drivers/console: Reimplement MUTLI_CONSOLE_API framework in C

Now that we have switched to using the stack in MULTI_CONSOLE_API
framework functions and have factored all code involved in crash
reporting out into a separate file, there's really no reason to keep the
main framework code in assembly anymore. This patch rewrites it in C
which allows us to have a single implementation across aarch32/64 and
should be much easier to maintain going forward.

Change-Id: I6c85a01e89a79e8b233f3f8bee812f0dbd026221
Signed-off-by: Julius Werner <jwerner@chromium.org>
This commit is contained in:
Julius Werner 2018-11-27 22:10:56 -08:00
parent 985ee0b7e8
commit 91b48c9f8f
4 changed files with 123 additions and 652 deletions

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@ -214,7 +214,7 @@ include lib/libc/libc.mk
BL_COMMON_SOURCES += common/bl_common.c \
common/tf_log.c \
common/${ARCH}/debug.S \
drivers/console/${ARCH}/multi_console.S \
drivers/console/multi_console.c \
lib/${ARCH}/cache_helpers.S \
lib/${ARCH}/misc_helpers.S \
plat/common/plat_bl_common.c \

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@ -1,322 +0,0 @@
/*
* Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#if MULTI_CONSOLE_API
#include <asm_macros.S>
#include <assert_macros.S>
#include <console.h>
.globl console_register
.globl console_unregister
.globl console_is_registered
.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 2
console_list: .word 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 : r0 - address of console_t structure
* Out: r0 - Always 1 (for easier tail calling)
* Clobber list: r0, r1
* -----------------------------------------------
*/
func console_register
push {r6, lr}
#if ENABLE_ASSERTIONS
/* Assert that r0 isn't a NULL pointer */
cmp r0, #0
ASM_ASSERT(ne)
/* Assert that the struct isn't in the stack */
ldr r1, =__STACKS_START__
cmp r0, r1
blo not_on_stack
ldr r1, =__STACKS_END__
cmp r0, r1
ASM_ASSERT(hs)
not_on_stack:
/* Assert that this struct isn't in the list */
mov r1, r0 /* Preserve r0 and lr */
bl console_is_registered
cmp r0, #0
ASM_ASSERT(eq)
mov r0, r1
#endif /* ENABLE_ASSERTIONS */
ldr r6, =console_list
ldr r1, [r6] /* R1 = first struct in list */
str r0, [r6] /* list head = new console */
str r1, [r0, #CONSOLE_T_NEXT] /* new console next ptr = R1 */
mov r0, #1
pop {r6, pc}
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: r0 - address of console_t struct to remove
* Out: r0 - removed address, or NULL if not found
* Clobber list: r0, r1
* -----------------------------------------------
*/
func console_unregister
#if ENABLE_ASSERTIONS
/* Assert that r0 isn't a NULL pointer */
cmp r0, #0
ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
push {r6}
ldr r6, =console_list /* R6 = ptr to first struct */
ldr r1, [r6] /* R1 = first struct */
unregister_loop:
cmp r1, #0
beq unregister_not_found
cmp r0, r1
beq unregister_found
ldr r6, [r6] /* R6 = next ptr of struct */
ldr r1, [r6] /* R1 = next struct */
b unregister_loop
unregister_found:
ldr r1, [r1] /* R1 = next struct */
str r1, [r6] /* prev->next = cur->next */
pop {r6}
bx lr
unregister_not_found:
mov r0, #0 /* return NULL if not found */
pop {r6}
bx lr
endfunc console_unregister
/* -----------------------------------------------
* int console_is_registered(console_t *console)
* Function to detect if a specific console is
* registered or not.
* In: r0 - address of console_t struct to remove
* Out: r0 - 1 if it is registered, 0 if not.
* Clobber list: r0
* -----------------------------------------------
*/
func console_is_registered
#if ENABLE_ASSERTIONS
/* Assert that r0 isn't a NULL pointer */
cmp r0, #0
ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
push {r6}
ldr r6, =console_list
ldr r6, [r6] /* R6 = first console struct */
check_registered_loop:
cmp r6, #0 /* Check if end of list */
beq console_not_registered
cmp r0, r6 /* Check if the pointers are different */
beq console_registered
ldr r6, [r6, #CONSOLE_T_NEXT] /* Get pointer to next struct */
b check_registered_loop
console_not_registered:
mov r0, #0
pop {r6}
bx lr
console_registered:
mov r0, #1
pop {r6}
bx lr
endfunc console_is_registered
/* -----------------------------------------------
* 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 : r0 - global console state to move to
* Clobber list: r0, r1
* -----------------------------------------------
*/
func console_switch_state
ldr r1, =console_state
strb r0, [r1]
bx lr
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 : r0 - pointer to console_t struct
* : r1 - new active state mask
* Clobber list: r0, r1, r2
* -----------------------------------------------
*/
func console_set_scope
#if ENABLE_ASSERTIONS
ands r2, r1, #~CONSOLE_FLAG_SCOPE_MASK
ASM_ASSERT(eq)
#endif /* ENABLE_ASSERTIONS */
ldr r2, [r0, #CONSOLE_T_FLAGS]
and r2, r2, #~CONSOLE_FLAG_SCOPE_MASK
orr r2, r2, r1
str r2, [r0, #CONSOLE_T_FLAGS]
bx lr
endfunc console_set_scope
/* ---------------------------------------------
* int console_putc(int c)
* Function to output a character. Calls all
* active console's putc() handlers in succession.
