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Message-ID: <fc9ebfc8-87cd-9488-20cd-85ed2a164bc9@infradead.org>
Date:   Wed, 5 Jul 2023 22:30:02 -0700
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Subject: Re: [RESEND PATCH v3 2/2] RISC-V: mm: Update documentation and
 include test
To:     Charlie Jenkins <charlie@rivosinc.com>,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Cc:     conor@kernel.org, paul.walmsley@sifive.com, palmer@rivosinc.com,
        aou@eecs.berkeley.edu, anup@brainfault.org,
        konstantin@linuxfoundation.org, linux-doc@vger.kernel.org,
        linux-kselftest@vger.kernel.org, linux-mm@kvack.org,
        mick@ics.forth.gr, jrtc27@jrtc27.com
References: <20230705190002.384799-1-charlie@rivosinc.com>
 <20230705190002.384799-3-charlie@rivosinc.com>
Content-Language: en-US
From:   Randy Dunlap <rdunlap@infradead.org>
In-Reply-To: <20230705190002.384799-3-charlie@rivosinc.com>
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Precedence: bulk

Hi--

On 7/5/23 11:59, Charlie Jenkins wrote:
> Add documentation explaining the behavior of mmap. Include
> a simple test that ensures that mmap returns an address less
> than the hint address while there are still addresses available.
> 
> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
> ---
>  Documentation/riscv/vm-layout.rst             | 22 +++++++++
>  arch/riscv/include/asm/pgtable.h              |  8 +--
>  tools/testing/selftests/riscv/Makefile        |  2 +-
>  tools/testing/selftests/riscv/mm/.gitignore   |  1 +
>  tools/testing/selftests/riscv/mm/Makefile     | 21 ++++++++
>  .../selftests/riscv/mm/testcases/mmap.c       | 49 +++++++++++++++++++
>  6 files changed, 99 insertions(+), 4 deletions(-)
>  create mode 100644 tools/testing/selftests/riscv/mm/.gitignore
>  create mode 100644 tools/testing/selftests/riscv/mm/Makefile
>  create mode 100644 tools/testing/selftests/riscv/mm/testcases/mmap.c
> 
> diff --git a/Documentation/riscv/vm-layout.rst b/Documentation/riscv/vm-layout.rst
> index 5462c84f4723..a610c68c9f3f 100644
> --- a/Documentation/riscv/vm-layout.rst
> +++ b/Documentation/riscv/vm-layout.rst
> @@ -133,3 +133,25 @@ RISC-V Linux Kernel SV57
>     ffffffff00000000 |  -4     GB | ffffffff7fffffff |    2 GB | modules, BPF
>     ffffffff80000000 |  -2     GB | ffffffffffffffff |    2 GB | kernel
>    __________________|____________|__________________|_________|____________________________________________________________
> +
> +
> +Userspace VAs
> +--------------------
> +To maintain compatibility with software that relies on the VA space
> +with a maximum of 39-bits, the kernel will, by default, return virtual

                     39 bits,

> +return virtual addresses to userspace from a 48-bit range (sv48). This

^^ duplicate "return virtual"

> +default behavior is achieved by passing 0 into the hint address parameter
> +of mmap.
> +

> diff --git a/tools/testing/selftests/riscv/mm/.gitignore b/tools/testing/selftests/riscv/mm/.gitignore
> new file mode 100644
> index 000000000000..022ea0a3f7df
> --- /dev/null
> +++ b/tools/testing/selftests/riscv/mm/.gitignore
> @@ -0,0 +1 @@
> +mmap
> \ No newline at end of file

add a newline, please.

> diff --git a/tools/testing/selftests/riscv/mm/Makefile b/tools/testing/selftests/riscv/mm/Makefile
> new file mode 100644
> index 000000000000..d41a0b3d2ca2
> --- /dev/null
> +++ b/tools/testing/selftests/riscv/mm/Makefile
> @@ -0,0 +1,21 @@
> +# SPDX-License-Identifier: GPL-2.0
> +# Originally tools/testing/selftests/arm64/signal
> +
> +# Additional include paths needed by kselftest.h and local headers
> +CFLAGS += -D_GNU_SOURCE -std=gnu99 -I.
> +
> +SRCS := $(filter-out testcases/testcases.c,$(wildcard testcases/*.c))
> +PROGS := $(patsubst %.c,%,$(SRCS))
> +
> +# Generated binaries to be installed by top KSFT script
> +TEST_GEN_PROGS := $(notdir $(PROGS))
> +
> +# Get Kernel headers installed and use them.
> +
> +# Including KSFT lib.mk here will also mangle the TEST_GEN_PROGS list
> +# to account for any OUTPUT target-dirs optionally provided by
> +# the toplevel makefile
> +include ../../lib.mk
> +
> +$(TEST_GEN_PROGS): $(PROGS)
> +	cp $(PROGS) $(OUTPUT)/
> \ No newline at end of file

add a newline, please.

-- 
~Randy