Re: [Qemu-devel] [PATCH v8 04/25] tcg: move TCG_MO/BAR types into own file

[Pranith Kumar]

Alex Bennée writes:

> We'll be using the memory ordering definitions to define values for
> both the host and guest. To avoid fighting with circular header
> dependencies just move these types into their own minimal header.
>
> Signed-off-by: Alex Bennée <address@hidden>
> Reviewed-by: Richard Henderson <address@hidden>
> ---
>  tcg/tcg-mo.h | 45 +++++++++++++++++++++++++++++++++++++++++++++
>  tcg/tcg.h    | 18 +-----------------
>  2 files changed, 46 insertions(+), 17 deletions(-)
>  create mode 100644 tcg/tcg-mo.h
>
> diff --git a/tcg/tcg-mo.h b/tcg/tcg-mo.h
> new file mode 100644
> index 0000000000..429b022561
> --- /dev/null
> +++ b/tcg/tcg-mo.h
> @@ -0,0 +1,45 @@
> +/*
> + * Tiny Code Generator for QEMU
> + *
> + * Copyright (c) 2008 Fabrice Bellard
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a 
> copy
> + * of this software and associated documentation files (the "Software"), to 
> deal
> + * in the Software without restriction, including without limitation the 
> rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
> FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#ifndef TCG_MO_H
> +#define TCG_MO_H
> +
> +typedef enum {
> +    /* Used to indicate the type of accesses on which ordering
> +       is to be ensured.  Modeled after SPARC barriers.  */
> +    TCG_MO_LD_LD  = 0x01,
> +    TCG_MO_ST_LD  = 0x02,
> +    TCG_MO_LD_ST  = 0x04,
> +    TCG_MO_ST_ST  = 0x08,
> +    TCG_MO_ALL    = 0x0F,  /* OR of the above */
> +
> +    /* Used to indicate the kind of ordering which is to be ensured by the
> +       instruction.  These types are derived from x86/aarch64 instructions.
> +       It should be noted that these are different from C11 semantics.  */
> +    TCG_BAR_LDAQ  = 0x10,  /* Following ops will not come forward */
> +    TCG_BAR_STRL  = 0x20,  /* Previous ops will not be delayed */
> +    TCG_BAR_SC    = 0x30,  /* No ops cross barrier; OR of the above */
> +} TCGBar;
> +
> +#endif /* TCG_MO_H */
> diff --git a/tcg/tcg.h b/tcg/tcg.h
> index 631c6f69b1..f946452049 100644
> --- a/tcg/tcg.h
> +++ b/tcg/tcg.h
> @@ -29,6 +29,7 @@
>  #include "cpu.h"
>  #include "exec/tb-context.h"
>  #include "qemu/bitops.h"
> +#include "tcg-mo.h"
>  #include "tcg-target.h"
>  
>  /* XXX: make safe guess about sizes */
> @@ -498,23 +499,6 @@ static inline intptr_t QEMU_ARTIFICIAL 
> GET_TCGV_PTR(TCGv_ptr t)
>  #define TCG_CALL_DUMMY_TCGV     MAKE_TCGV_I32(-1)
>  #define TCG_CALL_DUMMY_ARG      ((TCGArg)(-1))
>  
> -typedef enum {
> -    /* Used to indicate the type of accesses on which ordering
> -       is to be ensured.  Modeled after SPARC barriers.  */
> -    TCG_MO_LD_LD  = 0x01,
> -    TCG_MO_ST_LD  = 0x02,
> -    TCG_MO_LD_ST  = 0x04,
> -    TCG_MO_ST_ST  = 0x08,
> -    TCG_MO_ALL    = 0x0F,  /* OR of the above */

Can you please add the following comment:

This is of the form TCG_MO_A_B where A is before B in program order.

Thanks,
-- 
Pranith