drivers/console/aarch64/multi_console.S - filogic/atf - Gitiles

 /*
  * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */

 #include <asm_macros.S>
 #include <assert_macros.S>
 #include <console.h>

 	.globl	console_register
 	.globl	console_unregister
 	.globl  console_set_scope
 	.globl	console_switch_state
 	.globl	console_putc
 	.globl	console_getc
 	.globl	console_flush

 	/*
 	 *  The console list pointer is in the data section and not in
 	 *  .bss even though it is zero-init. In particular, this allows
 	 *  the console functions to start using this variable before
 	 *  the runtime memory is initialized for images which do not
 	 *  need to copy the .data section from ROM to RAM.
 	 */
 .section .data.console_list ; .align 3
 	console_list: .quad 0x0
 .section .data.console_state ; .align 0
 	console_state: .byte CONSOLE_FLAG_BOOT

 	/* -----------------------------------------------
 	 * int console_register(console_t *console)
 	 * Function to insert a new console structure into
 	 * the console list. Should usually be called by
 	 * console_<driver>_register implementations. The
 	 * data structure passed will be taken over by the
 	 * console framework and *MUST* be allocated in
 	 * persistent memory (e.g. the data section).
 	 * In : x0 - address of console_t structure
 	 * Out: x0 - Always 1 (for easier tail calling)
 	 * Clobber list: x0, x1, x14
 	 * -----------------------------------------------
 	 */
 func console_register
 #if ENABLE_ASSERTIONS
 	cmp	x0, #0
 	ASM_ASSERT(ne)
 	adrp	x1, __STACKS_START__
 	add	x1, x1, :lo12:__STACKS_START__
 	cmp	x0, x1
 	b.lo	not_on_stack
 	adrp	x1, __STACKS_END__
 	add	x1, x1, :lo12:__STACKS_END__
 	cmp	x0, x1
 	ASM_ASSERT(hs)
 not_on_stack:
 #endif /* ENABLE_ASSERTIONS */
 	adrp	x14, console_list
 	ldr	x1, [x14, :lo12:console_list]	/* X1 = first struct in list */
 	str	x0, [x14, :lo12:console_list]	/* list head = new console */
 	str	x1, [x0, #CONSOLE_T_NEXT]	/* new console next ptr = X1 */
 	mov	x0, #1
 	ret
 endfunc console_register

 	/* -----------------------------------------------
 	 * int console_unregister(console_t *console)
 	 * Function to find a specific console in the list
 	 * of currently active consoles and remove it.
 	 * In: x0 - address of console_t struct to remove
 	 * Out: x0 - removed address, or NULL if not found
 	 * Clobber list: x0, x1, x14
 	 * -----------------------------------------------
 	 */
 func console_unregister
 	adrp	x14, console_list
 	add	x14, x14, :lo12:console_list	/* X14 = ptr to first struct */
 	ldr	x1, [x14]			/* X1 = first struct */

 unregister_loop:
 	cbz	x1, unregister_not_found
 	cmp	x0, x1
 	b.eq	unregister_found
 	ldr	x14, [x14]			/* X14 = next ptr of struct */
 	ldr	x1, [x14]			/* X1 = next struct */
 	b	unregister_loop

 unregister_found:
 	ldr	x1, [x1]			/* X1 = next struct */
 	str	x1, [x14]			/* prev->next = cur->next */
 	ret

 unregister_not_found:
 	mov	x0, #0				/* return NULL if not found */
 	ret
 endfunc console_unregister

 	/* -----------------------------------------------
 	 * void console_switch_state(unsigned int new_state)
 	 * Function to switch the current console state.
 	 * The console state determines which of the
 	 * registered consoles are actually used at a time.
 	 * In : w0 - global console state to move to
 	 * Clobber list: x0, x1
 	 * -----------------------------------------------
 	 */
 func console_switch_state
 	adrp	x1, console_state
 	strb	w0, [x1, :lo12:console_state]
 	ret
 endfunc console_switch_state

 	/* -----------------------------------------------
 	 * void console_set_scope(console_t *console,
 	 *                       unsigned int scope)
 	 * Function to update the states that a given console
 	 * may be active in.
 	 * In : x0 - pointer to console_t struct
 	 *    : w1 - new active state mask
 	 * Clobber list: x0, x1, x2
 	 * -----------------------------------------------
 	 */
 func console_set_scope
 #if ENABLE_ASSERTIONS
 	tst	w1, #~CONSOLE_FLAG_SCOPE_MASK
 	ASM_ASSERT(eq)
 #endif /* ENABLE_ASSERTIONS */
 	ldr	w2, [x0, #CONSOLE_T_FLAGS]
 	and	w2, w2, #~CONSOLE_FLAG_SCOPE_MASK
 	orr	w2, w2, w1
 	str	w2, [x0, #CONSOLE_T_FLAGS]
 	ret
 endfunc console_set_scope

