Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (25 commits)
  powerpc: Disable 64K hugetlb support when doing 64K SPU mappings
  powerpc/powermac: Fixup default serial port device for pmac_zilog
  powerpc/powermac: Use sane default baudrate for SCC debugging
  powerpc/mm: Implement _PAGE_SPECIAL & pte_special() for 64-bit
  powerpc: Show processor cache information in sysfs
  powerpc: Make core id information available to userspace
  powerpc: Make core sibling information available to userspace
  powerpc/vio: More fallout from dma_mapping_error API change
  ibmveth: Fix multiple errors with dma_mapping_error conversion
  powerpc/pseries: Fix CMO sysdev attribute API change fallout
  powerpc: Enable tracehook for the architecture
  powerpc: Add TIF_NOTIFY_RESUME support for tracehook
  powerpc: Add asm/syscall.h with the tracehook entry points
  powerpc: Make syscall tracing use tracehook.h helpers
  powerpc: Call tracehook_signal_handler() when setting up signal frames
  powerpc: Update cpu_sibling_maps dynamically
  powerpc: register_cpu_online should be __cpuinit
  powerpc: kill useless SMT code in prom_hold_cpus
  powerpc: Fix 8xx build failure
  powerpc: Fix vio build warnings
  ...

1 files changed, 72 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/powermac/setup.c b/arch/powerpc/platforms/powermac/setup.c
index 31635446901..88ccf3a08a9 100644
--- a/arch/powerpc/platforms/powermac/setup.c
+++ b/arch/powerpc/platforms/powermac/setup.c
@@ -541,6 +541,78 @@ static int __init pmac_declare_of_platform_devices(void)
 }
 machine_device_initcall(powermac, pmac_declare_of_platform_devices);
 
+#ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
+/*
+ * This is called very early, as part of console_init() (typically just after
+ * time_init()). This function is respondible for trying to find a good
+ * default console on serial ports. It tries to match the open firmware
+ * default output with one of the available serial console drivers.
+ */
+static int __init check_pmac_serial_console(void)
+{
+	struct device_node *prom_stdout = NULL;
+	int offset = 0;
+	const char *name;
+#ifdef CONFIG_SERIAL_PMACZILOG_TTYS
+	char *devname = "ttyS";
+#else
+	char *devname = "ttyPZ";
+#endif
+
+	pr_debug(" -> check_pmac_serial_console()\n");
+
+	/* The user has requested a console so this is already set up. */
+	if (strstr(boot_command_line, "console=")) {
+		pr_debug(" console was specified !\n");
+		return -EBUSY;
+	}
+
+	if (!of_chosen) {
+		pr_debug(" of_chosen is NULL !\n");
+		return -ENODEV;
+	}
+
+	/* We are getting a weird phandle from OF ... */
+	/* ... So use the full path instead */
+	name = of_get_property(of_chosen, "linux,stdout-path", NULL);
+	if (name == NULL) {
+		pr_debug(" no linux,stdout-path !\n");
+		return -ENODEV;
+	}
+	prom_stdout = of_find_node_by_path(name);
+	if (!prom_stdout) {
+		pr_debug(" can't find stdout package %s !\n", name);
+		return -ENODEV;
+	}
+	pr_debug("stdout is %s\n", prom_stdout->full_name);
+
+	name = of_get_property(prom_stdout, "name", NULL);
+	if (!name) {
+		pr_debug(" stdout package has no name !\n");
+		goto not_found;
+	}
+
+	if (strcmp(name, "ch-a") == 0)
+		offset = 0;
+	else if (strcmp(name, "ch-b") == 0)
+		offset = 1;
+	else
+		goto not_found;
+	of_node_put(prom_stdout);
+
+	pr_debug("Found serial console at %s%d\n", devname, offset);
+
+	return add_preferred_console(devname, offset, NULL);
+
+ not_found:
+	pr_debug("No preferred console found !\n");
+	of_node_put(prom_stdout);
+	return -ENODEV;
+}
+console_initcall(check_pmac_serial_console);
+
+#endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
+
 /*
  * Called very early, MMU is off, device-tree isn't unflattened
  */