[v2,AARCH64] Add support for new control bits CTR_EL0.DIC and CTR_EL0.IDC
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Message ID 1567499745-50548-1-git-send-email-zhangshaokun@hisilicon.com
State New
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Series
  • [v2,AARCH64] Add support for new control bits CTR_EL0.DIC and CTR_EL0.IDC
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Commit Message

Shaokun Zhang Sept. 3, 2019, 8:35 a.m. UTC
The DCache clean & ICache invalidation requirements for instructions
to be data coherence are discoverable through new fields in CTR_EL0.
Let's support the two bits if they are enabled, the CPU core will
not execute the unnecessary DCache clean or Icache Invalidation
instructions.

2019-09-03  Shaokun Zhang  <zhangshaokun@hisilicon.com>

    * config/aarch64/sync-cache.c: Support CTR_EL0.IDC and CTR_EL0.DIC in
__aarch64_sync_cache_range function.
---
 libgcc/config/aarch64/sync-cache.c | 57 ++++++++++++++++++++++++--------------
 1 file changed, 36 insertions(+), 21 deletions(-)

Comments

Kyrill Tkachov Sept. 3, 2019, 11:13 a.m. UTC | #1
Hi Shaokun,

On 9/3/19 9:35 AM, Shaokun Zhang wrote:
> The DCache clean & ICache invalidation requirements for instructions
> to be data coherence are discoverable through new fields in CTR_EL0.
> Let's support the two bits if they are enabled, the CPU core will
> not execute the unnecessary DCache clean or Icache Invalidation
> instructions.
>
> 2019-09-03  Shaokun Zhang <zhangshaokun@hisilicon.com>
>
>     * config/aarch64/sync-cache.c: Support CTR_EL0.IDC and CTR_EL0.DIC in
> __aarch64_sync_cache_range function.


This version looks ok to me. I've checked the assembly generated for 
sync-cache.c and it looks as expected.

Can you please confirm that you've bootstrapped and tested this patch on 
an aarch64 system?

Thanks,

Kyrill


> ---
>  libgcc/config/aarch64/sync-cache.c | 57 
> ++++++++++++++++++++++++--------------
>  1 file changed, 36 insertions(+), 21 deletions(-)
>
> diff --git a/libgcc/config/aarch64/sync-cache.c 
> b/libgcc/config/aarch64/sync-cache.c
> index 791f5e42ff44..ea3da4be02b3 100644
> --- a/libgcc/config/aarch64/sync-cache.c
> +++ b/libgcc/config/aarch64/sync-cache.c
> @@ -23,6 +23,9 @@ a copy of the GCC Runtime Library Exception along 
> with this program;
>  see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
>  <http://www.gnu.org/licenses/>. */
>
> +#define CTR_IDC_SHIFT           28
> +#define CTR_DIC_SHIFT           29
> +
>  void __aarch64_sync_cache_range (const void *, const void *);
>
>  void
> @@ -41,32 +44,44 @@ __aarch64_sync_cache_range (const void *base, 
> const void *end)
>    icache_lsize = 4 << (cache_info & 0xF);
>    dcache_lsize = 4 << ((cache_info >> 16) & 0xF);
>
> -  /* Loop over the address range, clearing one cache line at once.
> -     Data cache must be flushed to unification first to make sure the
> -     instruction cache fetches the updated data.  'end' is exclusive,
> -     as per the GNU definition of __clear_cache.  */
> +  /* If CTR_EL0.IDC is enabled, Data cache clean to the Point of 
> Unification is
> +     not required for instruction to data coherence.  */
> +
> +  if (((cache_info >> CTR_IDC_SHIFT) & 0x1) == 0x0) {
> +    /* Loop over the address range, clearing one cache line at once.
> +       Data cache must be flushed to unification first to make sure the
> +       instruction cache fetches the updated data.  'end' is exclusive,
> +       as per the GNU definition of __clear_cache.  */
>
> -  /* Make the start address of the loop cache aligned.  */
> -  address = (const char*) ((__UINTPTR_TYPE__) base
> -                          & ~ (__UINTPTR_TYPE__) (dcache_lsize - 1));
> +    /* Make the start address of the loop cache aligned. */
> +    address = (const char*) ((__UINTPTR_TYPE__) base
> +                            & ~ (__UINTPTR_TYPE__) (dcache_lsize - 1));
>
> -  for (; address < (const char *) end; address += dcache_lsize)
> -    asm volatile ("dc\tcvau, %0"
> -                 :
> -                 : "r" (address)
> -                 : "memory");
> +    for (; address < (const char *) end; address += dcache_lsize)
> +      asm volatile ("dc\tcvau, %0"
> +                   :
> +                   : "r" (address)
> +                   : "memory");
> +  }
>
>    asm volatile ("dsb\tish" : : : "memory");
>
> -  /* Make the start address of the loop cache aligned.  */
> -  address = (const char*) ((__UINTPTR_TYPE__) base
> -                          & ~ (__UINTPTR_TYPE__) (icache_lsize - 1));
> +  /* If CTR_EL0.DIC is enabled, Instruction cache cleaning to the 
> Point of
> +     Unification is not required for instruction to data coherence.  */
> +
> +  if (((cache_info >> CTR_DIC_SHIFT) & 0x1) == 0x0) {
> +    /* Make the start address of the loop cache aligned. */
> +    address = (const char*) ((__UINTPTR_TYPE__) base
> +                            & ~ (__UINTPTR_TYPE__) (icache_lsize - 1));
> +
> +    for (; address < (const char *) end; address += icache_lsize)
> +      asm volatile ("ic\tivau, %0"
> +                   :
> +                   : "r" (address)
> +                   : "memory");
>
> -  for (; address < (const char *) end; address += icache_lsize)
> -    asm volatile ("ic\tivau, %0"
> -                 :
> -                 : "r" (address)
> -                 : "memory");
> +    asm volatile ("dsb\tish" : : : "memory");
> +  }
>
> -  asm volatile ("dsb\tish; isb" : : : "memory");
> +  asm volatile("isb" : : : "memory");
>  }
> -- 
> 2.7.4
>
Shaokun Zhang Sept. 5, 2019, 9:37 a.m. UTC | #2
Hi Kyrill,

