[PATCH v3] scsi: storvsc: Removing Pre Win8 related logic

Saurabh Sengar
2022-05-24T11:43:11Z

The latest storvsc code has already removed the support for windows 7 and
earlier. There is still some code logic reamining which is there to support
pre Windows 8 OS. This patch removes these stale logic.
This patch majorly does three things :

1. Removes vmscsi_size_delta and its logic, as the vmscsi_request struct is
same for all the OS post windows 8 there is no need of delta.
2. Simplify sense_buffer_size logic, as there is single buffer size for
all the post windows 8 OS.
3. Embed the vmscsi_win8_extension structure inside the vmscsi_request,
as there is no separate handling required for different OS.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
---
v3 : Removed pre win8 macros:
- POST_WIN7_STORVSC_SENSE_BUFFER_SIZE
- VMSTOR_PROTO_VERSION_WIN6
- VMSTOR_PROTO_VERSION_WIN7

drivers/scsi/storvsc_drv.c | 152 ++++++++++---------------------------
1 file changed, 40 insertions(+), 112 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 5585e9d30bbf..66d9adb5487f 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -55,8 +55,6 @@
#define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_) ((((MAJOR_) & 0xff) << 8) | \
(((MINOR_) & 0xff)))

-#define VMSTOR_PROTO_VERSION_WIN6 VMSTOR_PROTO_VERSION(2, 0)
-#define VMSTOR_PROTO_VERSION_WIN7 VMSTOR_PROTO_VERSION(4, 2)
#define VMSTOR_PROTO_VERSION_WIN8 VMSTOR_PROTO_VERSION(5, 1)
#define VMSTOR_PROTO_VERSION_WIN8_1 VMSTOR_PROTO_VERSION(6, 0)
#define VMSTOR_PROTO_VERSION_WIN10 VMSTOR_PROTO_VERSION(6, 2)
@@ -136,19 +134,15 @@ struct hv_fc_wwn_packet {
*/
#define STORVSC_MAX_CMD_LEN 0x10

-#define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE 0x14
-#define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE 0x12
-
#define STORVSC_SENSE_BUFFER_SIZE 0x14
#define STORVSC_MAX_BUF_LEN_WITH_PADDING 0x14

/*
- * Sense buffer size changed in win8; have a run-time
- * variable to track the size we should use. This value will
- * likely change during protocol negotiation but it is valid
- * to start by assuming pre-Win8.
+ * Sense buffer size was differnt pre win8 but those OS are not supported any
+ * more starting 5.19 kernel. This results in to supporting a single value from
+ * win8 onwards.
*/
-static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
+static int sense_buffer_size = STORVSC_SENSE_BUFFER_SIZE;

/*
* The storage protocol version is determined during the
@@ -177,18 +171,6 @@ do { \
dev_warn(&(dev)->device, fmt, ##__VA_ARGS__); \
} while (0)

-struct vmscsi_win8_extension {
- /*
- * The following were added in Windows 8
- */
- u16 reserve;
- u8 queue_tag;
- u8 queue_action;
- u32 srb_flags;
- u32 time_out_value;
- u32 queue_sort_ey;
-} __packed;
-
struct vmscsi_request {
u16 length;
u8 srb_status;
@@ -214,46 +196,23 @@ struct vmscsi_request {
/*
* The following was added in win8.
*/
- struct vmscsi_win8_extension win8_extension;
+ u16 reserve;
+ u8 queue_tag;
+ u8 queue_action;
+ u32 srb_flags;
+ u32 time_out_value;
+ u32 queue_sort_ey;

} __attribute((packed));

/*
- * The list of storage protocols in order of preference.
+ * The list of windows version in order of preference.
*/
-struct vmstor_protocol {
- int protocol_version;
- int sense_buffer_size;
- int vmscsi_size_delta;
-};
-

-static const struct vmstor_protocol vmstor_protocols[] = {
- {
+static const int protocol_version[] = {
VMSTOR_PROTO_VERSION_WIN10,
- POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
- 0
- },
- {
VMSTOR_PROTO_VERSION_WIN8_1,
- POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
- 0
- },
- {
VMSTOR_PROTO_VERSION_WIN8,
- POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
- 0
- },
- {
- VMSTOR_PROTO_VERSION_WIN7,
- PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
- sizeof(struct vmscsi_win8_extension),
- },
- {
- VMSTOR_PROTO_VERSION_WIN6,
- PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
- sizeof(struct vmscsi_win8_extension),
- }
};

