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dma/rc4030: create custom DMA address space
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Add a new memory region in system address space where DMA address space
definition (the 'translation table') belongs, so we can update on the fly
the DMA address space.

Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
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@hpoussin
hpoussin authored and Leon Alrae committed Jun 11, 2015
1 parent 9b1d21c commit a3d586f
Showing 1 changed file with 126 additions and 37 deletions.
163 changes: 126 additions & 37 deletions hw/dma/rc4030.c
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Expand Up @@ -25,6 +25,7 @@
#include "hw/hw.h"
#include "hw/mips/mips.h"
#include "qemu/timer.h"
#include "exec/address-spaces.h"

/********************************************************/
/* debug rc4030 */
Expand All @@ -47,6 +48,8 @@ do { fprintf(stderr, "rc4030 ERROR: %s: " fmt, __func__ , ## __VA_ARGS__); } whi
/********************************************************/
/* rc4030 emulation */

#define MAX_TL_ENTRIES 512

typedef struct dma_pagetable_entry {
int32_t frame;
int32_t owner;
Expand Down Expand Up @@ -96,6 +99,16 @@ typedef struct rc4030State
qemu_irq timer_irq;
qemu_irq jazz_bus_irq;

/* biggest translation table */
MemoryRegion dma_tt;
/* translation table memory region alias, added to system RAM */
MemoryRegion dma_tt_alias;
/* whole DMA memory region, root of DMA address space */
MemoryRegion dma_mr;
/* translation table entry aliases, added to DMA memory region */
MemoryRegion dma_mrs[MAX_TL_ENTRIES];
AddressSpace dma_as;

MemoryRegion iomem_chipset;
MemoryRegion iomem_jazzio;
} rc4030State;
Expand Down Expand Up @@ -265,6 +278,97 @@ static uint32_t rc4030_readb(void *opaque, hwaddr addr)
return (v >> (8 * (addr & 0x3))) & 0xff;
}

static void rc4030_dma_as_update_one(rc4030State *s, int index, uint32_t frame)
{
if (index < MAX_TL_ENTRIES) {
memory_region_set_enabled(&s->dma_mrs[index], false);
}

if (!frame) {
return;
}

if (index >= MAX_TL_ENTRIES) {
qemu_log_mask(LOG_UNIMP,
"rc4030: trying to use too high "
"translation table entry %d (max allowed=%d)",
index, MAX_TL_ENTRIES);
return;
}
memory_region_set_alias_offset(&s->dma_mrs[index], frame);
memory_region_set_enabled(&s->dma_mrs[index], true);
}

static void rc4030_dma_tt_write(void *opaque, hwaddr addr, uint64_t data,
unsigned int size)
{
rc4030State *s = opaque;

/* write memory */
memcpy(memory_region_get_ram_ptr(&s->dma_tt) + addr, &data, size);

/* update dma address space (only if frame field has been written) */
if (addr % sizeof(dma_pagetable_entry) == 0) {
int index = addr / sizeof(dma_pagetable_entry);
memory_region_transaction_begin();
rc4030_dma_as_update_one(s, index, (uint32_t)data);
memory_region_transaction_commit();
}
}

static const MemoryRegionOps rc4030_dma_tt_ops = {
.write = rc4030_dma_tt_write,
.impl.min_access_size = 4,
.impl.max_access_size = 4,
};

static void rc4030_dma_tt_update(rc4030State *s, uint32_t new_tl_base,
uint32_t new_tl_limit)
{
int entries, i;
dma_pagetable_entry *dma_tl_contents;

if (s->dma_tl_limit) {
/* write old dma tl table to physical memory */
memory_region_del_subregion(get_system_memory(), &s->dma_tt_alias);
cpu_physical_memory_write(s->dma_tl_limit & 0x7fffffff,
memory_region_get_ram_ptr(&s->dma_tt),
memory_region_size(&s->dma_tt_alias));
}
object_unparent(OBJECT(&s->dma_tt_alias));

s->dma_tl_base = new_tl_base;
s->dma_tl_limit = new_tl_limit;
new_tl_base &= 0x7fffffff;

if (s->dma_tl_limit) {
uint64_t dma_tt_size;
if (s->dma_tl_limit <= memory_region_size(&s->dma_tt)) {
dma_tt_size = s->dma_tl_limit;
} else {
dma_tt_size = memory_region_size(&s->dma_tt);
}
memory_region_init_alias(&s->dma_tt_alias, NULL,
"dma-table-alias",
&s->dma_tt, 0, dma_tt_size);
dma_tl_contents = memory_region_get_ram_ptr(&s->dma_tt);
cpu_physical_memory_read(new_tl_base, dma_tl_contents, dma_tt_size);

memory_region_transaction_begin();
entries = dma_tt_size / sizeof(dma_pagetable_entry);
for (i = 0; i < entries; i++) {
rc4030_dma_as_update_one(s, i, dma_tl_contents[i].frame);
}
memory_region_add_subregion(get_system_memory(), new_tl_base,
&s->dma_tt_alias);
memory_region_transaction_commit();
} else {
memory_region_init(&s->dma_tt_alias, NULL,
"dma-table-alias", 0);
}
}


