phb4: Workaround PHB errata with CFG write UR/CA errors

[ Upstream commit 9a83ab7 ]

If the PHB encounters a UR or CA status on a CFG write, it will
incorrectly freeze the wrong PE. Instead of using the PE# specified
in the CONFIG_ADDRESS register, it will use the PE# of whatever
MMIO occurred last.

Work around this disabling freeze on such errors

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-By: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>

hw/phb4.c

@@ -4572,7 +4572,11 @@ static void phb4_init_errors(struct phb4 *p)
 	out_be64(p->regs + 0x0d00,	0xffffffffffffffffull);
 	out_be64(p->regs + 0x0d08,	0x0000000000000000ull);
 	out_be64(p->regs + 0x0d18,	0xffffff0fffffffffull);
-	out_be64(p->regs + 0x0d28,	0x0000400a00000000ull);
+
+	/* Errata: Clear bit 17, otherwise a CFG write UR/CA will incorrectly
+	 * freeze a "random" PE (whatever last PE did an MMIO)
+	 */
+	out_be64(p->regs + 0x0d28,	0x0000000a00000000ull);
 	out_be64(p->regs + 0x0d30,	0xdff7bd05f7ddfff0ull); /* XXX CAPI has diff. value */
 	out_be64(p->regs + 0x0d40,	0x0000000000000000ull);
 	out_be64(p->regs + 0x0d48,	0x0000000000000000ull);