static bool_t tick_timer_init(void)
{
u64_t timclk;
u32_t count;
if(!clk_get_rate("timclk", &timclk))
{
LOG_E("can't get the clock of \'timclk\'");
return FALSE;
}
/* for 1ms reload count */
count = (u32_t)div64(timclk, 1000);
if(!request_irq("TMIER2_3", timer_interrupt))
{
LOG_E("can't request irq \'TMIER2_3\'");
return FALSE;
}
/* using timer3 for tick, 1ms for reload value */
writel(REALVIEW_T3_LOAD, count);
/* setting timer controller */
writel(REALVIEW_T3_CTRL, REALVIEW_TC_32BIT | REALVIEW_TC_DIV1 | REALVIEW_TC_IE | REALVIEW_TC_PERIODIC);
/* clear all interrupt */
writel(REALVIEW_T3_ICLR, 0x0);
/* enable timer3 */
writel(REALVIEW_T3_CTRL, readl(REALVIEW_T3_CTRL) | REALVIEW_TC_ENABLE);
return TRUE;
}
static bool_t tick_timer_init(void)
{
u64_t pclk;
if(!clk_get_rate("pclk", &pclk))
return FALSE;
if(!request_irq("TIMER4", timer_interrupt))
return FALSE;
/* use pwm timer 4, prescaler for timer 4 is 16 */
writel(S3C6410_TCFG0, (readl(S3C6410_TCFG0) & ~(0xff<<8)) | (0x0f<<8));
/* select mux input for pwm timer4 is 1/2 */
writel(S3C6410_TCFG1, (readl(S3C6410_TCFG1) & ~(0xf<<16)) | (0x01<<16));
/* load value for 10 ms timeout */
writel(S3C6410_TCNTB4, (u32_t)div64(pclk, (2 * 16 * 100)));
/* auto load, manaual update of timer 4 and stop timer4 */
writel(S3C6410_TCON, (readl(S3C6410_TCON) & ~(0x7<<20)) | (0x06<<20));
/* enable timer4 interrupt and clear interrupt status bit */
writel(S3C6410_TINT_CSTAT, (readl(S3C6410_TINT_CSTAT) & ~(0x1<<4)) | (0x01<<4) | (0x01<<9));
/* start timer4 */
writel(S3C6410_TCON, (readl(S3C6410_TCON) & ~(0x7<<20)) | (0x05<<20));
return TRUE;
}
static void testdiv0(void)
{
int funcidx;
assert(cmp64u(j, 0) == 0);
/* loop through the 5 different division functions */
for (funcidx = 0; funcidx < 5; funcidx++) {
expect_SIGFPE = 1;
if (setjmp(jmpbuf_SIGFPE) == 0) {
/* divide by zero using various functions */
switch (funcidx) {
case 0: div64(i, j); ERR; break;
case 1: div64u64(i, ex64lo(j)); ERR; break;
case 2: div64u(i, ex64lo(j)); ERR; break;
case 3: rem64(i, j); ERR; break;
case 4: rem64u(i, ex64lo(j)); ERR; break;
default: assert(0); ERR; break;
}
/* if we reach this point there was no signal and an
* error has been recorded
*/
expect_SIGFPE = 0;
} else {
/* a signal has been received and expect_SIGFPE has
* been reset; all is ok now
*/
assert(!expect_SIGFPE);
}
}
}
static bool_t s5pv210fb_set_clock(struct s5pv210fb_lcd * lcd)
{
u64_t hclk, pixel_clock;
u32_t div;
u32_t cfg;
/*
* get hclk for lcd
*/
if(! clk_get_rate("dsys-hclk", &hclk))
return FALSE;
pixel_clock = ( lcd->freq * (lcd->timing.h_fp + lcd->timing.h_bp + lcd->timing.h_sw + lcd->width) *
(lcd->timing.v_fp + lcd->timing.v_bp + lcd->timing.v_sw + lcd->height) );
div = (u32_t)div64(hclk, pixel_clock);
if(mod64(hclk, pixel_clock) > 0)
div++;
/*
* fixed clock source: hclk
*/
cfg = readl(S5PV210_VIDCON0);
