Console: Use callee-saved registers
This allows the console drivers to be implemented in C Change-Id: Ibac859c4bcef0e92a0dcacc6b58ac19bc69b8342 Signed-off-by: Sathees Balya <sathees.balya@arm.com>
This commit is contained in:
Sathees Balya
parent
8ae41aec32
commit
d35cc347db
|
|
@ -39,10 +39,11 @@
|
|||
* 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, x15
|
||||
* 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
|
||||
|
|
@ -59,18 +60,17 @@ func console_register
|
|||
not_on_stack:
|
||||
/* Assert that this struct isn't in the list */
|
||||
mov x1, x0 /* Preserve x0 and x30 */
|
||||
mov x15, x30
|
||||
bl console_is_registered
|
||||
cmp x0, #0
|
||||
ASM_ASSERT(eq)
|
||||
mov x30, x15
|
||||
mov x0, x1
|
||||
#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 */
|
||||
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
|
||||
|
||||
|
|
@ -80,7 +80,7 @@ endfunc console_register
|
|||
* 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
|
||||
* Clobber list: x0, x1
|
||||
* -----------------------------------------------
|
||||
*/
|
||||
func console_unregister
|
||||
|
|
@ -89,25 +89,28 @@ func console_unregister
|
|||
cmp x0, #0
|
||||
ASM_ASSERT(ne)
|
||||
#endif /* ENABLE_ASSERTIONS */
|
||||
adrp x14, console_list
|
||||
add x14, x14, :lo12:console_list /* X14 = ptr to first struct */
|
||||
ldr x1, [x14] /* X1 = first struct */
|
||||
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 x14, [x14] /* X14 = next ptr of struct */
|
||||
ldr x1, [x14] /* X1 = next struct */
|
||||
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, [x14] /* prev->next = cur->next */
|
||||
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
|
||||
|
||||
|
|
@ -117,7 +120,7 @@ endfunc console_unregister
|
|||
* 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, x14
|
||||
* Clobber list: x0
|
||||
* -----------------------------------------------
|
||||
*/
|
||||
func console_is_registered
|
||||
|
|
@ -126,19 +129,22 @@ func console_is_registered
|
|||
cmp x0, #0
|
||||
ASM_ASSERT(ne)
|
||||
#endif /* ENABLE_ASSERTIONS */
|
||||
adrp x14, console_list
|
||||
ldr x14, [x14, :lo12:console_list] /* X14 = first console struct */
|
||||
stp x21, xzr, [sp, #-16]!
|
||||
adrp x21, console_list
|
||||
ldr x21, [x21, :lo12:console_list] /* X21 = first console struct */
|
||||
check_registered_loop:
|
||||
cbz x14, console_not_registered /* Check if end of list */
|
||||
cmp x0, x14 /* Check if the pointers are different */
|
||||
cbz x21, console_not_registered /* Check if end of list */
|
||||
cmp x0, x21 /* Check if the pointers are different */
|
||||
b.eq console_registered
|
||||
ldr x14, [x14, #CONSOLE_T_NEXT] /* Get pointer to next struct */
|
||||
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
|
||||
|
||||
|
|
@ -186,38 +192,41 @@ endfunc console_set_scope
|
|||
* 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
|
||||
* Clobber list : x0, x1, x2
|
||||
* ---------------------------------------------
|
||||
*/
|
||||
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 */
|
||||
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 x14, putc_done
|
||||
cbz x21, putc_done
|
||||
adrp x1, console_state
|
||||
ldrb w1, [x1, :lo12:console_state]
|
||||
ldr w2, [x14, #CONSOLE_T_FLAGS]
|
||||
ldr w2, [x21, #CONSOLE_T_FLAGS]
|
||||
tst w1, w2
|
||||
b.eq putc_continue
|
||||
ldr x2, [x14, #CONSOLE_T_PUTC]
|
||||
ldr x2, [x21, #CONSOLE_T_PUTC]
|
||||
cbz x2, putc_continue
|
||||
mov w0, w12
|
||||
mov x1, x14
|
||||
mov w0, w19
|
||||
mov x1, x21
|
||||
blr x2
|
||||
cmp w13, #ERROR_NO_VALID_CONSOLE /* update W13 if it's NOVALID */
|
||||
cmp w20, #ERROR_NO_VALID_CONSOLE /* update W20 if it's NOVALID */
|
||||
ccmp w0, #0, #0x8, ne /* else update it if W0 < 0 */
|
||||
csel w13, w0, w13, lt
|
||||
csel w20, w0, w20, lt
|
||||
putc_continue:
|
||||
ldr x14, [x14] /* X14 = next struct */
|
||||
ldr x21, [x21] /* X21 = next struct */
|
||||
b putc_loop
|
||||
|
||||
putc_done:
|
||||
mov w0, w13
|
||||
ret x15
|
||||
mov w0, w20
|
||||
ldp x19, x20, [sp], #16
|
||||
ldp x21, x30, [sp], #16
|
||||
ret
|
||||
endfunc console_putc
|
||||
|
||||
/* ---------------------------------------------
|
||||
|
|
@ -230,42 +239,47 @@ endfunc console_putc
|
|||
* 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
|
||||
* Clobber list : x0, x1
|
||||
* ---------------------------------------------
|
||||
*/
|
||||
func console_getc
|
||||
mov x15, x30
|
||||
stp x30, xzr, [sp, #-16]!
