int pcmcia_read_cis_mem()

in cistpl.c [134:206]

• 64 lines of code
• 13 McCabe index (conditional complexity)

int pcmcia_read_cis_mem(struct pcmcia_socket *s, int attr, u_int addr,
		 u_int len, void *ptr)
{
	void __iomem *sys, *end;
	unsigned char *buf = ptr;

	dev_dbg(&s->dev, "pcmcia_read_cis_mem(%d, %#x, %u)\n", attr, addr, len);

	if (attr & IS_INDIRECT) {
		/* Indirect accesses use a bunch of special registers at fixed
		   locations in common memory */
		u_char flags = ICTRL0_COMMON|ICTRL0_AUTOINC|ICTRL0_BYTEGRAN;
		if (attr & IS_ATTR) {
			addr *= 2;
			flags = ICTRL0_AUTOINC;
		}

		sys = set_cis_map(s, 0, MAP_ACTIVE |
				((cis_width) ? MAP_16BIT : 0));
		if (!sys) {
			dev_dbg(&s->dev, "could not map memory\n");
			memset(ptr, 0xff, len);
			return -1;
		}

		writeb(flags, sys+CISREG_ICTRL0);
		writeb(addr & 0xff, sys+CISREG_IADDR0);
		writeb((addr>>8) & 0xff, sys+CISREG_IADDR1);
		writeb((addr>>16) & 0xff, sys+CISREG_IADDR2);
		writeb((addr>>24) & 0xff, sys+CISREG_IADDR3);
		for ( ; len > 0; len--, buf++)
			*buf = readb(sys+CISREG_IDATA0);
	} else {
		u_int inc = 1, card_offset, flags;

		if (addr > CISTPL_MAX_CIS_SIZE) {
			dev_dbg(&s->dev,
				"attempt to read CIS mem at addr %#x", addr);
			memset(ptr, 0xff, len);
			return -1;
		}

		flags = MAP_ACTIVE | ((cis_width) ? MAP_16BIT : 0);
		if (attr) {
			flags |= MAP_ATTRIB;
			inc++;
			addr *= 2;
		}

		card_offset = addr & ~(s->map_size-1);
		while (len) {
			sys = set_cis_map(s, card_offset, flags);
			if (!sys) {
				dev_dbg(&s->dev, "could not map memory\n");
				memset(ptr, 0xff, len);
				return -1;
			}
			end = sys + s->map_size;
			sys = sys + (addr & (s->map_size-1));
			for ( ; len > 0; len--, buf++, sys += inc) {
				if (sys == end)
					break;
				*buf = readb(sys);
			}
			card_offset += s->map_size;
			addr = 0;
		}
	}
	dev_dbg(&s->dev, "  %#2.2x %#2.2x %#2.2x %#2.2x ...\n",
		*(u_char *)(ptr+0), *(u_char *)(ptr+1),
		*(u_char *)(ptr+2), *(u_char *)(ptr+3));
	return 0;
}