Skip to content

L
linux
Commit 8a48b711 authored by Alexander Viro's avatar Alexander Viro Committed by Linus Torvalds
Browse files
Options

[PATCH] drivers/atm/horizon.c delousing 

Same as with ambassador.c - same authors, same braindamage.
parent 5917ab47
Hide whitespace changes
Inline Side-by-side
Showing with 119 additions and 133 deletions
drivers/atm/horizon.c
View file @ 8a48b711
......@@ -597,126 +597,112 @@ static inline u16 rx_q_entry_to_rx_channel (u32 x) {
// p ranges from 1 to a power of 2
#define CR_MAXPEXP 4
static int make_rate (const hrz_dev * dev, u32 c, rounding r,
u16 * bits, unsigned int * actual) {
// note: rounding the rate down means rounding 'p' up
const unsigned long br = test_bit(ultra, &dev->flags) ? BR_ULT : BR_HRZ;
u32 div = CR_MIND;
u32 pre;
u16 * bits, unsigned int * actual)
{
// note: rounding the rate down means rounding 'p' up
const unsigned long br = test_bit(ultra, &dev->flags) ? BR_ULT : BR_HRZ;
// local fn to build the timer bits
int set_cr (void) {
// paranoia
if (div > CR_MAXD || (!pre) || pre > 1<<CR_MAXPEXP) {
PRINTD (DBG_QOS, "set_cr internal failure: d=%u p=%u",
div, pre);
return -EINVAL;
} else {
if (bits)
*bits = (div<<CLOCK_SELECT_SHIFT) | (pre-1);
if (actual) {
*actual = (br + (pre<<div) - 1) / (pre<<div);
PRINTD (DBG_QOS, "actual rate: %u", *actual);
}
return 0;
}
}
u32 div = CR_MIND;
u32 pre;
// br_exp and br_man are used to avoid overflowing (c*maxp*2^d) in
// the tests below. We could think harder about exact possibilities
// of failure...
// br_exp and br_man are used to avoid overflowing (c*maxp*2^d) in
// the tests below. We could think harder about exact possibilities
// of failure...
unsigned long br_man = br;
unsigned int br_exp = 0;
unsigned long br_man = br;
unsigned int br_exp = 0;
PRINTD (DBG_QOS|DBG_FLOW, "make_rate b=%lu, c=%u, %s", br, c,
(r == round_up) ? "up" : (r == round_down) ? "down" : "nearest");
PRINTD (DBG_QOS|DBG_FLOW, "make_rate b=%lu, c=%u, %s", br, c,
r == round_up ? "up" : r == round_down ? "down" : "nearest");
// avoid div by zero
if (!c) {
PRINTD (DBG_QOS|DBG_ERR, "zero rate is not allowed!");
return -EINVAL;
}
// avoid div by zero
if (!c) {
PRINTD (DBG_QOS|DBG_ERR, "zero rate is not allowed!");
return -EINVAL;
}
while (br_exp < CR_MAXPEXP + CR_MIND && (br_man % 2 == 0)) {
br_man = br_man >> 1;
++br_exp;
}
// (br >>br_exp) <<br_exp == br and
// br_exp <= CR_MAXPEXP+CR_MIND
while (br_exp < CR_MAXPEXP + CR_MIND && (br_man % 2 == 0)) {
br_man = br_man >> 1;
++br_exp;
}
// (br >>br_exp) <<br_exp == br and
// br_exp <= CR_MAXPEXP+CR_MIND
if (br_man <= (c << (CR_MAXPEXP+CR_MIND-br_exp))) {
// Equivalent to: B <= (c << (MAXPEXP+MIND))
// take care of rounding
switch (r) {
case round_down:
pre = (br+(c<<div)-1)/(c<<div);
// but p must be non-zero
if (!pre)
pre = 1;
break;
case round_nearest:
pre = (br+(c<<div)/2)/(c<<div);
// but p must be non-zero
if (!pre)
pre = 1;
break;
default: /* round_up */
pre = br/(c<<div);
// but p must be non-zero
if (!pre)
return -EINVAL;
}
PRINTD (DBG_QOS, "A: p=%u, d=%u", pre, div);
goto got_it;
}
if (br_man <= (c << (CR_MAXPEXP+CR_MIND-br_exp))) {
// Equivalent to: B <= (c << (MAXPEXP+MIND))
// take care of rounding
switch (r) {
case round_down:
pre = (br+(c<<div)-1)/(c<<div);
// but p must be non-zero
if (!pre)
pre = 1;
break;
case round_nearest:
pre = (br+(c<<div)/2)/(c<<div);
// but p must be non-zero
if (!pre)
pre = 1;
break;
case round_up:
pre = br/(c<<div);
// but p must be non-zero
if (!pre)
return -EINVAL;
break;
}
PRINTD (DBG_QOS, "A: p=%u, d=%u", pre, div);
return set_cr ();
}
// at this point we have
// d == MIND and (c << (MAXPEXP+MIND)) < B
while (div < CR_MAXD) {
div++;
if (br_man <= (c << (CR_MAXPEXP+div-br_exp))) {
// Equivalent to: B <= (c << (MAXPEXP+d))
// c << (MAXPEXP+d-1) < B <= c << (MAXPEXP+d)
