David Binderman reported that the exception injection code had a
couple of unused variables lingering around.
Upon examination, it looked like this code could do with an
anticipated spring cleaning, which amounts to deduplicating
the CPSR/SPSR update, and making it look a bit more like
the architecture spec.
The spurious variables are removed in the process.
Reported-by: David Binderman <dcb...@hotmail.com>
Reviewed-by: Christoffer Dall <christoffer.d...@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyng...@arm.com>
---
arch/arm/kvm/emulate.c | 74 ++++++++++++++++++++++++++------------------------
1 file changed, 38 insertions(+), 36 deletions(-)
diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
index d6c0052..dc99159 100644
--- a/arch/arm/kvm/emulate.c
+++ b/arch/arm/kvm/emulate.c
@@ -275,6 +275,40 @@ static u32 exc_vector_base(struct kvm_vcpu *vcpu)
return vbar;
}
+/*
+ * Switch to an exception mode, updating both CPSR and SPSR. Follow
+ * the logic described in AArch32.EnterMode() from the ARMv8 ARM.
+ */
+static void kvm_update_psr(struct kvm_vcpu *vcpu, unsigned long mode)
+{
+ unsigned long cpsr = *vcpu_cpsr(vcpu);
+ u32 sctlr = vcpu->arch.cp15[c1_SCTLR];
+
+ *vcpu_cpsr(vcpu) = (cpsr & ~MODE_MASK) | mode;
+
+ switch (mode) {
+ case FIQ_MODE:
+ *vcpu_cpsr(vcpu) |= PSR_F_BIT;
+ /* Fall through */
+ case ABT_MODE:
+ case IRQ_MODE:
+ *vcpu_cpsr(vcpu) |= PSR_A_BIT;
+ /* Fall through */
+ default:
+ *vcpu_cpsr(vcpu) |= PSR_I_BIT;
+ }
+
+ *vcpu_cpsr(vcpu) &= ~(PSR_IT_MASK | PSR_J_BIT | PSR_E_BIT | PSR_T_BIT);
+
+ if (sctlr & SCTLR_TE)
+ *vcpu_cpsr(vcpu) |= PSR_T_BIT;
+ if (sctlr & SCTLR_EE)
+ *vcpu_cpsr(vcpu) |= PSR_E_BIT;
+
+ /* Note: These now point to the mode banked copies */
+ *vcpu_spsr(vcpu) = cpsr;
+}
+
/**
* kvm_inject_undefined - inject an undefined exception into the guest
* @vcpu: The VCPU to receive the undefined exception
@@ -286,29 +320,13 @@ static u32 exc_vector_base(struct kvm_vcpu *vcpu)
*/
void kvm_inject_undefined(struct kvm_vcpu *vcpu)
{
- unsigned long new_lr_value;
- unsigned long new_spsr_value;
unsigned long cpsr = *vcpu_cpsr(vcpu);
- u32 sctlr = vcpu->arch.cp15[c1_SCTLR];
bool is_thumb = (cpsr & PSR_T_BIT);
u32 vect_offset = 4;
u32 return_offset = (is_thumb) ? 2 : 4;
- new_spsr_value = cpsr;
- new_lr_value = *vcpu_pc(vcpu) - return_offset;
-
- *vcpu_cpsr(vcpu) = (cpsr & ~MODE_MASK) | UND_MODE;
- *vcpu_cpsr(vcpu) |= PSR_I_BIT;
- *vcpu_cpsr(vcpu) &= ~(PSR_IT_MASK | PSR_J_BIT | PSR_E_BIT | PSR_T_BIT);
-
- if (sctlr & SCTLR_TE)
- *vcpu_cpsr(vcpu) |= PSR_T_BIT;
- if (sctlr & SCTLR_EE)
- *vcpu_cpsr(vcpu) |= PSR_E_BIT;
-
- /* Note: These now point to UND banked copies */
- *vcpu_spsr(vcpu) = cpsr;
- *vcpu_reg(vcpu, 14) = new_lr_value;
+ kvm_update_psr(vcpu, UND_MODE);
+ *vcpu_reg(vcpu, 14) = *vcpu_pc(vcpu) - return_offset;
/* Branch to exception vector */
*vcpu_pc(vcpu) = exc_vector_base(vcpu) + vect_offset;
@@ -320,30 +338,14 @@ void kvm_inject_undefined(struct kvm_vcpu *vcpu)
*/
static void inject_abt(struct kvm_vcpu *vcpu, bool is_pabt, unsigned long addr)
{
- unsigned long new_lr_value;
- unsigned long new_spsr_value;
unsigned long cpsr = *vcpu_cpsr(vcpu);
- u32 sctlr = vcpu->arch.cp15[c1_SCTLR];
bool is_thumb = (cpsr & PSR_T_BIT);
u32 vect_offset;
u32 return_offset = (is_thumb) ? 4 : 0;
bool is_lpae;
- new_spsr_value = cpsr;
- new_lr_value = *vcpu_pc(vcpu) + return_offset;
-
- *vcpu_cpsr(vcpu) = (cpsr & ~MODE_MASK) | ABT_MODE;
- *vcpu_cpsr(vcpu) |= PSR_I_BIT | PSR_A_BIT;
- *vcpu_cpsr(vcpu) &= ~(PSR_IT_MASK | PSR_J_BIT | PSR_E_BIT | PSR_T_BIT);
-
- if (sctlr & SCTLR_TE)
- *vcpu_cpsr(vcpu) |= PSR_T_BIT;
- if (sctlr & SCTLR_EE)
- *vcpu_cpsr(vcpu) |= PSR_E_BIT;
-
- /* Note: These now point to ABT banked copies */
- *vcpu_spsr(vcpu) = cpsr;
- *vcpu_reg(vcpu, 14) = new_lr_value;
+ kvm_update_psr(vcpu, ABT_MODE);
+ *vcpu_reg(vcpu, 14) = *vcpu_pc(vcpu) + return_offset;
if (is_pabt)
vect_offset = 12;
--
2.1.4
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