[PATCH 1/5] PCI: hv: use zero-length array in struct pci_packet

From: Dexuan Cui
Date: Tue Aug 23 2016 - 01:00:11 EST



And, rename struct pci_message's field "message_type" to "type.

This makes the code more readable.

No functionality change.

Cc: Jake Oshins <jakeo@xxxxxxxxxxxxx>
Cc: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
---
drivers/pci/host/pci-hyperv.c | 42 ++++++++++++++++++++----------------------
1 file changed, 20 insertions(+), 22 deletions(-)

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 7e9b2de..78758e9 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -200,11 +200,11 @@ struct tran_int_desc {
*/

struct pci_message {
- u32 message_type;
+ u32 type;
} __packed;

struct pci_child_message {
- u32 message_type;
+ struct pci_message message_type;
union win_slot_encoding wslot;
} __packed;

@@ -222,7 +222,8 @@ struct pci_packet {
void (*completion_func)(void *context, struct pci_response *resp,
int resp_packet_size);
void *compl_ctxt;
- struct pci_message message;
+
+ struct pci_message message[0];
};

/*
@@ -314,7 +315,7 @@ struct pci_dev_incoming {
} __packed;

struct pci_eject_response {
- u32 message_type;
+ struct pci_message message_type;
union win_slot_encoding wslot;
u32 status;
} __packed;
@@ -694,13 +695,12 @@ static void hv_int_desc_free(struct hv_pci_dev *hpdev,
struct pci_delete_interrupt *int_pkt;
struct {
struct pci_packet pkt;
- u8 buffer[sizeof(struct pci_delete_interrupt) -
- sizeof(struct pci_message)];
+ u8 buffer[sizeof(struct pci_delete_interrupt)];
} ctxt;

memset(&ctxt, 0, sizeof(ctxt));
int_pkt = (struct pci_delete_interrupt *)&ctxt.pkt.message;
- int_pkt->message_type.message_type =
+ int_pkt->message_type.type =
PCI_DELETE_INTERRUPT_MESSAGE;
int_pkt->wslot.slot = hpdev->desc.win_slot.slot;
int_pkt->int_desc = *int_desc;
@@ -845,8 +845,7 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
struct cpumask *affinity;
struct {
struct pci_packet pkt;
- u8 buffer[sizeof(struct pci_create_interrupt) -
- sizeof(struct pci_message)];
+ u8 buffer[sizeof(struct pci_create_interrupt)];
} ctxt;
int cpu;
int ret;
@@ -874,7 +873,7 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
ctxt.pkt.completion_func = hv_pci_compose_compl;
ctxt.pkt.compl_ctxt = &comp;
int_pkt = (struct pci_create_interrupt *)&ctxt.pkt.message;
- int_pkt->message_type.message_type = PCI_CREATE_INTERRUPT_MESSAGE;
+ int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE;
int_pkt->wslot.slot = hpdev->desc.win_slot.slot;
int_pkt->int_desc.vector = cfg->vector;
int_pkt->int_desc.vector_count = 1;
@@ -1287,7 +1286,7 @@ static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus,
pkt.init_packet.compl_ctxt = &comp_pkt;
pkt.init_packet.completion_func = q_resource_requirements;
res_req = (struct pci_child_message *)&pkt.init_packet.message;
- res_req->message_type = PCI_QUERY_RESOURCE_REQUIREMENTS;
+ res_req->message_type.type = PCI_QUERY_RESOURCE_REQUIREMENTS;
res_req->wslot.slot = desc->win_slot.slot;

ret = vmbus_sendpacket(hbus->hdev->channel, res_req,
@@ -1556,8 +1555,7 @@ static void hv_eject_device_work(struct work_struct *work)
int wslot;
struct {
struct pci_packet pkt;
- u8 buffer[sizeof(struct pci_eject_response) -
- sizeof(struct pci_message)];
+ u8 buffer[sizeof(struct pci_eject_response)];
} ctxt;

hpdev = container_of(work, struct hv_pci_dev, wrk);
@@ -1583,7 +1581,7 @@ static void hv_eject_device_work(struct work_struct *work)