// 1 << (MAXPEXP-1) < B/2^d/c <= 1 << MAXPEXP
// MAXP/2 < B/c2^d <= MAXP
// take care of rounding
switch (r) {
case round_down:
pre = (br+(c<<div)-1)/(c<<div);
break;
case round_nearest:
pre = (br+(c<<div)/2)/(c<<div);
break;
case round_up:
pre = br/(c<<div);
break;
}
PRINTD (DBG_QOS, "B: p=%u, d=%u", pre, div);
return set_cr ();
}
}
// at this point we have
// d == MAXD and (c << (MAXPEXP+MAXD)) < B
// but we cannot go any higher
// take care of rounding
switch (r) {
case round_down:
return -EINVAL;
break;
case round_nearest:
break;
case round_up:
break;
}
pre = 1 << CR_MAXPEXP;
PRINTD (DBG_QOS, "C: p=%u, d=%u", pre, div);
return set_cr ();
// at this point we have
// d == MIND and (c << (MAXPEXP+MIND)) < B
while (div < CR_MAXD) {
div++;
if (br_man <= (c << (CR_MAXPEXP+div-br_exp))) {
// Equivalent to: B <= (c << (MAXPEXP+d))
// c << (MAXPEXP+d-1) < B <= c << (MAXPEXP+d)
// 1 << (MAXPEXP-1) < B/2^d/c <= 1 << MAXPEXP
// MAXP/2 < B/c2^d <= MAXP
// take care of rounding
switch (r) {
case round_down:
pre = (br+(c<<div)-1)/(c<<div);
break;
case round_nearest:
pre = (br+(c<<div)/2)/(c<<div);
break;
default: /* round_up */
pre = br/(c<<div);
}
PRINTD (DBG_QOS, "B: p=%u, d=%u", pre, div);
goto got_it;
}
}
// at this point we have
// d == MAXD and (c << (MAXPEXP+MAXD)) < B
// but we cannot go any higher
// take care of rounding
if (r == round_down)
return -EINVAL;
pre = 1 << CR_MAXPEXP;
PRINTD (DBG_QOS, "C: p=%u, d=%u", pre, div);
got_it:
// paranoia
if (div > CR_MAXD || (!pre) || pre > 1<<CR_MAXPEXP) {
PRINTD (DBG_QOS, "set_cr internal failure: d=%u p=%u",
div, pre);
return -EINVAL;
} else {
if (bits)
*bits = (div<<CLOCK_SELECT_SHIFT) | (pre-1);
if (actual) {
*actual = (br + (pre<<div) - 1) / (pre<<div);
PRINTD (DBG_QOS, "actual rate: %u", *actual);
}
return 0;
}
}
static int make_rate_with_tolerance (const hrz_dev * dev, u32 c, rounding r, unsigned int tol,
......@@ -1823,23 +1809,23 @@ static void hrz_reset (const hrz_dev * dev) {
/********** read the burnt in address **********/
static u16 __init read_bia (const hrz_dev * dev, u16 addr) {
static inline void WRITE_IT_WAIT (const hrz_dev *dev, u32 ctrl)
{
wr_regl (dev, CONTROL_0_REG, ctrl);
udelay (5);
}
static inline void CLOCK_IT (const hrz_dev *dev, u32 ctrl)
{
// DI must be valid around rising SK edge
WRITE_IT_WAIT(dev, ctrl & ~SEEPROM_SK);
WRITE_IT_WAIT(dev, ctrl | SEEPROM_SK);
}
static u16 __init read_bia (const hrz_dev * dev, u16 addr)
{
u32 ctrl = rd_regl (dev, CONTROL_0_REG);
void WRITE_IT_WAIT (void) {
wr_regl (dev, CONTROL_0_REG, ctrl);
udelay (5);
}
void CLOCK_IT (void) {
// DI must be valid around rising SK edge
ctrl &= ~SEEPROM_SK;
WRITE_IT_WAIT();
ctrl |= SEEPROM_SK;
WRITE_IT_WAIT();
}
const unsigned int addr_bits = 6;
const unsigned int data_bits = 16;
......@@ -1848,17 +1834,17 @@ static u16 __init read_bia (const hrz_dev * dev, u16 addr) {
u16 res;
ctrl &= ~(SEEPROM_CS | SEEPROM_SK | SEEPROM_DI);
WRITE_IT_WAIT();
WRITE_IT_WAIT(dev, ctrl);
// wake Serial EEPROM and send 110 (READ) command
ctrl |= (SEEPROM_CS | SEEPROM_DI);
CLOCK_IT();
CLOCK_IT(dev, ctrl);
ctrl |= SEEPROM_DI;
CLOCK_IT();
CLOCK_IT(dev, ctrl);
ctrl &= ~SEEPROM_DI;
CLOCK_IT();
CLOCK_IT(dev, ctrl);
for (i=0; i<addr_bits; i++) {
if (addr & (1 << (addr_bits-1)))
......@@ -1866,7 +1852,7 @@ static u16 __init read_bia (const hrz_dev * dev, u16 addr) {
else
ctrl &= ~SEEPROM_DI;
CLOCK_IT();
CLOCK_IT(dev, ctrl);
addr = addr << 1;
}
......@@ -1878,14 +1864,14 @@ static u16 __init read_bia (const hrz_dev * dev, u16 addr) {
for (i=0;i<data_bits;i++) {
res = res >> 1;
CLOCK_IT();
CLOCK_IT(dev, ctrl);
if (rd_regl (dev, CONTROL_0_REG) & SEEPROM_DO)
res |= (1 << (data_bits-1));
}
ctrl &= ~(SEEPROM_SK | SEEPROM_CS);
WRITE_IT_WAIT();
WRITE_IT_WAIT(dev, ctrl);
return res;
}
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7