* In : r0 - character to be printed
* Out: r0 - printed character on success, or < 0
if at least one console had an error
* Clobber list : r0, r1, r2
* ---------------------------------------------
*/
func console_putc
push {r4-r6, lr}
mov r5, #ERROR_NO_VALID_CONSOLE /* R5 = current return value */
mov r4, r0 /* R4 = character to print */
ldr r6, =console_list
ldr r6, [r6] /* R6 = first console struct */
putc_loop:
cmp r6, #0
beq putc_done
ldr r1, =console_state
ldrb r1, [r1]
ldr r2, [r6, #CONSOLE_T_FLAGS]
tst r1, r2
beq putc_continue
ldr r2, [r6, #CONSOLE_T_PUTC]
cmp r2, #0
beq putc_continue
mov r0, r4
mov r1, r6
blx r2
cmp r5, #ERROR_NO_VALID_CONSOLE /* update R5 if it's NOVALID */
cmpne r0, #0 /* else update it if R0 < 0 */
movlt r5, r0
putc_continue:
ldr r6, [r6] /* R6 = next struct */
b putc_loop
putc_done:
mov r0, r5
pop {r4-r6, pc}
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 : r0 - read character, or < 0 on error
* Clobber list : r0, r1
* ---------------------------------------------
*/
func console_getc
push {r5-r6, lr}
getc_try_again:
mov r5, #ERROR_NO_VALID_CONSOLE /* R5 = current return value */
ldr r6, =console_list
ldr r6, [r6] /* R6 = first console struct */
cmp r6, #0
bne getc_loop
mov r0, r5 /* If no consoles registered */
pop {r5-r6, pc} /* return immediately. */
getc_loop:
ldr r0, =console_state
ldrb r0, [r0]
ldr r1, [r6, #CONSOLE_T_FLAGS]
tst r0, r1
beq getc_continue
ldr r1, [r6, #CONSOLE_T_GETC]
cmp r1, #0
beq getc_continue
mov r0, r6
blx r1
cmp r0, #0 /* if R0 >= 0: return */
bge getc_found
cmp r5, #ERROR_NO_PENDING_CHAR /* may update R5 (NOCHAR has */
movne r5, r0 /* precedence vs real errors) */
getc_continue:
ldr r6, [r6] /* R6 = next struct */
cmp r6, #0
bne getc_loop
cmp r5, #ERROR_NO_PENDING_CHAR /* Keep scanning if at least */
beq getc_try_again /* one console returns NOCHAR */
mov r0, r5
getc_found:
pop {r5-r6, pc}
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: r0 - 0 on success, < 0 if at least one error
* Clobber list : r0, r1, r2
* ---------------------------------------------
*/
func console_flush
push {r5-r6, lr}
mov r5, #ERROR_NO_VALID_CONSOLE /* R5 = current return value */
ldr r6, =console_list
ldr r6, [r6] /* R6 = first console struct */
flush_loop:
cmp r6, #0
beq flush_done
ldr r1, =console_state
ldrb r1, [r1]
ldr r2, [r6, #CONSOLE_T_FLAGS]
tst r1, r2
beq flush_continue
ldr r1, [r6, #CONSOLE_T_FLUSH]
cmp r1, #0
beq flush_continue
mov r0, r6
blx r1
cmp r5, #ERROR_NO_VALID_CONSOLE /* update R5 if it's NOVALID */
cmpne r0, #0 /* else update it if R0 < 0 */
movlt r5, r0
flush_continue:
ldr r6, [r6] /* R6 = next struct */
b flush_loop
flush_done:
mov r0, r5
pop {r5-r6, pc}
endfunc console_flush
#endif /* MULTI_CONSOLE_API */

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@ -1,329 +0,0 @@
/*
* Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#if MULTI_CONSOLE_API
#include <asm_macros.S>
#include <assert_macros.S>
#include <console.h>
.globl console_register
.globl console_unregister
.globl console_is_registered
.globl console_set_scope
.globl console_switch_state
.globl console_putc
.globl console_getc
.globl console_flush
.globl console_list
/*
* 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
* -----------------------------------------------
*/
func console_register
stp x21, x30, [sp, #-16]!
