[PATCH 12/16] gdth: Remove gdth_ctr_tab[]

Boaz Harrosh
2007-09-30T20:12:24Z

- Places like Initialization and Reset that Just loop on all devices can
use the link list with the list_for_each_entry macro.
But the io_ctrl from user mode now suffers performance-wise because
code has to do a sequential search for the requested host number.
I have isolated this search in a gdth_find_ha(int hanum) member
for future enhancement if needed.

Signed-off-by Boaz Harrosh <bharrosh@panasas.com>
---
drivers/scsi/gdth.c | 109 ++++++++++++++++++++++++---------------------------
1 files changed, 51 insertions(+), 58 deletions(-)

diff --git a/drivers/scsi/gdth.c b/drivers/scsi/gdth.c
index 986bfaf..0ae330d 100644
--- a/drivers/scsi/gdth.c
+++ b/drivers/scsi/gdth.c
@@ -296,8 +296,7 @@ static unchar gdth_polling; /* polling if TRUE */
static unchar gdth_from_wait = FALSE; /* gdth_wait() */
static int wait_index,wait_hanum; /* gdth_wait() */
static int gdth_ctr_count = 0; /* controller count */
-static struct Scsi_Host *gdth_ctr_tab[MAXHA]; /* controller table */
-static LIST_HEAD(gdth_instances);
+static LIST_HEAD(gdth_instances); /* controller list */
static unchar gdth_write_through = FALSE; /* write through */
static gdth_evt_str ebuffer[MAX_EVENTS]; /* event buffer */
static int elastidx;
@@ -387,6 +386,17 @@ static struct notifier_block gdth_notifier = {
};
static int notifier_disabled = 0;

+static gdth_ha_str *gdth_find_ha(int hanum)
+{
+ gdth_ha_str *ha;
+
+ list_for_each_entry(ha, &gdth_instances, list)
+ if (hanum == ha->hanum)
+ return ha;
+
+ return NULL;
+}
+
static void gdth_delay(int milliseconds)
{
if (milliseconds == 0) {
@@ -3752,7 +3762,7 @@ static void gdth_timeout(ulong data)
gdth_ha_str *ha;
ulong flags;

- ha = shost_priv(gdth_ctr_tab[0]);
+ ha = list_first_entry(&gdth_instances, gdth_ha_str, list);
spin_lock_irqsave(&ha->smp_lock, flags);

for (act_stats=0,i=0; i<GDTH_MAXCMDS; ++i)
@@ -4011,12 +4021,10 @@ static int gdth_queuecommand(Scsi_Cmnd *scp,void (*done)(Scsi_Cmnd *))
static int gdth_open(struct inode *inode, struct file *filep)
{
gdth_ha_str *ha;
- int i;

- for (i = 0; i < gdth_ctr_count; i++) {
- ha = shost_priv(gdth_ctr_tab[i]);
+ list_for_each_entry(ha, &gdth_instances, list) {
if (!ha->sdev)
- ha->sdev = scsi_get_host_dev(gdth_ctr_tab[i]);
+ ha->sdev = scsi_get_host_dev(ha->shost);
}

TRACE(("gdth_open()\n"));
@@ -4035,10 +4043,11 @@ static int ioc_event(void __user *arg)
gdth_ha_str *ha;
ulong flags;

- if (copy_from_user(&evt, arg, sizeof(gdth_ioctl_event)) ||
- evt.ionode >= gdth_ctr_count)
+ if (copy_from_user(&evt, arg, sizeof(gdth_ioctl_event)))
+ return -EFAULT;
+ ha = gdth_find_ha(evt.ionode);
+ if (!ha)
return -EFAULT;
- ha = shost_priv(gdth_ctr_tab[evt.ionode]);

if (evt.erase == 0xff) {
if (evt.event.event_source == ES_TEST)
@@ -4072,11 +4081,12 @@ static int ioc_lockdrv(void __user *arg)
ulong flags;
gdth_ha_str *ha;

- if (copy_from_user(&ldrv, arg, sizeof(gdth_ioctl_lockdrv)) ||
- ldrv.ionode >= gdth_ctr_count)
+ if (copy_from_user(&ldrv, arg, sizeof(gdth_ioctl_lockdrv)))
return -EFAULT;
- ha = shost_priv(gdth_ctr_tab[ldrv.ionode]);
-
+ ha = gdth_find_ha(ldrv.ionode);
+ if (!ha)
+ return -EFAULT;
+
for (i = 0; i < ldrv.drive_cnt && i < MAX_HDRIVES; ++i) {
j = ldrv.drives[i];
if (j >= MAX_HDRIVES || !ha->hdr[j].present)
@@ -4106,9 +4116,11 @@ static int ioc_resetdrv(void __user *arg, char *cmnd)
int rval;

