Re: [PATCH v3 08/10] RISC-V: Add auxiliary files

[Alexander Graf]

On 17.11.18 23:51, Auer, Lukas wrote:
> On Wed, 2018-11-14 at 18:27 +0100, Alexander Graf wrote:
>> To support a new architecture we need to provide a few helper
>> functions
>> for memory, cache, timer, etc support.
>>
>> This patch adds the remainders of those. Some bits are still
>> disabled,
>> as I couldn't guarantee that we're always running on models / in
>> modes
>> where the respective hardware is available.
>>
>> Signed-off-by: Alexander Graf <address@hidden>
>>
>> ---
>>
>> v2 -> v3:
>>
>>   - Fix riscv32 target
>> ---
>>  grub-core/kern/riscv/cache.c       | 64
>> +++++++++++++++++++++++++++++
>>  grub-core/kern/riscv/cache_flush.S | 40 +++++++++++++++++++
>>  grub-core/kern/riscv/efi/init.c    | 82
>> ++++++++++++++++++++++++++++++++++++++
>>  include/grub/riscv32/efi/memory.h  |  6 +++
>>  include/grub/riscv32/time.h        | 28 +++++++++++++
>>  include/grub/riscv32/types.h       | 34 ++++++++++++++++
>>  include/grub/riscv64/efi/memory.h  |  6 +++
>>  include/grub/riscv64/time.h        | 28 +++++++++++++
>>  include/grub/riscv64/types.h       | 34 ++++++++++++++++
>>  9 files changed, 322 insertions(+)
>>  create mode 100644 grub-core/kern/riscv/cache.c
>>  create mode 100644 grub-core/kern/riscv/cache_flush.S
>>  create mode 100644 grub-core/kern/riscv/efi/init.c
>>  create mode 100644 include/grub/riscv32/efi/memory.h
>>  create mode 100644 include/grub/riscv32/time.h
>>  create mode 100644 include/grub/riscv32/types.h
>>  create mode 100644 include/grub/riscv64/efi/memory.h
>>  create mode 100644 include/grub/riscv64/time.h
>>  create mode 100644 include/grub/riscv64/types.h
>>
>> diff --git a/grub-core/kern/riscv/cache.c b/grub-
>> core/kern/riscv/cache.c
>> new file mode 100644
>> index 000000000..15dbe6927
>> --- /dev/null
>> +++ b/grub-core/kern/riscv/cache.c
>> @@ -0,0 +1,64 @@
>> +/*
>> + *  GRUB  --  GRand Unified Bootloader
>> + *  Copyright (C) 2013  Free Software Foundation, Inc.
>> + *
>> + *  GRUB is free software: you can redistribute it and/or modify
>> + *  it under the terms of the GNU General Public License as
>> published by
>> + *  the Free Software Foundation, either version 3 of the License,
>> or
>> + *  (at your option) any later version.
>> + *
>> + *  GRUB is distributed in the hope that it will be useful,
>> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + *  GNU General Public License for more details.
>> + *
>> + *  You should have received a copy of the GNU General Public
>> License
>> + *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#include <grub/cache.h>
>> +#include <grub/misc.h>
>> +
>> +static grub_int64_t dlinesz;
>> +static grub_int64_t ilinesz;
>> +
>> +/* Prototypes for asm functions. */
>> +void grub_arch_clean_dcache_range (grub_addr_t beg, grub_addr_t end,
>> +                               grub_size_t line_size);
>> +void grub_arch_invalidate_icache_range (grub_addr_t beg, grub_addr_t
>> end,
>> +                                    grub_size_t line_size);
>> +
>> +static void
>> +probe_caches (void)
>> +{
>> +  /* TODO */
>> +  dlinesz = 32;
>> +  ilinesz = 32;
>> +}
>> +
>> +void
>> +grub_arch_sync_caches (void *address, grub_size_t len)
>> +{
>> +  grub_size_t start, end, max_align;
>> +
>> +  if (dlinesz == 0)
>> +    probe_caches();
>> +  if (dlinesz == 0)
>> +    grub_fatal ("Unknown cache line size!");
>> +
>> +  max_align = dlinesz > ilinesz ? dlinesz : ilinesz;
>> +
>> +  start = ALIGN_DOWN ((grub_size_t) address, max_align);
>> +  end = ALIGN_UP ((grub_size_t) address + len, max_align);
>> +
>> +  grub_arch_clean_dcache_range (start, end, dlinesz);
>> +  grub_arch_invalidate_icache_range (start, end, ilinesz);
>> +}
>> +
>> +void
>> +grub_arch_sync_dma_caches (volatile void *address, grub_size_t len)
>> +{
>> +  /* DMA incoherent devices not supported yet */
>> +  if (address || len || 1)
>> +    return;
>> +}
>> diff --git a/grub-core/kern/riscv/cache_flush.S b/grub-
>> core/kern/riscv/cache_flush.S
>> new file mode 100644
>> index 000000000..033a8aac3
>> --- /dev/null
>> +++ b/grub-core/kern/riscv/cache_flush.S
>> @@ -0,0 +1,40 @@
>> +/*
>> + *  GRUB  --  GRand Unified Bootloader
>> + *  Copyright (C) 2013  Free Software Foundation, Inc.
>> + *
>> + *  GRUB is free software: you can redistribute it and/or modify
>> + *  it under the terms of the GNU General Public License as
>> published by
>> + *  the Free Software Foundation, either version 3 of the License,
>> or
>> + *  (at your option) any later version.
>> + *
>> + *  GRUB is distributed in the hope that it will be useful,
>> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + *  GNU General Public License for more details.
>> + *
>> + *  You should have received a copy of the GNU General Public
>> License
>> + *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#include <grub/symbol.h>
>> +
>> +    .file   "cache_flush.S"
>> +    .text
>> +
>> +/*
>> + * Simple cache maintenance functions
>> + */
>> +
>> +// a0 - *beg (inclusive)
>> +// a1 - *end (exclusive)
>> +// a2 - line size
>> +FUNCTION(grub_arch_clean_dcache_range)
>> +    // TODO
>> +    ret
>> +
>> +// a0 - *beg (inclusive)
>> +// a1 - *end (exclusive)
>> +// a2 - line size
>> +FUNCTION(grub_arch_invalidate_icache_range)
>> +    // TODO
>> +    ret
> 
> You can use fence.i here to synchronize writes to instruction memory
> with instruction fetches. Essentially a instruction cache flush, but
> different processors may choose different implementations for it.

I suppose that one is implemented by every reasonable core? I'll add it
then :).


Thanks!

Alex