validate_mem(struct pcmcia_socket *s,
+ unsigned long base, unsigned long size,
+ int validate (struct pcmcia_socket *s,
+ struct resource *res,
+ unsigned int *value))
{
struct resource *res1, *res2;
- int a = -1, b = -1;
+ unsigned int info1 = 1, info2 = 1;
+ int ret = -EINVAL;
res1 = claim_region(s, base, size/2, IORESOURCE_MEM, "PCMCIA memprobe");
res2 = claim_region(s, base + size/2, size/2, IORESOURCE_MEM,
"PCMCIA memprobe");
if (res1 && res2) {
- a = checksum(s, res1);
- b = checksum(s, res2);
+ ret = 0;
+ if (validate) {
+ ret = validate(s, res1, &info1);
+ ret += validate(s, res2, &info2);
+ }
}
free_region(res2);
free_region(res1);
- return (a == b) && (a >= 0);
-}
+ dev_dbg(&s->dev, "cs: memory probe 0x%06lx-0x%06lx: %p %p %u %u %u",
+ base, base+size-1, res1, res2, ret, info1, info2);
-/*======================================================================
+ if ((ret) || (info1 != info2) || (info1 == 0))
+ return -EINVAL;
- The memory probe. If the memory list includes a 64K-aligned block
- below 1MB, we probe in 64K chunks, and as soon as we accumulate at
- least mem_limit free space, we quit.
+ return 0;
+}
-======================================================================*/
-static int do_mem_probe(u_long base, u_long num, struct pcmcia_socket *s)
+/**
+ * do_mem_probe() - validate a memory region for PCMCIA use
+ * @s: PCMCIA socket to validate
+ * @base: start address of resource to check
+ * @num: size of resource to check
+ * @validate: validation function to use
+ * @fallback: validation function to use if validate fails
+ *
+ * do_mem_probe() checks a memory region for use by the PCMCIA subsystem.
+ * To do so, the area is split up into sensible parts, and then passed
+ * into the @validate() function. Only if @validate() and @fallback() fail,
+ * the area is marked as unavaibale for use by the PCMCIA subsystem. The
+ * function returns the size of the usable memory area.
+ */
+static int do_mem_probe(struct pcmcia_socket *s, u_long base, u_long num,
+ int validate (struct pcmcia_socket *s,
+ struct resource *res,
+ unsigned int *value),
+ int fallback (struct pcmcia_socket *s,
+ struct resource *res,
+ unsigned int *value))
{
struct socket_data *s_data = s->resource_data;
u_long i, j, bad, fail, step;
@@ -392,15 +414,14 @@ static int do_mem_probe(u_long base, u_long num, struct pcmcia_socket *s)
for (i = j = base; i < base+num; i = j + step) {
if (!fail) {
for (j = i; j < base+num; j += step) {
- if (cis_readable(s, j, step))
+ if (!do_validate_mem(s, j, step, validate))
break;
}
fail = ((i == base) && (j == base+num));
}
- if (fail) {
- for (j = i; j < base+num; j += 2*step)
- if (checksum_match(s, j, step) &&
- checksum_match(s, j + step, step))
+ if ((fail) && (fallback)) {
+ for (j = i; j < base+num; j += step)
+ if (!do_validate_mem(s, j, step, fallback))
break;
}
if (i != j) {
@@ -415,8 +436,14 @@ static int do_mem_probe(u_long base, u_long num, struct pcmcia_socket *s)
return num - bad;
}
+
#ifdef CONFIG_PCMCIA_PROBE
+/**
+ * inv_probe() - top-to-bottom search for one usuable high memory area
+ * @s: PCMCIA socket to validate
+ * @m: resource_map to check
+ */
static u_long inv_probe(struct resource_map *m, struct pcmcia_socket *s)
{
struct socket_data *s_data = s->resource_data;
@@ -431,9 +458,18 @@ static u_long inv_probe(struct resource_map *m, struct pcmcia_socket *s)
}
if (m->base < 0x100000)
return 0;
- return do_mem_probe(m->base, m->num, s);
+ return do_mem_probe(s, m->base, m->num, readable, checksum);
}
+/**
+ * validate_mem() - memory probe function
+ * @s: PCMCIA socket to validate
+ * @probe_mask: MEM_PROBE_LOW | MEM_PROBE_HIGH
+ *
+ * The memory probe. If the memory list includes a 64K-aligned block
+ * below 1MB, we probe in 64K chunks, and as soon as we accumulate at
+ * least mem_limit free space, we quit. Returns 0 on usuable ports.
