aboutsummaryrefslogtreecommitdiff
path: root/drivers/char/agp/isoch.c
diff options
context:
space:
mode:
authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /drivers/char/agp/isoch.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'drivers/char/agp/isoch.c')
-rw-r--r--drivers/char/agp/isoch.c465
1 files changed, 465 insertions, 0 deletions
diff --git a/drivers/char/agp/isoch.c b/drivers/char/agp/isoch.c
new file mode 100644
index 000000000..7ecf20a6d
--- /dev/null
+++ b/drivers/char/agp/isoch.c
@@ -0,0 +1,465 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Setup routines for AGP 3.5 compliant bridges.
+ */
+
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <linux/agp_backend.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include "agp.h"
+
+/* Generic AGP 3.5 enabling routines */
+
+struct agp_3_5_dev {
+ struct list_head list;
+ u8 capndx;
+ u32 maxbw;
+ struct pci_dev *dev;
+};
+
+static void agp_3_5_dev_list_insert(struct list_head *head, struct list_head *new)
+{
+ struct agp_3_5_dev *cur, *n = list_entry(new, struct agp_3_5_dev, list);
+ struct list_head *pos;
+
+ list_for_each(pos, head) {
+ cur = list_entry(pos, struct agp_3_5_dev, list);
+ if (cur->maxbw > n->maxbw)
+ break;
+ }
+ list_add_tail(new, pos);
+}
+
+static void agp_3_5_dev_list_sort(struct agp_3_5_dev *list, unsigned int ndevs)
+{
+ struct agp_3_5_dev *cur;
+ struct pci_dev *dev;
+ struct list_head *pos, *tmp, *head = &list->list, *start = head->next;
+ u32 nistat;
+
+ INIT_LIST_HEAD(head);
+
+ for (pos=start; pos!=head; ) {
+ cur = list_entry(pos, struct agp_3_5_dev, list);
+ dev = cur->dev;
+
+ pci_read_config_dword(dev, cur->capndx+AGPNISTAT, &nistat);
+ cur->maxbw = (nistat >> 16) & 0xff;
+
+ tmp = pos;
+ pos = pos->next;
+ agp_3_5_dev_list_insert(head, tmp);
+ }
+}
+
+/*
+ * Initialize all isochronous transfer parameters for an AGP 3.0
+ * node (i.e. a host bridge in combination with the adapters
+ * lying behind it...)
+ */
+
+static int agp_3_5_isochronous_node_enable(struct agp_bridge_data *bridge,
+ struct agp_3_5_dev *dev_list, unsigned int ndevs)
+{
+ /*
+ * Convenience structure to make the calculations clearer
+ * here. The field names come straight from the AGP 3.0 spec.
+ */
+ struct isoch_data {
+ u32 maxbw;
+ u32 n;
+ u32 y;
+ u32 l;
+ u32 rq;
+ struct agp_3_5_dev *dev;
+ };
+
+ struct pci_dev *td = bridge->dev, *dev;
+ struct list_head *head = &dev_list->list, *pos;
+ struct agp_3_5_dev *cur;
+ struct isoch_data *master, target;
+ unsigned int cdev = 0;
+ u32 mnistat, tnistat, tstatus, mcmd;
+ u16 tnicmd, mnicmd;
+ u32 tot_bw = 0, tot_n = 0, tot_rq = 0, y_max, rq_isoch, rq_async;
+ u32 step, rem, rem_isoch, rem_async;
+ int ret = 0;
+
+ /*
+ * We'll work with an array of isoch_data's (one for each
+ * device in dev_list) throughout this function.
+ */
+ master = kmalloc_array(ndevs, sizeof(*master), GFP_KERNEL);
+ if (master == NULL) {
+ ret = -ENOMEM;
+ goto get_out;
+ }
+
+ /*
+ * Sort the device list by maxbw. We need to do this because the
+ * spec suggests that the devices with the smallest requirements
+ * have their resources allocated first, with all remaining resources
+ * falling to the device with the largest requirement.
+ *
+ * We don't exactly do this, we divide target resources by ndevs
+ * and split them amongst the AGP 3.0 devices. The remainder of such
+ * division operations are dropped on the last device, sort of like
+ * the spec mentions it should be done.
