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authorScott Wood <scottwood@freescale.com>2007-03-26 15:52:24 -0500
committerPaul Mackerras <paulus@samba.org>2007-04-13 03:55:15 +1000
commit6e1af384f1c1742ae6d86bbf779d4fa020c509bc (patch)
treee07f1cc421fdc4e51847d26bb9bdccc53341e1cc /arch/powerpc/boot/devtree.c
parentdbf8eefa2b814d6922492120bfa46d4bc42ceb20 (diff)
[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: Scott Wood <scottwood@freescale.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/boot/devtree.c')
-rw-r--r--arch/powerpc/boot/devtree.c178
1 files changed, 178 insertions, 0 deletions
diff --git a/arch/powerpc/boot/devtree.c b/arch/powerpc/boot/devtree.c
index 708cadebeb46..23492d7fb556 100644
--- a/arch/powerpc/boot/devtree.c
+++ b/arch/powerpc/boot/devtree.c
@@ -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;
+}