memset(&ctxt, 0, sizeof(ctxt));
ejct_pkt = (struct pci_eject_response *)&ctxt.pkt.message;
- ejct_pkt->message_type = PCI_EJECTION_COMPLETE;
+ ejct_pkt->message_type.type = PCI_EJECTION_COMPLETE;
ejct_pkt->wslot.slot = hpdev->desc.win_slot.slot;
vmbus_sendpacket(hpdev->hbus->hdev->channel, ejct_pkt,
sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt,
@@ -1685,7 +1683,7 @@ static void hv_pci_onchannelcallback(void *context)
case VM_PKT_DATA_INBAND:

new_message = (struct pci_incoming_message *)buffer;
- switch (new_message->message_type.message_type) {
+ switch (new_message->message_type.type) {
case PCI_BUS_RELATIONS:

bus_rel = (struct pci_bus_relations *)buffer;
@@ -1716,7 +1714,7 @@ static void hv_pci_onchannelcallback(void *context)
default:
dev_warn(&hbus->hdev->device,
"Unimplemented protocol message %x\n",
- new_message->message_type.message_type);
+ new_message->message_type.type);
break;
}
break;
@@ -1768,7 +1766,7 @@ static int hv_pci_protocol_negotiation(struct hv_device *hdev)
pkt->completion_func = hv_pci_generic_compl;
pkt->compl_ctxt = &comp_pkt;
version_req = (struct pci_version_request *)&pkt->message;
- version_req->message_type.message_type = PCI_QUERY_PROTOCOL_VERSION;
+ version_req->message_type.type = PCI_QUERY_PROTOCOL_VERSION;
version_req->protocol_version = PCI_PROTOCOL_VERSION_CURRENT;

ret = vmbus_sendpacket(hdev->channel, version_req,
@@ -1969,7 +1967,7 @@ static int hv_pci_enter_d0(struct hv_device *hdev)
pkt->completion_func = hv_pci_generic_compl;
pkt->compl_ctxt = &comp_pkt;
d0_entry = (struct pci_bus_d0_entry *)&pkt->message;
- d0_entry->message_type.message_type = PCI_BUS_D0ENTRY;
+ d0_entry->message_type.type = PCI_BUS_D0ENTRY;
d0_entry->mmio_base = hbus->mem_config->start;

ret = vmbus_sendpacket(hdev->channel, d0_entry, sizeof(*d0_entry),
@@ -2015,7 +2013,7 @@ static int hv_pci_query_relations(struct hv_device *hdev)
return -ENOTEMPTY;

memset(&message, 0, sizeof(message));
- message.message_type = PCI_QUERY_BUS_RELATIONS;
+ message.type = PCI_QUERY_BUS_RELATIONS;

ret = vmbus_sendpacket(hdev->channel, &message, sizeof(message),
0, VM_PKT_DATA_INBAND, 0);
@@ -2068,8 +2066,8 @@ static int hv_send_resources_allocated(struct hv_device *hdev)
init_completion(&comp_pkt.host_event);
pkt->completion_func = hv_pci_generic_compl;
pkt->compl_ctxt = &comp_pkt;
- pkt->message.message_type = PCI_RESOURCES_ASSIGNED;
res_assigned = (struct pci_resources_assigned *)&pkt->message;
+ res_assigned->message_type.type = PCI_RESOURCES_ASSIGNED;
res_assigned->wslot.slot = hpdev->desc.win_slot.slot;

put_pcichild(hpdev, hv_pcidev_ref_by_slot);
@@ -2119,7 +2117,7 @@ static int hv_send_resources_released(struct hv_device *hdev)
continue;

memset(&pkt, 0, sizeof(pkt));
- pkt.message_type = PCI_RESOURCES_RELEASED;
+ pkt.message_type.type = PCI_RESOURCES_RELEASED;
pkt.wslot.slot = hpdev->desc.win_slot.slot;

put_pcichild(hpdev, hv_pcidev_ref_by_slot);
@@ -2286,7 +2284,7 @@ static int hv_pci_remove(struct hv_device *hdev)
init_completion(&comp_pkt.host_event);
pkt.teardown_packet.completion_func = hv_pci_generic_compl;
pkt.teardown_packet.compl_ctxt = &comp_pkt;
- pkt.teardown_packet.message.message_type = PCI_BUS_D0EXIT;
+ pkt.teardown_packet.message[0].type = PCI_BUS_D0EXIT;

ret = vmbus_sendpacket(hdev->channel, &pkt.teardown_packet.message,
sizeof(struct pci_message),
--
2.7.4