+ *
+ * We can't do this sort when we initially construct the dev_list
+ * because we don't know until this function whether isochronous
+ * transfers are enabled and consequently whether maxbw will mean
+ * anything.
+ */
+ agp_3_5_dev_list_sort(dev_list, ndevs);
+
+ pci_read_config_dword(td, bridge->capndx+AGPNISTAT, &tnistat);
+ pci_read_config_dword(td, bridge->capndx+AGPSTAT, &tstatus);
+
+ /* Extract power-on defaults from the target */
+ target.maxbw = (tnistat >> 16) & 0xff;
+ target.n = (tnistat >> 8) & 0xff;
+ target.y = (tnistat >> 6) & 0x3;
+ target.l = (tnistat >> 3) & 0x7;
+ target.rq = (tstatus >> 24) & 0xff;
+
+ y_max = target.y;
+
+ /*
+ * Extract power-on defaults for each device in dev_list. Along
+ * the way, calculate the total isochronous bandwidth required
+ * by these devices and the largest requested payload size.
+ */
+ list_for_each(pos, head) {
+ cur = list_entry(pos, struct agp_3_5_dev, list);
+ dev = cur->dev;
+
+ pci_read_config_dword(dev, cur->capndx+AGPNISTAT, &mnistat);
+
+ master[cdev].maxbw = (mnistat >> 16) & 0xff;
+ master[cdev].n = (mnistat >> 8) & 0xff;
+ master[cdev].y = (mnistat >> 6) & 0x3;
+ master[cdev].dev = cur;
+
+ tot_bw += master[cdev].maxbw;
+ y_max = max(y_max, master[cdev].y);
+
+ cdev++;
+ }
+
+ /* Check if this configuration has any chance of working */
+ if (tot_bw > target.maxbw) {
+ dev_err(&td->dev, "isochronous bandwidth required "
+ "by AGP 3.0 devices exceeds that which is supported by "
+ "the AGP 3.0 bridge!\n");
+ ret = -ENODEV;
+ goto free_and_exit;
+ }
+
+ target.y = y_max;
+
+ /*
+ * Write the calculated payload size into the target's NICMD
+ * register. Doing this directly effects the ISOCH_N value
+ * in the target's NISTAT register, so we need to do this now
+ * to get an accurate value for ISOCH_N later.
+ */
+ pci_read_config_word(td, bridge->capndx+AGPNICMD, &tnicmd);
+ tnicmd &= ~(0x3 << 6);
+ tnicmd |= target.y << 6;
+ pci_write_config_word(td, bridge->capndx+AGPNICMD, tnicmd);
+
+ /* Reread the target's ISOCH_N */
+ pci_read_config_dword(td, bridge->capndx+AGPNISTAT, &tnistat);
+ target.n = (tnistat >> 8) & 0xff;
+
+ /* Calculate the minimum ISOCH_N needed by each master */
+ for (cdev=0; cdev<ndevs; cdev++) {
+ master[cdev].y = target.y;
+ master[cdev].n = master[cdev].maxbw / (master[cdev].y + 1);
+
+ tot_n += master[cdev].n;
+ }
+
+ /* Exit if the minimal ISOCH_N allocation among the masters is more
+ * than the target can handle. */
+ if (tot_n > target.n) {
+ dev_err(&td->dev, "number of isochronous "
+ "transactions per period required by AGP 3.0 devices "
+ "exceeds that which is supported by the AGP 3.0 "
+ "bridge!\n");
+ ret = -ENODEV;
+ goto free_and_exit;
+ }
+
+ /* Calculate left over ISOCH_N capability in the target. We'll give
+ * this to the hungriest device (as per the spec) */
+ rem = target.n - tot_n;
+
+ /*
+ * Calculate the minimum isochronous RQ depth needed by each master.
+ * Along the way, distribute the extra ISOCH_N capability calculated
+ * above.
+ */
+ for (cdev=0; cdev<ndevs; cdev++) {
+ /*
+ * This is a little subtle. If ISOCH_Y > 64B, then ISOCH_Y
+ * byte isochronous writes will be broken into 64B pieces.