cfg &= ~(S5PV210_VIDCON0_CLKSEL_MASK | S5PV210_VIDCON0_CLKVALUP_MASK | S5PV210_VIDCON0_VCLKEN_MASK | S5PV210_VIDCON0_CLKDIR_MASK);
cfg |= (S5PV210_VIDCON0_CLKSEL_HCLK | S5PV210_VIDCON0_CLKVALUP_ALWAYS | S5PV210_VIDCON0_VCLKEN_NORMAL | S5PV210_VIDCON0_CLKDIR_DIVIDED);
cfg |= S5PV210_VIDCON0_CLKVAL_F(div - 1);
writel(S5PV210_VIDCON0, cfg);
return TRUE;
}
static bool_t keyboard_probe(struct input * input)
{
u32_t divisor;
u64_t kclk;
u8_t data;
if(! clk_get_rate("kclk", &kclk))
{
LOG_E("can't get the clock of 'kclk'");
return FALSE;
}
/* set keyboard's clock divisor */
divisor = (u32_t)(div64(kclk, 8000000) - 1);
writeb(REALVIEW_KEYBOARD_CLKDIV, divisor);
/* enable keyboard controller */
writeb(REALVIEW_KEYBOARD_CR, REALVIEW_KEYBOARD_CR_EN);
/* clear a receive buffer */
kmi_read(&data);
/* reset keyboard, and wait ack and pass/fail code */
if(! kmi_write(0xff) )
return FALSE;
if(! kmi_read(&data))
return FALSE;
if(data != 0xaa)
return FALSE;
/* set keyboard's typematic rate/delay */
kmi_write(0xf3);
/* 10.9pcs, 500ms */
kmi_write(0x2b);
/* scan code set 2 */
kmi_write(0xf0);
kmi_write(0x02);
/* set all keys typematic/make/break */
kmi_write(0xfa);
/* set keyboard's number lock, caps lock, and scroll lock */
kmi_write(0xed);
kmi_write(0x02);
if(!request_irq("KMI0", keyboard_interrupt))
{
LOG_E("can't request irq 'KMI0'");
writeb(REALVIEW_KEYBOARD_CR, 0);
return FALSE;
}
/* re-enables keyboard */
writeb(REALVIEW_KEYBOARD_CR, REALVIEW_KEYBOARD_CR_EN | REALVIEW_KEYBOARD_CR_RXINTREN);
return TRUE;
}
static void testdiv(void)
{
u64_t q, r;
#if TIMED
struct timeval tvstart, tvend;
printf("i=0x%.8x%.8x; j=0x%.8x%.8x\n",
ex64hi(i), ex64lo(i),
ex64hi(j), ex64lo(j));
fflush(stdout);
if (gettimeofday(&tvstart, NULL) < 0) ERR;
#endif
/* division by zero has a separate test */
if (cmp64u(j, 0) == 0) {
testdiv0();
return;
}
/* perform division, store q in k to make ERR more informative */
q = div64(i, j);
r = rem64(i, j);
k = q;
#if TIMED
if (gettimeofday(&tvend, NULL) < 0) ERR;
tvend.tv_sec -= tvstart.tv_sec;
tvend.tv_usec -= tvstart.tv_usec;
if (tvend.tv_usec < 0) {
tvend.tv_sec -= 1;
tvend.tv_usec += 1000000;
}
printf("q=0x%.8x%.8x; r=0x%.8x%.8x; time=%d.%.6d\n",
ex64hi(q), ex64lo(q),
ex64hi(r), ex64lo(r),
tvend.tv_sec, tvend.tv_usec);
fflush(stdout);
#endif
/* compare to 64/32-bit division if possible */
if (!ex64hi(j)) {
if (cmp64(q, div64u64(i, ex64lo(j))) != 0) ERR;
if (!ex64hi(q)) {
if (cmp64u(q, div64u(i, ex64lo(j))) != 0) ERR;
}
if (cmp64u(r, rem64u(i, ex64lo(j))) != 0) ERR;
/* compare to 32-bit division if possible */
if (!ex64hi(i)) {
if (cmp64u(q, ex64lo(i) / ex64lo(j)) != 0) ERR;
if (cmp64u(r, ex64lo(i) % ex64lo(j)) != 0) ERR;
}
}
/* check results using i = q j + r and r < j */
if (cmp64(i, add64(mul64(q, j), r)) != 0) ERR;
if (cmp64(r, j) >= 0) ERR;
}
/*
* Send traffic from a scheduler instance due by 'now'.
