kolibrios-gitea/drivers/video/drm/i915/main.c
Sergey Semyonov (Serge) 87ba1ae914 i915-4.4 works_on_my_computer edition.
git-svn-id: svn://kolibrios.org@6084 a494cfbc-eb01-0410-851d-a64ba20cac60
2016-01-20 04:45:20 +00:00

920 lines
23 KiB
C

#include <syscall.h>
#include <drm/drmP.h>
#include <drm/i915_drm.h>
#include "i915_drv.h"
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/pci.h>
#include "bitmap.h"
#define DRV_NAME "i915 v4.4"
#define I915_DEV_CLOSE 0
#define I915_DEV_INIT 1
#define I915_DEV_READY 2
struct pci_device {
uint16_t domain;
uint8_t bus;
uint8_t dev;
uint8_t func;
uint16_t vendor_id;
uint16_t device_id;
uint16_t subvendor_id;
uint16_t subdevice_id;
uint32_t device_class;
uint8_t revision;
};
struct cmdtable
{
char *key;
int size;
int *val;
};
#define CMDENTRY(key, val) {(key), (sizeof(key)-1), &val}
void parse_cmdline(char *cmdline, struct cmdtable *table, char *log, videomode_t *mode);
int oops_in_progress;
int i915_fbsize = 16;
struct drm_device *main_device;
struct drm_file *drm_file_handlers[256];
videomode_t usermode;
void cpu_detect1();
int kmap_init();
int _stdcall display_handler(ioctl_t *io);
int init_agp(void);
void get_pci_info(struct pci_device *dev);
int i915_getparam(struct drm_device *dev, void *data,
struct drm_file *file_priv);
int i915_mask_update(struct drm_device *dev, void *data,
struct drm_file *file);
struct cmdtable cmdtable[]= {
CMDENTRY("-FB=", i915_fbsize),
/* CMDENTRY("-pm=", i915.powersave), */
CMDENTRY("-rc6=", i915.enable_rc6),
CMDENTRY("-fbc=", i915.enable_fbc),
CMDENTRY("-ppgt=", i915.enable_ppgtt),
{NULL, 0}
};
static char log[256];
unsigned long volatile jiffies;
struct workqueue_struct *system_wq;
int driver_wq_state;
int x86_clflush_size;
unsigned int tsc_khz;
int i915_modeset = 1;
typedef union __attribute__((packed))
{
uint32_t val;
struct
{
uint8_t state;
uint8_t code;
uint16_t ctrl_key;
};
}oskey_t;
static inline oskey_t get_key(void)
{
oskey_t val;
asm volatile("int $0x40":"=a"(val):"a"(2));
return val;
};
void i915_dpms(struct drm_device *dev, int mode);
void i915_driver_thread()
{
struct drm_i915_private *dev_priv = NULL;
struct workqueue_struct *cwq = NULL;
static int dpms = 1;
static int dpms_lock = 0;
oskey_t key;
unsigned long irqflags;
int tmp;
printf("%s\n",__FUNCTION__);
while(driver_wq_state == I915_DEV_INIT)
{
jiffies = GetClockNs() / 10000000;
delay(1);
};
if( driver_wq_state == I915_DEV_CLOSE)
{
asm volatile ("int $0x40"::"a"(-1));
};
dev_priv = main_device->dev_private;
cwq = dev_priv->wq;
asm volatile("int $0x40":"=a"(tmp):"a"(66),"b"(1),"c"(1));
asm volatile("int $0x40":"=a"(tmp):"a"(66),"b"(4),"c"(0x46),"d"(0x330));
asm volatile("int $0x40":"=a"(tmp):"a"(66),"b"(4),"c"(0xC6),"d"(0x330));
while(driver_wq_state != I915_DEV_CLOSE)
{
jiffies = GetClockNs() / 10000000;
key = get_key();
if( (key.val != 1) && (key.state == 0x02))
{
if(key.code == 0x46 && dpms_lock == 0)
{
dpms_lock = 1;
if(dpms == 1)
{
i915_dpms(main_device, DRM_MODE_DPMS_OFF);
