[PATCH v6 02/12] earlycon: Use common framework for earlycon declarations

From: Peter Hurley
Date: Sat Jan 16 2016 - 18:24:35 EST


Use a single common table of struct earlycon_id for both command line
and devicetree. Re-define OF_EARLYCON_DECLARE() macro to instance a
unique earlycon declaration (the declaration is only guaranteed to be
unique within a compilation unit; separate compilation units must still
use unique earlycon names).

The semantics of OF_EARLYCON_DECLARE() is different; it declares an
earlycon which can matched either on the command line or by devicetree.
EARLYCON_DECLARE() is semantically unchanged; it declares an earlycon
which is matched by command line only. Remove redundant instances of
EARLYCON_DECLARE().

This enables all earlycons to properly initialize struct console
with the appropriate name and index, which improves diagnostics and
enables direct earlycon-to-console handoff.

Acked-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
---
drivers/of/fdt.c | 14 +++++++-------
drivers/tty/serial/amba-pl011.c | 1 -
drivers/tty/serial/arc_uart.c | 1 -
drivers/tty/serial/earlycon.c | 10 +---------
drivers/tty/serial/msm_serial.c | 2 --
drivers/tty/serial/samsung.c | 6 ------
drivers/tty/serial/sprd_serial.c | 2 --
include/asm-generic/vmlinux.lds.h | 6 ++----
include/linux/serial_core.h | 22 +++++++++++++---------
9 files changed, 23 insertions(+), 41 deletions(-)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 655f79d..1686118 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -796,14 +796,13 @@ static inline void early_init_dt_check_for_initrd(unsigned long node)
#endif /* CONFIG_BLK_DEV_INITRD */

#ifdef CONFIG_SERIAL_EARLYCON
-extern struct of_device_id __earlycon_of_table[];

static int __init early_init_dt_scan_chosen_serial(void)
{
int offset;
const char *p;
int l;
- const struct of_device_id *match = __earlycon_of_table;
+ const struct earlycon_id *match;
const void *fdt = initial_boot_params;

offset = fdt_path_offset(fdt, "/chosen");
@@ -826,19 +825,20 @@ static int __init early_init_dt_scan_chosen_serial(void)
if (offset < 0)
return -ENODEV;

- while (match->compatible[0]) {
+ for (match = __earlycon_table; match < __earlycon_table_end; match++) {
u64 addr;

- if (fdt_node_check_compatible(fdt, offset, match->compatible)) {
- match++;
+ if (!match->compatible[0])
+ continue;
+
+ if (fdt_node_check_compatible(fdt, offset, match->compatible))
continue;
- }

addr = fdt_translate_address(fdt, offset);
if (addr == OF_BAD_ADDR)
return -ENXIO;

- of_setup_earlycon(addr, match->data);
+ of_setup_earlycon(addr, match->setup);
return 0;
}
return -ENODEV;
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index c0da0cc..de84602 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2327,7 +2327,6 @@ static int __init pl011_early_console_setup(struct earlycon_device *device,
device->con->write = pl011_early_write;
return 0;
}
-EARLYCON_DECLARE(pl011, pl011_early_console_setup);
OF_EARLYCON_DECLARE(pl011, "arm,pl011", pl011_early_console_setup);

#else
diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c
index 03ebe40..3a1de5c 100644
--- a/drivers/tty/serial/arc_uart.c
+++ b/drivers/tty/serial/arc_uart.c
@@ -576,7 +576,6 @@ static int __init arc_early_console_setup(struct earlycon_device *dev,
dev->con->write = arc_early_serial_write;
return 0;
}
-EARLYCON_DECLARE(arc_uart, arc_early_console_setup);
OF_EARLYCON_DECLARE(arc_uart, "snps,arc-uart", arc_early_console_setup);

#endif /* CONFIG_SERIAL_ARC_CONSOLE */
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index 54419a2..d50b700 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -19,7 +19,6 @@
#include <linux/io.h>
#include <linux/serial_core.h>
#include <linux/sizes.h>
-#include <linux/mod_devicetable.h>

#ifdef CONFIG_FIX_EARLYCON_MEM
#include <asm/fixmap.h>
@@ -37,13 +36,6 @@ static struct earlycon_device early_console_dev = {
.con = &early_con,
};

-extern struct earlycon_id __earlycon_table[];
-static const struct earlycon_id __earlycon_table_sentinel
- __used __section(__earlycon_table_end);
-
-static const struct of_device_id __earlycon_of_table_sentinel
- __used __section(__earlycon_of_table_end);
-
static void __iomem * __init earlycon_map(unsigned long paddr, size_t size)
{
void __iomem *base;
@@ -166,7 +158,7 @@ int __init setup_earlycon(char *buf)
if (early_con.flags & CON_ENABLED)
return -EALREADY;

- for (match = __earlycon_table; match->name[0]; match++) {
+ for (match = __earlycon_table; match < __earlycon_table_end; match++) {
size_t len = strlen(match->name);

if (strncmp(buf, match->name, len))
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
index dcde955..96d3ce8 100644
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -1478,7 +1478,6 @@ msm_serial_early_console_setup(struct earlycon_device *device, const char *opt)
device->con->write = msm_serial_early_write;
return 0;
}
-EARLYCON_DECLARE(msm_serial, msm_serial_early_console_setup);
OF_EARLYCON_DECLARE(msm_serial, "qcom,msm-uart",
msm_serial_early_console_setup);

