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authorLinus Torvalds <torvalds@linux-foundation.org>2026-09-25 15:55:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-09-25 15:55:03 -0700
commit75467f60a3d14f08f86f2b353298d2826382ff23 (patch)
treeacd8a7d5b5a675042449386efa5b42ec44d8bf81 /drivers/video/fbdev/bt455.h
downloadlinux-stable-75467f60a3d14f08f86f2b353298d2826382ff23.tar.gz
linux-stable-75467f60a3d14f08f86f2b353298d2826382ff23.zip
Merge tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipegrafted
Pull IPE fixes from Fan Wu: "Two fixes for use-after-free issues found by recent LLM-assisted code analysis. - move successful policy load auditing under the new policy directory's inode lock, preventing a concurrent policy deletion from freeing the policy while it is still being audited - protect the dm-verity root hash with RCU, preventing policy evaluation from racing with root hash replacement during preresume" * tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipe: ipe: protect the dm-verity root hash with RCU ipe: fix use-after-free when auditing a newly loaded policy
Diffstat (limited to 'drivers/video/fbdev/bt455.h')
-rw-r--r--drivers/video/fbdev/bt455.h90
1 files changed, 90 insertions, 0 deletions
diff --git a/drivers/video/fbdev/bt455.h b/drivers/video/fbdev/bt455.h
new file mode 100644
index 000000000..dd1404b40
--- /dev/null
+++ b/drivers/video/fbdev/bt455.h
@@ -0,0 +1,90 @@
+/*
+ * linux/drivers/video/bt455.h
+ *
+ * Copyright 2003 Thiemo Seufer <seufer@csv.ica.uni-stuttgart.de>
+ * Copyright 2016 Maciej W. Rozycki <macro@linux-mips.org>
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file COPYING in the main directory of this
+ * archive for more details.
+ */
+#include <linux/types.h>
+
+/*
+ * Bt455 byte-wide registers, 32-bit aligned.
+ */
+struct bt455_regs {
+ volatile u8 addr_cmap;
+ u8 pad0[3];
+ volatile u8 addr_cmap_data;
+ u8 pad1[3];
+ volatile u8 addr_clr;
+ u8 pad2[3];
+ volatile u8 addr_ovly;
+ u8 pad3[3];
+};
+
+static inline void bt455_select_reg(struct bt455_regs *regs, int ir)
+{
+ mb();
+ regs->addr_cmap = ir & 0x0f;
+}
+
+static inline void bt455_reset_reg(struct bt455_regs *regs)
+{
+ mb();
+ regs->addr_clr = 0;
+}
+
+/*
+ * Read/write to a Bt455 color map register.
+ */
+static inline void bt455_read_cmap_next(struct bt455_regs *regs, u8 *grey)
+{
+ mb();
+ regs->addr_cmap_data;
+ rmb();
+ *grey = regs->addr_cmap_data & 0xf;
+ rmb();
+ regs->addr_cmap_data;
+}
+
+static inline void bt455_write_cmap_next(struct bt455_regs *regs, u8 grey)
+{
+ wmb();
+ regs->addr_cmap_data = 0x0;
+ wmb();
+ regs->addr_cmap_data = grey & 0xf;
+ wmb();
+ regs->addr_cmap_data = 0x0;
+}
+
+static inline void bt455_write_ovly_next(struct bt455_regs *regs, u8 grey)
+{
+ wmb();
+ regs->addr_ovly = 0x0;
+ wmb();
+ regs->addr_ovly = grey & 0xf;
+ wmb();
+ regs->addr_ovly = 0x0;
+}
+
+static inline void bt455_read_cmap_entry(struct bt455_regs *regs,
+ int cr, u8 *grey)
+{
+ bt455_select_reg(regs, cr);
+ bt455_read_cmap_next(regs, grey);
+}
+
+static inline void bt455_write_cmap_entry(struct bt455_regs *regs,
+ int cr, u8 grey)
+{
+ bt455_select_reg(regs, cr);
+ bt455_write_cmap_next(regs, grey);
+}
+
+static inline void bt455_write_ovly_entry(struct bt455_regs *regs, u8 grey)
+{
+ bt455_reset_reg(regs);
+ bt455_write_ovly_next(regs, grey);
+}