mips: Update the MIPS threading code

Taken from Amaury Pouly's Fiio X1 patches in gerrit.

   Xduoo X3 no longer panics on startup

Change-Id: I4c2dee832306755b9e496084cb47fb61f804af20
This commit is contained in:
Solomon Peachy 2018-08-20 11:12:58 -04:00 committed by Marcin Bukat
parent 734be0d6aa
commit be801c61bb
2 changed files with 47 additions and 53 deletions

View file

@ -26,23 +26,24 @@
*--------------------------------------------------------------------------- *---------------------------------------------------------------------------
*/ */
static void USED_ATTR start_thread(void *addr) void start_thread(void); /* Provide C access to ASM label */
static void USED_ATTR _start_thread(void)
{ {
/* t1 = context */
asm volatile ( asm volatile (
"start_thread: \n"
".set noreorder \n" ".set noreorder \n"
".set noat \n" ".set noat \n"
"lw $25, 4(%0) \n" /* Fetch thread function pointer ($25 = t9) */ "lw $8, 4($9) \n" /* Fetch thread function pointer ($8 = t0, $9 = t1) */
"lw $25, 40(%0) \n" /* Set initial sp(=$29) */ "lw $29, 36($9) \n" /* Set initial sp(=$29) */
"jalr $25 \n" /* Start the thread */ "jalr $8 \n" /* Start the thread */
"sw $0, 48(%0) \n" /* Clear start address */ "sw $0, 44($9) \n" /* Clear start address */
".set at \n" ".set at \n"
".set reorder \n" ".set reorder \n"
: : "r" (addr) : "$25"
); );
thread_exit(); thread_exit();
} }
/* Place context pointer in s0 slot, function pointer in s1 slot, and /* Place context pointer in s0 slot, function pointer in s1 slot, and
* start_thread pointer in context_start */ * start_thread pointer in context_start */
#define THREAD_STARTUP_INIT(core, thread, function) \ #define THREAD_STARTUP_INIT(core, thread, function) \
@ -59,21 +60,25 @@ static inline void store_context(void* addr)
asm volatile ( asm volatile (
".set noreorder \n" ".set noreorder \n"
".set noat \n" ".set noat \n"
"sw $16, 0(%0) \n" /* s0 */ "move $8, %0 \n" /* Store addr in clobbered t0 othrewise
"sw $17, 4(%0) \n" /* s1 */ * compiler could select %0 to be s0-s7
"sw $18, 8(%0) \n" /* s2 */ * during inlining which would break
"sw $19, 12(%0) \n" /* s3 */ * things horribly.
"sw $20, 16(%0) \n" /* s4 */ */
"sw $21, 20(%0) \n" /* s5 */ "sw $16, 0($8) \n" /* s0 */
"sw $22, 24(%0) \n" /* s6 */ "sw $17, 4($8) \n" /* s1 */
"sw $23, 28(%0) \n" /* s7 */ "sw $18, 8($8) \n" /* s2 */
"sw $28, 32(%0) \n" /* gp */ "sw $19, 12($8) \n" /* s3 */
"sw $30, 36(%0) \n" /* fp */ "sw $20, 16($8) \n" /* s4 */
"sw $29, 40(%0) \n" /* sp */ "sw $21, 20($8) \n" /* s5 */
"sw $31, 44(%0) \n" /* ra */ "sw $22, 24($8) \n" /* s6 */
"sw $23, 28($8) \n" /* s7 */
"sw $30, 32($8) \n" /* fp */
"sw $29, 36($8) \n" /* sp */
"sw $31, 40($8) \n" /* ra */
".set at \n" ".set at \n"
".set reorder \n" ".set reorder \n"
: : "r" (addr) : : "r" (addr) : "t0"
); );
} }
@ -86,27 +91,31 @@ static inline void load_context(const void* addr)
asm volatile ( asm volatile (
".set noat \n" ".set noat \n"
".set noreorder \n" ".set noreorder \n"
"lw $25, 48(%0) \n" /* Get start address (t9 = $25) */ "lw $8, 44(%0) \n" /* Get start address ($8 = t0) */
"beqz $25, running \n" /* NULL -> already running */ "beqz $8, running \n" /* NULL -> already running */
"nop \n" "nop \n"
"jr $25 \n" "jr $8 \n"
"move $4, %0 \n" /* a0 = context branch delay slot anyway */ "move $9, %0 \n" /* t1 = context */
"running: \n" "running: \n"
"lw $16, 0(%0) \n" /* s0 */ "move $8, %0 \n" /* Store addr in clobbered t0 otherwise
"lw $17, 4(%0) \n" /* s1 */ * compiler could select %0 to be s0-s7
"lw $18, 8(%0) \n" /* s2 */ * during inlining which would break
"lw $19, 12(%0) \n" /* s3 */ * things horribly.
"lw $20, 16(%0) \n" /* s4 */ */
"lw $21, 20(%0) \n" /* s5 */ "lw $16, 0($8) \n" /* s0 */
"lw $22, 24(%0) \n" /* s6 */ "lw $17, 4($8) \n" /* s1 */
"lw $23, 28(%0) \n" /* s7 */ "lw $18, 8($8) \n" /* s2 */
"lw $28, 32(%0) \n" /* gp */ "lw $19, 12($8) \n" /* s3 */
"lw $30, 36(%0) \n" /* fp */ "lw $20, 16($8) \n" /* s4 */
"lw $29, 40(%0) \n" /* sp */ "lw $21, 20($8) \n" /* s5 */
"lw $31, 44(%0) \n" /* ra */ "lw $22, 24($8) \n" /* s6 */
"lw $23, 28($8) \n" /* s7 */
"lw $30, 32($8) \n" /* fp */
"lw $29, 36($8) \n" /* sp */
"lw $31, 40($8) \n" /* ra */
".set at \n" ".set at \n"
".set reorder \n" ".set reorder \n"
: : "r" (addr) : "$25" : : "r" (addr) : "t0", "t1"
); );
} }

View file

@ -19,24 +19,9 @@
* *
****************************************************************************/ ****************************************************************************/
/* index offset register
* 0 0 $16 s0
* 1 4 $17 s1
* 2 8 $18 s2
* 3 12 $19 s3
* 4 16 $20 s4
* 5 20 $21 s5
* 6 24 $22 s6
* 7 28 $23 s7
* 8 32 $28 gp
* 9 36 $30 s8 (s8)
* 10 40 $29 sp
* 11 44 $31 ra
* 12 48 start
*/
struct regs struct regs
{ {
uint32_t r[10]; /* 0-32 - Registers s0-s7, gp, fp */ uint32_t r[9]; /* 0-32 - Registers s0-s7, fp */
uint32_t sp; /* 36 - Stack pointer */ uint32_t sp; /* 36 - Stack pointer */
uint32_t ra; /* 40 - Return address */ uint32_t ra; /* 40 - Return address */
uint32_t start; /* 44 - Thread start address, or NULL when started */ uint32_t start; /* 44 - Thread start address, or NULL when started */