summaryrefslogtreecommitdiffstats
path: root/net/lapb/lapb_subr.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /net/lapb/lapb_subr.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
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 ...
Diffstat (limited to 'net/lapb/lapb_subr.c')
-rw-r--r--net/lapb/lapb_subr.c299
1 files changed, 299 insertions, 0 deletions
diff --git a/net/lapb/lapb_subr.c b/net/lapb/lapb_subr.c
new file mode 100644
index 000000000..592a22d86
--- /dev/null
+++ b/net/lapb/lapb_subr.c
@@ -0,0 +1,299 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * LAPB release 002
+ *
+ * This code REQUIRES 2.1.15 or higher/ NET3.038
+ *
+ * History
+ * LAPB 001 Jonathan Naylor Started Coding
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/inet.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <linux/uaccess.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <net/lapb.h>
+
+/*
+ * This routine purges all the queues of frames.
+ */
+void lapb_clear_queues(struct lapb_cb *lapb)
+{
+ skb_queue_purge(&lapb->write_queue);
+ skb_queue_purge(&lapb->ack_queue);
+}
+
+/*
+ * This routine purges the input queue of those frames that have been
+ * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
+ * SDL diagram.
+ */
+void lapb_frames_acked(struct lapb_cb *lapb, unsigned short nr)
+{
+ struct sk_buff *skb;
+ int modulus;
+
+ modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS;
+
+ /*
+ * Remove all the ack-ed frames from the ack queue.
+ */
+ if (lapb->va != nr)
+ while (skb_peek(&lapb->ack_queue) && lapb->va != nr) {
+ skb = skb_dequeue(&lapb->ack_queue);
+ kfree_skb(skb);
+ lapb->va = (lapb->va + 1) % modulus;
+ }
+}
+
+void lapb_requeue_frames(struct lapb_cb *lapb)
+{
+ struct sk_buff *skb, *skb_prev = NULL;
+
+ /*
+ * Requeue all the un-ack-ed frames on the output queue to be picked
+ * up by lapb_kick called from the timer. This arrangement handles the
+ * possibility of an empty output queue.
+ */
+ while ((skb = skb_dequeue(&lapb->ack_queue)) != NULL) {
+ if (!skb_prev)
+ skb_queue_head(&lapb->write_queue, skb);
+ else
+ skb_append(skb_prev, skb, &lapb->write_queue);
+ skb_prev = skb;
+ }
+}
+
+/*
+ * Validate that the value of nr is between va and vs. Return true or
+ * false for testing.
+ */
+int lapb_validate_nr(struct lapb_cb *lapb, unsigned short nr)
+{
+ unsigned short vc = lapb->va;
+ int modulus;
+
+ modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS;
+
+ while (vc != lapb->vs) {
+ if (nr == vc)
+ return 1;
+ vc = (vc + 1) % modulus;
+ }
+
+ return nr == lapb->vs;
+}
+
+/*
+ * This routine is the centralised routine for parsing the control
+ * information for the different frame formats.
+ */
+int lapb_decode(struct lapb_cb *lapb, struct sk_buff *skb,
+ struct lapb_frame *frame)
+{
+ frame->type = LAPB_ILLEGAL;
+
+ lapb_dbg(2, "(%p) S%d RX %3ph\n", lapb->dev, lapb->state, skb->data);
+
+ /* We always need to look at 2 bytes, sometimes we need
+ * to look at 3 and those cases are handled below.
+ */
+ if (!pskb_may_pull(skb, 2))
+ return -1;
+
+ if (lapb->mode & LAPB_MLP) {
+ if (lapb->mode & LAPB_DCE) {
+ if (skb->data[0] == LAPB_ADDR_D)
+ frame->cr = LAPB_COMMAND;
+ if (skb->data[0] == LAPB_ADDR_C)
+ frame->cr = LAPB_RESPONSE;
+ } else {
+ if (skb->data[0] == LAPB_ADDR_C)
+ frame->cr = LAPB_COMMAND;
+ if (skb->data[0] == LAPB_ADDR_D)
+ frame->cr = LAPB_RESPONSE;
+ }
+ } else {
+ if (lapb->mode & LAPB_DCE) {
+ if (skb->data[0] == LAPB_ADDR_B)
+ frame->cr = LAPB_COMMAND;
+ if (skb->data[0] == LAPB_ADDR_A)
+ frame->cr = LAPB_RESPONSE;
+ } else {
+ if (skb->data[0] == LAPB_ADDR_A)
+ frame->cr = LAPB_COMMAND;
+ if (skb->data[0] == LAPB_ADDR_B)
+ frame->cr = LAPB_RESPONSE;
+ }
+ }
+
+ skb_pull(skb, 1);
+
+ if (lapb->mode & LAPB_EXTENDED) {
+ if (!(skb->data[0] & LAPB_S)) {
