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Commit 2a815b5a authored by Rishi Mehta's avatar Rishi Mehta Committed by James Bottomley
Browse files

[SCSI] vmw_pvscsi: Add support for I/O requests coalescing. 



This change allows pvscsi driver to coalesce I/O requests
before issuing them. The number of I/O's coalesced can be
dynamically configured based on the workload.

Signed-off-by: default avatarRishi Mehta <rmehta@vmware.com>
Signed-off-by: default avatarArvind Kumar <arvindkumar@vmware.com>
Signed-off-by: default avatarJames Bottomley <JBottomley@Parallels.com>
parent a2713cce

drivers/scsi/vmw_pvscsi.c

+46 −3
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ struct pvscsi_adapter { 
	bool				use_msi;

	bool				use_msix;

	bool				use_msg;

	bool				use_req_threshold;



	spinlock_t			hw_lock;
@@ -109,6 +110,7 @@ static int pvscsi_cmd_per_lun = PVSCSI_DEFAULT_QUEUE_DEPTH; 
static bool pvscsi_disable_msi;

static bool pvscsi_disable_msix;

static bool pvscsi_use_msg       = true;

static bool pvscsi_use_req_threshold = true;



#define PVSCSI_RW (S_IRUSR | S_IWUSR)
@@ -133,6 +135,10 @@ MODULE_PARM_DESC(disable_msix, "Disable MSI-X use in driver - (default=0)"); 
module_param_named(use_msg, pvscsi_use_msg, bool, PVSCSI_RW);

MODULE_PARM_DESC(use_msg, "Use msg ring when available - (default=1)");



module_param_named(use_req_threshold, pvscsi_use_req_threshold,

		   bool, PVSCSI_RW);

MODULE_PARM_DESC(use_req_threshold, "Use driver-based request coalescing if configured - (default=1)");



static const struct pci_device_id pvscsi_pci_tbl[] = {

	{ PCI_VDEVICE(VMWARE, PCI_DEVICE_ID_VMWARE_PVSCSI) },

	{ 0 }
@@ -282,11 +288,16 @@ static int scsi_is_rw(unsigned char op) 
static void pvscsi_kick_io(const struct pvscsi_adapter *adapter,

			   unsigned char op)

{

	if (scsi_is_rw(op))

	if (scsi_is_rw(op)) {

		struct PVSCSIRingsState *s = adapter->rings_state;



		if (!adapter->use_req_threshold ||

		    s->reqProdIdx - s->reqConsIdx >= s->reqCallThreshold)

			pvscsi_kick_rw_io(adapter);

	else

	} else {

		pvscsi_process_request_ring(adapter);

	}

}



static void ll_adapter_reset(const struct pvscsi_adapter *adapter)

{
@@ -1077,6 +1088,34 @@ static int pvscsi_setup_msg_workqueue(struct pvscsi_adapter *adapter) 
	return 1;

}



static bool pvscsi_setup_req_threshold(struct pvscsi_adapter *adapter,

				      bool enable)

{

	u32 val;



	if (!pvscsi_use_req_threshold)

		return false;



	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_COMMAND,

			 PVSCSI_CMD_SETUP_REQCALLTHRESHOLD);

	val = pvscsi_reg_read(adapter, PVSCSI_REG_OFFSET_COMMAND_STATUS);

	if (val == -1) {

		printk(KERN_INFO "vmw_pvscsi: device does not support req_threshold\n");

		return false;

	} else {

		struct PVSCSICmdDescSetupReqCall cmd_msg = { 0 };

		cmd_msg.enable = enable;

		printk(KERN_INFO

		       "vmw_pvscsi: %sabling reqCallThreshold\n",

			enable ? "en" : "dis");

		pvscsi_write_cmd_desc(adapter,

				      PVSCSI_CMD_SETUP_REQCALLTHRESHOLD,

				      &cmd_msg, sizeof(cmd_msg));

		return pvscsi_reg_read(adapter,

				       PVSCSI_REG_OFFSET_COMMAND_STATUS) != 0;

	}

}



static irqreturn_t pvscsi_isr(int irq, void *devp)

{

	struct pvscsi_adapter *adapter = devp;
@@ -1416,6 +1455,10 @@ static int pvscsi_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
		flags = IRQF_SHARED;

	}



	adapter->use_req_threshold = pvscsi_setup_req_threshold(adapter, true);

	printk(KERN_DEBUG "vmw_pvscsi: driver-based request coalescing %sabled\n",

	       adapter->use_req_threshold ? "en" : "dis");



	error = request_irq(adapter->irq, pvscsi_isr, flags,

			    "vmw_pvscsi", adapter);

	if (error) {

drivers/scsi/vmw_pvscsi.h

+14 −3
Original line number Diff line number Diff line
@@ -26,7 +26,7 @@ 


#include <linux/types.h>



#define PVSCSI_DRIVER_VERSION_STRING   "1.0.3.0-k"

#define PVSCSI_DRIVER_VERSION_STRING   "1.0.4.0-k"



#define PVSCSI_MAX_NUM_SG_ENTRIES_PER_SEGMENT 128
@@ -117,8 +117,9 @@ enum PVSCSICommands { 
	PVSCSI_CMD_CONFIG            = 7,

	PVSCSI_CMD_SETUP_MSG_RING    = 8,

	PVSCSI_CMD_DEVICE_UNPLUG     = 9,

	PVSCSI_CMD_SETUP_REQCALLTHRESHOLD     = 10,



	PVSCSI_CMD_LAST              = 10  /* has to be last */

	PVSCSI_CMD_LAST              = 11  /* has to be last */

};



/*
@@ -141,6 +142,14 @@ struct PVSCSICmdDescConfigCmd { 
	u32 _pad;

} __packed;



/*

 * Command descriptor for PVSCSI_CMD_SETUP_REQCALLTHRESHOLD --

 */



struct PVSCSICmdDescSetupReqCall {

	u32 enable;

} __packed;



enum PVSCSIConfigPageType {

	PVSCSI_CONFIG_PAGE_CONTROLLER = 0x1958,

	PVSCSI_CONFIG_PAGE_PHY        = 0x1959,
@@ -261,7 +270,9 @@ struct PVSCSIRingsState { 
	u32	cmpConsIdx;

	u32	cmpNumEntriesLog2;



	u8	_pad[104];

	u32	reqCallThreshold;



	u8	_pad[100];



	u32	msgProdIdx;

	u32	msgConsIdx;