* Return a pointer to the head of the queue.
*/
static struct mbuf *
serve_sched(struct mq *q, struct dn_sch_inst *si, uint64_t now)
{
struct mq def_q;
struct dn_schk *s = si->sched;
struct mbuf *m = NULL;
int delay_line_idle = (si->dline.mq.head == NULL);
int done, bw;
if (q == NULL) {
q = &def_q;
q->head = NULL;
}
bw = s->link.bandwidth;
si->kflags &= ~DN_ACTIVE;
if (bw > 0)
si->credit += (now - si->sched_time) * bw;
else
si->credit = 0;
si->sched_time = now;
done = 0;
while (si->credit >= 0 && (m = s->fp->dequeue(si)) != NULL) {
uint64_t len_scaled;
done++;
len_scaled = (bw == 0) ? 0 : hz *
(m->m_pkthdr.len * 8 + extra_bits(m, s));
si->credit -= len_scaled;
/* Move packet in the delay line */
dn_tag_get(m)->output_time = dn_cfg.curr_time + s->link.delay ;
mq_append(&si->dline.mq, m);
}
/*
* If credit >= 0 the instance is idle, mark time.
* Otherwise put back in the heap, and adjust the output
* time of the last inserted packet, m, which was too early.
*/
if (si->credit >= 0) {
si->idle_time = now;
} else {
uint64_t t;
KASSERT (bw > 0, ("bw=0 and credit<0 ?"));
t = div64(bw - 1 - si->credit, bw);
if (m)
dn_tag_get(m)->output_time += t;
si->kflags |= DN_ACTIVE;
heap_insert(&dn_cfg.evheap, now + t, si);
}
if (delay_line_idle && done)
transmit_event(q, &si->dline, now);
return q->head;
}
void DivIntNum16(void) { /* 11 */
/*
64 bit 除算
var: 足す数の入った変数
*/
int *var = getCaliVariable();
gint64 i;
l_1000A0C8 = *var;
i = mul64(l_1000A0C8, numbase);
l_1000A0D8 = div64(l_1000A0D8, i);
DEBUG_COMMAND("ShCalc.DivIntNum16 %p:\n", var);
}
/*
* Convert the additional MAC overheads/delays into an equivalent
* number of bits for the given data rate. The samples are
* in milliseconds so we need to divide by 1000.
*/
static uint64_t
extra_bits(struct mbuf *m, struct dn_schk *s)
{
int index;
uint64_t bits;
struct dn_profile *pf = s->profile;
if (!pf || pf->samples_no == 0)
return 0;
index = random() % pf->samples_no;
bits = div64((uint64_t)pf->samples[index] * s->link.bandwidth, 1000);
if (index >= pf->loss_level) {
struct dn_pkt_tag *dt = dn_tag_get(m);
if (dt)
dt->dn_dir = DIR_DROP;
}
return bits;
}
void GetIntNum16(void) { /* 3 */
/*
64 bit 演算した結果を得る
var: 数値をいれる変数
*/
int *var = getCaliVariable();
gint64 i;
i = div64(l_1000A0D8, numbase);
if (i > 65535) {
i = l_1000A0C8 = 65535;
}
*var = i;
DEBUG_COMMAND("ShCalc.GetIntNum16 %d:\n", var);
}
PUBLIC short cpu_load(void)
{
u64_t current_tsc, *current_idle;
u64_t tsc_delta, idle_delta, busy;
struct proc *idle;
short load;
#ifdef CONFIG_SMP
unsigned cpu = cpuid;
#endif
u64_t *last_tsc, *last_idle;
last_tsc = get_cpu_var_ptr(cpu, cpu_last_tsc);
last_idle = get_cpu_var_ptr(cpu, cpu_last_idle);
idle = get_cpu_var_ptr(cpu, idle_proc);;
read_tsc_64(¤t_tsc);
current_idle = &idle->p_cycles; /* ptr to idle proc */
/* calculate load since last cpu_load invocation */
if (!is_zero64(*last_tsc)) {
tsc_delta = sub64(current_tsc, *last_tsc);
idle_delta = sub64(*current_idle, *last_idle);
busy = sub64(tsc_delta, idle_delta);
busy = mul64(busy, make64(100, 0));
load = ex64lo(div64(busy, tsc_delta));
if (load > 100)
load = 100;
} else
load = 0;
*last_tsc = current_tsc;
*last_idle = *current_idle;
return load;
}
/*
* common function for ioctl.
