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DMA memset

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Added DMA implementation of memset and bypass for transfers smaller than 64 bytes.
This commit is contained in:
David Kuder 2023-04-18 15:32:38 -04:00
parent 0a23cd3eff
commit 2176303980
2 changed files with 44 additions and 1 deletions
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43
common/dmacopy.c
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@ -11,7 +11,7 @@ void __noinline memcpy32(void *dst, void *src, uint32_t size) {
if(!size) return;
// Cowardly avoid unaligned transfers, let memcpy() handle them.
if((size & 0x3) || (((uint32_t)dst) & 0x3) || (((uint32_t)src) & 0x3)) {
if((size < 64) || (size & 0x3) || (((uint32_t)dst) & 0x3) || (((uint32_t)src) & 0x3)) {
memcpy(dst, src, size);
return;
}
@ -42,6 +42,47 @@ void __noinline memcpy32(void *dst, void *src, uint32_t size) {
channel_config_set_write_increment(&c, false);
}
void __noinline memset32(void *dst, uint8_t val, uint32_t size) {
dma_channel_config c;
uint32_t src = val;
src |= src << 8;
src |= src << 16;
// Nothing to do!
if(!size) return;
// Cowardly avoid unaligned transfers, let memset() handle them.
if((size < 64) || (size & 0x3) || (((uint32_t)dst) & 0x3)) {
memset(dst, val, size);
return;
}
// 32 bit transfers. Write address increments after each
// transfer (pointing to a location in dst).
// No DREQ is selected, so the DMA transfers as fast as it can.
// Get a free channel, panic() if there are none
if(dmacopy_channel == -1)
dmacopy_channel = dma_claim_unused_channel(true);
c = dma_channel_get_default_config(dmacopy_channel);
channel_config_set_transfer_data_size(&c, DMA_SIZE_32);
channel_config_set_read_increment(&c, false);
channel_config_set_write_increment(&c, true);
dma_channel_configure(dmacopy_channel, &c, dst, &src, (size >> 2), true);
dma_channel_wait_for_finish_blocking(dmacopy_channel);
dma_channel_abort(dmacopy_channel);
// Deinit the DMA channel
c = dma_channel_get_default_config(dmacopy_channel);
dma_channel_configure(dmacopy_channel, &c, NULL, NULL, 0, false);
channel_config_set_read_increment(&c, false);
channel_config_set_write_increment(&c, false);
}
void __noinline dmacpy32(void *start, void *end, void *source) {
uint32_t size = ((uint32_t)end) - ((uint32_t)start);

2
common/dmacopy.h
View File

@ -2,3 +2,5 @@
void memcpy32(void *dst, void *src, uint32_t size);
void dmacpy32(void *start, void *end, void *source);
void __noinline memset32(void *dst, uint8_t val, uint32_t size);