static void rc4030_writel(void *opaque, hwaddr addr, uint32_t val)
{
rc4030State *s = opaque;
Expand All @@ -279,11 +383,11 @@ static void rc4030_writel(void *opaque, hwaddr addr, uint32_t val)
break;
/* DMA transl. table base */
case 0x0018:
s->dma_tl_base = val;
rc4030_dma_tt_update(s, val, s->dma_tl_limit);
break;
/* DMA transl. table limit */
case 0x0020:
s->dma_tl_limit = val;
rc4030_dma_tt_update(s, s->dma_tl_base, val);
break;
/* DMA transl. table invalidated */
case 0x0028:
Expand Down Expand Up @@ -590,7 +694,7 @@ static void rc4030_reset(void *opaque)
s->invalid_address_register = 0;

memset(s->dma_regs, 0, sizeof(s->dma_regs));
s->dma_tl_base = s->dma_tl_limit = 0;
rc4030_dma_tt_update(s, 0, 0);

s->remote_failed_address = s->memory_failed_address = 0;
s->cache_maint = 0;
Expand Down Expand Up @@ -675,39 +779,8 @@ static void rc4030_save(QEMUFile *f, void *opaque)
void rc4030_dma_memory_rw(void *opaque, hwaddr addr, uint8_t *buf, int len, int is_write)
{
rc4030State *s = opaque;
hwaddr entry_addr;
hwaddr phys_addr;
dma_pagetable_entry entry;
int index;
int ncpy, i;

i = 0;
for (;;) {
if (i == len) {
break;
}

ncpy = DMA_PAGESIZE - (addr & (DMA_PAGESIZE - 1));
if (ncpy > len - i)
ncpy = len - i;

/* Get DMA translation table entry */
index = addr / DMA_PAGESIZE;
if (index >= s->dma_tl_limit / sizeof(dma_pagetable_entry)) {
break;
}
entry_addr = s->dma_tl_base + index * sizeof(dma_pagetable_entry);
/* XXX: not sure. should we really use only lowest bits? */
entry_addr &= 0x7fffffff;
cpu_physical_memory_read(entry_addr, &entry, sizeof(entry));

/* Read/write data at right place */
phys_addr = entry.frame + (addr & (DMA_PAGESIZE - 1));
cpu_physical_memory_rw(phys_addr, &buf[i], ncpy, is_write);

i += ncpy;
addr += ncpy;
}
address_space_rw(&s->dma_as, addr, MEMTXATTRS_UNSPECIFIED, buf, len,
is_write);
}

static void rc4030_do_dma(void *opaque, int n, uint8_t *buf, int len, int is_write)
Expand All @@ -733,7 +806,8 @@ static void rc4030_do_dma(void *opaque, int n, uint8_t *buf, int len, int is_wri
dma_addr = s->dma_regs[n][DMA_REG_ADDRESS];

/* Read/write data at right place */
rc4030_dma_memory_rw(opaque, dma_addr, buf, len, is_write);
address_space_rw(&s->dma_as, dma_addr, MEMTXATTRS_UNSPECIFIED,
buf, len, is_write);

s->dma_regs[n][DMA_REG_ENABLE] |= DMA_FLAG_TC_INTR;
s->dma_regs[n][DMA_REG_COUNT] -= len;
Expand Down Expand Up @@ -800,6 +874,7 @@ void *rc4030_init(qemu_irq timer, qemu_irq jazz_bus,
MemoryRegion *sysmem)
{
rc4030State *s;
int i;

s = g_malloc0(sizeof(rc4030State));

Expand All @@ -821,5 +896,19 @@ void *rc4030_init(qemu_irq timer, qemu_irq jazz_bus,
"rc4030.jazzio", 0x00001000);
memory_region_add_subregion(sysmem, 0xf0000000, &s->iomem_jazzio);

memory_region_init_rom_device(&s->dma_tt, NULL,
&rc4030_dma_tt_ops, s, "dma-table",
MAX_TL_ENTRIES * sizeof(dma_pagetable_entry),
NULL);
memory_region_init(&s->dma_tt_alias, NULL, "dma-table-alias", 0);
memory_region_init(&s->dma_mr, NULL, "dma", INT32_MAX);
for (i = 0; i < MAX_TL_ENTRIES; ++i) {
memory_region_init_alias(&s->dma_mrs[i], NULL, "dma-alias",
get_system_memory(), 0, DMA_PAGESIZE);
memory_region_set_enabled(&s->dma_mrs[i], false);
memory_region_add_subregion(&s->dma_mr, i * DMA_PAGESIZE,
&s->dma_mrs[i]);
}
address_space_init(&s->dma_as, &s->dma_mr, "rc4030-dma");
return s;
}

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