tile: various console improvements

This change improves and cleans up the tile console.

- We enable HVC_IRQ support on tilegx, with the addition of a new
  Tilera hypervisor API for tilegx to allow a console IPI.  If IPI
  support is not available we fall back to the previous polling mode.

- We simplify the earlyprintk code to use CON_BOOT and eliminate some
  of the other supporting earlyprintk code.

- A new tile_console_write() primitive is used to send output to
  the console and is factored out of the hvc_tile driver.
  This lets us support a "sim_console" boot argument to allow using
  simulator hooks to send output to the "console" as a slightly
  faster alternative to emulating the hardware more directly.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 13 insertions, 39 deletions

diff --git a/arch/tile/kernel/early_printk.c b/arch/tile/kernel/early_printk.c
index 34d72a151bf3..b608e00e7f6d 100644
--- a/arch/tile/kernel/early_printk.c
+++ b/arch/tile/kernel/early_printk.c
@@ -23,19 +23,24 @@
 
 static void early_hv_write(struct console *con, const char *s, unsigned n)
 {
-        hv_console_write((HV_VirtAddr) s, n);
+        tile_console_write(s, n);
+
+        /*
+         * Convert NL to NLCR (close enough to CRNL) during early boot.
+         * We assume newlines are at the ends of strings, which turns out
+         * to be good enough for early boot console output.
+         */
+        if (n && s[n-1] == '\n')
+                tile_console_write("\r", 1);
 }
 
 static struct console early_hv_console = {
         .name =         "earlyhv",
         .write =        early_hv_write,
-        .flags =        CON_PRINTBUFFER,
+        .flags =        CON_PRINTBUFFER | CON_BOOT,
         .index =        -1,
 };
 
-/* Direct interface for emergencies */
-static int early_console_complete;
-
 void early_panic(const char *fmt, ...)
 {
         va_list ap;
@@ -43,51 +48,21 @@ void early_panic(const char *fmt, ...)
         va_start(ap, fmt);
         early_printk("Kernel panic - not syncing: ");
         early_vprintk(fmt, ap);
-        early_console->write(early_console, "\n", 1);
+        early_printk("\n");
         va_end(ap);
         dump_stack();
         hv_halt();
 }
 
-static int __initdata keep_early;
-
 static int __init setup_early_printk(char *str)
 {
         if (early_console)
                 return 1;
 
-        if (str != NULL && strncmp(str, "keep", 4) == 0)
-                keep_early = 1;
-
         early_console = &early_hv_console;
         register_console(early_console);
 
         return 0;
 }
 
-void __init disable_early_printk(void)
-{
-        early_console_complete = 1;
-        if (!early_console)
-                return;
-        if (!keep_early) {
-                early_printk("disabling early console\n");
-                unregister_console(early_console);
-                early_console = NULL;
-        } else {
-                early_printk("keeping early console\n");
-        }
-}
-
-void warn_early_printk(void)
-{
-        if (early_console_complete || early_console)
-                return;
-        early_printk("\
-Machine shutting down before console output is fully initialized.\n\
-You may wish to reboot and add the option 'earlyprintk' to your\n\
-boot command line to see any diagnostic early console output.\n\
-");
-}
-
 early_param("earlyprintk", setup_early_printk);
diff --git a/arch/tile/kernel/hvglue.lds b/arch/tile/kernel/hvglue.lds
index d44c5a67a1ed..ef522900633a 100644
--- a/arch/tile/kernel/hvglue.lds
+++ b/arch/tile/kernel/hvglue.lds
@@ -56,4 +56,5 @@ hv_inquire_realpa = TEXT_OFFSET + 0x106c0;
 hv_flush_all = TEXT_OFFSET + 0x106e0;
 hv_get_ipi_pte = TEXT_OFFSET + 0x10700;
 hv_set_pte_super_shift = TEXT_OFFSET + 0x10720;
-hv_glue_internals = TEXT_OFFSET + 0x10740;
+hv_console_set_ipi = TEXT_OFFSET + 0x107e0;
+hv_glue_internals = TEXT_OFFSET + 0x10800;
diff --git a/arch/tile/kernel/reboot.c b/arch/tile/kernel/reboot.c
index d1b5c913ae72..6c5d2c070a12 100644
--- a/arch/tile/kernel/reboot.c
+++ b/arch/tile/kernel/reboot.c
@@ -27,7 +27,6 @@
 
 void machine_halt(void)
 {
-        warn_early_printk();
         arch_local_irq_disable_all();
         smp_send_stop();
         hv_halt();
@@ -35,7 +34,6 @@ void machine_halt(void)
 
 void machine_power_off(void)
 {
-        warn_early_printk();
         arch_local_irq_disable_all();
         smp_send_stop();
         hv_power_off();