@@ -1500,7 +1499,6 @@ msm_serial_early_console_setup_dm(struct earlycon_device *device,
device->con->write = msm_serial_early_write_dm;
return 0;
}
-EARLYCON_DECLARE(msm_serial_dm, msm_serial_early_console_setup_dm);
OF_EARLYCON_DECLARE(msm_serial_dm, "qcom,msm-uartdm",
msm_serial_early_console_setup_dm);

diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c
index d72cd73..fd9c47f 100644
--- a/drivers/tty/serial/samsung.c
+++ b/drivers/tty/serial/samsung.c
@@ -2451,7 +2451,6 @@ static int __init s3c2410_early_console_setup(struct earlycon_device *device,
}
OF_EARLYCON_DECLARE(s3c2410, "samsung,s3c2410-uart",
s3c2410_early_console_setup);
-EARLYCON_DECLARE(s3c2410, s3c2410_early_console_setup);

/* S3C2412, S3C2440, S3C64xx */
static struct samsung_early_console_data s3c2440_early_console_data = {
@@ -2470,9 +2469,6 @@ OF_EARLYCON_DECLARE(s3c2440, "samsung,s3c2440-uart",
s3c2440_early_console_setup);
OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart",
s3c2440_early_console_setup);
-EARLYCON_DECLARE(s3c2412, s3c2440_early_console_setup);
-EARLYCON_DECLARE(s3c2440, s3c2440_early_console_setup);
-EARLYCON_DECLARE(s3c6400, s3c2440_early_console_setup);

/* S5PV210, EXYNOS */
static struct samsung_early_console_data s5pv210_early_console_data = {
@@ -2489,8 +2485,6 @@ OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
s5pv210_early_console_setup);
OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
s5pv210_early_console_setup);
-EARLYCON_DECLARE(s5pv210, s5pv210_early_console_setup);
-EARLYCON_DECLARE(exynos4210, s5pv210_early_console_setup);
#endif

MODULE_ALIAS("platform:samsung-uart");
diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
index ef26c4a..1897106 100644
--- a/drivers/tty/serial/sprd_serial.c
+++ b/drivers/tty/serial/sprd_serial.c
@@ -624,8 +624,6 @@ static int __init sprd_early_console_setup(
device->con->write = sprd_early_write;
return 0;
}
-
-EARLYCON_DECLARE(sprd_serial, sprd_early_console_setup);
OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart",
sprd_early_console_setup);

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index c4bd0e2..e9a81a6 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -157,7 +157,7 @@
#define EARLYCON_TABLE() STRUCT_ALIGN(); \
VMLINUX_SYMBOL(__earlycon_table) = .; \
*(__earlycon_table) \
- *(__earlycon_table_end)
+ VMLINUX_SYMBOL(__earlycon_table_end) = .;
#else
#define EARLYCON_TABLE()
#endif
@@ -179,7 +179,6 @@
#define RESERVEDMEM_OF_TABLES() OF_TABLE(CONFIG_OF_RESERVED_MEM, reservedmem)
#define CPU_METHOD_OF_TABLES() OF_TABLE(CONFIG_SMP, cpu_method)
#define CPUIDLE_METHOD_OF_TABLES() OF_TABLE(CONFIG_CPU_IDLE, cpuidle_method)
-#define EARLYCON_OF_TABLES() OF_TABLE(CONFIG_SERIAL_EARLYCON, earlycon)

#ifdef CONFIG_ACPI
#define ACPI_PROBE_TABLE(name) \
@@ -526,8 +525,7 @@
IRQCHIP_OF_MATCH_TABLE() \
ACPI_PROBE_TABLE(irqchip) \
ACPI_PROBE_TABLE(clksrc) \
- EARLYCON_TABLE() \
- EARLYCON_OF_TABLES()
+ EARLYCON_TABLE()

#define INIT_TEXT \
*(.init.text) \
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index e03d6ba..25e0514 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -342,22 +342,26 @@ struct earlycon_device {

struct earlycon_id {
char name[16];
+ char compatible[128];
int (*setup)(struct earlycon_device *, const char *options);
} __aligned(32);

+extern const struct earlycon_id __earlycon_table[];
+extern const struct earlycon_id __earlycon_table_end[];
+
+#define OF_EARLYCON_DECLARE(_name, compat, fn) \
+ static const struct earlycon_id __UNIQUE_ID(__earlycon_##_name) \
+ __used __section(__earlycon_table) \
+ = { .name = __stringify(_name), \
+ .compatible = compat, \
+ .setup = fn }
+
+#define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn)
+
extern int setup_earlycon(char *buf);
extern int of_setup_earlycon(unsigned long addr,
int (*setup)(struct earlycon_device *, const char *));

-#define EARLYCON_DECLARE(_name, func) \
- static const struct earlycon_id __earlycon_##_name \
- __used __section(__earlycon_table) \
- = { .name = __stringify(_name), \
- .setup = func }
-
-#define OF_EARLYCON_DECLARE(name, compat, fn) \
- _OF_DECLARE(earlycon, name, compat, fn, void *)
-
struct uart_port *uart_get_console(struct uart_port *ports, int nr,
struct console *c);
int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
--
2.7.0