On 2019/9/3 19:13, Kyrill Tkachov wrote:
> Hi Shaokun,
> 
> On 9/3/19 9:35 AM, Shaokun Zhang wrote:
>> The DCache clean & ICache invalidation requirements for instructions
>> to be data coherence are discoverable through new fields in CTR_EL0.
>> Let's support the two bits if they are enabled, the CPU core will
>> not execute the unnecessary DCache clean or Icache Invalidation
>> instructions.
>>
>> 2019-09-03  Shaokun Zhang <zhangshaokun@hisilicon.com>
>>
>>     * config/aarch64/sync-cache.c: Support CTR_EL0.IDC and CTR_EL0.DIC in
>> __aarch64_sync_cache_range function.
> 
> 
> This version looks ok to me. I've checked the assembly generated for sync-cache.c and it looks as expected.
> 
> Can you please confirm that you've bootstrapped and tested this patch on an aarch64 system?
> 

Sorry to reply later.

I have bootstrapped and also check the prev-aarch64-unknown-linux-gnu/libgcc/sync-cache.o file.
It has been compiled the patch.

About the test, I run the self-modify testcase which calls __clear_cache directly,
and use the new GCC to compile it, it works ok on both Huawei Kunpeng 920 server whose cpu
is HiSilicon tsv110 core and HiSilicon D05 server board which uses A72 core.

