aboutsummaryrefslogtreecommitdiff
path: root/arch/i386/xen/multicalls.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/i386/xen/multicalls.c')
-rw-r--r--arch/i386/xen/multicalls.c90
1 files changed, 0 insertions, 90 deletions
diff --git a/arch/i386/xen/multicalls.c b/arch/i386/xen/multicalls.c
deleted file mode 100644
index c837e8e463d..00000000000
--- a/arch/i386/xen/multicalls.c
+++ /dev/null
@@ -1,90 +0,0 @@
-/*
- * Xen hypercall batching.
- *
- * Xen allows multiple hypercalls to be issued at once, using the
- * multicall interface. This allows the cost of trapping into the
- * hypervisor to be amortized over several calls.
- *
- * This file implements a simple interface for multicalls. There's a
- * per-cpu buffer of outstanding multicalls. When you want to queue a
- * multicall for issuing, you can allocate a multicall slot for the
- * call and its arguments, along with storage for space which is
- * pointed to by the arguments (for passing pointers to structures,
- * etc). When the multicall is actually issued, all the space for the
- * commands and allocated memory is freed for reuse.
- *
- * Multicalls are flushed whenever any of the buffers get full, or
- * when explicitly requested. There's no way to get per-multicall
- * return results back. It will BUG if any of the multicalls fail.
- *
- * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
- */
-#include <linux/percpu.h>
-#include <linux/hardirq.h>
-
-#include <asm/xen/hypercall.h>
-
-#include "multicalls.h"
-
-#define MC_BATCH 32
-#define MC_ARGS (MC_BATCH * 16 / sizeof(u64))
-
-struct mc_buffer {
- struct multicall_entry entries[MC_BATCH];
- u64 args[MC_ARGS];
- unsigned mcidx, argidx;
-};
-
-static DEFINE_PER_CPU(struct mc_buffer, mc_buffer);
-DEFINE_PER_CPU(unsigned long, xen_mc_irq_flags);
-
-void xen_mc_flush(void)
-{
- struct mc_buffer *b = &__get_cpu_var(mc_buffer);
- int ret = 0;
- unsigned long flags;
-
- BUG_ON(preemptible());
-
- /* Disable interrupts in case someone comes in and queues
- something in the middle */
- local_irq_save(flags);
-
- if (b->mcidx) {
- int i;
-
- if (HYPERVISOR_multicall(b->entries, b->mcidx) != 0)
- BUG();
- for (i = 0; i < b->mcidx; i++)
- if (b->entries[i].result < 0)
- ret++;
- b->mcidx = 0;
- b->argidx = 0;
- } else
- BUG_ON(b->argidx != 0);
-
- local_irq_restore(flags);
-
- BUG_ON(ret);
-}
-
-struct multicall_space __xen_mc_entry(size_t args)
-{
- struct mc_buffer *b = &__get_cpu_var(mc_buffer);
- struct multicall_space ret;
- unsigned argspace = (args + sizeof(u64) - 1) / sizeof(u64);
-
- BUG_ON(preemptible());
- BUG_ON(argspace > MC_ARGS);
-
- if (b->mcidx == MC_BATCH ||
- (b->argidx + argspace) > MC_ARGS)
- xen_mc_flush();
-
- ret.mc = &b->entries[b->mcidx];
- b->mcidx++;
- ret.args = &b->args[b->argidx];
- b->argidx += argspace;
-
- return ret;
-}