if (copy_from_user(&res, arg, sizeof(gdth_ioctl_reset)) ||
- res.ionode >= gdth_ctr_count || res.number >= MAX_HDRIVES)
+ res.number >= MAX_HDRIVES)
+ return -EFAULT;
+ ha = gdth_find_ha(res.ionode);
+ if (!ha)
return -EFAULT;
- ha = shost_priv(gdth_ctr_tab[res.ionode]);

if (!ha->hdr[res.number].present)
return 0;
@@ -4137,11 +4149,12 @@ static int ioc_general(void __user *arg, char *cmnd)
ulong64 paddr;
gdth_ha_str *ha;
int rval;
-
- if (copy_from_user(&gen, arg, sizeof(gdth_ioctl_general)) ||
- gen.ionode >= gdth_ctr_count)
+
+ if (copy_from_user(&gen, arg, sizeof(gdth_ioctl_general)))
+ return -EFAULT;
+ ha = gdth_find_ha(gen.ionode);
+ if (!ha)
return -EFAULT;
- ha = shost_priv(gdth_ctr_tab[gen.ionode]);
if (gen.data_len + gen.sense_len != 0) {
if (!(buf = gdth_ioctl_alloc(ha, gen.data_len + gen.sense_len,
FALSE, &paddr)))
@@ -4261,11 +4274,10 @@ static int ioc_hdrlist(void __user *arg, char *cmnd)
goto free_fail;

if (copy_from_user(rsc, arg, sizeof(gdth_ioctl_rescan)) ||
- rsc->ionode >= gdth_ctr_count) {
+ (NULL == (ha = gdth_find_ha(rsc->ionode)))) {
rc = -EFAULT;
goto free_fail;
}
- ha = shost_priv(gdth_ctr_tab[rsc->ionode]);
memset(cmd, 0, sizeof(gdth_cmd_str));

for (i = 0; i < MAX_HDRIVES; ++i) {
@@ -4317,11 +4329,10 @@ static int ioc_rescan(void __user *arg, char *cmnd)
goto free_fail;

if (copy_from_user(rsc, arg, sizeof(gdth_ioctl_rescan)) ||
- rsc->ionode >= gdth_ctr_count) {
+ (NULL == (ha = gdth_find_ha(rsc->ionode)))) {
rc = -EFAULT;
goto free_fail;
}
- ha = shost_priv(gdth_ctr_tab[rsc->ionode]);
memset(cmd, 0, sizeof(gdth_cmd_str));

if (rsc->flag == 0) {
@@ -4478,9 +4489,9 @@ static int gdth_ioctl(struct inode *inode, struct file *filep,
gdth_ioctl_ctrtype ctrt;

if (copy_from_user(&ctrt, argp, sizeof(gdth_ioctl_ctrtype)) ||
- ctrt.ionode >= gdth_ctr_count)
+ (NULL == (ha = gdth_find_ha(ctrt.ionode))))
return -EFAULT;
- ha = shost_priv(gdth_ctr_tab[ctrt.ionode]);
+
if (ha->type == GDT_ISA || ha->type == GDT_EISA) {
ctrt.type = (unchar)((ha->stype>>20) - 0x10);
} else {
@@ -4519,10 +4530,9 @@ static int gdth_ioctl(struct inode *inode, struct file *filep,
unchar i, j;

if (copy_from_user(&lchn, argp, sizeof(gdth_ioctl_lockchn)) ||
- lchn.ionode >= gdth_ctr_count)
+ (NULL == (ha = gdth_find_ha(lchn.ionode))))
return -EFAULT;
- ha = shost_priv(gdth_ctr_tab[lchn.ionode]);
-
+
i = lchn.channel;
if (i < ha->bus_cnt) {
if (lchn.lock) {
@@ -4558,9 +4568,8 @@ static int gdth_ioctl(struct inode *inode, struct file *filep,
int rval;

if (copy_from_user(&res, argp, sizeof(gdth_ioctl_reset)) ||
- res.ionode >= gdth_ctr_count)
+ (NULL == (ha = gdth_find_ha(res.ionode))))
return -EFAULT;
- ha = shost_priv(gdth_ctr_tab[res.ionode]);

scp = kzalloc(sizeof(*scp), GFP_KERNEL);
if (!scp)
@@ -4622,7 +4631,7 @@ static void gdth_flush(gdth_ha_str *ha)
/* shutdown routine */
static int gdth_halt(struct notifier_block *nb, ulong event, void *buf)
{
- int hanum;
+ gdth_ha_str *ha;
#ifndef __alpha__
gdth_cmd_str gdtcmd;
char cmnd[MAX_COMMAND_SIZE];
@@ -4637,8 +4646,7 @@ static int gdth_halt(struct notifier_block *nb, ulong event, void *buf)

notifier_disabled = 1;
printk("GDT-HA: Flushing all host drives .. ");
- for (hanum = 0; hanum < gdth_ctr_count; ++hanum) {
- gdth_ha_str *ha = shost_priv(gdth_ctr_tab[hanum]);
+ list_for_each_entry(ha, &gdth_instances, list) {
gdth_flush(ha);

