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Commit 6e1af384 authored by Scott Wood's avatar Scott Wood Committed by Paul Mackerras
Browse files

[POWERPC] bootwrapper: Add dt_xlate_reg(), and use it to find serial registers. 



dt_xlate_reg() uses the ranges properties of a node's parentage to find
the absolute physical address of the node's registers.

The ns16550 driver uses this when no virtual-reg property is found.

Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent dbf8eefa

arch/powerpc/boot/devtree.c

+178 −0
Original line number Diff line number Diff line
@@ -109,3 +109,181 @@ void __dt_fixup_mac_addresses(u32 startindex, ...) 
	}

	va_end(ap);

}



#define MAX_ADDR_CELLS 4

#define MAX_RANGES 8



static void get_reg_format(void *node, u32 *naddr, u32 *nsize)

{

	if (getprop(node, "#address-cells", naddr, 4) != 4)

		*naddr = 2;

	if (getprop(node, "#size-cells", nsize, 4) != 4)

		*nsize = 1;

}



static void copy_val(u32 *dest, u32 *src, int naddr)

{

	memset(dest, 0, (MAX_ADDR_CELLS - naddr) * 4);

	memcpy(dest, src, naddr * 4);

}



static int sub_reg(u32 *reg, u32 *sub)

{

	int i, borrow = 0;



	for (i = 0; i < MAX_ADDR_CELLS; i++) {

		int prev_borrow = borrow;

		borrow = reg[i] < sub[i] + prev_borrow;

		reg[i] -= sub[i] + prev_borrow;

	}



	return !borrow;

}



static int add_reg(u32 *reg, u32 *add)

{

	int i, carry = 0;



	for (i = 0; i < MAX_ADDR_CELLS; i++) {

		u64 tmp = (u64)reg[i] + add[i] + carry;

		carry = tmp >> 32;

		reg[i] = (u32)tmp;

	}



	return !carry;

}



/* It is assumed that if the first byte of reg fits in a

 * range, then the whole reg block fits.

 */

static int compare_reg(u32 *reg, u32 *range, u32 *rangesize)

{

	int i;

	u32 end;



	for (i = 0; i < MAX_ADDR_CELLS; i++) {

		if (reg[i] < range[i])

			return 0;

		if (reg[i] > range[i])

			break;

	}



	for (i = 0; i < MAX_ADDR_CELLS; i++) {

		end = range[i] + rangesize[i];



		if (reg[i] < end)

			break;

		if (reg[i] > end)

			return 0;

	}



	return reg[i] != end;

}



/* reg must be MAX_ADDR_CELLS */

static int find_range(u32 *reg, u32 *ranges, int nregaddr,

                      int naddr, int nsize, int buflen)

{

	int nrange = nregaddr + naddr + nsize;

	int i;



	for (i = 0; i + nrange <= buflen; i += nrange) {

		u32 range_addr[MAX_ADDR_CELLS];

		u32 range_size[MAX_ADDR_CELLS];



		copy_val(range_addr, ranges + i, naddr);

		copy_val(range_size, ranges + i + nregaddr + naddr, nsize);



		if (compare_reg(reg, range_addr, range_size))

			return i;

	}



	return -1;

}



/* Currently only generic buses without special encodings are supported.

 * In particular, PCI is not supported.  Also, only the beginning of the

 * reg block is tracked; size is ignored except in ranges.

 */

int dt_xlate_reg(void *node, int res, unsigned long *addr,

                 unsigned long *size)

{

	u32 last_addr[MAX_ADDR_CELLS];

	u32 this_addr[MAX_ADDR_CELLS];

	u32 buf[MAX_ADDR_CELLS * MAX_RANGES * 3];

	void *parent;

	u64 ret_addr, ret_size;

	u32 naddr, nsize, prev_naddr;

	int buflen, offset;



	parent = get_parent(node);

	if (!parent)

		return 0;



	get_reg_format(parent, &naddr, &nsize);



	if (nsize > 2)

		return 0;



	buflen = getprop(node, "reg", buf, sizeof(buf)) / 4;

	offset = (naddr + nsize) * res;



	if (buflen < offset + naddr + nsize)

		return 0;



	copy_val(last_addr, buf + offset, naddr);



	ret_size = buf[offset + naddr];

	if (nsize == 2) {

		ret_size <<= 32;

		ret_size |= buf[offset + naddr + 1];

	}



	while ((node = get_parent(node))) {

		prev_naddr = naddr;



		get_reg_format(node, &naddr, &nsize);



		buflen = getprop(node, "ranges", buf, sizeof(buf));

		if (buflen < 0)

			continue;

		if (buflen > sizeof(buf))

			return 0;



		offset = find_range(last_addr, buf, prev_naddr,

		                    naddr, nsize, buflen / 4);



		if (offset < 0)

			return 0;



		copy_val(this_addr, buf + offset, prev_naddr);



		if (!sub_reg(last_addr, this_addr))

			return 0;



		copy_val(this_addr, buf + offset + prev_naddr, naddr);



		if (!add_reg(last_addr, this_addr))

			return 0;

	}



	if (naddr > 2)

		return 0;



	ret_addr = last_addr[0];

	if (naddr == 2) {

		ret_addr <<= 32;

		ret_addr |= last_addr[1];

	}



	if (sizeof(void *) == 4 &&

	    (ret_addr >= 0x100000000ULL || ret_size > 0x100000000ULL ||

	     ret_addr + ret_size > 0x100000000ULL))

		return 0;



	*addr = ret_addr;

	if (size)

		*size = ret_size;



	return 1;

}

arch/powerpc/boot/ns16550.c

+7 −2
Original line number Diff line number Diff line
@@ -55,11 +55,16 @@ static u8 ns16550_tstc(void) 
int ns16550_console_init(void *devp, struct serial_console_data *scdp)

{

	int n;

	unsigned long reg_phys;



	n = getprop(devp, "virtual-reg", &reg_base, sizeof(reg_base));

	if (n != sizeof(reg_base))

	if (n != sizeof(reg_base)) {

		if (!dt_xlate_reg(devp, 0, &reg_phys, NULL))

			return -1;



		reg_base = (void *)reg_phys;

	}



	n = getprop(devp, "reg-shift", &reg_shift, sizeof(reg_shift));

	if (n != sizeof(reg_shift))

		reg_shift = 0;

arch/powerpc/boot/ops.h

+2 −0
Original line number Diff line number Diff line
@@ -82,6 +82,8 @@ int ns16550_console_init(void *devp, struct serial_console_data *scdp); 
void *simple_alloc_init(char *base, u32 heap_size, u32 granularity,

		u32 max_allocs);

extern void flush_cache(void *, unsigned long);

int dt_xlate_reg(void *node, int res, unsigned long *addr,

                 unsigned long *size);



static inline void *finddevice(const char *name)

{