*/
static int s5pv210_ioctl(u32_t ch, int cmd, void * arg)
{
const u32_t udivslot_code[16] = {0x0000, 0x0080, 0x0808, 0x0888,
0x2222, 0x4924, 0x4a52, 0x54aa,
0x5555, 0xd555, 0xd5d5, 0xddd5,
0xdddd, 0xdfdd, 0xdfdf, 0xffdf};
u32_t baud, baud_div_reg, baud_divslot_reg;
u8_t data_bit_reg, parity_reg, stop_bit_reg;
u64_t pclk;
struct serial_parameter param;
if((ch < 0) || (ch > 3))
return -1;
memcpy(¶m, &uart_param[ch], sizeof(struct serial_parameter));
switch(cmd)
{
case IOCTL_WR_SERIAL_BAUD_RATE:
param.baud_rate = *((enum SERIAL_BAUD_RATE *)arg);
break;
case IOCTL_WR_SERIAL_DATA_BITS:
param.data_bit = *((enum SERIAL_DATA_BITS *)arg);
break;
case IOCTL_WR_SERIAL_PARITY_BIT:
param.parity = *((enum SERIAL_PARITY_BIT *)arg);
break;
case IOCTL_WR_SERIAL_STOP_BITS:
param.stop_bit = *((enum SERIAL_STOP_BITS *)arg);
break;
case IOCTL_RD_SERIAL_BAUD_RATE:
*((enum SERIAL_BAUD_RATE *)arg) = param.baud_rate;
return 0;
case IOCTL_RD_SERIAL_DATA_BITS:
*((enum SERIAL_DATA_BITS *)arg) = param.data_bit;
return 0;
case IOCTL_RD_SERIAL_PARITY_BIT:
*((enum SERIAL_PARITY_BIT *)arg) = param.parity;
return 0;
case IOCTL_RD_SERIAL_STOP_BITS:
*((enum SERIAL_STOP_BITS *)arg) = param.stop_bit;
return 0;
default:
return -1;
}
switch(param.baud_rate)
{
case B50:
baud = 50; break;
case B75:
baud = 75; break;
case B110:
baud = 110; break;
case B134:
baud = 134; break;
case B200:
baud = 200; break;
case B300:
baud = 300; break;
case B600:
baud = 600; break;
case B1200:
baud = 1200; break;
case B1800:
baud = 1800; break;
case B2400:
baud = 2400; break;
case B4800:
baud = 4800; break;
case B9600:
baud = 9600; break;
case B19200:
baud = 19200; break;
case B38400:
baud = 38400; break;
case B57600:
baud = 57600; break;
case B76800:
baud = 76800; break;
case B115200:
baud = 115200; break;
case B230400:
baud = 230400; break;
case B380400:
baud = 380400; break;
case B460800:
baud = 460800; break;
case B921600:
baud = 921600; break;
default:
return -1;
}
switch(param.data_bit)
{
case DATA_BITS_5:
data_bit_reg = 0x0; break;
case DATA_BITS_6:
data_bit_reg = 0x1; break;
case DATA_BITS_7:
data_bit_reg = 0x2; break;
case DATA_BITS_8:
data_bit_reg = 0x3; break;
default:
return -1;
}
switch(param.parity)
{
case PARITY_NONE:
parity_reg = 0x0; break;
case PARITY_EVEN:
parity_reg = 0x5; break;
case PARITY_ODD:
parity_reg = 0x4; break;
default:
return -1;
}
switch(param.stop_bit)
{
case STOP_BITS_1:
stop_bit_reg = 0; break;
case STOP_BITS_1_5:
return -1;
case STOP_BITS_2:
stop_bit_reg = 1; break;
default:
return -1;
}
if(clk_get_rate("psys-pclk", &pclk))
{
baud_div_reg = (u32_t)(div64(pclk, (baud * 16)) ) - 1;
baud_divslot_reg = udivslot_code[( (u32_t)div64(mod64(pclk, (baud*16)), baud) ) & 0xf];
}
else
