linux/drivers/pnp/support.c
Bjorn Helgaas ea44c1d60d PNP: fix formatting of dbg_pnp_show_resources() output
Each resource should be printed on its own line, so start snprintf'ing
at the beginning of the buffer every time through the loop.

Also, use scnprintf() rather than snprintf() when building up the
buffer to print.  scnprintf() returns the number of characters actually
written into the buffer (not including the trailing NULL).

snprintf() returns the number of characters that *would be* written,
assuming everything would fit in the buffer.  That's nice if we want to
resize the buffer to make sure everything fits, but in this case, I
just want to keep from overflowing the buffer, and it's OK if the
output is truncated.

Using snprintf() meant that my "len" could grow to be more than the
the buffer size, which makes "sizeof(buf) - len" negative, which causes
this alarming WARN_ON:
    http://marc.info/?l=linux-kernel&m=121736480005656&w=2

More useful snprintf/scnprintf discussion:
    http://lwn.net/Articles/69419/

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Reported-by: Pete Clements <clem@clem.clem-digital.net>
Cc: Rene Herman <rene.herman@keyaccess.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-01 12:46:41 -07:00

214 lines
5.5 KiB
C

/*
* support.c - standard functions for the use of pnp protocol drivers
*
* Copyright 2003 Adam Belay <ambx1@neo.rr.com>
* Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
* Bjorn Helgaas <bjorn.helgaas@hp.com>
*/
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/pnp.h>
#include "base.h"
/**
* pnp_is_active - Determines if a device is active based on its current
* resources
* @dev: pointer to the desired PnP device
*/
int pnp_is_active(struct pnp_dev *dev)
{
/*
* I don't think this is very reliable because pnp_disable_dev()
* only clears out auto-assigned resources.
*/
if (!pnp_port_start(dev, 0) && pnp_port_len(dev, 0) <= 1 &&
!pnp_mem_start(dev, 0) && pnp_mem_len(dev, 0) <= 1 &&
pnp_irq(dev, 0) == -1 && pnp_dma(dev, 0) == -1)
return 0;
else
return 1;
}
EXPORT_SYMBOL(pnp_is_active);
/*
* Functionally similar to acpi_ex_eisa_id_to_string(), but that's
* buried in the ACPI CA, and we can't depend on it being present.
*/
void pnp_eisa_id_to_string(u32 id, char *str)
{
id = be32_to_cpu(id);
/*
* According to the specs, the first three characters are five-bit
* compressed ASCII, and the left-over high order bit should be zero.
* However, the Linux ISAPNP code historically used six bits for the
* first character, and there seem to be IDs that depend on that,
* e.g., "nEC8241" in the Linux 8250_pnp serial driver and the
* FreeBSD sys/pc98/cbus/sio_cbus.c driver.
*/
str[0] = 'A' + ((id >> 26) & 0x3f) - 1;
str[1] = 'A' + ((id >> 21) & 0x1f) - 1;
str[2] = 'A' + ((id >> 16) & 0x1f) - 1;
str[3] = hex_asc_hi(id >> 8);
str[4] = hex_asc_lo(id >> 8);
str[5] = hex_asc_hi(id);
str[6] = hex_asc_lo(id);
str[7] = '\0';
}
char *pnp_resource_type_name(struct resource *res)
{
switch (pnp_resource_type(res)) {
case IORESOURCE_IO:
return "io";
case IORESOURCE_MEM:
return "mem";
case IORESOURCE_IRQ:
return "irq";
case IORESOURCE_DMA:
return "dma";
}
return NULL;
}
void dbg_pnp_show_resources(struct pnp_dev *dev, char *desc)
{
#ifdef DEBUG
