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pflash: Buffer block writes

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Buffer block writes to avoid flushing every word access onto backing
storage device. This significantly speeds up flash emulation for flashes
connected through an 8 or 16-bit bus combined with backing storage (-pflash).

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@petalogix.com>
This commit is contained in:
Edgar E. Iglesias 2010-01-24 20:38:29 +01:00 committed by Edgar E. Iglesias
parent 625a5befc2
commit b4bf0a9a69
1 changed files with 9 additions and 3 deletions
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12
hw/pflash_cfi01.c
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@ -72,6 +72,7 @@ struct pflash_t {
uint8_t cfi_len;
uint8_t cfi_table[0x52];
target_phys_addr_t counter;
unsigned int writeblock_size;
QEMUTimer *timer;
ram_addr_t off;
int fl_mem;
@ -206,7 +207,6 @@ static inline void pflash_data_write(pflash_t *pfl, target_phys_addr_t offset,
switch (width) {
case 1:
p[offset] = value;
pflash_update(pfl, offset, 1);
break;
case 2:
#if defined(TARGET_WORDS_BIGENDIAN)
@ -216,7 +216,6 @@ static inline void pflash_data_write(pflash_t *pfl, target_phys_addr_t offset,
p[offset] = value;
p[offset + 1] = value >> 8;
#endif
pflash_update(pfl, offset, 2);
break;
case 4:
#if defined(TARGET_WORDS_BIGENDIAN)
@ -230,7 +229,6 @@ static inline void pflash_data_write(pflash_t *pfl, target_phys_addr_t offset,
p[offset + 2] = value >> 16;
p[offset + 3] = value >> 24;
#endif
pflash_update(pfl, offset, 4);
break;
}
@ -307,6 +305,7 @@ static void pflash_write(pflash_t *pfl, target_phys_addr_t offset,
case 0x40: /* Single Byte Program */
DPRINTF("%s: Single Byte Program\n", __func__);
pflash_data_write(pfl, offset, value, width);
pflash_update(pfl, offset, width);
pfl->status |= 0x80; /* Ready! */
pfl->wcycle = 0;
break;
@ -359,8 +358,13 @@ static void pflash_write(pflash_t *pfl, target_phys_addr_t offset,
pfl->status |= 0x80;
if (!pfl->counter) {
target_phys_addr_t mask = pfl->writeblock_size - 1;
mask = ~mask;
DPRINTF("%s: block write finished\n", __func__);
pfl->wcycle++;
/* Flush the entire write buffer onto backing storage. */
pflash_update(pfl, offset & mask, pfl->writeblock_size);
}
pfl->counter--;
@ -606,6 +610,8 @@ pflash_t *pflash_cfi01_register(target_phys_addr_t base, ram_addr_t off,
} else {
pfl->cfi_table[0x2A] = 0x0B;
}
pfl->writeblock_size = 1 << pfl->cfi_table[0x2A];
pfl->cfi_table[0x2B] = 0x00;
/* Number of erase block regions (uniform) */
pfl->cfi_table[0x2C] = 0x01;