From 3f32b3c093eddc03ed477ae0d7a6938db6b94a05 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sat, 2 Jan 2010 22:22:50 +0100 Subject: [PATCH] pcmcia: rsrc_nonstatic io memory probe improvements 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 Signed-off-by: Dominik Brodowski --- drivers/pcmcia/rsrc_nonstatic.c | 180 +++++++++++++++++++++----------- 1 file changed, 117 insertions(+), 63 deletions(-) diff --git a/drivers/pcmcia/rsrc_nonstatic.c b/drivers/pcmcia/rsrc_nonstatic.c index b886385f12e2..120d5ad99296 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); + if (b == -1) + return -EINVAL; + + *value = a; + + return 0; } -static int -cis_readable(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; - unsigned int info1, info2; - int ret = 0; + 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) { - ret = readable(s, res1, &info1); - ret += readable(s, res2, &info2); + ret = 0; + if (validate) { + ret = validate(s, res1, &info1); + ret += validate(s, res2, &info2); + } } free_region(res2); free_region(res1); - return (ret == 2) && (info1 == info2); + 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; + + return 0; } -static int -checksum_match(struct pcmcia_socket *s, unsigned long base, unsigned long size) -{ - struct resource *res1, *res2; - int a = -1, b = -1; - 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); - } - - free_region(res2); - free_region(res1); - - return (a == b) && (a >= 0); -} - -/*====================================================================== - - 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. - -======================================================================*/ - -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);