[PATCH RESEND 09/27] drivers:hv: Export the API to invoke a hypercall on Hyper-V

From: K. Y. Srinivasan
Date: Fri Dec 11 2015 - 21:56:13 EST


From: Jake Oshins <jakeo@xxxxxxxxxxxxx>

This patch exposes the function that hv_vmbus.ko uses to make hypercalls. This
is necessary for retargeting an interrupt when it is given a new affinity.

Since we are exporting this API, rename the API as it will be visible outside
the hv.c file.

Signed-off-by: Jake Oshins <jakeo@xxxxxxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
---
drivers/hv/hv.c | 20 ++++++++++----------
drivers/hv/hyperv_vmbus.h | 2 +-
include/linux/hyperv.h | 1 +
3 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 6341be8..7a06933 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -89,9 +89,9 @@ static int query_hypervisor_info(void)
}

/*
- * do_hypercall- Invoke the specified hypercall
+ * hv_do_hypercall- Invoke the specified hypercall
*/
-static u64 do_hypercall(u64 control, void *input, void *output)
+u64 hv_do_hypercall(u64 control, void *input, void *output)
{
u64 input_address = (input) ? virt_to_phys(input) : 0;
u64 output_address = (output) ? virt_to_phys(output) : 0;
@@ -132,6 +132,7 @@ static u64 do_hypercall(u64 control, void *input, void *output)
return hv_status_lo | ((u64)hv_status_hi << 32);
#endif /* !x86_64 */
}
+EXPORT_SYMBOL_GPL(hv_do_hypercall);

#ifdef CONFIG_X86_64
static cycle_t read_hv_clock_tsc(struct clocksource *arg)
@@ -315,7 +316,7 @@ int hv_post_message(union hv_connection_id connection_id,
{

struct hv_input_post_message *aligned_msg;
- u16 status;
+ u64 status;

if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
return -EMSGSIZE;
@@ -329,11 +330,10 @@ int hv_post_message(union hv_connection_id connection_id,
aligned_msg->payload_size = payload_size;
memcpy((void *)aligned_msg->payload, payload, payload_size);

- status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
- & 0xFFFF;
+ status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);

put_cpu();
- return status;
+ return status & 0xFFFF;
}


@@ -343,13 +343,13 @@ int hv_post_message(union hv_connection_id connection_id,
*
* This involves a hypercall.
*/
-u16 hv_signal_event(void *con_id)
+int hv_signal_event(void *con_id)
{
- u16 status;
+ u64 status;

- status = (do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) & 0xFFFF);
+ status = hv_do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL);

- return status;
+ return status & 0xFFFF;
}

static int hv_ce_set_next_event(unsigned long delta,
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 12156db..9beeb14 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -587,7 +587,7 @@ extern int hv_post_message(union hv_connection_id connection_id,
enum hv_message_type message_type,
void *payload, size_t payload_size);

-extern u16 hv_signal_event(void *con_id);
+extern int hv_signal_event(void *con_id);

extern int hv_synic_alloc(void);

diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index fddb3e0..24d0b65 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -984,6 +984,7 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
bool fb_overlap_ok);

int vmbus_cpu_number_to_vp_number(int cpu_number);
+u64 hv_do_hypercall(u64 control, void *input, void *output);

/**
* VMBUS_DEVICE - macro used to describe a specific hyperv vmbus device
--
1.7.4.1

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