Thanks,
Shaokun

> Thanks,
> 
> Kyrill
> 
> 
>> ---
>>  libgcc/config/aarch64/sync-cache.c | 57 ++++++++++++++++++++++++--------------
>>  1 file changed, 36 insertions(+), 21 deletions(-)
>>
>> diff --git a/libgcc/config/aarch64/sync-cache.c b/libgcc/config/aarch64/sync-cache.c
>> index 791f5e42ff44..ea3da4be02b3 100644
>> --- a/libgcc/config/aarch64/sync-cache.c
>> +++ b/libgcc/config/aarch64/sync-cache.c
>> @@ -23,6 +23,9 @@ a copy of the GCC Runtime Library Exception along with this program;
>>  see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
>>  <http://www.gnu.org/licenses/>. */
>>
>> +#define CTR_IDC_SHIFT           28
>> +#define CTR_DIC_SHIFT           29
>> +
>>  void __aarch64_sync_cache_range (const void *, const void *);
>>
>>  void
>> @@ -41,32 +44,44 @@ __aarch64_sync_cache_range (const void *base, const void *end)
>>    icache_lsize = 4 << (cache_info & 0xF);
>>    dcache_lsize = 4 << ((cache_info >> 16) & 0xF);
>>
>> -  /* Loop over the address range, clearing one cache line at once.
>> -     Data cache must be flushed to unification first to make sure the
>> -     instruction cache fetches the updated data.  'end' is exclusive,
>> -     as per the GNU definition of __clear_cache.  */
>> +  /* If CTR_EL0.IDC is enabled, Data cache clean to the Point of Unification is
>> +     not required for instruction to data coherence.  */
>> +
>> +  if (((cache_info >> CTR_IDC_SHIFT) & 0x1) == 0x0) {
>> +    /* Loop over the address range, clearing one cache line at once.
>> +       Data cache must be flushed to unification first to make sure the
>> +       instruction cache fetches the updated data.  'end' is exclusive,
>> +       as per the GNU definition of __clear_cache.  */
>>
>> -  /* Make the start address of the loop cache aligned.  */
>> -  address = (const char*) ((__UINTPTR_TYPE__) base
>> -                          & ~ (__UINTPTR_TYPE__) (dcache_lsize - 1));
>> +    /* Make the start address of the loop cache aligned. */
>> +    address = (const char*) ((__UINTPTR_TYPE__) base
>> +                            & ~ (__UINTPTR_TYPE__) (dcache_lsize - 1));
>>
>> -  for (; address < (const char *) end; address += dcache_lsize)
>> -    asm volatile ("dc\tcvau, %0"
>> -                 :
>> -                 : "r" (address)
>> -                 : "memory");
>> +    for (; address < (const char *) end; address += dcache_lsize)
>> +      asm volatile ("dc\tcvau, %0"
>> +                   :
>> +                   : "r" (address)
>> +                   : "memory");
>> +  }
>>
>>    asm volatile ("dsb\tish" : : : "memory");
>>
>> -  /* Make the start address of the loop cache aligned.  */
>> -  address = (const char*) ((__UINTPTR_TYPE__) base
>> -                          & ~ (__UINTPTR_TYPE__) (icache_lsize - 1));
>> +  /* If CTR_EL0.DIC is enabled, Instruction cache cleaning to the Point of
>> +     Unification is not required for instruction to data coherence.  */
>> +
>> +  if (((cache_info >> CTR_DIC_SHIFT) & 0x1) == 0x0) {
>> +    /* Make the start address of the loop cache aligned. */
>> +    address = (const char*) ((__UINTPTR_TYPE__) base
>> +                            & ~ (__UINTPTR_TYPE__) (icache_lsize - 1));
>> +
>> +    for (; address < (const char *) end; address += icache_lsize)
>> +      asm volatile ("ic\tivau, %0"
>> +                   :
>> +                   : "r" (address)
>> +                   : "memory");
>>
>> -  for (; address < (const char *) end; address += icache_lsize)
>> -    asm volatile ("ic\tivau, %0"
>> -                 :
>> -                 : "r" (address)
>> -                 : "memory");
>> +    asm volatile ("dsb\tish" : : : "memory");
>> +  }
>>
>> -  asm volatile ("dsb\tish; isb" : : : "memory");
>> +  asm volatile("isb" : : : "memory");
>>  }
>> -- 
>> 2.7.4
>>
> 
> .
>
Kyrill Tkachov Sept. 5, 2019, 9:41 a.m. UTC | #3
Hi Shaokun,