printf("dpms off\n");
}
else
{
i915_dpms(main_device, DRM_MODE_DPMS_ON);
printf("dpms on\n");
};
dpms ^= 1;
}
else if(key.code == 0xC6)
dpms_lock = 0;
};
spin_lock_irqsave(&cwq->lock, irqflags);
while (!list_empty(&cwq->worklist))
{
struct work_struct *work = list_entry(cwq->worklist.next,
struct work_struct, entry);
work_func_t f = work->func;
list_del_init(cwq->worklist.next);
spin_unlock_irqrestore(&cwq->lock, irqflags);
f(work);
spin_lock_irqsave(&cwq->lock, irqflags);
}
spin_unlock_irqrestore(&cwq->lock, irqflags);
delay(1);
};
asm volatile ("int $0x40"::"a"(-1));
}
u32 __attribute__((externally_visible)) drvEntry(int action, char *cmdline)
{
static pci_dev_t device;
const struct pci_device_id *ent;
int err = 0;
if(action != 1)
{
driver_wq_state = I915_DEV_CLOSE;
return 0;
};
if( GetService("DISPLAY") != 0 )
return 0;
printf("\n%s build %s %s\nusage: i915 [options]\n"
"-FB=<0-9> Set framebuffer size in megabytes (default: 16)\n",
"-pm=<0,1> Enable powersavings, fbc, downclocking, etc. (default: 1 - true)\n",
DRV_NAME, __DATE__, __TIME__);
printf("-rc6=<-1,0-7> Enable power-saving render C-state 6.\n"
" Different stages can be selected via bitmask values\n"
" (0 = disable; 1 = enable rc6; 2 = enable deep rc6; 4 = enable deepest rc6).\n"
" For example, 3 would enable rc6 and deep rc6, and 7 would enable everything.\n"
" default: -1 (use per-chip default)\n");
printf("-fbc=<-1,0,1> Enable frame buffer compression for power savings\n"
" (default: -1 (use per-chip default))\n");
printf("-ppgt=<0,1> Enable PPGTT (default: true)\n");
printf("-l<path> path to log file\n");
printf("-m<WxHxHz> set videomode\n");
printf("cmdline %s\n", cmdline);
if( cmdline && *cmdline )
parse_cmdline(cmdline, cmdtable, log, &usermode);
if( *log && !dbg_open(log))
{
printf("Can't open %s\nExit\n", log);
return 0;
}
else
{
dbgprintf("\nLOG: %s build %s %s\n",DRV_NAME,__DATE__, __TIME__);
}
cpu_detect1();
// dbgprintf("\ncache line size %d\n", x86_clflush_size);
err = enum_pci_devices();
if( unlikely(err != 0) )
{
dbgprintf("Device enumeration failed\n");
return 0;
}
err = kmap_init();
if( unlikely(err != 0) )
{
dbgprintf("kmap initialization failed\n");
return 0;
}
dmi_scan_machine();
driver_wq_state = I915_DEV_INIT;
CreateKernelThread(i915_driver_thread);
err = i915_init();
if(unlikely(err!= 0))
{
driver_wq_state = I915_DEV_CLOSE;
dbgprintf("Epic Fail :(\n");
delay(100);
return 0;
};
driver_wq_state = I915_DEV_READY;
init_display_kms(main_device, &usermode);
err = RegService("DISPLAY", display_handler);
if( err != 0)
dbgprintf("Set DISPLAY handler\n");
return err;
};
#define CURRENT_API 0x0200 /* 2.00 */
#define COMPATIBLE_API 0x0100 /* 1.00 */
#define API_VERSION (COMPATIBLE_API << 16) | CURRENT_API
#define DISPLAY_VERSION API_VERSION
#define SRV_GETVERSION 0
#define SRV_ENUM_MODES 1
#define SRV_SET_MODE 2
#define SRV_GET_CAPS 3
#define SRV_GET_PCI_INFO 20
#define SRV_I915_GET_PARAM 21
#define SRV_I915_GEM_CREATE 22