+ */
static int validate_mem(struct pcmcia_socket *s, unsigned int probe_mask)
{
struct resource_map *m, mm;
@@ -456,7 +492,8 @@ static int validate_mem(struct pcmcia_socket *s, unsigned int probe_mask)
if (mm.base >= 0x100000)
continue;
if ((mm.base | mm.num) & 0xffff) {
- ok += do_mem_probe(mm.base, mm.num, s);
+ ok += do_mem_probe(s, mm.base, mm.num, readable,
+ checksum);
continue;
}
/* Special probe for 64K-aligned block */
@@ -466,7 +503,8 @@ static int validate_mem(struct pcmcia_socket *s, unsigned int probe_mask)
if (ok >= mem_limit)
sub_interval(&s_data->mem_db, b, 0x10000);
else
- ok += do_mem_probe(b, 0x10000, s);
+ ok += do_mem_probe(s, b, 0x10000,
+ readable, checksum);
}
}
}
@@ -479,6 +517,13 @@ static int validate_mem(struct pcmcia_socket *s, unsigned int probe_mask)
#else /* CONFIG_PCMCIA_PROBE */
+/**
+ * validate_mem() - memory probe function
+ * @s: PCMCIA socket to validate
+ * @probe_mask: ignored
+ *
+ * Returns 0 on usuable ports.
+ */
static int validate_mem(struct pcmcia_socket *s, unsigned int probe_mask)
{
struct resource_map *m, mm;
@@ -487,7 +532,7 @@ static int validate_mem(struct pcmcia_socket *s, unsigned int probe_mask)
for (m = s_data->mem_db.next; m != &s_data->mem_db; m = mm.next) {
mm = *m;
- ok += do_mem_probe(mm.base, mm.num, s);
+ ok += do_mem_probe(s, mm.base, mm.num, readable, checksum);
}
if (ok > 0)
return 0;
@@ -497,7 +542,13 @@ static int validate_mem(struct pcmcia_socket *s, unsigned int probe_mask)
#endif /* CONFIG_PCMCIA_PROBE */
-/*
+/**
+ * pcmcia_nonstatic_validate_mem() - try to validate iomem for PCMCIA use
+ * @s: PCMCIA socket to validate
+ *
+ * This is tricky... when we set up CIS memory, we try to validate
+ * the memory window space allocations.
+ *
* Locking note: Must be called with skt_mutex held!
*/
static int pcmcia_nonstatic_validate_mem(struct pcmcia_socket *s)
@@ -515,10 +566,11 @@ static int pcmcia_nonstatic_validate_mem(struct pcmcia_socket *s)
probe_mask = MEM_PROBE_HIGH;
if (probe_mask & ~s_data->rsrc_mem_probe) {
- if (s->state & SOCKET_PRESENT)
+ if (s->state & SOCKET_PRESENT) {
ret = validate_mem(s, probe_mask);
- if (!ret)
- s_data->rsrc_mem_probe |= probe_mask;
+ if (!ret)
+ s_data->rsrc_mem_probe |= probe_mask;
+ }
}
mutex_unlock(&rsrc_mutex);
@@ -723,6 +775,8 @@ static int adjust_memory(struct pcmcia_socket *s, unsigned int action, unsigned
switch (action) {
case ADD_MANAGED_RESOURCE:
ret = add_interval(&data->mem_db, start, size);
+ if (!ret)
+ do_mem_probe(s, start, size, NULL, NULL);
break;
case REMOVE_MANAGED_RESOURCE:
ret = sub_interval(&data->mem_db, start, size);
--
1.6.3.3
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