diff options
| author | Christian Cunningham <cc@localhost> | 2022-02-13 01:54:51 -0700 |
|---|---|---|
| committer | Christian Cunningham <cc@localhost> | 2022-02-13 01:54:51 -0700 |
| commit | 958696be616aaaa4fe18fc2b886216f191bb6f9b (patch) | |
| tree | 1bdef3ca97744487cfaad680665adce83dc60d47 /src/exceptions | |
| parent | fcf70bcd6a2b2d3bbf76280041438fb1abf33d52 (diff) | |
Mutex Waiting Implemented
Svc 4 and 5
Diffstat (limited to 'src/exceptions')
| -rw-r--r-- | src/exceptions/svc.S | 41 |
1 files changed, 40 insertions, 1 deletions
diff --git a/src/exceptions/svc.S b/src/exceptions/svc.S index 48d03a5..fc4653a 100644 --- a/src/exceptions/svc.S +++ b/src/exceptions/svc.S @@ -5,8 +5,12 @@ svc: stmfd sp!, {r0-r12,lr} ldr r0, [lr, #-4] bic r0, #0xFF000000 - cmp r0, #3 + cmp r0, #5 bgt svc_exit + beq svc_000005 + cmp r0, #4 + beq svc_000004 + cmp r0, #3 beq svc_000003 cmp r0, #2 beq svc_000002 @@ -42,6 +46,41 @@ svc_000003: // Clean task stack mov r0, r2 bl kfree b svc_exit +svc_000004: // Lock Mutex (usr_r0 = struct Mutex*) + ldr r3, =scheduler + ldr r2, [r3, #0] // struct Thread* rthread + ldr r1, [r2, #0x10] // unsigned long pid + ldr r0, [sp, #0] // struct Mutex* m + add r0, #4 // Point to pid +1: clrex + ldrex r2, [r0, #0] + cmp r2, #0 + bne svc_000004_delay_mutex + strexeq r2, r1, [r0, #0] + teq r2, #0 + bne 1b + dmb + b svc_exit +svc_000004_delay_mutex: + // r0 = struct Mutex* m + sub r0, #4 + bl sched_mutex_yield + ldmfd sp!, {r0-r12,lr} + b schedule +svc_000005: // Release Mutex + ldr r0, [sp, #0] // struct Mutex* m + add r0, #4 + mov r1, #0 + dmb + str r1, [r0, #0] + dsb + sev + // TODO: Branch to scheduler to awake threads awaiting mutex + sub r0, #4 + bl sched_mutex_resurrect + ldmfd sp!, {r0-r12,lr} + b schedule + b svc_exit svc_exit: ldmfd sp!, {r0-r12,pc}^ |