On 9/5/19 10:37 AM, Shaokun Zhang wrote:
> Hi Kyrill,
>
> On 2019/9/3 19:13, Kyrill Tkachov wrote:
>> Hi Shaokun,
>>
>> On 9/3/19 9:35 AM, Shaokun Zhang wrote:
>>> The DCache clean & ICache invalidation requirements for instructions
>>> to be data coherence are discoverable through new fields in CTR_EL0.
>>> Let's support the two bits if they are enabled, the CPU core will
>>> not execute the unnecessary DCache clean or Icache Invalidation
>>> instructions.
>>>
>>> 2019-09-03  Shaokun Zhang <zhangshaokun@hisilicon.com>
>>>
>>>      * config/aarch64/sync-cache.c: Support CTR_EL0.IDC and CTR_EL0.DIC in
>>> __aarch64_sync_cache_range function.
>>
>> This version looks ok to me. I've checked the assembly generated for sync-cache.c and it looks as expected.
>>
>> Can you please confirm that you've bootstrapped and tested this patch on an aarch64 system?
>>
> Sorry to reply later.
>
> I have bootstrapped and also check the prev-aarch64-unknown-linux-gnu/libgcc/sync-cache.o file.
> It has been compiled the patch.
>
> About the test, I run the self-modify testcase which calls __clear_cache directly,
> and use the new GCC to compile it, it works ok on both Huawei Kunpeng 920 server whose cpu
> is HiSilicon tsv110 core and HiSilicon D05 server board which uses A72 core.

Thanks, that looks good to me now.

Kyrill


> Thanks,
> Shaokun
>
>> Thanks,
>>
>> Kyrill
>>
>>
>>> ---
>>>   libgcc/config/aarch64/sync-cache.c | 57 ++++++++++++++++++++++++--------------
>>>   1 file changed, 36 insertions(+), 21 deletions(-)
>>>
>>> diff --git a/libgcc/config/aarch64/sync-cache.c b/libgcc/config/aarch64/sync-cache.c
>>> index 791f5e42ff44..ea3da4be02b3 100644
>>> --- a/libgcc/config/aarch64/sync-cache.c
>>> +++ b/libgcc/config/aarch64/sync-cache.c
>>> @@ -23,6 +23,9 @@ a copy of the GCC Runtime Library Exception along with this program;
>>>   see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
>>>   <http://www.gnu.org/licenses/>. */
>>>
>>> +#define CTR_IDC_SHIFT           28
>>> +#define CTR_DIC_SHIFT           29
>>> +
>>>   void __aarch64_sync_cache_range (const void *, const void *);
>>>
>>>   void
>>> @@ -41,32 +44,44 @@ __aarch64_sync_cache_range (const void *base, const void *end)
>>>     icache_lsize = 4 << (cache_info & 0xF);
>>>     dcache_lsize = 4 << ((cache_info >> 16) & 0xF);
>>>
>>> -  /* Loop over the address range, clearing one cache line at once.
>>> -     Data cache must be flushed to unification first to make sure the
>>> -     instruction cache fetches the updated data.  'end' is exclusive,
>>> -     as per the GNU definition of __clear_cache.  */
>>> +  /* If CTR_EL0.IDC is enabled, Data cache clean to the Point of Unification is
>>> +     not required for instruction to data coherence.  */
>>> +
>>> +  if (((cache_info >> CTR_IDC_SHIFT) & 0x1) == 0x0) {
>>> +    /* Loop over the address range, clearing one cache line at once.
>>> +       Data cache must be flushed to unification first to make sure the
>>> +       instruction cache fetches the updated data.  'end' is exclusive,
>>> +       as per the GNU definition of __clear_cache.  */
>>>
>>> -  /* Make the start address of the loop cache aligned.  */
>>> -  address = (const char*) ((__UINTPTR_TYPE__) base
>>> -                          & ~ (__UINTPTR_TYPE__) (dcache_lsize - 1));
>>> +    /* Make the start address of the loop cache aligned. */
>>> +    address = (const char*) ((__UINTPTR_TYPE__) base
>>> +                            & ~ (__UINTPTR_TYPE__) (dcache_lsize - 1));
>>>
>>> -  for (; address < (const char *) end; address += dcache_lsize)
>>> -    asm volatile ("dc\tcvau, %0"
>>> -                 :
>>> -                 : "r" (address)
>>> -                 : "memory");
>>> +    for (; address < (const char *) end; address += dcache_lsize)
>>> +      asm volatile ("dc\tcvau, %0"
>>> +                   :
>>> +                   : "r" (address)
>>> +                   : "memory");
>>> +  }
>>>
>>>     asm volatile ("dsb\tish" : : : "memory");
>>>
>>> -  /* Make the start address of the loop cache aligned.  */
>>> -  address = (const char*) ((__UINTPTR_TYPE__) base
>>> -                          & ~ (__UINTPTR_TYPE__) (icache_lsize - 1));
>>> +  /* If CTR_EL0.DIC is enabled, Instruction cache cleaning to the Point of
>>> +     Unification is not required for instruction to data coherence.  */
>>> +
>>> +  if (((cache_info >> CTR_DIC_SHIFT) & 0x1) == 0x0) {
>>> +    /* Make the start address of the loop cache aligned. */
>>> +    address = (const char*) ((__UINTPTR_TYPE__) base
>>> +                            & ~ (__UINTPTR_TYPE__) (icache_lsize - 1));
>>> +
>>> +    for (; address < (const char *) end; address += icache_lsize)
>>> +      asm volatile ("ic\tivau, %0"
>>> +                   :
>>> +                   : "r" (address)
>>> +                   : "memory");
>>>
>>> -  for (; address < (const char *) end; address += icache_lsize)
>>> -    asm volatile ("ic\tivau, %0"
>>> -                 :
>>> -                 : "r" (address)
>>> -                 : "memory");
>>> +    asm volatile ("dsb\tish" : : : "memory");
>>> +  }
>>>
>>> -  asm volatile ("dsb\tish; isb" : : : "memory");
>>> +  asm volatile("isb" : : : "memory");
>>>   }
>>> -- 
>>> 2.7.4
>>>
>> .
>>
Shaokun Zhang Sept. 6, 2019, 12:59 a.m. UTC | #4
Hi Kyrill,

