[PATCH v2 7/9] riscv: Align the sv39 linear map to 16 GiB

From: Samuel Holland <samuel.holland@sifive.com>
To: Palmer Dabbelt <palmer@dabbelt.com>,
	linux-riscv@lists.infradead.org,
	Andrey Ryabinin <ryabinin.a.a@gmail.com>,
	Alexander Potapenko <glider@google.com>,
	Andrey Konovalov <andreyknvl@gmail.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	kasan-dev@googlegroups.com
Cc: llvm@lists.linux.dev, Catalin Marinas <catalin.marinas@arm.com>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Alexandre Ghiti <alexghiti@rivosinc.com>,
	Will Deacon <will@kernel.org>,
	Evgenii Stepanov <eugenis@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-arm-kernel@lists.infradead.org,
	Samuel Holland <samuel.holland@sifive.com>
Subject: [PATCH v2 7/9] riscv: Align the sv39 linear map to 16 GiB
Date: Mon, 21 Oct 2024 18:57:15 -0700	[thread overview]
Message-ID: <20241022015913.3524425-8-samuel.holland@sifive.com> (raw)
In-Reply-To: <20241022015913.3524425-1-samuel.holland@sifive.com>

The KASAN implementation on RISC-V requires the shadow memory for the
vmemmap and linear map regions to be aligned to a PMD boundary (1 GiB).
For KASAN_GENERIC (KASAN_SHADOW_SCALE_SHIFT == 3), this enforces 8 GiB
alignment for the memory regions themselves. KASAN_SW_TAGS uses 16-byte
granules (KASAN_SHADOW_SCALE_SHIFT == 4), so now the memory regions must
be aligned to a 16 GiB boundary.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
---

(no changes since v1)

 Documentation/arch/riscv/vm-layout.rst | 10 +++++-----
 arch/riscv/include/asm/page.h          |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/Documentation/arch/riscv/vm-layout.rst b/Documentation/arch/riscv/vm-layout.rst
index eabec99b5852..c0778c421b34 100644
--- a/Documentation/arch/riscv/vm-layout.rst
+++ b/Documentation/arch/riscv/vm-layout.rst
@@ -47,11 +47,11 @@ RISC-V Linux Kernel SV39
                                                               | Kernel-space virtual memory, shared between all processes:
   ____________________________________________________________|___________________________________________________________
                     |            |                  |         |
-   ffffffc4fea00000 | -236    GB | ffffffc4feffffff |    6 MB | fixmap
-   ffffffc4ff000000 | -236    GB | ffffffc4ffffffff |   16 MB | PCI io
-   ffffffc500000000 | -236    GB | ffffffc5ffffffff |    4 GB | vmemmap
-   ffffffc600000000 | -232    GB | ffffffd5ffffffff |   64 GB | vmalloc/ioremap space
-   ffffffd600000000 | -168    GB | fffffff5ffffffff |  128 GB | direct mapping of all physical memory
+   ffffffc2fea00000 | -244    GB | ffffffc2feffffff |    6 MB | fixmap
+   ffffffc2ff000000 | -244    GB | ffffffc2ffffffff |   16 MB | PCI io
+   ffffffc300000000 | -244    GB | ffffffc3ffffffff |    4 GB | vmemmap
+   ffffffc400000000 | -240    GB | ffffffd3ffffffff |   64 GB | vmalloc/ioremap space
+   ffffffd400000000 | -176    GB | fffffff3ffffffff |  128 GB | direct mapping of all physical memory
                     |            |                  |         |
    fffffff700000000 |  -36    GB | fffffffeffffffff |   32 GB | kasan
   __________________|____________|__________________|_________|____________________________________________________________
diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
index 32d308a3355f..6e2f79cf77c5 100644
--- a/arch/riscv/include/asm/page.h
+++ b/arch/riscv/include/asm/page.h
@@ -37,7 +37,7 @@
  * define the PAGE_OFFSET value for SV48 and SV39.
  */
 #define PAGE_OFFSET_L4		_AC(0xffffaf8000000000, UL)
-#define PAGE_OFFSET_L3		_AC(0xffffffd600000000, UL)
+#define PAGE_OFFSET_L3		_AC(0xffffffd400000000, UL)
 #else
 #define PAGE_OFFSET		_AC(CONFIG_PAGE_OFFSET, UL)
 #endif /* CONFIG_64BIT */
-- 
2.45.1

