From:   Ard Biesheuvel <ardb@kernel.org>
To:     linux-kernel@vger.kernel.org
Cc:     linux-arm-kernel@lists.infradead.org,
        Ard Biesheuvel <ardb@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Ryan Roberts <ryan.roberts@arm.com>,
        Anshuman Khandual <anshuman.khandual@arm.com>,
        Kees Cook <keescook@chromium.org>
Subject: [PATCH v3 04/60] arm64: mm: Move PCI I/O emulation region above the vmemmap region
Date:   Tue,  7 Mar 2023 15:04:26 +0100
Message-Id: <20230307140522.2311461-5-ardb@kernel.org>
In-Reply-To: <20230307140522.2311461-1-ardb@kernel.org>
References: <20230307140522.2311461-1-ardb@kernel.org>
MIME-Version: 1.0
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Move the PCI I/O region above the vmemmap region in the kernel's VA
space. This will permit us to reclaim the lower part of the vmemmap
region for vmalloc/vmap allocations when running a 52-bit VA capable
build on a 48-bit VA capable system.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/arm64/include/asm/memory.h | 4 ++--
 arch/arm64/mm/ptdump.c          | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index a4e1d832a15a2d7a..6e321cc06a3c30f0 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -49,8 +49,8 @@
 #define MODULES_VSIZE		(SZ_128M)
 #define VMEMMAP_START		(-(UL(1) << (VA_BITS - VMEMMAP_SHIFT)))
 #define VMEMMAP_END		(VMEMMAP_START + VMEMMAP_SIZE)
-#define PCI_IO_END		(VMEMMAP_START - SZ_8M)
-#define PCI_IO_START		(PCI_IO_END - PCI_IO_SIZE)
+#define PCI_IO_START		(VMEMMAP_END + SZ_8M)
+#define PCI_IO_END		(PCI_IO_START + PCI_IO_SIZE)
 #define FIXADDR_TOP		(VMEMMAP_START - SZ_32M)
 
 #if VA_BITS > 48
diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c
index 9bc4066c5bf33a72..9d1f4cdc6672ed5f 100644
--- a/arch/arm64/mm/ptdump.c
+++ b/arch/arm64/mm/ptdump.c
@@ -47,10 +47,10 @@ static struct addr_marker address_markers[] = {
 	{ VMALLOC_END,			"vmalloc() end" },
 	{ FIXADDR_START,		"Fixmap start" },
 	{ FIXADDR_TOP,			"Fixmap end" },
-	{ PCI_IO_START,			"PCI I/O start" },
-	{ PCI_IO_END,			"PCI I/O end" },
 	{ VMEMMAP_START,		"vmemmap start" },
 	{ VMEMMAP_START + VMEMMAP_SIZE,	"vmemmap end" },
+	{ PCI_IO_START,			"PCI I/O start" },
+	{ PCI_IO_END,			"PCI I/O end" },
 	{ -1,				NULL },
 };
 
-- 
2.39.2