Re: [PATCH] hw/sd/allwinner-sdhost: Use AddressSpace for DMA transfers

On Fri, Aug 14, 2020 at 1:01 PM Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:

Allow the device to execute the DMA transfers in a different
AddressSpace.

The A10 and H3 SoC keep using the system_memory address space,
but via the proper dma_memory_access() API.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
Based-on: <20200814092346.21825-1-f4bug@amsat.org" target="_blank">20200814092346.21825-1-f4bug@amsat.org>
"hw/sd: Use sdbus_read_data/sdbus_write_data for multiple bytes access"

Tested with:
AVOCADO_ALLOW_LARGE_STORAGE=1 avocado run -t machine:orangepi-pc -t machine:cubieboard tests/acceptance/
---
include/hw/sd/allwinner-sdhost.h | 6 ++++++
hw/arm/allwinner-a10.c | 2 ++
hw/arm/allwinner-h3.c | 2 ++
hw/sd/allwinner-sdhost.c | 37 ++++++++++++++++++++++++++------
4 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/include/hw/sd/allwinner-sdhost.h b/include/hw/sd/allwinner-sdhost.h
index d94606a853..839732ebf3 100644
--- a/include/hw/sd/allwinner-sdhost.h
+++ b/include/hw/sd/allwinner-sdhost.h
@@ -71,6 +71,12 @@ typedef struct AwSdHostState {
/** Interrupt output signal to notify CPU */
qemu_irq irq;

+ /** Memory region where DMA transfers are done */
+ MemoryRegion *dma_mr;
+
+ /** Address space used internally for DMA transfers */
+ AddressSpace dma_as;
+
/** Number of bytes left in current DMA transfer */
uint32_t transfer_cnt;

diff --git a/hw/arm/allwinner-a10.c b/hw/arm/allwinner-a10.c
index e258463747..d404f31e02 100644
--- a/hw/arm/allwinner-a10.c
+++ b/hw/arm/allwinner-a10.c
@@ -155,6 +155,8 @@ static void aw_a10_realize(DeviceState *dev, Error **errp)
}

/* SD/MMC */
+ object_property_set_link(OBJECT(&s->mmc0), "dma-memory",
+ OBJECT(get_system_memory()), &error_fatal);
sysbus_realize(SYS_BUS_DEVICE(&s->mmc0), &error_fatal);
sysbus_mmio_map(SYS_BUS_DEVICE(&s->mmc0), 0, AW_A10_MMC0_BASE);
sysbus_connect_irq(SYS_BUS_DEVICE(&s->mmc0), 0, qdev_get_gpio_in(dev, 32));
diff --git a/hw/arm/allwinner-h3.c b/hw/arm/allwinner-h3.c
index ff92ded82c..43a8d3dc48 100644
--- a/hw/arm/allwinner-h3.c
+++ b/hw/arm/allwinner-h3.c
@@ -349,6 +349,8 @@ static void allwinner_h3_realize(DeviceState *dev, Error **errp)
sysbus_mmio_map(SYS_BUS_DEVICE(&s->sid), 0, s->memmap[AW_H3_SID]);

/* SD/MMC */
+ object_property_set_link(OBJECT(&s->mmc0), "dma-memory",
+ OBJECT(get_system_memory()), &error_fatal);
sysbus_realize(SYS_BUS_DEVICE(&s->mmc0), &error_fatal);
sysbus_mmio_map(SYS_BUS_DEVICE(&s->mmc0), 0, s->memmap[AW_H3_MMC0]);
sysbus_connect_irq(SYS_BUS_DEVICE(&s->mmc0), 0,
diff --git a/hw/sd/allwinner-sdhost.c b/hw/sd/allwinner-sdhost.c
index f9eb92c09e..e82afb75eb 100644
--- a/hw/sd/allwinner-sdhost.c
+++ b/hw/sd/allwinner-sdhost.c
@@ -21,7 +21,10 @@
#include "qemu/log.h"
#include "qemu/module.h"
#include "qemu/units.h"
+#include "qapi/error.h"
#include "sysemu/blockdev.h"
+#include "sysemu/dma.h"
+#include "hw/qdev-properties.h"
#include "hw/irq.h"
#include "hw/sd/allwinner-sdhost.h"
#include "migration/vmstate.h"
@@ -306,7 +309,7 @@ static uint32_t allwinner_sdhost_process_desc(AwSdHostState *s,
uint8_t buf[1024];