return -1;
switch(ch)
{
case 0:
writel(S5PV210_UBRDIV0, baud_div_reg);
writel(S5PV210_UDIVSLOT0, baud_divslot_reg);
writel(S5PV210_ULCON0, (data_bit_reg<<0 | stop_bit_reg <<2 | parity_reg<<3));
break;
case 1:
writel(S5PV210_UBRDIV1, baud_div_reg);
writel(S5PV210_UDIVSLOT1, baud_divslot_reg);
writel(S5PV210_ULCON1, (data_bit_reg<<0 | stop_bit_reg <<2 | parity_reg<<3));
break;
case 2:
writel(S5PV210_UBRDIV2, baud_div_reg);
writel(S5PV210_UDIVSLOT2, baud_divslot_reg);
writel(S5PV210_ULCON2, (data_bit_reg<<0 | stop_bit_reg <<2 | parity_reg<<3));
break;
case 3:
writel(S5PV210_UBRDIV3, baud_div_reg);
writel(S5PV210_UDIVSLOT3, baud_divslot_reg);
writel(S5PV210_ULCON3, (data_bit_reg<<0 | stop_bit_reg <<2 | parity_reg<<3));
break;
default:
return -1;
}
memcpy(&uart_param[ch], ¶m, sizeof(struct serial_parameter));
return 0;
}
static bool_t mouse_probe(struct input * input)
{
u32_t divisor;
u64_t kclk;
u8_t data;
if(! clk_get_rate("kclk", &kclk))
{
LOG_E("can't get the clock of 'kclk'");
return FALSE;
}
/* set mouse's clock divisor */
divisor = (u32_t)(div64(kclk, 8000000) - 1);
writeb(REALVIEW_MOUSE_CLKDIV, divisor);
/* enable mouse controller */
writeb(REALVIEW_MOUSE_CR, REALVIEW_MOUSE_CR_EN);
/* reset mouse, and wait ack and pass/fail code */
if(! kmi_write(0xff) )
return FALSE;
if(! kmi_read(&data))
return FALSE;
if(data != 0xaa)
return FALSE;
/* enable scroll wheel */
kmi_write(0xf3);
kmi_write(200);
kmi_write(0xf3);
kmi_write(100);
kmi_write(0xf3);
kmi_write(80);
kmi_write(0xf2);
kmi_read(&data);
kmi_read(&data);
/* set sample rate, 100 samples/sec */
kmi_write(0xf3);
kmi_write(100);
/* set resolution, 4 counts per mm, 1:1 scaling */
kmi_write(0xe8);
kmi_write(0x02);
kmi_write(0xe6);
/* enable data reporting */
kmi_write(0xf4);
/* clear a receive buffer */
kmi_read(&data);
kmi_read(&data);
kmi_read(&data);
kmi_read(&data);
if(!request_irq("KMI1", mouse_interrupt))
{
LOG_E("can't request irq 'KMI1'");
writeb(REALVIEW_MOUSE_CR, 0);
return FALSE;
}
/* re-enables mouse */
writeb(REALVIEW_MOUSE_CR, REALVIEW_MOUSE_CR_EN | REALVIEW_MOUSE_CR_RXINTREN);
return TRUE;
}
static void fb_init(struct fb * fb)
{
u64_t hclk;
/* set gpf15 (backlight pin) output and pull up and low level */
writel(S3C6410_GPFCON, (readl(S3C6410_GPFCON) & ~(0x3<<30)) | (0x1<<30));
writel(S3C6410_GPFPUD, (readl(S3C6410_GPFPUD) & ~(0x3<<30)) | (0x2<<30));
writel(S3C6410_GPFDAT, (readl(S3C6410_GPFDAT) & ~(0x1<<15)) | (0x0<<15));
/* must be '0' for normal-path instead of by-pass */
writel(S3C6410_MIFPCON, 0);
/* select tft lcd type (rgb i/f) */
writel(S3C6410_SPCON, (readl(S3C6410_SPCON) & ~(0x3<<0)) | (0x1<<0));
/* lcd port config */
writel(S3C6410_GPICON, 0xaaaaaaaa);
writel(S3C6410_GPJCON, 0xaaaaaaaa);