 	/* ---------------------------------------------
 	 * int console_putc(int c)
 	 * Function to output a character. Calls all
 	 * active console's putc() handlers in succession.
 	 * In : x0 - character to be printed
 	 * Out: x0 - printed character on success, or < 0
 	             if at least one console had an error
 	 * Clobber list : x0, x1, x2, x12, x13, x14, x15
 	 * ---------------------------------------------
 	 */
 func console_putc
 	mov	x15, x30
 	mov	w13, #ERROR_NO_VALID_CONSOLE	/* W13 = current return value */
 	mov	w12, w0				/* W12 = character to print */
 	adrp	x14, console_list
 	ldr	x14, [x14, :lo12:console_list]	/* X14 = first console struct */

 putc_loop:
 	cbz	x14, putc_done
 	adrp	x1, console_state
 	ldrb	w1, [x1, :lo12:console_state]
 	ldr	x2, [x14, #CONSOLE_T_FLAGS]
 	tst	w1, w2
 	b.eq	putc_continue
 	ldr	x2, [x14, #CONSOLE_T_PUTC]
 	cbz	x2, putc_continue
 	mov	w0, w12
 	mov	x1, x14
 	blr	x2
 	cmp	w13, #ERROR_NO_VALID_CONSOLE	/* update W13 if it's NOVALID */
 	ccmp	w0, #0, #0x8, ne		/* else update it if W0 < 0 */
 	csel	w13, w0, w13, lt
 putc_continue:
 	ldr	x14, [x14]			/* X14 = next struct */
 	b	putc_loop

 putc_done:
 	mov	w0, w13
 	ret	x15
 endfunc console_putc

 	/* ---------------------------------------------
 	 * int console_getc(void)
 	 * Function to get a character from any console.
 	 * Keeps looping through all consoles' getc()
 	 * handlers until one of them returns a
 	 * character, then stops iterating and returns
 	 * that character to the caller. Will stop looping
 	 * if all active consoles report real errors
 	 * (other than just not having a char available).
 	 * Out : x0 - read character, or < 0 on error
 	 * Clobber list : x0, x1, x13, x14, x15
 	 * ---------------------------------------------
 	 */
 func console_getc
 	mov	x15, x30
 getc_try_again:
 	mov	w13, #ERROR_NO_VALID_CONSOLE	/* W13 = current return value */
 	adrp	x14, console_list
 	ldr	x14, [x14, :lo12:console_list]	/* X14 = first console struct */
 	cbnz	x14, getc_loop
 	mov	w0, w13				/* If no consoles registered */
 	ret	x15				/* return immediately. */

 getc_loop:
 	adrp	x0, console_state
 	ldrb	w0, [x0, :lo12:console_state]
 	ldr	x1, [x14, #CONSOLE_T_FLAGS]
 	tst	w0, w1
 	b.eq	getc_continue
 	ldr	x1, [x14, #CONSOLE_T_GETC]
 	cbz	x1, getc_continue
 	mov	x0, x14
 	blr	x1
 	cmp	w0, #0				/* if X0 >= 0: return */
 	b.ge	getc_found
 	cmp	w13, #ERROR_NO_PENDING_CHAR	/* may update W13 (NOCHAR has */
 	csel	w13, w13, w0, eq		/* precedence vs real errors) */
 getc_continue:
 	ldr	x14, [x14]			/* X14 = next struct */
 	cbnz	x14, getc_loop
 	cmp	w13, #ERROR_NO_PENDING_CHAR	/* Keep scanning if at least */
 	b.eq	getc_try_again			/* one console returns NOCHAR */
 	mov	w0, w13

 getc_found:
 	ret	x15
 endfunc console_getc

 	/* ---------------------------------------------
 	 * int console_flush(void)
 	 * Function to force a write of all buffered
 	 * data that hasn't been output. Calls all
 	 * console's flush() handlers in succession.
 	 * Out: x0 - 0 on success, < 0 if at least one error
 	 * Clobber list : x0, x1, x2, x3, x4, x5, x13, x14, x15
 	 * ---------------------------------------------
 	 */
 func console_flush
 	mov	x15, x30
 	mov	w13, #ERROR_NO_VALID_CONSOLE	/* W13 = current return value */
 	adrp	x14, console_list
 	ldr	x14, [x14, :lo12:console_list]	/* X14 = first console struct */

 flush_loop:
 	cbz	x14, flush_done
 	adrp	x1, console_state
 	ldrb	w1, [x1, :lo12:console_state]
 	ldr	x2, [x14, #CONSOLE_T_FLAGS]
 	tst	w1, w2
 	b.eq	flush_continue
 	ldr	x1, [x14, #CONSOLE_T_FLUSH]
 	cbz	x1, flush_continue
 	mov	x0, x14
 	blr	x1
 	cmp	w13, #ERROR_NO_VALID_CONSOLE	/* update W13 if it's NOVALID */
 	ccmp	w0, #0, #0x8, ne		/* else update it if W0 < 0 */
 	csel	w13, w0, w13, lt
 flush_continue:
 	ldr	x14, [x14]			/* X14 = next struct */
 	b	flush_loop

 flush_done:
 	mov	w0, w13
 	ret	x15
 endfunc console_flush
	/*
	* Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
	*
	* SPDX-License-Identifier: BSD-3-Clause
	*/