@@ -409,9 +368,7 @@ static void storvsc_on_channel_callback(void *context);
#define STORVSC_IDE_MAX_CHANNELS 1

/*
- * Upper bound on the size of a storvsc packet. vmscsi_size_delta is not
- * included in the calculation because it is set after STORVSC_MAX_PKT_SIZE
- * is used in storvsc_connect_to_vsp
+ * Upper bound on the size of a storvsc packet.
*/
#define STORVSC_MAX_PKT_SIZE (sizeof(struct vmpacket_descriptor) +\
sizeof(struct vstor_packet))
@@ -452,17 +409,6 @@ struct storvsc_device {
unsigned char path_id;
unsigned char target_id;

- /*
- * The size of the vmscsi_request has changed in win8. The
- * additional size is because of new elements added to the
- * structure. These elements are valid only when we are talking
- * to a win8 host.
- * Track the correction to size we need to apply. This value
- * will likely change during protocol negotiation but it is
- * valid to start by assuming pre-Win8.
- */
- int vmscsi_size_delta;
-
/*
* Max I/O, the device can support.
*/
@@ -795,8 +741,7 @@ static void handle_multichannel_storage(struct hv_device *device, int max_chns)
vstor_packet->sub_channel_count = num_sc;

ret = vmbus_sendpacket(device->channel, vstor_packet,
- (sizeof(struct vstor_packet) -
- stor_device->vmscsi_size_delta),
+ sizeof(struct vstor_packet),
VMBUS_RQST_INIT,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
@@ -864,8 +809,7 @@ static int storvsc_execute_vstor_op(struct hv_device *device,
vstor_packet->flags = REQUEST_COMPLETION_FLAG;

ret = vmbus_sendpacket(device->channel, vstor_packet,
- (sizeof(struct vstor_packet) -
- stor_device->vmscsi_size_delta),
+ sizeof(struct vstor_packet),
VMBUS_RQST_INIT,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
@@ -915,14 +859,13 @@ static int storvsc_channel_init(struct hv_device *device, bool is_fc)
* Query host supported protocol version.
*/

- for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
+ for (i = 0; i < ARRAY_SIZE(protocol_version); i++) {
/* reuse the packet for version range supported */
memset(vstor_packet, 0, sizeof(struct vstor_packet));
vstor_packet->operation =
VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;

- vstor_packet->version.major_minor =
- vmstor_protocols[i].protocol_version;
+ vstor_packet->version.major_minor = protocol_version[i];

/*
* The revision number is only used in Windows; set it to 0.
@@ -936,21 +879,16 @@ static int storvsc_channel_init(struct hv_device *device, bool is_fc)
return -EINVAL;

if (vstor_packet->status == 0) {
- vmstor_proto_version =
- vmstor_protocols[i].protocol_version;
-
- sense_buffer_size =
- vmstor_protocols[i].sense_buffer_size;
-
- stor_device->vmscsi_size_delta =
- vmstor_protocols[i].vmscsi_size_delta;
+ vmstor_proto_version = protocol_version[i];

break;
}
}

- if (vstor_packet->status != 0)
+ if (vstor_packet->status != 0) {
+ dev_err(&device->device, "Obsolete Hyper-V version\n");
return -EINVAL;
+ }

memset(vstor_packet, 0, sizeof(struct vstor_packet));
@@ -986,11 +924,10 @@ static int storvsc_channel_init(struct hv_device *device, bool is_fc)
cpumask_set_cpu(device->channel->target_cpu,
&stor_device->alloced_cpus);

- if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
- if (vstor_packet->storage_channel_properties.flags &
- STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
- process_sub_channels = true;
- }
+ if (vstor_packet->storage_channel_properties.flags &
+ STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
+ process_sub_channels = true;
+
stor_device->max_transfer_bytes =
vstor_packet->storage_channel_properties.max_transfer_bytes;

