* [Qemu-devel] [PATCH v2] cpu_defs: Simplify CPUTLB padding logic
@ 2015-07-09 3:26 Peter Crosthwaite
2015-07-09 6:56 ` Richard Henderson
2015-07-09 15:04 ` Paolo Bonzini
0 siblings, 2 replies; 3+ messages in thread
From: Peter Crosthwaite @ 2015-07-09 3:26 UTC (permalink / raw)
To: qemu-devel; +Cc: pbonzini, Peter Crosthwaite, rth
There was a complicated subtractive arithmetic for determining the
padding on the CPUTLBEntry structure. Simplify this with a union.
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
---
Changed since v1:
Remove un-needed anonymous union (Paolo review)
---
include/exec/cpu-defs.h | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h
index 98b9cff..c6828cc 100644
--- a/include/exec/cpu-defs.h
+++ b/include/exec/cpu-defs.h
@@ -98,24 +98,23 @@ typedef uint64_t target_ulong;
#define CPU_TLB_SIZE (1 << CPU_TLB_BITS)
-typedef struct CPUTLBEntry {
+typedef union CPUTLBEntry {
/* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address
bit TARGET_PAGE_BITS-1..4 : Nonzero for accesses that should not
go directly to ram.
bit 3 : indicates that the entry is invalid
bit 2..0 : zero
*/
- target_ulong addr_read;
- target_ulong addr_write;
- target_ulong addr_code;
- /* Addend to virtual address to get host address. IO accesses
- use the corresponding iotlb value. */
- uintptr_t addend;
+ struct {
+ target_ulong addr_read;
+ target_ulong addr_write;
+ target_ulong addr_code;
+ /* Addend to virtual address to get host address. IO accesses
+ use the corresponding iotlb value. */
+ uintptr_t addend;
+ };
/* padding to get a power of two size */
- uint8_t dummy[(1 << CPU_TLB_ENTRY_BITS) -
- (sizeof(target_ulong) * 3 +
- ((-sizeof(target_ulong) * 3) & (sizeof(uintptr_t) - 1)) +
- sizeof(uintptr_t))];
+ uint8_t dummy[1 << CPU_TLB_ENTRY_BITS];
} CPUTLBEntry;
QEMU_BUILD_BUG_ON(sizeof(CPUTLBEntry) != (1 << CPU_TLB_ENTRY_BITS));
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH v2] cpu_defs: Simplify CPUTLB padding logic
2015-07-09 3:26 [Qemu-devel] [PATCH v2] cpu_defs: Simplify CPUTLB padding logic Peter Crosthwaite
@ 2015-07-09 6:56 ` Richard Henderson
2015-07-09 15:04 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Richard Henderson @ 2015-07-09 6:56 UTC (permalink / raw)
To: Peter Crosthwaite, qemu-devel; +Cc: pbonzini, Peter Crosthwaite
On 07/09/2015 04:26 AM, Peter Crosthwaite wrote:
> There was a complicated subtractive arithmetic for determining the
> padding on the CPUTLBEntry structure. Simplify this with a union.
>
> Signed-off-by: Peter Crosthwaite<crosthwaite.peter@gmail.com>
> ---
> Changed since v1:
> Remove un-needed anonymous union (Paolo review)
> ---
> include/exec/cpu-defs.h | 21 ++++++++++-----------
> 1 file changed, 10 insertions(+), 11 deletions(-)
Reviewed-by: Richard Henderson <rth@twiddle.net>
r~
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH v2] cpu_defs: Simplify CPUTLB padding logic
2015-07-09 3:26 [Qemu-devel] [PATCH v2] cpu_defs: Simplify CPUTLB padding logic Peter Crosthwaite
2015-07-09 6:56 ` Richard Henderson
@ 2015-07-09 15:04 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Paolo Bonzini @ 2015-07-09 15:04 UTC (permalink / raw)
To: Peter Crosthwaite, qemu-devel; +Cc: Peter Crosthwaite, rth
On 09/07/2015 05:26, Peter Crosthwaite wrote:
> There was a complicated subtractive arithmetic for determining the
> padding on the CPUTLBEntry structure. Simplify this with a union.
>
> Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
> ---
> Changed since v1:
> Remove un-needed anonymous union (Paolo review)
> ---
> include/exec/cpu-defs.h | 21 ++++++++++-----------
> 1 file changed, 10 insertions(+), 11 deletions(-)
>
> diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h
> index 98b9cff..c6828cc 100644
> --- a/include/exec/cpu-defs.h
> +++ b/include/exec/cpu-defs.h
> @@ -98,24 +98,23 @@ typedef uint64_t target_ulong;
>
> #define CPU_TLB_SIZE (1 << CPU_TLB_BITS)
>
> -typedef struct CPUTLBEntry {
> +typedef union CPUTLBEntry {
> /* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address
> bit TARGET_PAGE_BITS-1..4 : Nonzero for accesses that should not
> go directly to ram.
> bit 3 : indicates that the entry is invalid
> bit 2..0 : zero
> */
> - target_ulong addr_read;
> - target_ulong addr_write;
> - target_ulong addr_code;
> - /* Addend to virtual address to get host address. IO accesses
> - use the corresponding iotlb value. */
> - uintptr_t addend;
> + struct {
> + target_ulong addr_read;
> + target_ulong addr_write;
> + target_ulong addr_code;
> + /* Addend to virtual address to get host address. IO accesses
> + use the corresponding iotlb value. */
> + uintptr_t addend;
> + };
> /* padding to get a power of two size */
> - uint8_t dummy[(1 << CPU_TLB_ENTRY_BITS) -
> - (sizeof(target_ulong) * 3 +
> - ((-sizeof(target_ulong) * 3) & (sizeof(uintptr_t) - 1)) +
> - sizeof(uintptr_t))];
> + uint8_t dummy[1 << CPU_TLB_ENTRY_BITS];
> } CPUTLBEntry;
>
> QEMU_BUILD_BUG_ON(sizeof(CPUTLBEntry) != (1 << CPU_TLB_ENTRY_BITS));
>
Thanks, queued for 2.5.
Paolo
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2015-07-09 15:04 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-07-09 3:26 [Qemu-devel] [PATCH v2] cpu_defs: Simplify CPUTLB padding logic Peter Crosthwaite
2015-07-09 6:56 ` Richard Henderson
2015-07-09 15:04 ` Paolo Bonzini
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.