	#include <asm_macros.S>
	#include <assert_macros.S>
	#include <console.h>

	.globl console_register
	.globl console_unregister
	.globl console_set_scope
	.globl console_switch_state
	.globl console_putc
	.globl console_getc
	.globl console_flush

	/*
	* The console list pointer is in the data section and not in
	* .bss even though it is zero-init. In particular, this allows
	* the console functions to start using this variable before
	* the runtime memory is initialized for images which do not
	* need to copy the .data section from ROM to RAM.
	*/
	.section .data.console_list ; .align 3
	console_list: .quad 0x0
	.section .data.console_state ; .align 0
	console_state: .byte CONSOLE_FLAG_BOOT

	/* -----------------------------------------------
	* int console_register(console_t *console)
	* Function to insert a new console structure into
	* the console list. Should usually be called by
	* console_<driver>_register implementations. The
	* data structure passed will be taken over by the
	* console framework and MUST be allocated in
	* persistent memory (e.g. the data section).
	* In : x0 - address of console_t structure
	* Out: x0 - Always 1 (for easier tail calling)
	* Clobber list: x0, x1, x14
	* -----------------------------------------------
	*/
	func console_register
	#if ENABLE_ASSERTIONS
	cmp x0, #0
	ASM_ASSERT(ne)
	adrp x1, __STACKS_START__
	add x1, x1, :lo12:__STACKS_START__
	cmp x0, x1
	b.lo not_on_stack
	adrp x1, __STACKS_END__
	add x1, x1, :lo12:__STACKS_END__
	cmp x0, x1
	ASM_ASSERT(hs)
	not_on_stack:
	#endif /* ENABLE_ASSERTIONS */
	adrp x14, console_list
	ldr x1, [x14, :lo12:console_list] /* X1 = first struct in list */
	str x0, [x14, :lo12:console_list] /* list head = new console */
	str x1, [x0, #CONSOLE_T_NEXT] /* new console next ptr = X1 */
	mov x0, #1
	ret
	endfunc console_register

	/* -----------------------------------------------
	* int console_unregister(console_t *console)
	* Function to find a specific console in the list
	* of currently active consoles and remove it.
	* In: x0 - address of console_t struct to remove
	* Out: x0 - removed address, or NULL if not found
	* Clobber list: x0, x1, x14
	* -----------------------------------------------
	*/
	func console_unregister
	adrp x14, console_list
	add x14, x14, :lo12:console_list /* X14 = ptr to first struct */
	ldr x1, [x14] /* X1 = first struct */

	unregister_loop:
	cbz x1, unregister_not_found
	cmp x0, x1
	b.eq unregister_found
	ldr x14, [x14] /* X14 = next ptr of struct */
	ldr x1, [x14] /* X1 = next struct */
	b unregister_loop

	unregister_found:
	ldr x1, [x1] /* X1 = next struct */
	str x1, [x14] /* prev->next = cur->next */
	ret

	unregister_not_found:
	mov x0, #0 /* return NULL if not found */
	ret
	endfunc console_unregister

	/* -----------------------------------------------
	* void console_switch_state(unsigned int new_state)
	* Function to switch the current console state.
	* The console state determines which of the
	* registered consoles are actually used at a time.
	* In : w0 - global console state to move to
	* Clobber list: x0, x1
	* -----------------------------------------------
	*/
	func console_switch_state
	adrp x1, console_state
	strb w0, [x1, :lo12:console_state]
	ret
	endfunc console_switch_state

	/* -----------------------------------------------
	* void console_set_scope(console_t *console,
	* unsigned int scope)
	* Function to update the states that a given console
	* may be active in.
	* In : x0 - pointer to console_t struct
	* : w1 - new active state mask
	* Clobber list: x0, x1, x2
	* -----------------------------------------------
	*/
	func console_set_scope
	#if ENABLE_ASSERTIONS
	tst w1, #~CONSOLE_FLAG_SCOPE_MASK
	ASM_ASSERT(eq)
	#endif /* ENABLE_ASSERTIONS */
	ldr w2, [x0, #CONSOLE_T_FLAGS]
	and w2, w2, #~CONSOLE_FLAG_SCOPE_MASK
	orr w2, w2, w1
	str w2, [x0, #CONSOLE_T_FLAGS]
	ret
	endfunc console_set_scope