/* initial lcd controler */
writel(S3C6410_VIDCON1, REGS_VIDCON1);
writel(S3C6410_VIDTCON0, REGS_VIDTCON0);
writel(S3C6410_VIDTCON1, REGS_VIDTCON1);
writel(S3C6410_VIDTCON2, REGS_VIDTCON2);
writel(S3C6410_DITHMODE, REGS_DITHMODE);
/* get hclk for lcd */
clk_get_rate("hclk", &hclk);
writel(S3C6410_VIDCON0, (REGS_VIDCON0 | S3C6410_VIDCON0_CLKVAL_F((u32_t)(div64(hclk, PIXEL_CLOCK) - 1)) ) );
/* turn all windows off */
writel(S3C6410_WINCON0, (readl(S3C6410_WINCON0) & ~0x1));
writel(S3C6410_WINCON1, (readl(S3C6410_WINCON1) & ~0x1));
writel(S3C6410_WINCON2, (readl(S3C6410_WINCON2) & ~0x1));
writel(S3C6410_WINCON3, (readl(S3C6410_WINCON3) & ~0x1));
writel(S3C6410_WINCON4, (readl(S3C6410_WINCON4) & ~0x1));
/* turn all windows color map off */
writel(S3C6410_WIN0MAP, (readl(S3C6410_WIN0MAP) & ~(1<<24)));
writel(S3C6410_WIN1MAP, (readl(S3C6410_WIN1MAP) & ~(1<<24)));
writel(S3C6410_WIN2MAP, (readl(S3C6410_WIN2MAP) & ~(1<<24)));
writel(S3C6410_WIN3MAP, (readl(S3C6410_WIN3MAP) & ~(1<<24)));
writel(S3C6410_WIN4MAP, (readl(S3C6410_WIN4MAP) & ~(1<<24)));
/* turn all windows color key off */
writel(S3C6410_W1KEYCON0, (readl(S3C6410_W1KEYCON0) & ~(3<<25)));
writel(S3C6410_W2KEYCON0, (readl(S3C6410_W2KEYCON0) & ~(3<<25)));
writel(S3C6410_W3KEYCON0, (readl(S3C6410_W3KEYCON0) & ~(3<<25)));
writel(S3C6410_W4KEYCON0, (readl(S3C6410_W4KEYCON0) & ~(3<<25)));
/* config window 0 */
writel(S3C6410_WINCON0, (readl(S3C6410_WINCON0) & ~(0x1<<22 | 0x1<<16 | 0x3<<9 | 0xf<<2 | 0x1<<0)) | (0x5<<2 | 0x1<<16));
/* window 0 frambuffer addresss */
writel(S3C6410_VIDW00ADD0B0, ((u32_t)fb->info->surface.pixels));
writel(S3C6410_VIDW00ADD0B1, ((u32_t)fb->info->surface.pixels));
writel(S3C6410_VIDW00ADD1B0, (((u32_t)fb->info->surface.pixels) + LCD_WIDTH*LCD_HEIGHT*LCD_BPP/8)& 0x00ffffff);
writel(S3C6410_VIDW00ADD1B1, (((u32_t)fb->info->surface.pixels) + LCD_WIDTH*LCD_HEIGHT*LCD_BPP/8)& 0x00ffffff);
writel(S3C6410_VIDW00ADD2, (LCD_WIDTH*LCD_BPP/8) & 0x00001fff);
/* config view port */
writel(S3C6410_VIDOSD0A, OSD_LTX(0) | OSD_LTY(0));
writel(S3C6410_VIDOSD0B, OSD_RBX(LCD_WIDTH) | OSD_RBY(LCD_HEIGHT));
writel(S3C6410_VIDOSD0C, OSDSIZE(LCD_WIDTH * LCD_HEIGHT));
/* enable window 0 */
writel(S3C6410_WINCON0, (readl(S3C6410_WINCON0) | 0x1));
/* enable video controller output */
writel(S3C6410_VIDCON0, (readl(S3C6410_VIDCON0) | 0x3));
/* delay for avoid flash screen */
mdelay(50);
}
static int
red_drops (struct dn_queue *q, int len)
{
/*
* RED algorithm
*
* RED calculates the average queue size (avg) using a low-pass filter
* with an exponential weighted (w_q) moving average:
* avg <- (1-w_q) * avg + w_q * q_size
* where q_size is the queue length (measured in bytes or * packets).
