Re-add ACPI SPCR (serial console) support

Four SPCR patches were merged upstream into 4.9, but one was reverted by a
subsequent commit (due to a trivial merge conflict with a later, unrelated
patch). A fixed up version of the missing patch is queued up for 4.10 in
tty-next. Carry it to make sure users see serial console output on ACPI
systems. Otherwise manually setting console=ttyAMAn would be required.

2 files changed, 107 insertions, 0 deletions

diff --git a/arm64-ACPI-parse-SPCR-table.patch b/arm64-ACPI-parse-SPCR-table.patch
new file mode 100644
index 000000000..ad85b0214
--- /dev/null
+++ b/arm64-ACPI-parse-SPCR-table.patch
@@ -0,0 +1,101 @@
+From 10879ae5f12e9cab3c4e8e9504c1aaa8a033bde7 Mon Sep 17 00:00:00 2001
+From: Aleksey Makarov <aleksey.makarov@linaro.org>
+Date: Tue, 4 Oct 2016 10:15:32 +0300
+Subject: serial: pl011: add console matching function
+
+This patch adds function pl011_console_match() that implements
+method match of struct console.  It allows to match consoles against
+data specified in a string, for example taken from command line or
+compiled by ACPI SPCR table handler.
+
+This patch was merged to tty-next but then reverted because of
+conflict with
+
+commit 46e36683f433 ("serial: earlycon: Extend earlycon command line option to support 64-bit addresses")
+
+Now it is fixed.
+
+Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
+Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
+Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
+Tested-by: Christopher Covington <cov@codeaurora.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/tty/serial/amba-pl011.c | 55 +++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 55 insertions(+)
+
+diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
+index e2c33b9..c00ab22 100644
+--- a/drivers/tty/serial/amba-pl011.c
++++ b/drivers/tty/serial/amba-pl011.c
+@@ -2315,12 +2315,67 @@ static int __init pl011_console_setup(struct console *co, char *options)
+ 	return uart_set_options(&uap->port, co, baud, parity, bits, flow);
+ }
+ 
++/**
++ *	pl011_console_match - non-standard console matching
++ *	@co:	  registering console
++ *	@name:	  name from console command line
++ *	@idx:	  index from console command line
++ *	@options: ptr to option string from console command line
++ *
++ *	Only attempts to match console command lines of the form:
++ *	    console=pl011,mmio|mmio32,<addr>[,<options>]
++ *	    console=pl011,0x<addr>[,<options>]
++ *	This form is used to register an initial earlycon boot console and
++ *	replace it with the amba_console at pl011 driver init.
++ *
++ *	Performs console setup for a match (as required by interface)
++ *	If no <options> are specified, then assume the h/w is already setup.
++ *
++ *	Returns 0 if console matches; otherwise non-zero to use default matching
++ */
++static int __init pl011_console_match(struct console *co, char *name, int idx,
++				      char *options)
++{
++	unsigned char iotype;
++	resource_size_t addr;
++	int i;
++
++	if (strcmp(name, "pl011") != 0)
++		return -ENODEV;
++
++	if (uart_parse_earlycon(options, &iotype, &addr, &options))
++		return -ENODEV;
++
++	if (iotype != UPIO_MEM && iotype != UPIO_MEM32)
++		return -ENODEV;
++
++	/* try to match the port specified on the command line */
++	for (i = 0; i < ARRAY_SIZE(amba_ports); i++) {
++		struct uart_port *port;
++
++		if (!amba_ports[i])
++			continue;
++
++		port = &amba_ports[i]->port;
++
++		if (port->mapbase != addr)
++			continue;
++
++		co->index = i;
++		port->cons = co;
++		return pl011_console_setup(co, options);
++	}
++
++	return -ENODEV;
++}
++
+ static struct uart_driver amba_reg;
+ static struct console amba_console = {
+ 	.name		= "ttyAMA",
+ 	.write		= pl011_console_write,
+ 	.device		= uart_console_device,
+ 	.setup		= pl011_console_setup,
++	.match		= pl011_console_match,
+ 	.flags		= CON_PRINTBUFFER,
+ 	.index		= -1,
+ 	.data		= &amba_reg,
+-- 
+cgit v0.12
+
diff --git a/kernel.spec b/kernel.spec
index 2fc8909a5..9e20308da 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -492,6 +492,9 @@ Source5005: kbuild-AFTER_LINK.patch
 
 # Standalone patches
 
+# http://www.spinics.net/lists/linux-serial/msg24272.html
+Patch420: arm64-ACPI-parse-SPCR-table.patch
+
 # a tempory patch for QCOM hardware enablement. Will be gone by end of 2016/F-26 GA
 Patch421: qcom-QDF2432-tmp-errata.patch
 
@@ -2174,6 +2177,9 @@ fi
 #
 #
 %changelog
+* Sat Dec 10 2016 Christopher Covington <cov@codeaurora.org>
+- Re-add ACPI SPCR (serial console) support
+
 * Fri Dec 09 2016 Laura Abbott <labbott@fedoraproject.org> - 4.9.0-0.rc8.git4.1
 - Linux v4.9-rc8-85-ga37102d