Peter Maydell <peter.mayd...@linaro.org> writes:
> Instead of the bitband device doing a cpu_physical_memory_read/write,
> make it take a MemoryRegion which specifies where it should be
> accessing, and use address_space_read/write to access the
> corresponding AddressSpace.
>
> Since this entails pretty much a rewrite, convert away from
> old_mmio in the process.
>
> Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
Reviewed-by: Alex Bennée <alex.ben...@linaro.org>
> ---
> include/hw/arm/armv7m.h | 2 +
> hw/arm/armv7m.c | 166
> +++++++++++++++++++++++-------------------------
> 2 files changed, 81 insertions(+), 87 deletions(-)
>
> diff --git a/include/hw/arm/armv7m.h b/include/hw/arm/armv7m.h
> index 3333c91..a9b3f2a 100644
> --- a/include/hw/arm/armv7m.h
> +++ b/include/hw/arm/armv7m.h
> @@ -21,8 +21,10 @@ typedef struct {
> SysBusDevice parent_obj;
> /*< public >*/
>
> + AddressSpace *source_as;
> MemoryRegion iomem;
> uint32_t base;
> + MemoryRegion *source_memory;
> } BitBandState;
>
> #define TYPE_ARMV7M "armv7m"
> diff --git a/hw/arm/armv7m.c b/hw/arm/armv7m.c
> index fb21f74..4481106 100644
> --- a/hw/arm/armv7m.c
> +++ b/hw/arm/armv7m.c
> @@ -23,103 +23,73 @@
> /* Bitbanded IO. Each word corresponds to a single bit. */
>
> /* Get the byte address of the real memory for a bitband access. */
> -static inline uint32_t bitband_addr(void * opaque, uint32_t addr)
> +static inline hwaddr bitband_addr(BitBandState *s, hwaddr offset)
> {
> - uint32_t res;
> -
> - res = *(uint32_t *)opaque;
> - res |= (addr & 0x1ffffff) >> 5;
> - return res;
> -
> -}
> -
> -static uint32_t bitband_readb(void *opaque, hwaddr offset)
> -{
> - uint8_t v;
> - cpu_physical_memory_read(bitband_addr(opaque, offset), &v, 1);
> - return (v & (1 << ((offset >> 2) & 7))) != 0;
> -}
> -
> -static void bitband_writeb(void *opaque, hwaddr offset,
> - uint32_t value)
> -{
> - uint32_t addr;
> - uint8_t mask;
> - uint8_t v;
> - addr = bitband_addr(opaque, offset);
> - mask = (1 << ((offset >> 2) & 7));
> - cpu_physical_memory_read(addr, &v, 1);
> - if (value & 1)
> - v |= mask;
> - else
> - v &= ~mask;
> - cpu_physical_memory_write(addr, &v, 1);
> -}
> -
> -static uint32_t bitband_readw(void *opaque, hwaddr offset)
> -{
> - uint32_t addr;
> - uint16_t mask;
> - uint16_t v;
> - addr = bitband_addr(opaque, offset) & ~1;
> - mask = (1 << ((offset >> 2) & 15));
> - mask = tswap16(mask);
> - cpu_physical_memory_read(addr, &v, 2);
> - return (v & mask) != 0;
> -}
> -
> -static void bitband_writew(void *opaque, hwaddr offset,
> - uint32_t value)
> -{
> - uint32_t addr;
> - uint16_t mask;
> - uint16_t v;
> - addr = bitband_addr(opaque, offset) & ~1;
> - mask = (1 << ((offset >> 2) & 15));
> - mask = tswap16(mask);
> - cpu_physical_memory_read(addr, &v, 2);
> - if (value & 1)
> - v |= mask;
> - else
> - v &= ~mask;
> - cpu_physical_memory_write(addr, &v, 2);
> + return s->base | (offset & 0x1ffffff) >> 5;
> }
>
> -static uint32_t bitband_readl(void *opaque, hwaddr offset)
> +static MemTxResult bitband_read(void *opaque, hwaddr offset,
> + uint64_t *data, unsigned size, MemTxAttrs
> attrs)
> {
> - uint32_t addr;
> - uint32_t mask;
> - uint32_t v;
> - addr = bitband_addr(opaque, offset) & ~3;
> - mask = (1 << ((offset >> 2) & 31));
> - mask = tswap32(mask);
> - cpu_physical_memory_read(addr, &v, 4);
> - return (v & mask) != 0;
> + BitBandState *s = opaque;
> + uint8_t buf[4];
> + MemTxResult res;
> + int bitpos, bit;
> + hwaddr addr;
> +
> + assert(size <= 4);
> +
> + /* Find address in underlying memory and round down to multiple of size
> */