/* Read descriptor */
- cpu_physical_memory_read(desc_addr, desc, sizeof(*desc));
+ dma_memory_read(&s->dma_as, desc_addr, desc, sizeof(*desc));
if (desc->size == 0) {
desc->size = klass->max_desc_size;
} else if (desc->size > klass->max_desc_size) {
@@ -331,22 +334,24 @@ static uint32_t allwinner_sdhost_process_desc(AwSdHostState *s,

/* Write to SD bus */
if (is_write) {
- cpu_physical_memory_read((desc->addr & DESC_SIZE_MASK) + num_done,
- buf, buf_bytes);
+ dma_memory_read(&s->dma_as,
+ (desc->addr & DESC_SIZE_MASK) + num_done,
+ buf, buf_bytes);
sdbus_write_data(&s->sdbus, buf, buf_bytes);

/* Read from SD bus */
} else {
sdbus_read_data(&s->sdbus, buf, buf_bytes);
- cpu_physical_memory_write((desc->addr & DESC_SIZE_MASK) + num_done,
- buf, buf_bytes);
+ dma_memory_write(&s->dma_as,
+ (desc->addr & DESC_SIZE_MASK) + num_done,
+ buf, buf_bytes);
}
num_done += buf_bytes;
}

/* Clear hold flag and flush descriptor */
desc->status &= ~DESC_STATUS_HOLD;
- cpu_physical_memory_write(desc_addr, desc, sizeof(*desc));
+ dma_memory_write(&s->dma_as, desc_addr, desc, sizeof(*desc));

return num_done;
}
@@ -721,6 +726,12 @@ static const VMStateDescription vmstate_allwinner_sdhost = {
}
};

+static Property allwinner_sdhost_properties[] = {
+ DEFINE_PROP_LINK("dma-memory", AwSdHostState, dma_mr,
+ TYPE_MEMORY_REGION, MemoryRegion *),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
static void allwinner_sdhost_init(Object *obj)
{
AwSdHostState *s = AW_SDHOST(obj);
@@ -734,6 +745,18 @@ static void allwinner_sdhost_init(Object *obj)
sysbus_init_irq(SYS_BUS_DEVICE(s), &s->irq);
}

+static void allwinner_sdhost_realize(DeviceState *dev, Error **errp)
+{
+ AwSdHostState *s = AW_SDHOST(dev);
+
+ if (!s->dma_mr) {
+ error_setg(errp, TYPE_AW_SDHOST " 'dma-memory' link not set");
+ return;
+ }
+
+ address_space_init(&s->dma_as, s->dma_mr, "sdhost-dma");
+}
+
static void allwinner_sdhost_reset(DeviceState *dev)
{
AwSdHostState *s = AW_SDHOST(dev);
@@ -792,6 +815,8 @@ static void allwinner_sdhost_class_init(ObjectClass *klass, void *data)

dc->reset = allwinner_sdhost_reset;
dc->vmsd = &vmstate_allwinner_sdhost;
+ dc->realize = allwinner_sdhost_realize;
+ device_class_set_props(dc, allwinner_sdhost_properties);
}

static void allwinner_sdhost_sun4i_class_init(ObjectClass *klass, void *data)
--
2.21.3

From:	Niek Linnenbank
Subject:	Re: [PATCH] hw/sd/allwinner-sdhost: Use AddressSpace for DMA transfers
Date:	Mon, 17 Aug 2020 20:40:01 +0200