On 2019/9/5 17:41, Kyrill Tkachov wrote:
> Hi Shaokun,
> 
> On 9/5/19 10:37 AM, Shaokun Zhang wrote:
>> Hi Kyrill,
>>
>> On 2019/9/3 19:13, Kyrill Tkachov wrote:
>>> Hi Shaokun,
>>>
>>> On 9/3/19 9:35 AM, Shaokun Zhang wrote:
>>>> The DCache clean & ICache invalidation requirements for instructions
>>>> to be data coherence are discoverable through new fields in CTR_EL0.
>>>> Let's support the two bits if they are enabled, the CPU core will
>>>> not execute the unnecessary DCache clean or Icache Invalidation
>>>> instructions.
>>>>
>>>> 2019-09-03  Shaokun Zhang <zhangshaokun@hisilicon.com>
>>>>
>>>>      * config/aarch64/sync-cache.c: Support CTR_EL0.IDC and CTR_EL0.DIC in
>>>> __aarch64_sync_cache_range function.
>>>
>>> This version looks ok to me. I've checked the assembly generated for sync-cache.c and it looks as expected.
>>>
>>> Can you please confirm that you've bootstrapped and tested this patch on an aarch64 system?
>>>
>> Sorry to reply later.
>>
>> I have bootstrapped and also check the prev-aarch64-unknown-linux-gnu/libgcc/sync-cache.o file.
>> It has been compiled the patch.
>>
>> About the test, I run the self-modify testcase which calls __clear_cache directly,
>> and use the new GCC to compile it, it works ok on both Huawei Kunpeng 920 server whose cpu
>> is HiSilicon tsv110 core and HiSilicon D05 server board which uses A72 core.
> 
> Thanks, that looks good to me now.
> 

Thanks your reply.

