rsr a0, sar
s32i a3, a2, PT_AREG3
- s32i a4, a2, PT_AREG4
- s32i a0, a2, PT_AREG5 # store SAR to PT_AREG5
+ s32i a0, a2, PT_SAR
- /* The spill routine might clobber a7, a11, and a15. */
+ /* The spill routine might clobber a4, a7, a8, a11, a12, and a15. */
+ s32i a4, a2, PT_AREG4
s32i a7, a2, PT_AREG7
+ s32i a8, a2, PT_AREG8
s32i a11, a2, PT_AREG11
+ s32i a12, a2, PT_AREG12
s32i a15, a2, PT_AREG15
- call0 _spill_registers # destroys a3, a4, and SAR
+ /*
+ * Rotate ws so that the current windowbase is at bit 0.
+ * Assume ws = xxxwww1yy (www1 current window frame).
+ * Rotate ws right so that a4 = yyxxxwww1.
+ */
+
+ rsr a0, windowbase
+ rsr a3, windowstart # a3 = xxxwww1yy
+ ssr a0 # holds WB
+ slli a0, a3, WSBITS
+ or a3, a3, a0 # a3 = xxxwww1yyxxxwww1yy
+ srl a3, a3 # a3 = 00xxxwww1yyxxxwww1
+
+ /* We are done if there are no more than the current register frame. */
+
+ extui a3, a3, 1, WSBITS-1 # a3 = 0yyxxxwww
+ movi a0, (1 << (WSBITS-1))
+ _beqz a3, .Lnospill # only one active frame? jump
+
+ /* We want 1 at the top, so that we return to the current windowbase */
+
+ or a3, a3, a0 # 1yyxxxwww
+
+ /* Skip empty frames - get 'oldest' WINDOWSTART-bit. */
+
+ wsr a3, windowstart # save shifted windowstart
+ neg a0, a3
+ and a3, a0, a3 # first bit set from right: 000010000
+
+ ffs_ws a0, a3 # a0: shifts to skip empty frames
+ movi a3, WSBITS
+ sub a0, a3, a0 # WSBITS-a0:number of 0-bits from right
+ ssr a0 # save in SAR for later.
+
+ rsr a3, windowbase
+ add a3, a3, a0
+ wsr a3, windowbase
+ rsync
+
+ rsr a3, windowstart
+ srl a3, a3 # shift windowstart
+
+ /* WB is now just one frame below the oldest frame in the register
+ window. WS is shifted so the oldest frame is in bit 0, thus, WB
+ and WS differ by one 4-register frame. */
+
+ /* Save frames. Depending what call was used (call4, call8, call12),
+ * we have to save 4,8. or 12 registers.
+ */
+
+
+.Lloop: _bbsi.l a3, 1, .Lc4
+ _bbci.l a3, 2, .Lc12
+
+.Lc8: s32e a4, a13, -16
+ l32e a4, a5, -12
+ s32e a8, a4, -32
+ s32e a5, a13, -12
+ s32e a6, a13, -8
+ s32e a7, a13, -4
+ s32e a9, a4, -28
+ s32e a10, a4, -24
+ s32e a11, a4, -20
+ srli a11, a3, 2 # shift windowbase by 2
+ rotw 2
+ _bnei a3, 1, .Lloop
+ j .Lexit
+
+.Lc4: s32e a4, a9, -16
+ s32e a5, a9, -12
+ s32e a6, a9, -8
+ s32e a7, a9, -4
+
+ srli a7, a3, 1
+ rotw 1
+ _bnei a3, 1, .Lloop
+ j .Lexit
+
+.Lc12: _bbci.l a3, 3, .Linvalid_mask # bit 2 shouldn't be zero!
+
+ /* 12-register frame (call12) */
+
+ l32e a0, a5, -12
+ s32e a8, a0, -48
+ mov a8, a0
+
+ s32e a9, a8, -44
+ s32e a10, a8, -40
+ s32e a11, a8, -36
+ s32e a12, a8, -32
+ s32e a13, a8, -28
+ s32e a14, a8, -24
+ s32e a15, a8, -20
+ srli a15, a3, 3
+
+ /* The stack pointer for a4..a7 is out of reach, so we rotate the
+ * window, grab the stackpointer, and rotate back.