char buf[128];
int len;
struct pnp_resource *pnp_res;
struct resource *res;
if (list_empty(&dev->resources)) {
dev_dbg(&dev->dev, "%s: no current resources\n", desc);
return;
}
dev_dbg(&dev->dev, "%s: current resources:\n", desc);
list_for_each_entry(pnp_res, &dev->resources, list) {
res = &pnp_res->res;
len = 0;
len += scnprintf(buf + len, sizeof(buf) - len, " %-3s ",
pnp_resource_type_name(res));
if (res->flags & IORESOURCE_DISABLED) {
dev_dbg(&dev->dev, "%sdisabled\n", buf);
continue;
}
switch (pnp_resource_type(res)) {
case IORESOURCE_IO:
case IORESOURCE_MEM:
len += scnprintf(buf + len, sizeof(buf) - len,
"%#llx-%#llx flags %#lx",
(unsigned long long) res->start,
(unsigned long long) res->end,
res->flags);
break;
case IORESOURCE_IRQ:
case IORESOURCE_DMA:
len += scnprintf(buf + len, sizeof(buf) - len,
"%lld flags %#lx",
(unsigned long long) res->start,
res->flags);
break;
}
dev_dbg(&dev->dev, "%s\n", buf);
}
#endif
}
char *pnp_option_priority_name(struct pnp_option *option)
{
switch (pnp_option_priority(option)) {
case PNP_RES_PRIORITY_PREFERRED:
return "preferred";
case PNP_RES_PRIORITY_ACCEPTABLE:
return "acceptable";
case PNP_RES_PRIORITY_FUNCTIONAL:
return "functional";
}
return "invalid";
}
void dbg_pnp_show_option(struct pnp_dev *dev, struct pnp_option *option)
{
#ifdef DEBUG
char buf[128];
int len = 0, i;
struct pnp_port *port;
struct pnp_mem *mem;
struct pnp_irq *irq;
struct pnp_dma *dma;
if (pnp_option_is_dependent(option))
len += scnprintf(buf + len, sizeof(buf) - len,
" dependent set %d (%s) ",
pnp_option_set(option),
pnp_option_priority_name(option));
else
len += scnprintf(buf + len, sizeof(buf) - len,
" independent ");
switch (option->type) {
case IORESOURCE_IO:
port = &option->u.port;
len += scnprintf(buf + len, sizeof(buf) - len, "io min %#llx "
"max %#llx align %lld size %lld flags %#x",
(unsigned long long) port->min,
(unsigned long long) port->max,
(unsigned long long) port->align,
(unsigned long long) port->size, port->flags);
break;
case IORESOURCE_MEM:
mem = &option->u.mem;
len += scnprintf(buf + len, sizeof(buf) - len, "mem min %#llx "
"max %#llx align %lld size %lld flags %#x",
(unsigned long long) mem->min,
(unsigned long long) mem->max,
(unsigned long long) mem->align,
(unsigned long long) mem->size, mem->flags);
break;
case IORESOURCE_IRQ:
irq = &option->u.irq;
len += scnprintf(buf + len, sizeof(buf) - len, "irq");
if (bitmap_empty(irq->map.bits, PNP_IRQ_NR))
len += scnprintf(buf + len, sizeof(buf) - len,
" <none>");
else {
for (i = 0; i < PNP_IRQ_NR; i++)
if (test_bit(i, irq->map.bits))
len += scnprintf(buf + len,
sizeof(buf) - len,
" %d", i);
}
len += scnprintf(buf + len, sizeof(buf) - len, " flags %#x",
irq->flags);
if (irq->flags & IORESOURCE_IRQ_OPTIONAL)
len += scnprintf(buf + len, sizeof(buf) - len,
" (optional)");
break;
case IORESOURCE_DMA:
dma = &option->u.dma;
len += scnprintf(buf + len, sizeof(buf) - len, "dma");
if (!dma->map)
len += scnprintf(buf + len, sizeof(buf) - len,
" <none>");
else {
for (i = 0; i < 8; i++)
if (dma->map & (1 << i))
len += scnprintf(buf + len,
sizeof(buf) - len,
" %d", i);
}
len += scnprintf(buf + len, sizeof(buf) - len, " (bitmask %#x) "
"flags %#x", dma->map, dma->flags);
break;
}
dev_dbg(&dev->dev, "%s\n", buf);
#endif
}