#define SRV_DRM_GEM_CLOSE 23
#define SRV_DRM_GEM_FLINK 24
#define SRV_DRM_GEM_OPEN 25
#define SRV_I915_GEM_PIN 26
#define SRV_I915_GEM_UNPIN 27
#define SRV_I915_GEM_GET_CACHING 28
#define SRV_I915_GEM_SET_CACHING 29
#define SRV_I915_GEM_PWRITE 30
#define SRV_I915_GEM_BUSY 31
#define SRV_I915_GEM_SET_DOMAIN 32
#define SRV_I915_GEM_MMAP 33
#define SRV_I915_GEM_SET_TILING 34
#define SRV_I915_GEM_GET_TILING 35
#define SRV_I915_GEM_GET_APERTURE 36
#define SRV_I915_GEM_MMAP_GTT 37
#define SRV_I915_GEM_THROTTLE 38
#define SRV_I915_GEM_EXECBUFFER2 39
#define SRV_I915_GEM_WAIT 40
#define SRV_I915_GEM_CONTEXT_CREATE 41
#define SRV_I915_GEM_CONTEXT_DESTROY 42
#define SRV_I915_REG_READ 43
#define SRV_FBINFO 44
#define SRV_MASK_UPDATE 45
#define SRV_MASK_UPDATE_EX 46
#define check_input(size) \
if( unlikely((inp==NULL)||(io->inp_size != (size))) ) \
break;
#define check_output(size) \
if( unlikely((outp==NULL)||(io->out_size != (size))) ) \
break;
int _stdcall display_handler(ioctl_t *io)
{
struct drm_file *file;
int retval = -1;
u32 *inp;
u32 *outp;
inp = io->input;
outp = io->output;
file = drm_file_handlers[0];
switch(io->io_code)
{
case SRV_GETVERSION:
check_output(4);
*outp = DISPLAY_VERSION;
retval = 0;
break;
case SRV_ENUM_MODES:
// dbgprintf("SRV_ENUM_MODES inp %x inp_size %x out_size %x\n",
// inp, io->inp_size, io->out_size );
check_output(4);
// check_input(*outp * sizeof(videomode_t));
if( i915_modeset)
retval = get_videomodes((videomode_t*)inp, outp);
break;
case SRV_SET_MODE:
// dbgprintf("SRV_SET_MODE inp %x inp_size %x\n",
// inp, io->inp_size);
check_input(sizeof(videomode_t));
if( i915_modeset )
retval = set_user_mode((videomode_t*)inp);
break;
case SRV_GET_CAPS:
retval = get_driver_caps((hwcaps_t*)inp);
break;
case SRV_GET_PCI_INFO:
get_pci_info((struct pci_device *)inp);
retval = 0;
break;
case SRV_I915_GET_PARAM:
retval = i915_getparam(main_device, inp, file);
break;
case SRV_I915_GEM_CREATE:
retval = i915_gem_create_ioctl(main_device, inp, file);
break;
case SRV_DRM_GEM_CLOSE:
retval = drm_gem_close_ioctl(main_device, inp, file);
break;
case SRV_DRM_GEM_FLINK:
retval = drm_gem_flink_ioctl(main_device, inp, file);
break;
case SRV_DRM_GEM_OPEN:
retval = drm_gem_open_ioctl(main_device, inp, file);
break;
case SRV_I915_GEM_GET_CACHING:
retval = i915_gem_get_caching_ioctl(main_device, inp, file);
break;
case SRV_I915_GEM_SET_CACHING:
retval = i915_gem_set_caching_ioctl(main_device, inp, file);
break;
case SRV_I915_GEM_PWRITE:
retval = i915_gem_pwrite_ioctl(main_device, inp, file);
break;
case SRV_I915_GEM_BUSY:
retval = i915_gem_busy_ioctl(main_device, inp, file);
break;
case SRV_I915_GEM_SET_DOMAIN:
retval = i915_gem_set_domain_ioctl(main_device, inp, file);
break;
case SRV_I915_GEM_MMAP:
retval = i915_gem_mmap_ioctl(main_device, inp, file);
break;
case SRV_I915_GEM_SET_TILING:
retval = i915_gem_set_tiling(main_device, inp, file);
break;
case SRV_I915_GEM_GET_TILING:
retval = i915_gem_get_tiling(main_device, inp, file);
