Multi-console: Deprecate the `finish_console_register` macro

The `finish_console_register` macro is used by the multi console
framework to register the `console_t` driver callbacks. It relied
on weak references to the `ldr` instruction to populate 0 to the
callback in case the driver has not defined the appropriate
function. Use of `ldr` instruction to load absolute address to a
reference makes the binary position dependant. These instructions
should be replaced with adrp/adr instruction for position independant
executable(PIE). But adrp/adr instructions don't work well with weak
references as described in GNU ld bugzilla issue 22589.

This patch defines a new version of `finish_console_register` macro
which can spcify which driver callbacks are valid and deprecates the
old one. If any of the argument is not specified, then the macro
populates 0 for that callback. Hence the functionality of the previous
deprecated macro is preserved. The USE_FINISH_CONSOLE_REG_2 define
is used to select the new variant of the macro and will be removed
once the deprecated variant is removed.

All the upstream console drivers have been migrated to use the new
macro in this patch.

NOTE: Platforms be aware that the new variant of the
`finish_console_register` should be used and the old variant is
deprecated.

Change-Id: Ia6a67aaf2aa3ba93932992d683587bbd0ad25259
Signed-off-by: Soby Mathew <soby.mathew@arm.com>

6 files changed, 18 insertions, 7 deletions

diff --git a/drivers/arm/pl011/aarch32/pl011_console.S b/drivers/arm/pl011/aarch32/pl011_console.S
index 841ea446c..46ff22587 100644
--- a/drivers/arm/pl011/aarch32/pl011_console.S
+++ b/drivers/arm/pl011/aarch32/pl011_console.S
@@ -6,6 +6,7 @@
 #include <arch.h>
 #include <asm_macros.S>
 #include <assert_macros.S>
+#define USE_FINISH_CONSOLE_REG_2
 #include <console_macros.S>
 #include <pl011.h>
 
@@ -116,7 +117,7 @@ func console_pl011_register
 
 	mov	r0, r4
 	pop	{r4, lr}
-	finish_console_register pl011
+	finish_console_register pl011 putc=1, getc=1, flush=1
 
 register_fail:
 	pop	{r4, pc}
diff --git a/drivers/arm/pl011/aarch64/pl011_console.S b/drivers/arm/pl011/aarch64/pl011_console.S
index d6a2d6b89..3886f3b77 100644
--- a/drivers/arm/pl011/aarch64/pl011_console.S
+++ b/drivers/arm/pl011/aarch64/pl011_console.S
@@ -6,6 +6,7 @@
 #include <arch.h>
 #include <asm_macros.S>
 #include <assert_macros.S>
+#define USE_FINISH_CONSOLE_REG_2
 #include <console_macros.S>
 #include <pl011.h>
 
@@ -110,7 +111,7 @@ func console_pl011_register
 
 	mov	x0, x6
 	mov	x30, x7
-	finish_console_register pl011
+	finish_console_register pl011 putc=1, getc=1, flush=1
 
 register_fail:
 	ret	x7
diff --git a/drivers/cadence/uart/aarch64/cdns_console.S b/drivers/cadence/uart/aarch64/cdns_console.S
index 71359a6d2..8f46a6272 100644
--- a/drivers/cadence/uart/aarch64/cdns_console.S
+++ b/drivers/cadence/uart/aarch64/cdns_console.S
@@ -7,6 +7,8 @@
 #include <asm_macros.S>
 #include <assert_macros.S>
 #include <cadence/cdns_uart.h>
+#define USE_FINISH_CONSOLE_REG_2
+#include <console_macros.S>
 
 	/*
 	 * "core" functions are low-level implementations that don't require
@@ -77,7 +79,7 @@ func console_cdns_register
 
 	mov	x0, x6
 	mov	x30, v7
-	finish_console_register cdns
+	finish_console_register cdns putc=1, getc=1, flush=1
 
 register_fail:
 	ret	x7
diff --git a/drivers/console/aarch64/skeleton_console.S b/drivers/console/aarch64/skeleton_console.S
index 1b5d7393c..3993eef99 100644
--- a/drivers/console/aarch64/skeleton_console.S
+++ b/drivers/console/aarch64/skeleton_console.S
@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 #include <asm_macros.S>
+#define USE_FINISH_CONSOLE_REG_2
 #include <console_macros.S>
 
 	/*
@@ -60,8 +61,12 @@ func console_xxx_register
 	 * Keep console_t pointer in x0 for later.
 	 */
 
-	/* Macro to finish up registration and return (needs valid x0 + x30). */
-	finish_console_register xxx
+	/*
+	 * Macro to finish up registration and return (needs valid x0 + x30).
+	 * If any of the argument is unspecified, then the corresponding
+	 * entry in console_t is set to 0.
+	 */
+	finish_console_register xxx putc=1, getc=1, flush=1
 
 	/* Jump here if hardware init fails or parameters are invalid. */
 register_fail:
diff --git a/drivers/coreboot/cbmem_console/aarch64/cbmem_console.S b/drivers/coreboot/cbmem_console/aarch64/cbmem_console.S
index 184853d9d..89be349c0 100644
--- a/drivers/coreboot/cbmem_console/aarch64/cbmem_console.S
+++ b/drivers/coreboot/cbmem_console/aarch64/cbmem_console.S
@@ -6,6 +6,7 @@
 
 #include <asm_macros.S>
 #include <cbmem_console.h>
+#define USE_FINISH_CONSOLE_REG_2
 #include <console_macros.S>
 
 /*
@@ -39,7 +40,7 @@ func console_cbmc_register
 	ldr	w2, [x0]
 	str	w2, [x1, #CONSOLE_T_CBMC_SIZE]
 	mov	x0, x1
-	finish_console_register cbmc
+	finish_console_register cbmc putc=1, flush=1
 endfunc console_cbmc_register
 
 	/* -----------------------------------------------
diff --git a/drivers/ti/uart/aarch64/16550_console.S b/drivers/ti/uart/aarch64/16550_console.S
index 0f9a9d576..785b640dd 100644
--- a/drivers/ti/uart/aarch64/16550_console.S
+++ b/drivers/ti/uart/aarch64/16550_console.S
@@ -7,6 +7,7 @@
 #include <arch.h>
 #include <asm_macros.S>
 #include <assert_macros.S>
+#define USE_FINISH_CONSOLE_REG_2
 #include <console_macros.S>
 #include <uart_16550.h>
 
@@ -112,7 +113,7 @@ func console_16550_register
 
 	mov	x0, x6
 	mov	x30, x7
-	finish_console_register 16550
+	finish_console_register 16550 putc=1, getc=1, flush=1
 
 register_fail:
 	ret	x7