#if ENABLE_ASSERTIONS
/* Assert that x0 isn't a NULL pointer */
cmp x0, #0
ASM_ASSERT(ne)
/* Assert that the struct isn't in the stack */
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:
/* Assert that this struct isn't in the list */
mov x1, x0 /* Preserve x0 and x30 */
bl console_is_registered
cmp x0, #0
ASM_ASSERT(eq)
mov x0, x1
#endif /* ENABLE_ASSERTIONS */
adrp x21, console_list
ldr x1, [x21, :lo12:console_list] /* X1 = first struct in list */
str x0, [x21, :lo12:console_list] /* list head = new console */
str x1, [x0, #CONSOLE_T_NEXT] /* new console next ptr = X1 */
mov x0, #1
ldp x21, x30, [sp], #16
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
* -----------------------------------------------
*/
func console_unregister
#if ENABLE_ASSERTIONS
/* Assert that x0 isn't a NULL pointer */
cmp x0, #0
ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
stp x21, xzr, [sp, #-16]!
adrp x21, console_list
add x21, x21, :lo12:console_list /* X21 = ptr to first struct */
ldr x1, [x21] /* X1 = first struct */
unregister_loop:
cbz x1, unregister_not_found
cmp x0, x1
b.eq unregister_found
ldr x21, [x21] /* X21 = next ptr of struct */
ldr x1, [x21] /* X1 = next struct */
b unregister_loop
unregister_found:
ldr x1, [x1] /* X1 = next struct */
str x1, [x21] /* prev->next = cur->next */
ldp x21, xzr, [sp], #16
ret
unregister_not_found:
mov x0, #0 /* return NULL if not found */
ldp x21, xzr, [sp], #16
ret
endfunc console_unregister
/* -----------------------------------------------
* int console_is_registered(console_t *console)
* Function to detect if a specific console is
* registered or not.
* In: x0 - address of console_t struct to remove
* Out: x0 - 1 if it is registered, 0 if not.
* Clobber list: x0
* -----------------------------------------------
*/
func console_is_registered
#if ENABLE_ASSERTIONS
/* Assert that x0 isn't a NULL pointer */
cmp x0, #0
ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
stp x21, xzr, [sp, #-16]!
adrp x21, console_list
ldr x21, [x21, :lo12:console_list] /* X21 = first console struct */
check_registered_loop:
cbz x21, console_not_registered /* Check if end of list */
cmp x0, x21 /* Check if the pointers are different */
b.eq console_registered
ldr x21, [x21, #CONSOLE_T_NEXT] /* Get pointer to next struct */
b check_registered_loop
console_not_registered:
mov x0, #0
ldp x21, xzr, [sp], #16
ret
console_registered:
mov x0, #1
ldp x21, xzr, [sp], #16
ret
endfunc console_is_registered
/* -----------------------------------------------
* 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
* ---------------------------------------------
*/
func console_putc
stp x21, x30, [sp, #-16]!
stp x19, x20, [sp, #-16]!
mov w20, #ERROR_NO_VALID_CONSOLE /* W20 = current return value */
mov w19, w0 /* W19 = character to print */
adrp x21, console_list
ldr x21, [x21, :lo12:console_list] /* X21 = first console struct */
putc_loop:
cbz x21, putc_done
adrp x1, console_state
ldrb w1, [x1, :lo12:console_state]
ldr w2, [x21, #CONSOLE_T_FLAGS]
tst w1, w2
b.eq putc_continue
ldr x2, [x21, #CONSOLE_T_PUTC]
cbz x2, putc_continue
mov w0, w19
mov x1, x21
blr x2
cmp w20, #ERROR_NO_VALID_CONSOLE /* update W20 if it's NOVALID */
ccmp w0, #0, #0x8, ne /* else update it if W0 < 0 */
csel w20, w0, w20, lt
putc_continue:
ldr x21, [x21] /* X21 = next struct */
b putc_loop
putc_done:
mov w0, w20
ldp x19, x20, [sp], #16
ldp x21, x30, [sp], #16
ret
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
* ---------------------------------------------
*/
func console_getc
stp x30, xzr, [sp, #-16]!
stp x20, x21, [sp, #-16]!