break;
case SRV_I915_GEM_GET_APERTURE:
// printf("SRV_I915_GEM_GET_APERTURE ");
retval = i915_gem_get_aperture_ioctl(main_device, inp, file);
// printf(" retval=%d\n", retval);
break;
case SRV_I915_GEM_MMAP_GTT:
retval = i915_gem_mmap_gtt_ioctl(main_device, inp, file);
break;
case SRV_I915_GEM_THROTTLE:
retval = i915_gem_throttle_ioctl(main_device, inp, file);
break;
case SRV_I915_GEM_EXECBUFFER2:
// printf("SRV_I915_GEM_EXECBUFFER2\n");
retval = i915_gem_execbuffer2(main_device, inp, file);
break;
case SRV_I915_GEM_WAIT:
retval = i915_gem_wait_ioctl(main_device, inp, file);
break;
case SRV_I915_GEM_CONTEXT_CREATE:
retval = i915_gem_context_create_ioctl(main_device, inp, file);
break;
case SRV_I915_GEM_CONTEXT_DESTROY:
retval = i915_gem_context_destroy_ioctl(main_device, inp, file);
break;
case SRV_I915_REG_READ:
retval = i915_reg_read_ioctl(main_device, inp, file);
break;
case SRV_FBINFO:
retval = i915_fbinfo(inp);
break;
case SRV_MASK_UPDATE:
retval = i915_mask_update(main_device, inp, file);
break;
case SRV_MASK_UPDATE_EX:
retval = i915_mask_update_ex(main_device, inp, file);
break;
};
return retval;
}
#define PCI_CLASS_REVISION 0x08
#define PCI_CLASS_DISPLAY_VGA 0x0300
#define PCI_CLASS_BRIDGE_HOST 0x0600
#define PCI_CLASS_BRIDGE_ISA 0x0601
int pci_scan_filter(u32 id, u32 busnr, u32 devfn)
{
u16 vendor, device;
u32 class;
int ret = 0;
vendor = id & 0xffff;
device = (id >> 16) & 0xffff;
if(vendor == 0x8086)
{
class = PciRead32(busnr, devfn, PCI_CLASS_REVISION);
class >>= 16;
if( (class == PCI_CLASS_DISPLAY_VGA) ||
(class == PCI_CLASS_BRIDGE_HOST) ||
(class == PCI_CLASS_BRIDGE_ISA))
ret = 1;
}
return ret;
};
struct mtrr
{
u64 base;
u64 mask;
};
struct cpuinfo
{
u64 caps;
u64 def_mtrr;
u64 mtrr_cap;
int var_mtrr_count;
int fix_mtrr_count;
struct mtrr var_mtrr[9];
char model_name[64];
};
#define MTRRphysBase_MSR(reg) (0x200 + 2 * (reg))
#define MTRRphysMask_MSR(reg) (0x200 + 2 * (reg) + 1)
#define MSR_MTRRdefType 0x000002ff
#define IA32_MTRRCAP 0xFE
#define IA32_CR_PAT_MSR 0x277
#define PAT_TYPE_UC 0
#define PAT_TYPE_WC 1
#define PAT_TYPE_WB 6
#define PAT_TYPE_UCM 7
#define MTRR_UC 0
#define MTRR_WC 1
#define MTRR_WB 6
static inline u64 read_msr(u32 msr)
{
union {
u64 val;
struct {
u32 low;
u32 high;
};
}tmp;
asm volatile (
"rdmsr"
: "=a" (tmp.low), "=d" (tmp.high)
: "c" (msr));
return tmp.val;
}
static inline void write_msr(u32 msr, u64 val)
{
union {
u64 val;
struct {
u32 low;
u32 high;
};
}tmp;
tmp.val = val;
asm volatile (
"wrmsr"
:: "a" (tmp.low), "d" (tmp.high), "c" (msr));
}
#define SIZE_OR_MASK_BITS(n) (~((1ULL << ((n) - PAGE_SHIFT)) - 1))
static void set_mtrr(unsigned int reg, unsigned long base,
unsigned long size, int type)
{
unsigned int base_lo, base_hi, mask_lo, mask_hi;
u64 size_or_mask, size_and_mask;
size_or_mask = SIZE_OR_MASK_BITS(36);
size_and_mask = 0x00f00000;
if (size == 0) {
/*
* The invalid bit is kept in the mask, so we simply
* clear the relevant mask register to disable a range.