	/* ---------------------------------------------
	* int console_putc(int c)
	* Function to output a character. Calls all
	* active console's putc() handlers in succession.
	* In : x0 - character to be printed
	* Out: x0 - printed character on success, or < 0
	if at least one console had an error
	* Clobber list : x0, x1, x2, x12, x13, x14, x15
	* ---------------------------------------------
	*/
	func console_putc
	mov x15, x30
	mov w13, #ERROR_NO_VALID_CONSOLE /* W13 = current return value */
	mov w12, w0 /* W12 = character to print */
	adrp x14, console_list
	ldr x14, [x14, :lo12:console_list] /* X14 = first console struct */

	putc_loop:
	cbz x14, putc_done
	adrp x1, console_state
	ldrb w1, [x1, :lo12:console_state]
	ldr x2, [x14, #CONSOLE_T_FLAGS]
	tst w1, w2
	b.eq putc_continue
	ldr x2, [x14, #CONSOLE_T_PUTC]
	cbz x2, putc_continue
	mov w0, w12
	mov x1, x14
	blr x2
	cmp w13, #ERROR_NO_VALID_CONSOLE /* update W13 if it's NOVALID */
	ccmp w0, #0, #0x8, ne /* else update it if W0 < 0 */
	csel w13, w0, w13, lt
	putc_continue:
	ldr x14, [x14] /* X14 = next struct */
	b putc_loop

	putc_done:
	mov w0, w13
	ret x15
	endfunc console_putc

	/* ---------------------------------------------
	* int console_getc(void)
	* Function to get a character from any console.
	* Keeps looping through all consoles' getc()
	* handlers until one of them returns a
	* character, then stops iterating and returns
	* that character to the caller. Will stop looping
	* if all active consoles report real errors
	* (other than just not having a char available).
	* Out : x0 - read character, or < 0 on error
	* Clobber list : x0, x1, x13, x14, x15
	* ---------------------------------------------
	*/
	func console_getc
	mov x15, x30
	getc_try_again:
	mov w13, #ERROR_NO_VALID_CONSOLE /* W13 = current return value */
	adrp x14, console_list
	ldr x14, [x14, :lo12:console_list] /* X14 = first console struct */
	cbnz x14, getc_loop
	mov w0, w13 /* If no consoles registered */
	ret x15 /* return immediately. */

	getc_loop:
	adrp x0, console_state
	ldrb w0, [x0, :lo12:console_state]
	ldr x1, [x14, #CONSOLE_T_FLAGS]
	tst w0, w1
	b.eq getc_continue
	ldr x1, [x14, #CONSOLE_T_GETC]
	cbz x1, getc_continue
	mov x0, x14
	blr x1
	cmp w0, #0 /* if X0 >= 0: return */
	b.ge getc_found
	cmp w13, #ERROR_NO_PENDING_CHAR /* may update W13 (NOCHAR has */
	csel w13, w13, w0, eq /* precedence vs real errors) */
	getc_continue:
	ldr x14, [x14] /* X14 = next struct */
	cbnz x14, getc_loop
	cmp w13, #ERROR_NO_PENDING_CHAR /* Keep scanning if at least */
	b.eq getc_try_again /* one console returns NOCHAR */
	mov w0, w13

	getc_found:
	ret x15
	endfunc console_getc

	/* ---------------------------------------------
	* int console_flush(void)
	* Function to force a write of all buffered
	* data that hasn't been output. Calls all
	* console's flush() handlers in succession.
	* Out: x0 - 0 on success, < 0 if at least one error
	* Clobber list : x0, x1, x2, x3, x4, x5, x13, x14, x15
	* ---------------------------------------------
	*/
	func console_flush
	mov x15, x30
	mov w13, #ERROR_NO_VALID_CONSOLE /* W13 = current return value */
	adrp x14, console_list
	ldr x14, [x14, :lo12:console_list] /* X14 = first console struct */

	flush_loop:
	cbz x14, flush_done
	adrp x1, console_state
	ldrb w1, [x1, :lo12:console_state]
	ldr x2, [x14, #CONSOLE_T_FLAGS]
	tst w1, w2
	b.eq flush_continue
	ldr x1, [x14, #CONSOLE_T_FLUSH]
	cbz x1, flush_continue
	mov x0, x14
	blr x1
	cmp w13, #ERROR_NO_VALID_CONSOLE /* update W13 if it's NOVALID */
	ccmp w0, #0, #0x8, ne /* else update it if W0 < 0 */
	csel w13, w0, w13, lt
	flush_continue:
	ldr x14, [x14] /* X14 = next struct */
	b flush_loop

	flush_done:
	mov w0, w13
	ret x15
	endfunc console_flush