*
* If q_size == 0, we compute the idle time for the link, and set
* avg = (1 - w_q)^(idle/s)
* where s is the time needed for transmitting a medium-sized packet.
*
* Now, if avg < min_th the packet is enqueued.
* If avg > max_th the packet is dropped. Otherwise, the packet is
* dropped with probability P function of avg.
*/
struct dn_fsk *fs = q->fs;
int64_t p_b = 0;
/* Queue in bytes or packets? */
uint32_t q_size = (fs->fs.flags & DN_QSIZE_BYTES) ?
q->ni.len_bytes : q->ni.length;
/* Average queue size estimation. */
if (q_size != 0) {
/* Queue is not empty, avg <- avg + (q_size - avg) * w_q */
int diff = SCALE(q_size) - q->avg;
int64_t v = SCALE_MUL((int64_t)diff, (int64_t)fs->w_q);
q->avg += (int)v;
} else {
/*
* Queue is empty, find for how long the queue has been
* empty and use a lookup table for computing
* (1 - * w_q)^(idle_time/s) where s is the time to send a
* (small) packet.
* XXX check wraps...
*/
if (q->avg) {
u_int t = div64((dn_cfg.curr_time - q->q_time), fs->lookup_step);
q->avg = (t < fs->lookup_depth) ?
SCALE_MUL(q->avg, fs->w_q_lookup[t]) : 0;
}
}
/* Should i drop? */
if (q->avg < fs->min_th) {
q->count = -1;
return (0); /* accept packet */
}
if (q->avg >= fs->max_th) { /* average queue >= max threshold */
if (fs->fs.flags & DN_IS_GENTLE_RED) {
/*
* According to Gentle-RED, if avg is greater than
* max_th the packet is dropped with a probability
* p_b = c_3 * avg - c_4
* where c_3 = (1 - max_p) / max_th
* c_4 = 1 - 2 * max_p
*/
p_b = SCALE_MUL((int64_t)fs->c_3, (int64_t)q->avg) -
fs->c_4;
} else {
q->count = -1;
return (1);
}
} else if (q->avg > fs->min_th) {
/*
* We compute p_b using the linear dropping function
* p_b = c_1 * avg - c_2
* where c_1 = max_p / (max_th - min_th)
* c_2 = max_p * min_th / (max_th - min_th)
*/
p_b = SCALE_MUL((int64_t)fs->c_1, (int64_t)q->avg) - fs->c_2;
}
if (fs->fs.flags & DN_QSIZE_BYTES)
p_b = div64((p_b * len) , fs->max_pkt_size);
if (++q->count == 0)
q->random = random() & 0xffff;
else {
/*
* q->count counts packets arrived since last drop, so a greater
* value of q->count means a greater packet drop probability.
*/
if (SCALE_MUL(p_b, SCALE((int64_t)q->count)) > q->random) {
q->count = 0;
/* After a drop we calculate a new random value. */
q->random = random() & 0xffff;
return (1); /* drop */
}
}
/* End of RED algorithm. */
return (0); /* accept */
}