*/
native_write_msr(MTRRphysMask_MSR(reg), 0, 0);
}
else {
base_lo = base << PAGE_SHIFT | type;
base_hi = (base & size_and_mask) >> (32 - PAGE_SHIFT);
mask_lo = -size << PAGE_SHIFT | 0x800;
mask_hi = (-size & size_and_mask) >> (32 - PAGE_SHIFT);
native_write_msr(MTRRphysBase_MSR(reg), base_lo, base_hi);
native_write_msr(MTRRphysMask_MSR(reg), mask_lo, mask_hi);
};
}
static u32 deftype_lo, deftype_hi;
void cpu_detect1()
{
struct cpuinfo cpuinfo;
u32 junk, tfms, cap0, misc;
int i;
cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
if (cap0 & (1<<19))
{
x86_clflush_size = ((misc >> 8) & 0xff) * 8;
}
#if 0
cpuid(0x80000002, (unsigned int*)&cpuinfo.model_name[0], (unsigned int*)&cpuinfo.model_name[4],
(unsigned int*)&cpuinfo.model_name[8], (unsigned int*)&cpuinfo.model_name[12]);
cpuid(0x80000003, (unsigned int*)&cpuinfo.model_name[16], (unsigned int*)&cpuinfo.model_name[20],
(unsigned int*)&cpuinfo.model_name[24], (unsigned int*)&cpuinfo.model_name[28]);
cpuid(0x80000004, (unsigned int*)&cpuinfo.model_name[32], (unsigned int*)&cpuinfo.model_name[36],
(unsigned int*)&cpuinfo.model_name[40], (unsigned int*)&cpuinfo.model_name[44]);
printf("\n%s\n\n",cpuinfo.model_name);
cpuinfo.def_mtrr = read_msr(MSR_MTRRdefType);
cpuinfo.mtrr_cap = read_msr(IA32_MTRRCAP);
printf("MSR_MTRRdefType %016llx\n\n", cpuinfo.def_mtrr);
cpuinfo.var_mtrr_count = (u8_t)cpuinfo.mtrr_cap;
for(i = 0; i < cpuinfo.var_mtrr_count; i++)
{
u64_t mtrr_base;
u64_t mtrr_mask;
cpuinfo.var_mtrr[i].base = read_msr(MTRRphysBase_MSR(i));
cpuinfo.var_mtrr[i].mask = read_msr(MTRRphysMask_MSR(i));
printf("MTRR_%d base: %016llx mask: %016llx\n", i,
cpuinfo.var_mtrr[i].base,
cpuinfo.var_mtrr[i].mask);
};
unsigned int cr0, cr3, cr4, eflags;
eflags = safe_cli();
/* Enter the no-fill (CD=1, NW=0) cache mode and flush caches. */
cr0 = read_cr0() | (1<<30);
write_cr0(cr0);
wbinvd();
cr4 = read_cr4();
write_cr4(cr4 & ~(1<<7));
cr3 = read_cr3();
write_cr3(cr3);
/* Save MTRR state */
rdmsr(MSR_MTRRdefType, deftype_lo, deftype_hi);
/* Disable MTRRs, and set the default type to uncached */
native_write_msr(MSR_MTRRdefType, deftype_lo & ~0xcff, deftype_hi);
wbinvd();
i = 0;
set_mtrr(i++,0,0x80000000>>12,MTRR_WB);
set_mtrr(i++,0x80000000>>12,0x40000000>>12,MTRR_WB);
set_mtrr(i++,0xC0000000>>12,0x20000000>>12,MTRR_WB);
set_mtrr(i++,0xdb800000>>12,0x00800000>>12,MTRR_UC);
set_mtrr(i++,0xdc000000>>12,0x04000000>>12,MTRR_UC);
set_mtrr(i++,0xE0000000>>12,0x10000000>>12,MTRR_WC);
for(; i < cpuinfo.var_mtrr_count; i++)
set_mtrr(i,0,0,0);
write_cr3(cr3);
/* Intel (P6) standard MTRRs */
native_write_msr(MSR_MTRRdefType, deftype_lo, deftype_hi);
/* Enable caches */
write_cr0(read_cr0() & ~(1<<30));
/* Restore value of CR4 */
write_cr4(cr4);
safe_sti(eflags);
printf("\nnew MTRR map\n\n");
for(i = 0; i < cpuinfo.var_mtrr_count; i++)
{
u64_t mtrr_base;
u64_t mtrr_mask;
cpuinfo.var_mtrr[i].base = read_msr(MTRRphysBase_MSR(i));
