From 2bc6b218717b9d08f466f88209251d54bc09b207 Mon Sep 17 00:00:00 2001
From: Fuad Tabba <fuad.tabba@linux.dev>
Date: Tue, 22 Sep 2026 19:14:30 +0100
Subject: arm64/boot: Disable trapping of PMZR_EL0 writes to EL2

__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.
PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in
HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host
traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The
kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU
driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a
write from EL0 reaches the trap and takes the host down without a panic
message.

Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already
does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9
bits.

Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9")
Cc: stable@vger.kernel.org
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
---
 include/asm-generic/video.h | 136 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 136 insertions(+)
 create mode 100644 include/asm-generic/video.h

(limited to 'include/asm-generic/video.h')

diff --git a/include/asm-generic/video.h b/include/asm-generic/video.h
new file mode 100644
index 000000000..b1da2309d
--- /dev/null
+++ b/include/asm-generic/video.h
@@ -0,0 +1,136 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_GENERIC_VIDEO_H_
+#define __ASM_GENERIC_VIDEO_H_
+
+/*
+ * Only include this header file from your architecture's <asm/fb.h>.
+ */
+
+#include <linux/io.h>
+#include <linux/mm_types.h>
+#include <linux/pgtable.h>
+#include <linux/types.h>
+
+struct device;
+
+#ifndef pgprot_framebuffer
+#define pgprot_framebuffer pgprot_framebuffer
+static inline pgprot_t pgprot_framebuffer(pgprot_t prot,
+					  unsigned long vm_start, unsigned long vm_end,
+					  unsigned long offset)
+{
+	return pgprot_writecombine(prot);
+}
+#endif
+
+#ifndef video_is_primary_device
+#define video_is_primary_device video_is_primary_device
+static inline bool video_is_primary_device(struct device *dev)
+{
+	return false;
+}
+#endif
+
+/*
+ * I/O helpers for the framebuffer. Prefer these functions over their
+ * regular counterparts. The regular I/O functions provide in-order
+ * access and swap bytes to/from little-endian ordering. Neither is
+ * required for framebuffers. Instead, the helpers read and write
+ * raw framebuffer data. Independent operations can be reordered for
+ * improved performance.
+ */
+
+#ifndef fb_readb
+static inline u8 fb_readb(const volatile void __iomem *addr)
+{
+	return __raw_readb(addr);
+}
+#define fb_readb fb_readb
+#endif
+
+#ifndef fb_readw
+static inline u16 fb_readw(const volatile void __iomem *addr)
+{
+	return __raw_readw(addr);
+}
+#define fb_readw fb_readw
+#endif
+
+#ifndef fb_readl
+static inline u32 fb_readl(const volatile void __iomem *addr)
+{
+	return __raw_readl(addr);
+}
+#define fb_readl fb_readl
+#endif
+
+#ifndef fb_readq
+#if defined(__raw_readq)
+static inline u64 fb_readq(const volatile void __iomem *addr)
+{
+	return __raw_readq(addr);
+}
+#define fb_readq fb_readq
+#endif
+#endif
+
+#ifndef fb_writeb
+static inline void fb_writeb(u8 b, volatile void __iomem *addr)
+{
+	__raw_writeb(b, addr);
+}
+#define fb_writeb fb_writeb
+#endif
+
+#ifndef fb_writew
+static inline void fb_writew(u16 b, volatile void __iomem *addr)
+{
+	__raw_writew(b, addr);
+}
+#define fb_writew fb_writew
+#endif
+
+#ifndef fb_writel
+static inline void fb_writel(u32 b, volatile void __iomem *addr)
+{
+	__raw_writel(b, addr);
+}
+#define fb_writel fb_writel
+#endif
+
+#ifndef fb_writeq
+#if defined(__raw_writeq)
+static inline void fb_writeq(u64 b, volatile void __iomem *addr)
+{
+	__raw_writeq(b, addr);
+}
+#define fb_writeq fb_writeq
+#endif
+#endif
+
+#ifndef fb_memcpy_fromio
+static inline void fb_memcpy_fromio(void *to, const volatile void __iomem *from, size_t n)
+{
+	memcpy_fromio(to, from, n);
+}
+#define fb_memcpy_fromio fb_memcpy_fromio
+#endif
+
+#ifndef fb_memcpy_toio
+static inline void fb_memcpy_toio(volatile void __iomem *to, const void *from, size_t n)
+{
+	memcpy_toio(to, from, n);
+}
+#define fb_memcpy_toio fb_memcpy_toio
+#endif
+
+#ifndef fb_memset
+static inline void fb_memset_io(volatile void __iomem *addr, int c, size_t n)
+{
+	memset_io(addr, c, n);
+}
+#define fb_memset fb_memset_io
+#endif
+
+#endif /* __ASM_GENERIC_VIDEO_H_ */
-- 
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