Shaokun

> Kyrill
> 
> 
>> Thanks,
>> Shaokun
>>
>>> Thanks,
>>>
>>> Kyrill
>>>
>>>
>>>> ---
>>>>   libgcc/config/aarch64/sync-cache.c | 57 ++++++++++++++++++++++++--------------
>>>>   1 file changed, 36 insertions(+), 21 deletions(-)
>>>>
>>>> diff --git a/libgcc/config/aarch64/sync-cache.c b/libgcc/config/aarch64/sync-cache.c
>>>> index 791f5e42ff44..ea3da4be02b3 100644
>>>> --- a/libgcc/config/aarch64/sync-cache.c
>>>> +++ b/libgcc/config/aarch64/sync-cache.c
>>>> @@ -23,6 +23,9 @@ a copy of the GCC Runtime Library Exception along with this program;
>>>>   see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
>>>>   <http://www.gnu.org/licenses/>. */
>>>>
>>>> +#define CTR_IDC_SHIFT           28
>>>> +#define CTR_DIC_SHIFT           29
>>>> +
>>>>   void __aarch64_sync_cache_range (const void *, const void *);
>>>>
>>>>   void
>>>> @@ -41,32 +44,44 @@ __aarch64_sync_cache_range (const void *base, const void *end)
>>>>     icache_lsize = 4 << (cache_info & 0xF);
>>>>     dcache_lsize = 4 << ((cache_info >> 16) & 0xF);
>>>>
>>>> -  /* Loop over the address range, clearing one cache line at once.
>>>> -     Data cache must be flushed to unification first to make sure the
>>>> -     instruction cache fetches the updated data.  'end' is exclusive,
>>>> -     as per the GNU definition of __clear_cache.  */
>>>> +  /* If CTR_EL0.IDC is enabled, Data cache clean to the Point of Unification is
>>>> +     not required for instruction to data coherence.  */
>>>> +
>>>> +  if (((cache_info >> CTR_IDC_SHIFT) & 0x1) == 0x0) {
>>>> +    /* Loop over the address range, clearing one cache line at once.
>>>> +       Data cache must be flushed to unification first to make sure the
>>>> +       instruction cache fetches the updated data.  'end' is exclusive,
>>>> +       as per the GNU definition of __clear_cache.  */
>>>>
>>>> -  /* Make the start address of the loop cache aligned.  */
>>>> -  address = (const char*) ((__UINTPTR_TYPE__) base
>>>> -                          & ~ (__UINTPTR_TYPE__) (dcache_lsize - 1));
>>>> +    /* Make the start address of the loop cache aligned. */
>>>> +    address = (const char*) ((__UINTPTR_TYPE__) base
>>>> +                            & ~ (__UINTPTR_TYPE__) (dcache_lsize - 1));
>>>>
>>>> -  for (; address < (const char *) end; address += dcache_lsize)
>>>> -    asm volatile ("dc\tcvau, %0"
>>>> -                 :
>>>> -                 : "r" (address)
>>>> -                 : "memory");
>>>> +    for (; address < (const char *) end; address += dcache_lsize)
>>>> +      asm volatile ("dc\tcvau, %0"
>>>> +                   :
>>>> +                   : "r" (address)
>>>> +                   : "memory");
>>>> +  }
>>>>
>>>>     asm volatile ("dsb\tish" : : : "memory");
>>>>
>>>> -  /* Make the start address of the loop cache aligned.  */
>>>> -  address = (const char*) ((__UINTPTR_TYPE__) base
>>>> -                          & ~ (__UINTPTR_TYPE__) (icache_lsize - 1));
>>>> +  /* If CTR_EL0.DIC is enabled, Instruction cache cleaning to the Point of
>>>> +     Unification is not required for instruction to data coherence.  */
>>>> +
>>>> +  if (((cache_info >> CTR_DIC_SHIFT) & 0x1) == 0x0) {
>>>> +    /* Make the start address of the loop cache aligned. */
>>>> +    address = (const char*) ((__UINTPTR_TYPE__) base
>>>> +                            & ~ (__UINTPTR_TYPE__) (icache_lsize - 1));
>>>> +
>>>> +    for (; address < (const char *) end; address += icache_lsize)
>>>> +      asm volatile ("ic\tivau, %0"
>>>> +                   :
>>>> +                   : "r" (address)
>>>> +                   : "memory");
>>>>
>>>> -  for (; address < (const char *) end; address += icache_lsize)
>>>> -    asm volatile ("ic\tivau, %0"
>>>> -                 :
>>>> -                 : "r" (address)
>>>> -                 : "memory");
>>>> +    asm volatile ("dsb\tish" : : : "memory");
>>>> +  }
>>>>
>>>> -  asm volatile ("dsb\tish; isb" : : : "memory");
>>>> +  asm volatile("isb" : : : "memory");
>>>>   }
>>>> -- 
>>>> 2.7.4
>>>>
>>> .
>>>
> 
> .
>
Kyrill Tkachov Sept. 25, 2019, 12:40 p.m. UTC | #5
Hi all,

On 9/3/19 9:35 AM, Shaokun Zhang wrote:
> The DCache clean & ICache invalidation requirements for instructions
> to be data coherence are discoverable through new fields in CTR_EL0.
> Let's support the two bits if they are enabled, the CPU core will
> not execute the unnecessary DCache clean or Icache Invalidation
> instructions.
>
> 2019-09-03  Shaokun Zhang <zhangshaokun@hisilicon.com>
>
>     * config/aarch64/sync-cache.c: Support CTR_EL0.IDC and CTR_EL0.DIC in
> __aarch64_sync_cache_range function.