cpuinfo.var_mtrr[i].mask = read_msr(MTRRphysMask_MSR(i));
printf("MTRR_%d base: %016llx mask: %016llx\n", i,
cpuinfo.var_mtrr[i].base,
cpuinfo.var_mtrr[i].mask);
};
#endif
tsc_khz = (unsigned int)(GetCpuFreq()/1000);
}
int get_driver_caps(hwcaps_t *caps)
{
int ret = 0;
switch(caps->idx)
{
case 0:
caps->opt[0] = 0;
caps->opt[1] = 0;
break;
case 1:
caps->cap1.max_tex_width = 4096;
caps->cap1.max_tex_height = 4096;
break;
default:
ret = 1;
};
caps->idx = 1;
return ret;
}
void get_pci_info(struct pci_device *dev)
{
struct pci_dev *pdev = main_device->pdev;
memset(dev, sizeof(*dev), 0);
dev->domain = 0;
dev->bus = pdev->busnr;
dev->dev = pdev->devfn >> 3;
dev->func = pdev->devfn & 7;
dev->vendor_id = pdev->vendor;
dev->device_id = pdev->device;
dev->revision = pdev->revision;
};
char *strstr(const char *cs, const char *ct);
static int my_atoi(char **cmd)
{
char* p = *cmd;
int val = 0;
int sign = 1;
if(*p == '-')
{
sign = -1;
p++;
};
for (;; *p++) {
switch (*p) {
case '0' ... '9':
val = 10*val+(*p-'0');
break;
default:
*cmd = p;
return val*sign;
}
}
}
char* parse_mode(char *p, videomode_t *mode)
{
char c;
while( (c = *p++) == ' ');
if( c )
{
p--;
mode->width = my_atoi(&p);
if(*p == 'x') p++;
mode->height = my_atoi(&p);
if(*p == 'x') p++;
mode->bpp = 32;
mode->freq = my_atoi(&p);
if( mode->freq == 0 )
mode->freq = 60;
}
return p;
};
static char* parse_path(char *p, char *log)
{
char c;
while( (c = *p++) == ' ');
p--;
while((c = *p++) && (c != ' '))
*log++ = c;
*log = 0;
return p;
};
void parse_cmdline(char *cmdline, struct cmdtable *table, char *log, videomode_t *mode)
{
char *p = cmdline;
char *p1;
int val;
char c = *p++;
if( table )
{
while(table->key)
{
if(p1 = strstr(cmdline, table->key))
{
p1+= table->size;
*table->val = my_atoi(&p1);
}
table++;
}
}
while( c )
{
if( c == '-')
{
switch(*p++)
{
case 'l':
p = parse_path(p, log);
break;
case 'm':
p = parse_mode(p, mode);
break;
};
};
c = *p++;
};
};
char *strstr(const char *cs, const char *ct)
{
int d0, d1;
register char *__res;
__asm__ __volatile__(
"movl %6,%%edi\n\t"
"repne\n\t"
"scasb\n\t"
"notl %%ecx\n\t"
"decl %%ecx\n\t" /* NOTE! This also sets Z if searchstring='' */
"movl %%ecx,%%edx\n"
"1:\tmovl %6,%%edi\n\t"
"movl %%esi,%%eax\n\t"
"movl %%edx,%%ecx\n\t"
"repe\n\t"
"cmpsb\n\t"
"je 2f\n\t" /* also works for empty string, see above */
"xchgl %%eax,%%esi\n\t"
"incl %%esi\n\t"
"cmpb $0,-1(%%eax)\n\t"
"jne 1b\n\t"
"xorl %%eax,%%eax\n\t"
"2:"
: "=a" (__res), "=&c" (d0), "=&S" (d1)
: "0" (0), "1" (0xffffffff), "2" (cs), "g" (ct)
: "dx", "di");
return __res;
}
#include <linux/math64.h>
u64 long_div(u64 dividend, u64 divisor)
{
#if 1
u32 high = divisor >> 32;
u64 quot;
if (high == 0) {
quot = div_u64(dividend, divisor);
} else {
int n = 1 + fls(high);
quot = div_u64(dividend >> n, divisor >> n);
if (quot != 0)
quot--;
if ((dividend - quot * divisor) >= divisor)
quot++;
}
return quot;
#endif
// return dividend / divisor;
};