@@ -1289,8 +1226,8 @@ static void storvsc_on_channel_callback(void *context)
struct storvsc_cmd_request *request = NULL;
u32 pktlen = hv_pkt_datalen(desc);
u64 rqst_id = desc->trans_id;
- u32 minlen = rqst_id ? sizeof(struct vstor_packet) -
- stor_device->vmscsi_size_delta : sizeof(enum vstor_packet_operation);
+ u32 minlen = rqst_id ? sizeof(struct vstor_packet) :
+ sizeof(enum vstor_packet_operation);

if (pktlen < minlen) {
dev_err(&device->device,
@@ -1346,7 +1283,7 @@ static void storvsc_on_channel_callback(void *context)
}

memcpy(&request->vstor_packet, packet,
- (sizeof(struct vstor_packet) - stor_device->vmscsi_size_delta));
+ sizeof(struct vstor_packet));
complete(&request->wait_event);
}
}
@@ -1557,8 +1494,7 @@ static int storvsc_do_io(struct hv_device *device,
found_channel:
vstor_packet->flags |= REQUEST_COMPLETION_FLAG;

- vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
- stor_device->vmscsi_size_delta);
+ vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);

vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
@@ -1574,13 +1510,11 @@ static int storvsc_do_io(struct hv_device *device,
ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
request->payload, request->payload_sz,
vstor_packet,
- (sizeof(struct vstor_packet) -
- stor_device->vmscsi_size_delta),
+ sizeof(struct vstor_packet),
(unsigned long)request);
} else {
ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
- (sizeof(struct vstor_packet) -
- stor_device->vmscsi_size_delta),
+ sizeof(struct vstor_packet),
(unsigned long)request,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
@@ -1684,8 +1618,7 @@ static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
vstor_packet->vm_srb.path_id = stor_device->path_id;

ret = vmbus_sendpacket(device->channel, vstor_packet,
- (sizeof(struct vstor_packet) -
- stor_device->vmscsi_size_delta),
+ sizeof(struct vstor_packet),
VMBUS_RQST_RESET,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
@@ -1778,31 +1711,31 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)

memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
vm_srb = &cmd_request->vstor_packet.vm_srb;
- vm_srb->win8_extension.time_out_value = 60;
+ vm_srb->time_out_value = 60;

- vm_srb->win8_extension.srb_flags |=
+ vm_srb->srb_flags |=
SRB_FLAGS_DISABLE_SYNCH_TRANSFER;

if (scmnd->device->tagged_supported) {
- vm_srb->win8_extension.srb_flags |=
+ vm_srb->srb_flags |=
(SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
- vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
- vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
+ vm_srb->queue_tag = SP_UNTAGGED;
+ vm_srb->queue_action = SRB_SIMPLE_TAG_REQUEST;
}

/* Build the SRB */
switch (scmnd->sc_data_direction) {
case DMA_TO_DEVICE:
vm_srb->data_in = WRITE_TYPE;
- vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
+ vm_srb->srb_flags |= SRB_FLAGS_DATA_OUT;
break;
case DMA_FROM_DEVICE:
vm_srb->data_in = READ_TYPE;
- vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
+ vm_srb->srb_flags |= SRB_FLAGS_DATA_IN;
break;
case DMA_NONE:
vm_srb->data_in = UNKNOWN_TYPE;
- vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
+ vm_srb->srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
break;
default:
/*
@@ -2004,7 +1937,6 @@ static int storvsc_probe(struct hv_device *device,
init_waitqueue_head(&stor_device->waiting_to_drain);
stor_device->device = device;
stor_device->host = host;
- stor_device->vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
spin_lock_init(&stor_device->lock);
hv_set_drvdata(device, stor_device);
dma_set_min_align_mask(&device->device, HV_HYP_PAGE_SIZE - 1);
@@ -2217,10 +2149,6 @@ static int __init storvsc_drv_init(void)
* than the ring buffer size since that page is reserved for
* the ring buffer indices) by the max request size (which is
* vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
- *
- * The computation underestimates max_outstanding_req_per_channel
- * for Win7 and older hosts because it does not take into account
- * the vmscsi_size_delta correction to the max request size.
*/
max_outstanding_req_per_channel =
((storvsc_ringbuffer_size - PAGE_SIZE) /
--
2.25.1