From: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
Storvsc driver needs to reverse additional bounce
buffers to receive multipagebuffer packet and copy
data from brounce buffer when get response messge
from message.
Signed-off-by: Sunil Muthuswamy <sunilmut@xxxxxxxxxxxxx>
Co-Developed-by: Sunil Muthuswamy <sunilmut@xxxxxxxxxxxxx>
Signed-off-by: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
---
drivers/scsi/storvsc_drv.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index c5b4974eb41f..4ae8e2a427e4 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -33,6 +33,8 @@
#include <scsi/scsi_transport.h>
#include <asm/mshyperv.h>
+#include "../hv/hyperv_vmbus.h"
+
/*
* All wire protocol details (storage protocol between the guest and the host)
* are consolidated here.
@@ -725,6 +727,10 @@ static void handle_sc_creation(struct vmbus_channel *new_sc)
/* Add the sub-channel to the array of available channels. */
stor_device->stor_chns[new_sc->target_cpu] = new_sc;
cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
+
+ if (hv_bounce_resources_reserve(device->channel,
+ stor_device->max_transfer_bytes))
+ pr_warn("Fail to reserve bounce buffer\n");
}
static void handle_multichannel_storage(struct hv_device *device, int max_chns)
@@ -964,6 +970,18 @@ static int storvsc_channel_init(struct hv_device *device, bool is_fc)
stor_device->max_transfer_bytes =
vstor_packet->storage_channel_properties.max_transfer_bytes;
+ /*
+ * Reserve enough bounce resources to be able to support paging
+ * operations under low memory conditions, that cannot rely on
+ * additional resources to be allocated.
+ */
+ ret = hv_bounce_resources_reserve(device->channel,
+ stor_device->max_transfer_bytes);
+ if (ret < 0) {
+ pr_warn("Fail to reserve bounce buffer\n");
+ goto done;
+ }
+
if (!is_fc)
goto done;
@@ -1263,6 +1281,11 @@ static void storvsc_on_channel_callback(void *context)
request = (struct storvsc_cmd_request *)(unsigned long)cmd_rqst;
+ if (desc->type == VM_PKT_COMP && request->bounce_pkt) {
+ hv_pkt_bounce(channel, request->bounce_pkt);
+ request->bounce_pkt = NULL;
+ }
+
if (request == &stor_device->init_request ||
request == &stor_device->reset_request) {
memcpy(&request->vstor_packet, packet,
--
2.25.1