+ * Alternatively, we could also use the following approach, but that
+ * makes the fixup routine much more complicated:
+ * rotw 1
+ * s32e a0, a13, -16
+ * ...
+ * rotw 2
+ */
+
+ rotw 1
+ mov a4, a13
+ rotw -1
+
+ s32e a4, a8, -16
+ s32e a5, a8, -12
+ s32e a6, a8, -8
+ s32e a7, a8, -4
+
+ rotw 3
+
+ _beqi a3, 1, .Lexit
+ j .Lloop
+
+.Lexit:
+
+ /* Done. Do the final rotation and set WS */
+
+ rotw 1
+ rsr a3, windowbase
+ ssl a3
+ movi a3, 1
+ sll a3, a3
+ wsr a3, windowstart
+.Lnospill:
/* Advance PC, restore registers and SAR, and return from exception. */
- l32i a3, a2, PT_AREG5
- l32i a4, a2, PT_AREG4
+ l32i a3, a2, PT_SAR
l32i a0, a2, PT_AREG0
wsr a3, sar
l32i a3, a2, PT_AREG3
/* Restore clobbered registers. */
+ l32i a4, a2, PT_AREG4
l32i a7, a2, PT_AREG7
+ l32i a8, a2, PT_AREG8
l32i a11, a2, PT_AREG11
+ l32i a12, a2, PT_AREG12
l32i a15, a2, PT_AREG15
movi a2, 0
rfe
+.Linvalid_mask:
+
+ /* We get here because of an unrecoverable error in the window
+ * registers, so set up a dummy frame and kill the user application.
+ * Note: We assume EXC_TABLE_KSTK contains a valid stack pointer.
+ */
+
+ movi a0, 1
+ movi a1, 0
+
+ wsr a0, windowstart
+ wsr a1, windowbase
+ rsync
+
+ movi a0, 0
+
+ rsr a3, excsave1
+ l32i a1, a3, EXC_TABLE_KSTK
+
+ movi a4, (1 << PS_WOE_BIT) | LOCKLEVEL
+ wsr a4, ps
+ rsync
+
+ movi a6, SIGSEGV
+ movi a4, do_exit
+ callx4 a4
+
+ /* shouldn't return, so panic */
+
+ wsr a0, excsave1
+ movi a0, unrecoverable_exception
+ callx0 a0 # should not return
+1: j 1b
+
+
ENDPROC(fast_syscall_spill_registers)
/* Fixup handler.
ENDPROC(fast_syscall_spill_registers_fixup_return)
-/*
- * spill all registers.
- *
- * This is not a real function. The following conditions must be met:
- *
- * - must be called with call0.
- * - uses a3, a4 and SAR.
- * - the last 'valid' register of each frame are clobbered.
- * - the caller must have registered a fixup handler
- * (or be inside a critical section)
- * - PS_EXCM must be set (PS_WOE cleared?)
- */
-
-ENTRY(_spill_registers)
-
- /*
- * Rotate ws so that the current windowbase is at bit 0.
- * Assume ws = xxxwww1yy (www1 current window frame).
- * Rotate ws right so that a4 = yyxxxwww1.
- */
-
- rsr a4, windowbase
- rsr a3, windowstart # a3 = xxxwww1yy
- ssr a4 # holds WB
- slli a4, a3, WSBITS
- or a3, a3, a4 # a3 = xxxwww1yyxxxwww1yy
- srl a3, a3 # a3 = 00xxxwww1yyxxxwww1
-
- /* We are done if there are no more than the current register frame. */
-
- extui a3, a3, 1, WSBITS-1 # a3 = 0yyxxxwww
- movi a4, (1 << (WSBITS-1))
- _beqz a3, .Lnospill # only one active frame? jump
-
- /* We want 1 at the top, so that we return to the current windowbase */
-
- or a3, a3, a4 # 1yyxxxwww
-
- /* Skip empty frames - get 'oldest' WINDOWSTART-bit. */
-
- wsr a3, windowstart # save shifted windowstart
- neg a4, a3
- and a3, a4, a3 # first bit set from right: 000010000
-
- ffs_ws a4, a3 # a4: shifts to skip empty frames
- movi a3, WSBITS
- sub a4, a3, a4 # WSBITS-a4:number of 0-bits from right
- ssr a4 # save in SAR for later.