James has approved this offline, so I've committed it on Shaokun's 
behalf with r276122 with a slightly adjusted ChangeLog.

2019-09-25  Shaokun Zhang  <zhangshaokun@hisilicon.com>

     * config/aarch64/sync-cache.c (__aarch64_sync_cache_range): Add 
support for
     CTR_EL0.IDC and CTR_EL0.DIC.

Thanks,

Kyrill

> ---
>  libgcc/config/aarch64/sync-cache.c | 57 
> ++++++++++++++++++++++++--------------
>  1 file changed, 36 insertions(+), 21 deletions(-)
>
> diff --git a/libgcc/config/aarch64/sync-cache.c 
> b/libgcc/config/aarch64/sync-cache.c
> index 791f5e42ff44..ea3da4be02b3 100644
> --- a/libgcc/config/aarch64/sync-cache.c
> +++ b/libgcc/config/aarch64/sync-cache.c
> @@ -23,6 +23,9 @@ a copy of the GCC Runtime Library Exception along 
> with this program;
>  see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
>  <http://www.gnu.org/licenses/>. */
>
> +#define CTR_IDC_SHIFT           28
> +#define CTR_DIC_SHIFT           29
> +
>  void __aarch64_sync_cache_range (const void *, const void *);
>
>  void
> @@ -41,32 +44,44 @@ __aarch64_sync_cache_range (const void *base, 
> const void *end)
>    icache_lsize = 4 << (cache_info & 0xF);
>    dcache_lsize = 4 << ((cache_info >> 16) & 0xF);
>
> -  /* Loop over the address range, clearing one cache line at once.
> -     Data cache must be flushed to unification first to make sure the
> -     instruction cache fetches the updated data.  'end' is exclusive,
> -     as per the GNU definition of __clear_cache.  */
> +  /* If CTR_EL0.IDC is enabled, Data cache clean to the Point of 
> Unification is
> +     not required for instruction to data coherence.  */
> +
> +  if (((cache_info >> CTR_IDC_SHIFT) & 0x1) == 0x0) {
> +    /* Loop over the address range, clearing one cache line at once.
> +       Data cache must be flushed to unification first to make sure the
> +       instruction cache fetches the updated data.  'end' is exclusive,
> +       as per the GNU definition of __clear_cache.  */
>
> -  /* Make the start address of the loop cache aligned.  */
> -  address = (const char*) ((__UINTPTR_TYPE__) base
> -                          & ~ (__UINTPTR_TYPE__) (dcache_lsize - 1));
> +    /* Make the start address of the loop cache aligned. */
> +    address = (const char*) ((__UINTPTR_TYPE__) base
> +                            & ~ (__UINTPTR_TYPE__) (dcache_lsize - 1));
>
> -  for (; address < (const char *) end; address += dcache_lsize)
> -    asm volatile ("dc\tcvau, %0"
> -                 :
> -                 : "r" (address)
> -                 : "memory");
> +    for (; address < (const char *) end; address += dcache_lsize)
> +      asm volatile ("dc\tcvau, %0"
> +                   :
> +                   : "r" (address)
> +                   : "memory");
> +  }
>
>    asm volatile ("dsb\tish" : : : "memory");
>
> -  /* Make the start address of the loop cache aligned.  */
> -  address = (const char*) ((__UINTPTR_TYPE__) base
> -                          & ~ (__UINTPTR_TYPE__) (icache_lsize - 1));
> +  /* If CTR_EL0.DIC is enabled, Instruction cache cleaning to the 
> Point of
> +     Unification is not required for instruction to data coherence.  */
> +
> +  if (((cache_info >> CTR_DIC_SHIFT) & 0x1) == 0x0) {
> +    /* Make the start address of the loop cache aligned. */
> +    address = (const char*) ((__UINTPTR_TYPE__) base
> +                            & ~ (__UINTPTR_TYPE__) (icache_lsize - 1));
> +
> +    for (; address < (const char *) end; address += icache_lsize)
> +      asm volatile ("ic\tivau, %0"
> +                   :
> +                   : "r" (address)
> +                   : "memory");
>
> -  for (; address < (const char *) end; address += icache_lsize)
> -    asm volatile ("ic\tivau, %0"
> -                 :
> -                 : "r" (address)
> -                 : "memory");
> +    asm volatile ("dsb\tish" : : : "memory");
> +  }
>
> -  asm volatile ("dsb\tish; isb" : : : "memory");
> +  asm volatile("isb" : : : "memory");
>  }
> -- 
> 2.7.4
>

