[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v7 03/12] register: Add Memory API glue
From: |
Peter Maydell |
Subject: |
Re: [Qemu-devel] [PATCH v7 03/12] register: Add Memory API glue |
Date: |
Thu, 23 Jun 2016 13:21:02 +0100 |
On 22 June 2016 at 21:23, Alistair Francis <address@hidden> wrote:
> Add memory io handlers that glue the register API to the memory API.
> Just translation functions at this stage. Although it does allow for
> devices to be created without all-in-one mmio r/w handlers.
>
> This patch also adds the RegisterInfoArray struct, which allows all of
> the individual RegisterInfo structs to be grouped into a single memory
> region.
>
> Signed-off-by: Peter Crosthwaite <address@hidden>
> Signed-off-by: Alistair Francis <address@hidden>
> ---
> V7:
> - Remove endianess handling
> - Remove assert() and log missing registers
> V6:
> - Add the memory region later
> V5:
> - Convert to using only one memory region
>
> hw/core/register.c | 58
> +++++++++++++++++++++++++++++++++++++++++++++++++++
> include/hw/register.h | 43 ++++++++++++++++++++++++++++++++++++++
> 2 files changed, 101 insertions(+)
>
> diff --git a/hw/core/register.c b/hw/core/register.c
> index cc067f1..149aebb 100644
> --- a/hw/core/register.c
> +++ b/hw/core/register.c
> @@ -154,3 +154,61 @@ void register_reset(RegisterInfo *reg)
>
> register_write_val(reg, reg->access->reset);
> }
> +
> +void register_write_memory(void *opaque, hwaddr addr,
> + uint64_t value, unsigned size)
> +{
> + RegisterInfoArray *reg_array = opaque;
> + RegisterInfo *reg = NULL;
> + uint64_t we = ~0;
Really ~0 and not ~0ULL ? In any case this shouldn't need
initializing as we will always set it later.
> + int i;
> +
> + for (i = 0; i < reg_array->num_elements; i++) {
> + if (reg_array->r[i]->access->addr == addr) {
> + reg = reg_array->r[i];
> + break;
> + }
> + }
> +
> + if (!reg) {
> + qemu_log_mask(LOG_UNIMP, "Write to unimplemented register at " \
> + "address: %#" PRIx64 "\n", addr);
Shouldn't this be a LOG_GUEST_ERROR ?
> + return;
> + }
> +
> + /* Generate appropriate write enable mask */
> + if (reg->data_size < size) {
> + we = MAKE_64BIT_MASK(0, reg->data_size * 8);
> + } else if (reg->data_size >= size) {
Why not just "else {" ?
> + we = MAKE_64BIT_MASK(0, size * 8);
> + }
> +
> + register_write(reg, value, we, reg_array->prefix,
> + reg_array->debug);
> +}
> +
> +uint64_t register_read_memory(void *opaque, hwaddr addr,
> + unsigned size)
> +{
> + RegisterInfoArray *reg_array = opaque;
> + RegisterInfo *reg = NULL;
> + uint64_t read_val;
> + int i;
> +
> + for (i = 0; i < reg_array->num_elements; i++) {
> + if (reg_array->r[i]->access->addr == addr) {
> + reg = reg_array->r[i];
> + break;
> + }
> + }
> +
> + if (!reg) {
> + qemu_log_mask(LOG_UNIMP, "Read to unimplemented register at " \
> + "address: %#" PRIx64 "\n", addr);
> + return 0;
> + }
> +
> + read_val = register_read(reg, reg_array->prefix, reg_array->debug);
This will silently affect bits of the register outside the
specified size with clear-on-read or other "reads have
side effects" behaviour, which isn't consistent with how
we handle writes.
> /**
> + * This structure is used to group all of the individual registers which are
> + * modeled using the RegisterInfo strucutre.
"structure"
> + *
> + * @r is an aray containing of all the relevent RegisterInfo structures.
> + *
> + * @num_elements is the number of elements in the array r
> + *
> + * @mem: optional Memory region for the register
> + */
> +
> +struct RegisterInfoArray {
> + int num_elements;
> + RegisterInfo **r;
> +
> + bool debug;
> + const char *prefix;
> +};
> +
thanks
-- PMM