|
||||
stp x20, x21, [sp, #-16]!
|
||||
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. */
|
||||
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, [x14, #CONSOLE_T_FLAGS]
|
||||
ldr w1, [x21, #CONSOLE_T_FLAGS]
|
||||
tst w0, w1
|
||||
b.eq getc_continue
|
||||
ldr x1, [x14, #CONSOLE_T_GETC]
|
||||
ldr x1, [x21, #CONSOLE_T_GETC]
|
||||
cbz x1, getc_continue
|
||||
mov x0, x14
|
||||
mov x0, x21
|
||||
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) */
|
||||
cmp w20, #ERROR_NO_PENDING_CHAR /* may update W20 (NOCHAR has */
|
||||
csel w20, w20, 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 */
|
||||
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, w13
|
||||
mov w0, w20
|
||||
|
||||
getc_found:
|
||||
ret x15
|
||||
ldp x20, x21, [sp], #16
|
||||
ldp x30, xzr, [sp], #16
|
||||
ret
|
||||
endfunc console_getc
|
||||
|
||||
/* ---------------------------------------------
|
||||
|
|
@ -274,34 +288,37 @@ endfunc console_getc
|
|||
* 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
|
||||
* Clobber list : x0, x1, x2
|
||||
* ---------------------------------------------
|
||||
*/
|
||||
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 */
|
||||
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 x14, flush_done
|
||||
cbz x21, flush_done
|
||||
adrp x1, console_state
|
||||
ldrb w1, [x1, :lo12:console_state]
|
||||
ldr w2, [x14, #CONSOLE_T_FLAGS]
|
||||
ldr w2, [x21, #CONSOLE_T_FLAGS]
|
||||
tst w1, w2
|
||||
b.eq flush_continue
|
||||
ldr x1, [x14, #CONSOLE_T_FLUSH]
|
||||
ldr x1, [x21, #CONSOLE_T_FLUSH]
|
||||
cbz x1, flush_continue
|
||||
mov x0, x14
|
||||
mov x0, x21
|
||||
blr x1
|
||||
cmp w13, #ERROR_NO_VALID_CONSOLE /* update W13 if it's NOVALID */
|
||||
cmp w20, #ERROR_NO_VALID_CONSOLE /* update W20 if it's NOVALID */
|
||||
ccmp w0, #0, #0x8, ne /* else update it if W0 < 0 */
|
||||
csel w13, w0, w13, lt
|
||||
csel w20, w0, w20, lt
|
||||
flush_continue:
|
||||
ldr x14, [x14] /* X14 = next struct */
|
||||
ldr x21, [x21] /* X21 = next struct */
|
||||
b flush_loop
|
||||
|
||||
flush_done:
|
||||
mov w0, w13
|
||||
ret x15
|
||||
mov w0, w20
|
||||
ldp x20, x21, [sp], #16
|
||||
ldp x30, xzr, [sp], #16
|
||||
ret
|
||||
endfunc console_flush
|
||||
|
|
|
|||
Loading…
Reference in New Issue