tlbex.c uses the implementation dependent $22 CP0 register group on
NetLogic cores, with the help of the c0_kscratch() helper. Allow these
registers to be allocated by the KVM entry code too instead of assuming
KScratch registers are all $31, which will also allow pgd_reg to be
handled since it is allocated that way.
We also drop the masking of kscratch_mask with 0xfc, as it is redundant
for the standard KScratch registers (Config4.KScrExist won't have the
low 2 bits set anyway), and apparently not necessary for NetLogic.
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: "Radim Krčmář" <rkrcmar@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
---
arch/mips/kvm/entry.c | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)
diff --git a/arch/mips/kvm/entry.c b/arch/mips/kvm/entry.c
index f683d123172c..7424d3d566ff 100644
--- a/arch/mips/kvm/entry.c
+++ b/arch/mips/kvm/entry.c
@@ -91,6 +91,21 @@ static void *kvm_mips_build_ret_from_exit(void *addr);
static void *kvm_mips_build_ret_to_guest(void *addr);
static void *kvm_mips_build_ret_to_host(void *addr);
+/*
+ * The version of this function in tlbex.c uses current_cpu_type(), but for KVM
+ * we assume symmetry.
+ */
+static int c0_kscratch(void)
+{
+ switch (boot_cpu_type()) {
+ case CPU_XLP:
+ case CPU_XLR:
+ return 22;
+ default:
+ return 31;
+ }
+}
+
/**
* kvm_mips_entry_setup() - Perform global setup for entry code.
*
@@ -105,18 +120,18 @@ int kvm_mips_entry_setup(void)
* We prefer to use KScratchN registers if they are available over the
* defaults above, which may not work on all cores.
*/
- unsigned int kscratch_mask = cpu_data[0].kscratch_mask & 0xfc;
+ unsigned int kscratch_mask = cpu_data[0].kscratch_mask;
/* Pick a scratch register for storing VCPU */
if (kscratch_mask) {
- scratch_vcpu[0] = 31;
+ scratch_vcpu[0] = c0_kscratch();
scratch_vcpu[1] = ffs(kscratch_mask) - 1;
kscratch_mask &= ~BIT(scratch_vcpu[1]);
}
/* Pick a scratch register to use as a temp for saving state */
if (kscratch_mask) {
- scratch_tmp[0] = 31;
+ scratch_tmp[0] = c0_kscratch();
scratch_tmp[1] = ffs(kscratch_mask) - 1;
kscratch_mask &= ~BIT(scratch_tmp[1]);
}
@@ -132,7 +147,7 @@ static void kvm_mips_build_save_scratch(u32 **p, unsigned int tmp,
UASM_i_SW(p, tmp, offsetof(struct pt_regs, cp0_epc), frame);
/* Save the temp scratch register value in cp0_cause of stack frame */
- if (scratch_tmp[0] == 31) {
+ if (scratch_tmp[0] == c0_kscratch()) {
UASM_i_MFC0(p, tmp, scratch_tmp[0], scratch_tmp[1]);
UASM_i_SW(p, tmp, offsetof(struct pt_regs, cp0_cause), frame);
}
@@ -148,7 +163,7 @@ static void kvm_mips_build_restore_scratch(u32 **p, unsigned int tmp,
UASM_i_LW(p, tmp, offsetof(struct pt_regs, cp0_epc), frame);
UASM_i_MTC0(p, tmp, scratch_vcpu[0], scratch_vcpu[1]);
- if (scratch_tmp[0] == 31) {
+ if (scratch_tmp[0] == c0_kscratch()) {
UASM_i_LW(p, tmp, offsetof(struct pt_regs, cp0_cause), frame);
UASM_i_MTC0(p, tmp, scratch_tmp[0], scratch_tmp[1]);
}
--
git-series 0.8.10
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