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pcmcia: rsrc_nonstatic io memory probe improvements
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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.

Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
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Dominik Brodowski committed Jan 17, 2010
1 parent 180c33e commit 3f32b3c
Showing 1 changed file with 114 additions and 60 deletions.
174 changes: 114 additions & 60 deletions drivers/pcmcia/rsrc_nonstatic.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand All @@ -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;
Expand Down Expand Up @@ -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;
Expand All @@ -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) {
Expand All @@ -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;
Expand All @@ -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;
Expand All @@ -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 */
Expand All @@ -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);
}
}
}
Expand All @@ -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;
Expand All @@ -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;
Expand All @@ -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)
Expand All @@ -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);
Expand Down Expand Up @@ -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);
Expand Down

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