+ if (!pskb_may_pull(skb, 2))
+ return -1;
+ /*
+ * I frame - carries NR/NS/PF
+ */
+ frame->type = LAPB_I;
+ frame->ns = (skb->data[0] >> 1) & 0x7F;
+ frame->nr = (skb->data[1] >> 1) & 0x7F;
+ frame->pf = skb->data[1] & LAPB_EPF;
+ frame->control[0] = skb->data[0];
+ frame->control[1] = skb->data[1];
+ skb_pull(skb, 2);
+ } else if ((skb->data[0] & LAPB_U) == 1) {
+ if (!pskb_may_pull(skb, 2))
+ return -1;
+ /*
+ * S frame - take out PF/NR
+ */
+ frame->type = skb->data[0] & 0x0F;
+ frame->nr = (skb->data[1] >> 1) & 0x7F;
+ frame->pf = skb->data[1] & LAPB_EPF;
+ frame->control[0] = skb->data[0];
+ frame->control[1] = skb->data[1];
+ skb_pull(skb, 2);
+ } else if ((skb->data[0] & LAPB_U) == 3) {
+ /*
+ * U frame - take out PF
+ */
+ frame->type = skb->data[0] & ~LAPB_SPF;
+ frame->pf = skb->data[0] & LAPB_SPF;
+ frame->control[0] = skb->data[0];
+ frame->control[1] = 0x00;
+ skb_pull(skb, 1);
+ }
+ } else {
+ if (!(skb->data[0] & LAPB_S)) {
+ /*
+ * I frame - carries NR/NS/PF
+ */
+ frame->type = LAPB_I;
+ frame->ns = (skb->data[0] >> 1) & 0x07;
+ frame->nr = (skb->data[0] >> 5) & 0x07;
+ frame->pf = skb->data[0] & LAPB_SPF;
+ } else if ((skb->data[0] & LAPB_U) == 1) {
+ /*
+ * S frame - take out PF/NR
+ */
+ frame->type = skb->data[0] & 0x0F;
+ frame->nr = (skb->data[0] >> 5) & 0x07;
+ frame->pf = skb->data[0] & LAPB_SPF;
+ } else if ((skb->data[0] & LAPB_U) == 3) {
+ /*
+ * U frame - take out PF
+ */
+ frame->type = skb->data[0] & ~LAPB_SPF;
+ frame->pf = skb->data[0] & LAPB_SPF;
+ }
+
+ frame->control[0] = skb->data[0];
+
+ skb_pull(skb, 1);
+ }
+
+ return 0;
+}
+
+/*
+ * This routine is called when the HDLC layer internally generates a
+ * command or response for the remote machine ( eg. RR, UA etc. ).
+ * Only supervisory or unnumbered frames are processed, FRMRs are handled
+ * by lapb_transmit_frmr below.
+ */
+void lapb_send_control(struct lapb_cb *lapb, int frametype,
+ int poll_bit, int type)
+{
+ struct sk_buff *skb;
+ unsigned char *dptr;
+
+ if ((skb = alloc_skb(LAPB_HEADER_LEN + 3, GFP_ATOMIC)) == NULL)
+ return;
+
+ skb_reserve(skb, LAPB_HEADER_LEN + 1);
+
+ if (lapb->mode & LAPB_EXTENDED) {
+ if ((frametype & LAPB_U) == LAPB_U) {
+ dptr = skb_put(skb, 1);
+ *dptr = frametype;
+ *dptr |= poll_bit ? LAPB_SPF : 0;
+ } else {
+ dptr = skb_put(skb, 2);
+ dptr[0] = frametype;
+ dptr[1] = (lapb->vr << 1);
+ dptr[1] |= poll_bit ? LAPB_EPF : 0;
+ }
+ } else {
+ dptr = skb_put(skb, 1);
+ *dptr = frametype;
+ *dptr |= poll_bit ? LAPB_SPF : 0;
+ if ((frametype & LAPB_U) == LAPB_S) /* S frames carry NR */
+ *dptr |= (lapb->vr << 5);
+ }
+
+ lapb_transmit_buffer(lapb, skb, type);
+}
+
+/*
+ * This routine generates FRMRs based on information previously stored in
+ * the LAPB control block.
+ */
+void lapb_transmit_frmr(struct lapb_cb *lapb)
+{
+ struct sk_buff *skb;
+ unsigned char *dptr;
+
+ if ((skb = alloc_skb(LAPB_HEADER_LEN + 7, GFP_ATOMIC)) == NULL)
+ return;
+
+ skb_reserve(skb, LAPB_HEADER_LEN + 1);
+
+ if (lapb->mode & LAPB_EXTENDED) {
+ dptr = skb_put(skb, 6);
+ *dptr++ = LAPB_FRMR;
+ *dptr++ = lapb->frmr_data.control[0];
+ *dptr++ = lapb->frmr_data.control[1];
+ *dptr++ = (lapb->vs << 1) & 0xFE;
+ *dptr = (lapb->vr << 1) & 0xFE;
+ if (lapb->frmr_data.cr == LAPB_RESPONSE)
+ *dptr |= 0x01;
+ dptr++;
+ *dptr++ = lapb->frmr_type;
+
+ lapb_dbg(1, "(%p) S%d TX FRMR %5ph\n",
+ lapb->dev, lapb->state,
+ &skb->data[1]);
+ } else {
+ dptr = skb_put(skb, 4);
+ *dptr++ = LAPB_FRMR;
+ *dptr++ = lapb->frmr_data.control[0];
+ *dptr = (lapb->vs << 1) & 0x0E;
+ *dptr |= (lapb->vr << 5) & 0xE0;
+ if (lapb->frmr_data.cr == LAPB_RESPONSE)
+ *dptr |= 0x10;
+ dptr++;
+ *dptr++ = lapb->frmr_type;
+
+ lapb_dbg(1, "(%p) S%d TX FRMR %3ph\n",
+ lapb->dev, lapb->state, &skb->data[1]);
+ }
+
+ lapb_transmit_buffer(lapb, skb, LAPB_RESPONSE);
+}