io.h: read/write[bwl] should use barrier

Add barrier() calls to low-level read/write io calls so that their
callers don't need to.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
This commit is contained in:
Kevin O'Connor 2017-01-23 11:13:19 -05:00
parent 9c1bf1387c
commit 5beceaae5c
3 changed files with 13 additions and 9 deletions

View File

@ -126,12 +126,10 @@ console_get_output(uint8_t len)
return NULL;
// Disable TX irq and move buffer
writeb(&transmit_max, 0);
barrier();
tpos = readb(&transmit_pos);
tmax -= tpos;
memmove(&transmit_buf[0], &transmit_buf[tpos], tmax);
writeb(&transmit_pos, 0);
barrier();
writeb(&transmit_max, tmax);
enable_tx_irq();
return &transmit_buf[tmax];
@ -141,7 +139,6 @@ console_get_output(uint8_t len)
void
console_push_output(uint8_t len)
{
barrier();
writeb(&transmit_max, readb(&transmit_max) + len);
enable_tx_irq();
}

View File

@ -2,24 +2,34 @@
#define __GENERIC_IO_H
#include <stdint.h> // uint32_t
#include "compiler.h" // barrier
static inline void writel(void *addr, uint32_t val) {
barrier();
*(volatile uint32_t *)addr = val;
}
static inline void writew(void *addr, uint16_t val) {
barrier();
*(volatile uint16_t *)addr = val;
}
static inline void writeb(void *addr, uint8_t val) {
barrier();
*(volatile uint8_t *)addr = val;
}
static inline uint32_t readl(const void *addr) {
return *(volatile const uint32_t *)addr;
uint32_t val = *(volatile const uint32_t *)addr;
barrier();
return val;
}
static inline uint16_t readw(const void *addr) {
return *(volatile const uint16_t *)addr;
uint16_t val = *(volatile const uint16_t *)addr;
barrier();
return val;
}
static inline uint8_t readb(const void *addr) {
return *(volatile const uint8_t *)addr;
uint8_t val = *(volatile const uint8_t *)addr;
barrier();
return val;
}
#endif // io.h

View File

@ -131,12 +131,10 @@ console_get_output(uint8_t len)
return NULL;
// Disable TX irq and move buffer
writeb(&transmit_max, 0);
barrier();
tpos = readb(&transmit_pos);
tmax -= tpos;
memmove(&transmit_buf[0], &transmit_buf[tpos], tmax);
writeb(&transmit_pos, 0);
barrier();
writeb(&transmit_max, tmax);
enable_tx_irq();
return &transmit_buf[tmax];
@ -146,7 +144,6 @@ console_get_output(uint8_t len)
void
console_push_output(uint8_t len)
{
barrier();
writeb(&transmit_max, readb(&transmit_max) + len);
enable_tx_irq();
}