getc_try_again:
mov w20, #ERROR_NO_VALID_CONSOLE /* W20 = current return value */
adrp x21, console_list
ldr x21, [x21, :lo12:console_list] /* X21 = first console struct */
cbnz x21, getc_loop
mov w0, w20 /* If no consoles registered */
ldp x20, x21, [sp], #16
ldp x30, xzr, [sp], #16
ret /* return immediately. */
getc_loop:
adrp x0, console_state
ldrb w0, [x0, :lo12:console_state]
ldr w1, [x21, #CONSOLE_T_FLAGS]
tst w0, w1
b.eq getc_continue
ldr x1, [x21, #CONSOLE_T_GETC]
cbz x1, getc_continue
mov x0, x21
blr x1
cmp w0, #0 /* if X0 >= 0: return */
b.ge getc_found
cmp w20, #ERROR_NO_PENDING_CHAR /* may update W20 (NOCHAR has */
csel w20, w20, w0, eq /* precedence vs real errors) */
getc_continue:
ldr x21, [x21] /* X21 = next struct */
cbnz x21, getc_loop
cmp w20, #ERROR_NO_PENDING_CHAR /* Keep scanning if at least */
b.eq getc_try_again /* one console returns NOCHAR */
mov w0, w20
getc_found:
ldp x20, x21, [sp], #16
ldp x30, xzr, [sp], #16
ret
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
* ---------------------------------------------
*/
func console_flush
stp x30, xzr, [sp, #-16]!
stp x20, x21, [sp, #-16]!
mov w20, #ERROR_NO_VALID_CONSOLE /* W20 = current return value */
adrp x21, console_list
ldr x21, [x21, :lo12:console_list] /* X21 = first console struct */
flush_loop:
cbz x21, flush_done
adrp x1, console_state
ldrb w1, [x1, :lo12:console_state]
ldr w2, [x21, #CONSOLE_T_FLAGS]
tst w1, w2
b.eq flush_continue
ldr x1, [x21, #CONSOLE_T_FLUSH]
cbz x1, flush_continue
mov x0, x21
blr x1
cmp w20, #ERROR_NO_VALID_CONSOLE /* update W20 if it's NOVALID */
ccmp w0, #0, #0x8, ne /* else update it if W0 < 0 */
csel w20, w0, w20, lt
flush_continue:
ldr x21, [x21] /* X21 = next struct */
b flush_loop
flush_done:
mov w0, w20
ldp x20, x21, [sp], #16
ldp x30, xzr, [sp], #16
ret
endfunc console_flush
#endif /* MULTI_CONSOLE_API */

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@ -0,0 +1,122 @@
/*
* Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#if MULTI_CONSOLE_API
#include <assert.h>
#include <drivers/console.h>
console_t *console_list;
uint8_t console_state = CONSOLE_FLAG_BOOT;
int console_register(console_t *console)
{
IMPORT_SYM(console_t *, __STACKS_START__, stacks_start)
IMPORT_SYM(console_t *, __STACKS_END__, stacks_end)
/* Assert that the struct is not on the stack (common mistake). */
assert((console < stacks_start) || (console >= stacks_end));
/* Assert that we won't make a circle in the list. */
assert(!console_is_registered(console));
console->next = console_list;
console_list = console;
/* Return 1 for convenient tail-calling from console_xxx_register(). */
return 1;
}
console_t *console_unregister(console_t *to_be_deleted)
{
console_t **ptr;
assert(to_be_deleted != NULL);
for (ptr = &console_list; *ptr != NULL; ptr = &(*ptr)->next)
if (*ptr == to_be_deleted) {
*ptr = (*ptr)->next;
return to_be_deleted;
}
return NULL;
}
int console_is_registered(console_t *to_find)
{
console_t *console;
assert(to_find != NULL);
for (console = console_list; console != NULL; console = console->next)
if (console == to_find)
return 1;
return 0;
}
void console_switch_state(unsigned int new_state)
{
console_state = new_state;
}
void console_set_scope(console_t *console, unsigned int scope)
{
assert(console != NULL);
console->flags = (console->flags & ~CONSOLE_FLAG_SCOPE_MASK) | scope;
}
int console_putc(int c)
{
int err = ERROR_NO_VALID_CONSOLE;
console_t *console;
for (console = console_list; console != NULL; console = console->next)
if (console->flags & console_state) {
int ret = console->putc(c, console);
if ((err == ERROR_NO_VALID_CONSOLE) || (ret < err))
err = ret;
}
return err;
}
int console_getc(void)
{
int err = ERROR_NO_VALID_CONSOLE;
console_t *console;
do { /* Keep polling while at least one console works correctly. */
for (console = console_list; console != NULL;
console = console->next)
if (console->flags & console_state) {
int ret = console->getc(console);
if (ret >= 0)
return ret;
if (err != ERROR_NO_PENDING_CHAR)
err = ret;
}
} while (err == ERROR_NO_PENDING_CHAR);
return err;
}
int console_flush(void)
{
int err = ERROR_NO_VALID_CONSOLE;
console_t *console;
for (console = console_list; console != NULL; console = console->next)
if (console->flags & console_state) {
int ret = console->flush(console);
if ((err == ERROR_NO_VALID_CONSOLE) || (ret < err))
err = ret;
}
return err;
}
#endif /* MULTI_CONSOLE_API */