-
- rsr a3, windowbase
- add a3, a3, a4
- wsr a3, windowbase
- rsync
-
- rsr a3, windowstart
- srl a3, a3 # shift windowstart
-
- /* WB is now just one frame below the oldest frame in the register
- window. WS is shifted so the oldest frame is in bit 0, thus, WB
- and WS differ by one 4-register frame. */
-
- /* Save frames. Depending what call was used (call4, call8, call12),
- * we have to save 4,8. or 12 registers.
- */
-
- _bbsi.l a3, 1, .Lc4
- _bbsi.l a3, 2, .Lc8
-
- /* Special case: we have a call12-frame starting at a4. */
-
- _bbci.l a3, 3, .Lc12 # bit 3 shouldn't be zero! (Jump to Lc12 first)
-
- s32e a4, a1, -16 # a1 is valid with an empty spill area
- l32e a4, a5, -12
- s32e a8, a4, -48
- mov a8, a4
- l32e a4, a1, -16
- j .Lc12c
-
-.Lnospill:
- ret
-
-.Lloop: _bbsi.l a3, 1, .Lc4
- _bbci.l a3, 2, .Lc12
-
-.Lc8: s32e a4, a13, -16
- l32e a4, a5, -12
- s32e a8, a4, -32
- s32e a5, a13, -12
- s32e a6, a13, -8
- s32e a7, a13, -4
- s32e a9, a4, -28
- s32e a10, a4, -24
- s32e a11, a4, -20
-
- srli a11, a3, 2 # shift windowbase by 2
- rotw 2
- _bnei a3, 1, .Lloop
-
-.Lexit: /* Done. Do the final rotation, set WS, and return. */
-
- rotw 1
- rsr a3, windowbase
- ssl a3
- movi a3, 1
- sll a3, a3
- wsr a3, windowstart
- ret
-
-.Lc4: s32e a4, a9, -16
- s32e a5, a9, -12
- s32e a6, a9, -8
- s32e a7, a9, -4
-
- srli a7, a3, 1
- rotw 1
- _bnei a3, 1, .Lloop
- j .Lexit
-
-.Lc12: _bbci.l a3, 3, .Linvalid_mask # bit 2 shouldn't be zero!
-
- /* 12-register frame (call12) */
-
- l32e a2, a5, -12
- s32e a8, a2, -48
- mov a8, a2
-
-.Lc12c: s32e a9, a8, -44
- s32e a10, a8, -40
- s32e a11, a8, -36
- s32e a12, a8, -32
- s32e a13, a8, -28
- s32e a14, a8, -24
- s32e a15, a8, -20
- srli a15, a3, 3
-
- /* The stack pointer for a4..a7 is out of reach, so we rotate the
- * window, grab the stackpointer, and rotate back.
- * Alternatively, we could also use the following approach, but that
- * makes the fixup routine much more complicated:
- * rotw 1
- * s32e a0, a13, -16
- * ...
- * rotw 2
- */
-
- rotw 1
- mov a5, a13
- rotw -1
-
- s32e a4, a9, -16
- s32e a5, a9, -12
- s32e a6, a9, -8
- s32e a7, a9, -4
-
- rotw 3
-
- _beqi a3, 1, .Lexit
- j .Lloop
-
-.Linvalid_mask:
-
- /* We get here because of an unrecoverable error in the window
- * registers. If we are in user space, we kill the application,
- * however, this condition is unrecoverable in kernel space.
- */
-
- rsr a0, ps
- _bbci.l a0, PS_UM_BIT, 1f
-
- /* User space: Setup a dummy frame and kill application.
- * Note: We assume EXC_TABLE_KSTK contains a valid stack pointer.
- */
-
- movi a0, 1
- movi a1, 0
-
- wsr a0, windowstart
- wsr a1, windowbase
- rsync
-
- movi a0, 0
-
- rsr a3, excsave1
- l32i a1, a3, EXC_TABLE_KSTK
-
- movi a4, (1 << PS_WOE_BIT) | LOCKLEVEL
- wsr a4, ps
- rsync
-
- movi a6, SIGSEGV
- movi a4, do_exit
- callx4 a4
-
-1: /* Kernel space: PANIC! */
-
- wsr a0, excsave1
- movi a0, unrecoverable_exception
- callx0 a0 # should not return
-1: j 1b
-
-ENDPROC(_spill_registers)
-
#ifdef CONFIG_MMU
/*
* We should never get here. Bail out!
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff