Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

1 files changed, 169 insertions, 0 deletions

diff --git a/drivers/android/dbitmap.h b/drivers/android/dbitmap.h
new file mode 100644
index 000000000..c7299ce8b
--- /dev/null
+++ b/drivers/android/dbitmap.h
@@ -0,0 +1,169 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2024 Google LLC
+ *
+ * dbitmap - dynamically sized bitmap library.
+ *
+ * Used by the binder driver to optimize the allocation of the smallest
+ * available descriptor ID. Each bit in the bitmap represents the state
+ * of an ID.
+ *
+ * A dbitmap can grow or shrink as needed. This part has been designed
+ * considering that users might need to briefly release their locks in
+ * order to allocate memory for the new bitmap. These operations then,
+ * are verified to determine if the grow or shrink is sill valid.
+ *
+ * This library does not provide protection against concurrent access
+ * by itself. Binder uses the proc->outer_lock for this purpose.
+ */
+
+#ifndef _LINUX_DBITMAP_H
+#define _LINUX_DBITMAP_H
+#include <linux/bitmap.h>
+
+#define NBITS_MIN	BITS_PER_TYPE(unsigned long)
+
+struct dbitmap {
+	unsigned int nbits;
+	unsigned long *map;
+};
+
+static inline int dbitmap_enabled(struct dbitmap *dmap)
+{
+	return !!dmap->nbits;
+}
+
+static inline void dbitmap_free(struct dbitmap *dmap)
+{
+	dmap->nbits = 0;
+	kfree(dmap->map);
+	dmap->map = NULL;
+}
+
+/* Returns the nbits that a dbitmap can shrink to, 0 if not possible. */
+static inline unsigned int dbitmap_shrink_nbits(struct dbitmap *dmap)
+{
+	unsigned int bit;
+
+	if (dmap->nbits <= NBITS_MIN)
+		return 0;
+
+	/*
+	 * Determine if the bitmap can shrink based on the position of
+	 * its last set bit. If the bit is within the first quarter of
+	 * the bitmap then shrinking is possible. In this case, the
+	 * bitmap should shrink to half its current size.
+	 */
+	bit = find_last_bit(dmap->map, dmap->nbits);
+	if (bit < (dmap->nbits >> 2))
+		return dmap->nbits >> 1;
+
+	/* find_last_bit() returns dmap->nbits when no bits are set. */
+	if (bit == dmap->nbits)
+		return NBITS_MIN;
+
+	return 0;
+}
+
+/* Replace the internal bitmap with a new one of different size */
+static inline void
+dbitmap_replace(struct dbitmap *dmap, unsigned long *new, unsigned int nbits)
+{
+	bitmap_copy(new, dmap->map, min(dmap->nbits, nbits));
+	kfree(dmap->map);
+	dmap->map = new;
+	dmap->nbits = nbits;
+}
+
+static inline void
+dbitmap_shrink(struct dbitmap *dmap, unsigned long *new, unsigned int nbits)
+{
+	if (!new)
+		return;
+
+	/*
+	 * Verify that shrinking to @nbits is still possible. The @new
+	 * bitmap might have been allocated without locks, so this call
+	 * could now be outdated. In this case, free @new and move on.
+	 */
+	if (!dbitmap_enabled(dmap) || dbitmap_shrink_nbits(dmap) != nbits) {
+		kfree(new);
+		return;
+	}
+
+	dbitmap_replace(dmap, new, nbits);
+}
+
+/* Returns the nbits that a dbitmap can grow to. */
+static inline unsigned int dbitmap_grow_nbits(struct dbitmap *dmap)
+{
+	return dmap->nbits << 1;
+}
+
+static inline void
+dbitmap_grow(struct dbitmap *dmap, unsigned long *new, unsigned int nbits)
+{
+	/*
+	 * Verify that growing to @nbits is still possible. The @new
+	 * bitmap might have been allocated without locks, so this call
+	 * could now be outdated. In this case, free @new and move on.
+	 */
+	if (!dbitmap_enabled(dmap) || nbits <= dmap->nbits) {
+		kfree(new);
+		return;
+	}
+
+	/*
+	 * Check for ENOMEM after confirming the grow operation is still
+	 * required. This ensures we only disable the dbitmap when it's
+	 * necessary. Once the dbitmap is disabled, binder will fallback
+	 * to slow_desc_lookup_olocked().
+	 */
+	if (!new) {
+		dbitmap_free(dmap);
+		return;
+	}
+
+	dbitmap_replace(dmap, new, nbits);
+}
+
+/*
+ * Finds and sets the next zero bit in the bitmap. Upon success @bit
+ * is populated with the index and 0 is returned. Otherwise, -ENOSPC
+ * is returned to indicate that a dbitmap_grow() is needed.
+ */
+static inline int
+dbitmap_acquire_next_zero_bit(struct dbitmap *dmap, unsigned long offset,
+			      unsigned long *bit)
+{
+	unsigned long n;
+
+	n = find_next_zero_bit(dmap->map, dmap->nbits, offset);
+	if (n == dmap->nbits)
+		return -ENOSPC;
+
+	*bit = n;
+	set_bit(n, dmap->map);
+
+	return 0;
+}
+
+static inline void
+dbitmap_clear_bit(struct dbitmap *dmap, unsigned long bit)
+{
+	clear_bit(bit, dmap->map);
+}
+
+static inline int dbitmap_init(struct dbitmap *dmap)
+{
+	dmap->map = bitmap_zalloc(NBITS_MIN, GFP_KERNEL);
+	if (!dmap->map) {
+		dmap->nbits = 0;
+		return -ENOMEM;
+	}
+
+	dmap->nbits = NBITS_MIN;
+
+	return 0;
+}
+#endif