From be801c61bbe95d75e4285da1982017da7fa1736b Mon Sep 17 00:00:00 2001 From: Solomon Peachy Date: Mon, 20 Aug 2018 11:12:58 -0400 Subject: [PATCH] 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 --- firmware/asm/mips/thread-mips32.c | 83 +++++++++++++++++-------------- firmware/asm/mips/thread.h | 17 +------ 2 files changed, 47 insertions(+), 53 deletions(-) diff --git a/firmware/asm/mips/thread-mips32.c b/firmware/asm/mips/thread-mips32.c index 3e38685f1b..b8e684bb80 100644 --- a/firmware/asm/mips/thread-mips32.c +++ b/firmware/asm/mips/thread-mips32.c @@ -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 ( + "start_thread: \n" ".set noreorder \n" ".set noat \n" - "lw $25, 4(%0) \n" /* Fetch thread function pointer ($25 = t9) */ - "lw $25, 40(%0) \n" /* Set initial sp(=$29) */ - "jalr $25 \n" /* Start the thread */ - "sw $0, 48(%0) \n" /* Clear start address */ + "lw $8, 4($9) \n" /* Fetch thread function pointer ($8 = t0, $9 = t1) */ + "lw $29, 36($9) \n" /* Set initial sp(=$29) */ + "jalr $8 \n" /* Start the thread */ + "sw $0, 44($9) \n" /* Clear start address */ ".set at \n" ".set reorder \n" - : : "r" (addr) : "$25" ); thread_exit(); } - /* Place context pointer in s0 slot, function pointer in s1 slot, and * start_thread pointer in context_start */ #define THREAD_STARTUP_INIT(core, thread, function) \ @@ -59,21 +60,25 @@ static inline void store_context(void* addr) asm volatile ( ".set noreorder \n" ".set noat \n" - "sw $16, 0(%0) \n" /* s0 */ - "sw $17, 4(%0) \n" /* s1 */ - "sw $18, 8(%0) \n" /* s2 */ - "sw $19, 12(%0) \n" /* s3 */ - "sw $20, 16(%0) \n" /* s4 */ - "sw $21, 20(%0) \n" /* s5 */ - "sw $22, 24(%0) \n" /* s6 */ - "sw $23, 28(%0) \n" /* s7 */ - "sw $28, 32(%0) \n" /* gp */ - "sw $30, 36(%0) \n" /* fp */ - "sw $29, 40(%0) \n" /* sp */ - "sw $31, 44(%0) \n" /* ra */ + "move $8, %0 \n" /* Store addr in clobbered t0 othrewise + * compiler could select %0 to be s0-s7 + * during inlining which would break + * things horribly. + */ + "sw $16, 0($8) \n" /* s0 */ + "sw $17, 4($8) \n" /* s1 */ + "sw $18, 8($8) \n" /* s2 */ + "sw $19, 12($8) \n" /* s3 */ + "sw $20, 16($8) \n" /* s4 */ + "sw $21, 20($8) \n" /* s5 */ + "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 reorder \n" - : : "r" (addr) + : : "r" (addr) : "t0" ); } @@ -86,27 +91,31 @@ static inline void load_context(const void* addr) asm volatile ( ".set noat \n" ".set noreorder \n" - "lw $25, 48(%0) \n" /* Get start address (t9 = $25) */ - "beqz $25, running \n" /* NULL -> already running */ + "lw $8, 44(%0) \n" /* Get start address ($8 = t0) */ + "beqz $8, running \n" /* NULL -> already running */ "nop \n" - "jr $25 \n" - "move $4, %0 \n" /* a0 = context branch delay slot anyway */ + "jr $8 \n" + "move $9, %0 \n" /* t1 = context */ "running: \n" - "lw $16, 0(%0) \n" /* s0 */ - "lw $17, 4(%0) \n" /* s1 */ - "lw $18, 8(%0) \n" /* s2 */ - "lw $19, 12(%0) \n" /* s3 */ - "lw $20, 16(%0) \n" /* s4 */ - "lw $21, 20(%0) \n" /* s5 */ - "lw $22, 24(%0) \n" /* s6 */ - "lw $23, 28(%0) \n" /* s7 */ - "lw $28, 32(%0) \n" /* gp */ - "lw $30, 36(%0) \n" /* fp */ - "lw $29, 40(%0) \n" /* sp */ - "lw $31, 44(%0) \n" /* ra */ + "move $8, %0 \n" /* Store addr in clobbered t0 otherwise + * compiler could select %0 to be s0-s7 + * during inlining which would break + * things horribly. + */ + "lw $16, 0($8) \n" /* s0 */ + "lw $17, 4($8) \n" /* s1 */ + "lw $18, 8($8) \n" /* s2 */ + "lw $19, 12($8) \n" /* s3 */ + "lw $20, 16($8) \n" /* s4 */ + "lw $21, 20($8) \n" /* s5 */ + "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 reorder \n" - : : "r" (addr) : "$25" + : : "r" (addr) : "t0", "t1" ); } diff --git a/firmware/asm/mips/thread.h b/firmware/asm/mips/thread.h index 42b0f7049f..ac37560a68 100644 --- a/firmware/asm/mips/thread.h +++ b/firmware/asm/mips/thread.h @@ -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 { - 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 ra; /* 40 - Return address */ uint32_t start; /* 44 - Thread start address, or NULL when started */