#ifndef __alpha__
@@ -4691,7 +4699,7 @@ static int gdth_isa_probe_one(ulong32 isa_bios)
struct Scsi_Host *shp;
gdth_ha_str *ha;
dma_addr_t scratch_dma_handle = 0;
- int error, hanum, i;
+ int error, i;

if (!gdth_search_isa(isa_bios))
return -ENXIO;
@@ -4726,10 +4734,8 @@ static int gdth_isa_probe_one(ulong32 isa_bios)
shp->unchecked_isa_dma = 1;
shp->irq = ha->irq;
shp->dma_channel = ha->drq;
- hanum = gdth_ctr_count;
- gdth_ctr_tab[gdth_ctr_count++] = shp;

- ha->hanum = (ushort)hanum;
+ ha->hanum = gdth_ctr_count++;
ha->shost = shp;

ha->pccb = &ha->cmdext;
@@ -4821,7 +4827,7 @@ static int gdth_eisa_probe_one(ushort eisa_slot)
struct Scsi_Host *shp;
gdth_ha_str *ha;
dma_addr_t scratch_dma_handle = 0;
- int error, hanum, i;
+ int error, i;

if (!gdth_search_eisa(eisa_slot))
return -ENXIO;
@@ -4848,10 +4854,8 @@ static int gdth_eisa_probe_one(ushort eisa_slot)
shp->unchecked_isa_dma = 0;
shp->irq = ha->irq;
shp->dma_channel = 0xff;
- hanum = gdth_ctr_count;
- gdth_ctr_tab[gdth_ctr_count++] = shp;

- ha->hanum = (ushort)hanum;
+ ha->hanum = gdth_ctr_count++;
ha->shost = shp;

TRACE2(("EISA detect Bus 0: hanum %d\n", ha->hanum));
@@ -4952,7 +4956,7 @@ static int gdth_pci_probe_one(gdth_pci_str *pcistr, int ctr)
struct Scsi_Host *shp;
gdth_ha_str *ha;
dma_addr_t scratch_dma_handle = 0;
- int error, hanum, i;
+ int error, i;

shp = scsi_host_alloc(&gdth_template, sizeof(gdth_ha_str));
if (!shp)
@@ -4979,10 +4983,8 @@ static int gdth_pci_probe_one(gdth_pci_str *pcistr, int ctr)
shp->unchecked_isa_dma = 0;
shp->irq = ha->irq;
shp->dma_channel = 0xff;
- hanum = gdth_ctr_count;
- gdth_ctr_tab[gdth_ctr_count++] = shp;

- ha->hanum = (ushort)hanum;
+ ha->hanum = gdth_ctr_count++;
ha->shost = shp;

ha->pccb = &ha->cmdext;
@@ -5147,18 +5149,12 @@ static int __init gdth_init(void)
/* scanning for controllers, at first: ISA controller */
#ifdef CONFIG_ISA
for (isa_bios = 0xc8000UL; isa_bios <= 0xd8000UL;
- isa_bios += 0x8000UL) {
- if (gdth_ctr_count >= MAXHA)
- break;
+ isa_bios += 0x8000UL)
gdth_isa_probe_one(isa_bios);
- }
#endif
#ifdef CONFIG_EISA
- for (eisa_slot = 0x1000; eisa_slot <= 0x8000; eisa_slot += 0x1000) {
- if (gdth_ctr_count >= MAXHA)
- break;
+ for (eisa_slot = 0x1000; eisa_slot <= 0x8000; eisa_slot += 0x1000)
gdth_eisa_probe_one(eisa_slot);
- }
}
#endif
#ifdef CONFIG_PCI
@@ -5166,11 +5162,8 @@ static int __init gdth_init(void)
cnt = gdth_search_pci(pcistr);
printk("GDT-HA: Found %d PCI Storage RAID Controllers\n",cnt);
gdth_sort_pci(pcistr,cnt);
- for (ctr = 0; ctr < cnt; ++ctr) {
- if (gdth_ctr_count >= MAXHA)
- break;
+ for (ctr = 0; ctr < cnt; ++ctr)
gdth_pci_probe_one(pcistr, ctr);
- }
#endif

TRACE2(("gdth_detect() %d controller detected\n",gdth_ctr_count));