> + addr = bitband_addr(s, offset) & (-size);
> + res = address_space_read(s->source_as, addr, attrs, buf, size);
> + if (res) {
> + return res;
> + }
> + /* Bit position in the N bytes read... */
> + bitpos = (offset >> 2) & ((size * 8) - 1);
> + /* ...converted to byte in buffer and bit in byte */
> + bit = (buf[bitpos >> 3] >> (bitpos & 7)) & 1;
> + *data = bit;
> + return MEMTX_OK;
> }
>
> -static void bitband_writel(void *opaque, hwaddr offset,
> - uint32_t value)
> +static MemTxResult bitband_write(void *opaque, hwaddr offset, uint64_t value,
> + unsigned size, MemTxAttrs attrs)
> {
> - uint32_t addr;
> - uint32_t mask;
> - uint32_t v;
> - addr = bitband_addr(opaque, offset) & ~3;
> - mask = (1 << ((offset >> 2) & 31));
> - mask = tswap32(mask);
> - cpu_physical_memory_read(addr, &v, 4);
> - if (value & 1)
> - v |= mask;
> - else
> - v &= ~mask;
> - cpu_physical_memory_write(addr, &v, 4);
> + BitBandState *s = opaque;
> + uint8_t buf[4];
> + MemTxResult res;
> + int bitpos, bit;
> + hwaddr addr;
> +
> + assert(size <= 4);
> +
> + /* Find address in underlying memory and round down to multiple of size
> */
> + addr = bitband_addr(s, offset) & (-size);
> + res = address_space_read(s->source_as, addr, attrs, buf, size);
> + if (res) {
> + return res;
> + }
> + /* Bit position in the N bytes read... */
> + bitpos = (offset >> 2) & ((size * 8) - 1);
> + /* ...converted to byte in buffer and bit in byte */
> + bit = 1 << (bitpos & 7);
> + if (value & 1) {
> + buf[bitpos >> 3] |= bit;
> + } else {
> + buf[bitpos >> 3] &= ~bit;
> + }
> + return address_space_write(s->source_as, addr, attrs, buf, size);
> }
>
> static const MemoryRegionOps bitband_ops = {
> - .old_mmio = {
> - .read = { bitband_readb, bitband_readw, bitband_readl, },
> - .write = { bitband_writeb, bitband_writew, bitband_writel, },
> - },
> + .read_with_attrs = bitband_read,
> + .write_with_attrs = bitband_write,
> .endianness = DEVICE_NATIVE_ENDIAN,
> + .impl.min_access_size = 1,
> + .impl.max_access_size = 4,
> + .valid.min_access_size = 1,
> + .valid.max_access_size = 4,
> };
>
> static void bitband_init(Object *obj)
> @@ -127,11 +97,30 @@ static void bitband_init(Object *obj)
> BitBandState *s = BITBAND(obj);
> SysBusDevice *dev = SYS_BUS_DEVICE(obj);
>
> - memory_region_init_io(&s->iomem, obj, &bitband_ops, &s->base,
> + object_property_add_link(obj, "source-memory",
> + TYPE_MEMORY_REGION,
> + (Object **)&s->source_memory,
> + qdev_prop_allow_set_link_before_realize,
> + OBJ_PROP_LINK_UNREF_ON_RELEASE,
> + &error_abort);
> + memory_region_init_io(&s->iomem, obj, &bitband_ops, s,
> "bitband", 0x02000000);
> sysbus_init_mmio(dev, &s->iomem);
> }
>
> +static void bitband_realize(DeviceState *dev, Error **errp)
> +{
> + BitBandState *s = BITBAND(dev);
> +
> + if (!s->source_memory) {
> + error_setg(errp, "source-memory property not set");
> + return;
> + }
> +
> + s->source_as = address_space_init_shareable(s->source_memory,
> + "bitband-source");
> +}
> +
> /* Board init. */
>
> static const hwaddr bitband_input_addr[ARMV7M_NUM_BITBANDS] = {
> @@ -251,6 +240,8 @@ static void armv7m_realize(DeviceState *dev, Error **errp)
> error_propagate(errp, err);
> return;
> }
> + object_property_set_link(obj, OBJECT(s->board_memory),
> + "source-memory", &error_abort);
> object_property_set_bool(obj, true, "realized", &err);
> if (err != NULL) {
> error_propagate(errp, err);
> @@ -366,6 +357,7 @@ static void bitband_class_init(ObjectClass *klass, void
> *data)
> {
> DeviceClass *dc = DEVICE_CLASS(klass);
>
> + dc->realize = bitband_realize;
> dc->props = bitband_properties;
> }
--
Alex Bennée
