diff mbox series

[v5,13/15] cputlb: Byte swap memory transaction attribute

Message ID 1564123712210.75919@bt.com
State New
Headers show
Series Invert Endian bit in SPARCv9 MMU TTE | expand

Commit Message

Tony Nguyen July 26, 2019, 6:48 a.m. UTC
Notice new attribute, byte swap, and force the transaction through the
memory slow path.

Required by architectures that can invert endianness of memory
transaction, e.g. SPARC64 has the Invert Endian TTE bit.

Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
---
 accel/tcg/cputlb.c      | 11 +++++++++++
 include/exec/memattrs.h |  2 ++
 2 files changed, 13 insertions(+)

--
1.8.3.1

Comments

Richard Henderson July 26, 2019, 2:52 p.m. UTC | #1
On 7/25/19 11:48 PM, tony.nguyen@bt.com wrote:
> Notice new attribute, byte swap, and force the transaction through the
> memory slow path.
> 
> Required by architectures that can invert endianness of memory
> transaction, e.g. SPARC64 has the Invert Endian TTE bit.
> 
> Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
> ---
>  accel/tcg/cputlb.c      | 11 +++++++++++
>  include/exec/memattrs.h |  2 ++
>  2 files changed, 13 insertions(+)
> 
> diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
> index e61b1eb..f292a87 100644
> --- a/accel/tcg/cputlb.c
> +++ b/accel/tcg/cputlb.c
> @@ -738,6 +738,9 @@ void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
>           */
>          address |= TLB_RECHECK;
>      }
> +    if (attrs.byte_swap) {
> +        address |= TLB_FORCE_SLOW;
> +    }
>      if (!memory_region_is_ram(section->mr) &&
>          !memory_region_is_romd(section->mr)) {
>          /* IO memory case */
> @@ -891,6 +894,10 @@ static uint64_t io_readx(CPUArchState *env, CPUIOTLBEntry *iotlbentry,
>      bool locked = false;
>      MemTxResult r;
> 
> +    if (iotlbentry->attrs.byte_swap) {
> +        op ^= MO_BSWAP;
> +    }
> +
>      section = iotlb_to_section(cpu, iotlbentry->addr, iotlbentry->attrs);
>      mr = section->mr;
>      mr_offset = (iotlbentry->addr & TARGET_PAGE_MASK) + addr;
> @@ -933,6 +940,10 @@ static void io_writex(CPUArchState *env, CPUIOTLBEntry *iotlbentry,
>      bool locked = false;
>      MemTxResult r;
> 
> +    if (iotlbentry->attrs.byte_swap) {
> +        op ^= MO_BSWAP;
> +    }
> +
>      section = iotlb_to_section(cpu, iotlbentry->addr, iotlbentry->attrs);
>      mr = section->mr;
>      mr_offset = (iotlbentry->addr & TARGET_PAGE_MASK) + addr;
> diff --git a/include/exec/memattrs.h b/include/exec/memattrs.h
> index d4a3477..a0644eb 100644
> --- a/include/exec/memattrs.h
> +++ b/include/exec/memattrs.h
> @@ -37,6 +37,8 @@ typedef struct MemTxAttrs {
>      unsigned int user:1;
>      /* Requester ID (for MSI for example) */
>      unsigned int requester_id:16;
> +    /* SPARC64: TTE invert endianness */
> +    unsigned int byte_swap:1;

Don't mention Sparc here, otherwise it seems like it only applies to Sparc,
when it is really a generic feature only currently used by Sparc.

Just say "Invert endianness for this page".

With that,

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~
diff mbox series

Patch

diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index e61b1eb..f292a87 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -738,6 +738,9 @@  void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
          */
         address |= TLB_RECHECK;
     }
+    if (attrs.byte_swap) {
+        address |= TLB_FORCE_SLOW;
+    }
     if (!memory_region_is_ram(section->mr) &&
         !memory_region_is_romd(section->mr)) {
         /* IO memory case */
@@ -891,6 +894,10 @@  static uint64_t io_readx(CPUArchState *env, CPUIOTLBEntry *iotlbentry,
     bool locked = false;
     MemTxResult r;

+    if (iotlbentry->attrs.byte_swap) {
+        op ^= MO_BSWAP;
+    }
+
     section = iotlb_to_section(cpu, iotlbentry->addr, iotlbentry->attrs);
     mr = section->mr;
     mr_offset = (iotlbentry->addr & TARGET_PAGE_MASK) + addr;
@@ -933,6 +940,10 @@  static void io_writex(CPUArchState *env, CPUIOTLBEntry *iotlbentry,
     bool locked = false;
     MemTxResult r;

+    if (iotlbentry->attrs.byte_swap) {
+        op ^= MO_BSWAP;
+    }
+
     section = iotlb_to_section(cpu, iotlbentry->addr, iotlbentry->attrs);
     mr = section->mr;
     mr_offset = (iotlbentry->addr & TARGET_PAGE_MASK) + addr;
diff --git a/include/exec/memattrs.h b/include/exec/memattrs.h
index d4a3477..a0644eb 100644
--- a/include/exec/memattrs.h
+++ b/include/exec/memattrs.h
@@ -37,6 +37,8 @@  typedef struct MemTxAttrs {
     unsigned int user:1;
     /* Requester ID (for MSI for example) */
     unsigned int requester_id:16;
+    /* SPARC64: TTE invert endianness */
+    unsigned int byte_swap:1;
     /*
      * The following are target-specific page-table bits.  These are not
      * related to actual memory transactions at all.  However, this structure