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[Qemu-ppc] [PULL 066/107] ppc: Prevent inifnite loop in decrementer auto
From: |
David Gibson |
Subject: |
[Qemu-ppc] [PULL 066/107] ppc: Prevent inifnite loop in decrementer auto-reload. |
Date: |
Thu, 2 Feb 2017 16:14:04 +1100 |
From: Roman Kapl <address@hidden>
If the DECAR register is set to 0, QEMU tries to reload the decrementer with
zero in an inifinite loop. According to PPC documentation, the decrementer is
triggered on 1->0 transition, so avoid reloading the decrementer if if is
already zero.
The problem does not manifest under Linux, but it is valid to set DECAR to zero
(and may make sense as part of decrementer initialization when interrupts are
disabled).
Signed-off-by: Roman Kapl <address@hidden>
[dwg: Fixed style nit]
Signed-off-by: David Gibson <address@hidden>
---
hw/ppc/ppc_booke.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/hw/ppc/ppc_booke.c b/hw/ppc/ppc_booke.c
index ab8d026..60baffa 100644
--- a/hw/ppc/ppc_booke.c
+++ b/hw/ppc/ppc_booke.c
@@ -198,8 +198,12 @@ static void booke_decr_cb(void *opaque)
booke_update_irq(cpu);
if (env->spr[SPR_BOOKE_TCR] & TCR_ARE) {
- /* Auto Reload */
- cpu_ppc_store_decr(env, env->spr[SPR_BOOKE_DECAR]);
+ /* Do not reload 0, it is already there. It would just trigger
+ * the timer again and lead to infinite loop */
+ if (env->spr[SPR_BOOKE_DECAR] != 0) {
+ /* Auto Reload */
+ cpu_ppc_store_decr(env, env->spr[SPR_BOOKE_DECAR]);
+ }
}
}
--
2.9.3
- [Qemu-ppc] [PULL 031/107] hw/ppc/spapr: Fix boot path of usb-host storage devices, (continued)
- [Qemu-ppc] [PULL 031/107] hw/ppc/spapr: Fix boot path of usb-host storage devices, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 039/107] libqos: fix spapr qpci_map(), David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 044/107] hw/ppc: QOM'ify ppce500_spin.c, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 034/107] ppc: Rewrite ppc_set_compat(), David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 051/107] target-ppc: Use float64 arg in helper_compute_fprf(), David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 047/107] target-ppc: Add xxinsertw instruction, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 026/107] target-ppc: Add xxperm and xxpermr instructions, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 059/107] target-ppc: Add xsxsigqp instructions, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 028/107] target-ppc: implement lxvll instruction, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 042/107] hw/gpio: QOM'ify mpc8xxx.c, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 066/107] ppc: Prevent inifnite loop in decrementer auto-reload.,
David Gibson <=
- [Qemu-ppc] [PULL 069/107] softfloat: Fix the default qNAN for target-ppc, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 049/107] prep: add IBM RS/6000 7020 (40p) memory controller, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 067/107] ppc: Fix a warning in bcdcfz code and improve BCD_DIG_BYTE macro, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 029/107] target-ppc: implement stxvl instruction, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 043/107] hw/ppc: QOM'ify e500.c, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 035/107] ppc: Rewrite ppc_get_compat_smt_threads(), David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 030/107] target-ppc: implement stxvll instructions, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 046/107] target-ppc: Add xxextractuw instruction, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 040/107] qtest: convert ivshmem-test to use libqos, David Gibson, 2017/02/02
- [Qemu-ppc] [PULL 058/107] target-ppc: Add xsxsigdp instruction, David Gibson, 2017/02/02