Use BITS_PER_BYTE and sizeof_field() to compute the number of Xen event
channels. The compat version at least uses sizeof_field(), but the
regular version open codes sizeof_field(), BITS_PER_BYTE, and combines
literals in the process, which makes it far too difficult to understand
relatively straightforward code.
No functional change intended.
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Paul Durrant <paul@xxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/xen.h | 8 +++++---
include/xen/interface/event_channel.h | 6 ++++--
2 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/xen.h b/arch/x86/kvm/xen.h
index 532a535a9e99..c771fbed7058 100644
--- a/arch/x86/kvm/xen.h
+++ b/arch/x86/kvm/xen.h
@@ -9,6 +9,8 @@
#ifndef __ARCH_X86_KVM_XEN_H__
#define __ARCH_X86_KVM_XEN_H__
+#include <linux/bits.h>
+
#ifdef CONFIG_KVM_XEN
#include <linux/jump_label_ratelimit.h>
@@ -198,9 +200,9 @@ struct compat_shared_info {
struct compat_arch_shared_info arch;
};
-#define COMPAT_EVTCHN_2L_NR_CHANNELS (8 * \
- sizeof_field(struct compat_shared_info, \
- evtchn_pending))
+#define COMPAT_EVTCHN_2L_NR_CHANNELS \
+ (sizeof_field(struct compat_shared_info, evtchn_pending) * BITS_PER_BYTE)
+
struct compat_vcpu_runstate_info {
int state;
uint64_t state_entry_time;
diff --git a/include/xen/interface/event_channel.h b/include/xen/interface/event_channel.h
index 5f8da466e8a9..c7b97c206226 100644
--- a/include/xen/interface/event_channel.h
+++ b/include/xen/interface/event_channel.h
@@ -10,6 +10,8 @@
#ifndef __XEN_PUBLIC_EVENT_CHANNEL_H__
#define __XEN_PUBLIC_EVENT_CHANNEL_H__
+#include <linux/bits.h>
+
#include <xen/interface/xen.h>
typedef uint32_t evtchn_port_t;
@@ -244,8 +246,8 @@ DEFINE_GUEST_HANDLE_STRUCT(evtchn_op);
/*
* 2-level ABI
*/
-
-#define EVTCHN_2L_NR_CHANNELS (sizeof(xen_ulong_t) * sizeof(xen_ulong_t) * 64)
+#define EVTCHN_2L_NR_CHANNELS \
+ (sizeof_field(struct shared_info, evtchn_pending) * BITS_PER_BYTE)
/*
* FIFO ABI
base-commit: d663b8a285986072428a6a145e5994bc275df994
--
2.38.1.431.g37b22c650d-goog