Patch
diff mbox series

diff --git a/libgcc/config/aarch64/sync-cache.c b/libgcc/config/aarch64/sync-cache.c
index 791f5e42ff44..ea3da4be02b3 100644
--- a/libgcc/config/aarch64/sync-cache.c
+++ b/libgcc/config/aarch64/sync-cache.c
@@ -23,6 +23,9 @@  a copy of the GCC Runtime Library Exception along with this program;
 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 <http://www.gnu.org/licenses/>.  */
 
+#define CTR_IDC_SHIFT           28
+#define CTR_DIC_SHIFT           29
+
 void __aarch64_sync_cache_range (const void *, const void *);
 
 void
@@ -41,32 +44,44 @@  __aarch64_sync_cache_range (const void *base, const void *end)
   icache_lsize = 4 << (cache_info & 0xF);
   dcache_lsize = 4 << ((cache_info >> 16) & 0xF);
 
-  /* Loop over the address range, clearing one cache line at once.
-     Data cache must be flushed to unification first to make sure the
-     instruction cache fetches the updated data.  'end' is exclusive,
-     as per the GNU definition of __clear_cache.  */
+  /* If CTR_EL0.IDC is enabled, Data cache clean to the Point of Unification is
+     not required for instruction to data coherence.  */
+
+  if (((cache_info >> CTR_IDC_SHIFT) & 0x1) == 0x0) {
+    /* Loop over the address range, clearing one cache line at once.
+       Data cache must be flushed to unification first to make sure the
+       instruction cache fetches the updated data.  'end' is exclusive,
+       as per the GNU definition of __clear_cache.  */
 
-  /* Make the start address of the loop cache aligned.  */
-  address = (const char*) ((__UINTPTR_TYPE__) base
-			   & ~ (__UINTPTR_TYPE__) (dcache_lsize - 1));
+    /* Make the start address of the loop cache aligned.  */
+    address = (const char*) ((__UINTPTR_TYPE__) base
+			     & ~ (__UINTPTR_TYPE__) (dcache_lsize - 1));
 
-  for (; address < (const char *) end; address += dcache_lsize)
-    asm volatile ("dc\tcvau, %0"
-		  :
-		  : "r" (address)
-		  : "memory");
+    for (; address < (const char *) end; address += dcache_lsize)
+      asm volatile ("dc\tcvau, %0"
+		    :
+		    : "r" (address)
+		    : "memory");
+  }
 
   asm volatile ("dsb\tish" : : : "memory");
 
-  /* Make the start address of the loop cache aligned.  */
-  address = (const char*) ((__UINTPTR_TYPE__) base
-			   & ~ (__UINTPTR_TYPE__) (icache_lsize - 1));
+  /* If CTR_EL0.DIC is enabled, Instruction cache cleaning to the Point of
+     Unification is not required for instruction to data coherence.  */
+
+  if (((cache_info >> CTR_DIC_SHIFT) & 0x1) == 0x0) {
+    /* Make the start address of the loop cache aligned.  */
+    address = (const char*) ((__UINTPTR_TYPE__) base
+			     & ~ (__UINTPTR_TYPE__) (icache_lsize - 1));
+
+    for (; address < (const char *) end; address += icache_lsize)
+      asm volatile ("ic\tivau, %0"
+		    :
+		    : "r" (address)
+		    : "memory");
 
-  for (; address < (const char *) end; address += icache_lsize)
-    asm volatile ("ic\tivau, %0"
-		  :
-		  : "r" (address)
-		  : "memory");
+    asm volatile ("dsb\tish" : : : "memory");
+  }
 
-  asm volatile ("dsb\tish; isb" : : : "memory");
+  asm volatile("isb" : : : "memory");
 }