From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Fri, 8 Apr 2016 17:52:39 +0200
Subject: KVM: s390: use switch vs jump table in priv.c
Git-commit: 6db4263fec9e550e0cdaed732f4af77a44c10f5f
Patch-mainline: v4.16-rc4
References: jsc#SLE-6412
Instead of having huge jump tables for function selection,
let's use normal switch/case statements for the instruction
handlers in priv.c
This allows the compiler to make the right decision depending
on the situation (e.g. avoid jump-tables for thunks).
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
arch/s390/kvm/priv.c | 183 +++++++++++++++++++++++++--------------------------
1 file changed, 91 insertions(+), 92 deletions(-)
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 0af614773c57..c05c28a61de2 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -834,55 +834,60 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
return rc;
}
-static const intercept_handler_t b2_handlers[256] = {
- [0x02] = handle_stidp,
- [0x04] = handle_set_clock,
- [0x10] = handle_set_prefix,
- [0x11] = handle_store_prefix,
- [0x12] = handle_store_cpu_address,
- [0x14] = kvm_s390_handle_vsie,
- [0x21] = handle_ipte_interlock,
- [0x29] = handle_iske,
- [0x2a] = handle_rrbe,
- [0x2b] = handle_sske,
- [0x2c] = handle_test_block,
- [0x30] = handle_io_inst,
- [0x31] = handle_io_inst,
- [0x32] = handle_io_inst,
- [0x33] = handle_io_inst,
- [0x34] = handle_io_inst,
- [0x35] = handle_io_inst,
- [0x36] = handle_io_inst,
- [0x37] = handle_io_inst,
- [0x38] = handle_io_inst,
- [0x39] = handle_io_inst,
- [0x3a] = handle_io_inst,
- [0x3b] = handle_io_inst,
- [0x3c] = handle_io_inst,
- [0x50] = handle_ipte_interlock,
- [0x56] = handle_sthyi,
- [0x5f] = handle_io_inst,
- [0x74] = handle_io_inst,
- [0x76] = handle_io_inst,
- [0x7d] = handle_stsi,
- [0xb1] = handle_stfl,
- [0xb2] = handle_lpswe,
-};
-
int kvm_s390_handle_b2(struct kvm_vcpu *vcpu)
{
- intercept_handler_t handler;
-
- /*
- * A lot of B2 instructions are priviledged. Here we check for
- * the privileged ones, that we can handle in the kernel.
- * Anything else goes to userspace.
- */
- handler = b2_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
- if (handler)
- return handler(vcpu);
-
- return -EOPNOTSUPP;
+ switch (vcpu->arch.sie_block->ipa & 0x00ff) {
+ case 0x02:
+ return handle_stidp(vcpu);
+ case 0x04:
+ return handle_set_clock(vcpu);
+ case 0x10:
+ return handle_set_prefix(vcpu);
+ case 0x11:
+ return handle_store_prefix(vcpu);
+ case 0x12:
+ return handle_store_cpu_address(vcpu);
+ case 0x14:
+ return kvm_s390_handle_vsie(vcpu);
+ case 0x21:
+ case 0x50:
+ return handle_ipte_interlock(vcpu);
+ case 0x29:
+ return handle_iske(vcpu);
+ case 0x2a:
+ return handle_rrbe(vcpu);
+ case 0x2b:
+ return handle_sske(vcpu);
+ case 0x2c:
+ return handle_test_block(vcpu);
+ case 0x30:
+ case 0x31:
+ case 0x32:
+ case 0x33:
+ case 0x34:
+ case 0x35:
+ case 0x36:
+ case 0x37:
+ case 0x38:
+ case 0x39:
+ case 0x3a:
+ case 0x3b:
+ case 0x3c:
+ case 0x5f:
+ case 0x74:
+ case 0x76:
+ return handle_io_inst(vcpu);
+ case 0x56:
+ return handle_sthyi(vcpu);
+ case 0x7d:
+ return handle_stsi(vcpu);
+ case 0xb1:
+ return handle_stfl(vcpu);
+ case 0xb2:
+ return handle_lpswe(vcpu);
+ default:
+ return -EOPNOTSUPP;
+ }
}
static int handle_epsw(struct kvm_vcpu *vcpu)
@@ -1153,25 +1158,22 @@ static int handle_essa(struct kvm_vcpu *vcpu)
return 0;
}
-static const intercept_handler_t b9_handlers[256] = {
- [0x8a] = handle_ipte_interlock,
- [0x8d] = handle_epsw,
- [0x8e] = handle_ipte_interlock,
- [0x8f] = handle_ipte_interlock,
- [0xab] = handle_essa,
- [0xaf] = handle_pfmf,
-};
-
int kvm_s390_handle_b9(struct kvm_vcpu *vcpu)
{
- intercept_handler_t handler;
-
- /* This is handled just as for the B2 instructions. */
- handler = b9_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
- if (handler)
- return handler(vcpu);
-
- return -EOPNOTSUPP;
+ switch (vcpu->arch.sie_block->ipa & 0x00ff) {
+ case 0x8a:
+ case 0x8e:
+ case 0x8f:
+ return handle_ipte_interlock(vcpu);
+ case 0x8d:
+ return handle_epsw(vcpu);
+ case 0xab:
+ return handle_essa(vcpu);
+ case 0xaf:
+ return handle_pfmf(vcpu);
+ default:
+ return -EOPNOTSUPP;
+ }
}
int kvm_s390_handle_lctl(struct kvm_vcpu *vcpu)
@@ -1319,22 +1321,20 @@ static int handle_stctg(struct kvm_vcpu *vcpu)
return rc ? kvm_s390_inject_prog_cond(vcpu, rc) : 0;
}
-static const intercept_handler_t eb_handlers[256] = {
- [0x2f] = handle_lctlg,
- [0x25] = handle_stctg,
- [0x60] = handle_ri,
- [0x61] = handle_ri,
- [0x62] = handle_ri,
-};
-
int kvm_s390_handle_eb(struct kvm_vcpu *vcpu)
{
- intercept_handler_t handler;
-
- handler = eb_handlers[vcpu->arch.sie_block->ipb & 0xff];
- if (handler)
- return handler(vcpu);
- return -EOPNOTSUPP;
+ switch (vcpu->arch.sie_block->ipb & 0x000000ff) {
+ case 0x25:
+ return handle_stctg(vcpu);
+ case 0x2f:
+ return handle_lctlg(vcpu);
+ case 0x60:
+ case 0x61:
+ case 0x62:
+ return handle_ri(vcpu);
+ default:
+ return -EOPNOTSUPP;
+ }
}
static int handle_tprot(struct kvm_vcpu *vcpu)
@@ -1394,10 +1394,12 @@ static int handle_tprot(struct kvm_vcpu *vcpu)
int kvm_s390_handle_e5(struct kvm_vcpu *vcpu)
{
- /* For e5xx... instructions we only handle TPROT */
- if ((vcpu->arch.sie_block->ipa & 0x00ff) == 0x01)
+ switch (vcpu->arch.sie_block->ipa & 0x00ff) {
+ case 0x01:
return handle_tprot(vcpu);
- return -EOPNOTSUPP;
+ default:
+ return -EOPNOTSUPP;
+ }
}
static int handle_sckpf(struct kvm_vcpu *vcpu)
@@ -1428,17 +1430,14 @@ static int handle_ptff(struct kvm_vcpu *vcpu)
return 0;
}
-static const intercept_handler_t x01_handlers[256] = {
- [0x04] = handle_ptff,
- [0x07] = handle_sckpf,
-};
-
int kvm_s390_handle_01(struct kvm_vcpu *vcpu)
{
- intercept_handler_t handler;
-
- handler = x01_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
- if (handler)
- return handler(vcpu);
- return -EOPNOTSUPP;
+ switch (vcpu->arch.sie_block->ipa & 0x00ff) {
+ case 0x04:
+ return handle_ptff(vcpu);
+ case 0x07:
+ return handle_sckpf(vcpu);
+ default:
+ return -EOPNOTSUPP;
+ }
}