+ * This means we need to budget more RQ depth to account for
+ * these kind of writes (each isochronous write is actually
+ * many writes on the AGP bus).
+ */
+ master[cdev].rq = master[cdev].n;
+ if (master[cdev].y > 0x1)
+ master[cdev].rq *= (1 << (master[cdev].y - 1));
+
+ tot_rq += master[cdev].rq;
+ }
+ master[ndevs-1].n += rem;
+
+ /* Figure the number of isochronous and asynchronous RQ slots the
+ * target is providing. */
+ rq_isoch = (target.y > 0x1) ? target.n * (1 << (target.y - 1)) : target.n;
+ rq_async = target.rq - rq_isoch;
+
+ /* Exit if the minimal RQ needs of the masters exceeds what the target
+ * can provide. */
+ if (tot_rq > rq_isoch) {
+ dev_err(&td->dev, "number of request queue slots "
+ "required by the isochronous bandwidth requested by "
+ "AGP 3.0 devices exceeds the number provided by the "
+ "AGP 3.0 bridge!\n");
+ ret = -ENODEV;
+ goto free_and_exit;
+ }
+
+ /* Calculate asynchronous RQ capability in the target (per master) as
+ * well as the total number of leftover isochronous RQ slots. */
+ step = rq_async / ndevs;
+ rem_async = step + (rq_async % ndevs);
+ rem_isoch = rq_isoch - tot_rq;
+
+ /* Distribute the extra RQ slots calculated above and write our
+ * isochronous settings out to the actual devices. */
+ for (cdev=0; cdev<ndevs; cdev++) {
+ cur = master[cdev].dev;
+ dev = cur->dev;
+
+ master[cdev].rq += (cdev == ndevs - 1)
+ ? (rem_async + rem_isoch) : step;
+
+ pci_read_config_word(dev, cur->capndx+AGPNICMD, &mnicmd);
+ pci_read_config_dword(dev, cur->capndx+AGPCMD, &mcmd);
+
+ mnicmd &= ~(0xff << 8);
+ mnicmd &= ~(0x3 << 6);
+ mcmd &= ~(0xff << 24);
+
+ mnicmd |= master[cdev].n << 8;
+ mnicmd |= master[cdev].y << 6;
+ mcmd |= master[cdev].rq << 24;
+
+ pci_write_config_dword(dev, cur->capndx+AGPCMD, mcmd);
+ pci_write_config_word(dev, cur->capndx+AGPNICMD, mnicmd);
+ }
+
+free_and_exit:
+ kfree(master);
+
+get_out:
+ return ret;
+}
+
+/*
+ * This function basically allocates request queue slots among the
+ * AGP 3.0 systems in nonisochronous nodes. The algorithm is
+ * pretty stupid, divide the total number of RQ slots provided by the
+ * target by ndevs. Distribute this many slots to each AGP 3.0 device,
+ * giving any left over slots to the last device in dev_list.
+ */
+static void agp_3_5_nonisochronous_node_enable(struct agp_bridge_data *bridge,
+ struct agp_3_5_dev *dev_list, unsigned int ndevs)
+{
+ struct agp_3_5_dev *cur;
+ struct list_head *head = &dev_list->list, *pos;
+ u32 tstatus, mcmd;
+ u32 trq, mrq, rem;
+ unsigned int cdev = 0;
+
+ pci_read_config_dword(bridge->dev, bridge->capndx+AGPSTAT, &tstatus);
+
+ trq = (tstatus >> 24) & 0xff;
+ mrq = trq / ndevs;
+
+ rem = mrq + (trq % ndevs);
+
+ for (pos=head->next; cdev<ndevs; cdev++, pos=pos->next) {
+ cur = list_entry(pos, struct agp_3_5_dev, list);
+
+ pci_read_config_dword(cur->dev, cur->capndx+AGPCMD, &mcmd);
+ mcmd &= ~(0xff << 24);
+ mcmd |= ((cdev == ndevs - 1) ? rem : mrq) << 24;
+ pci_write_config_dword(cur->dev, cur->capndx+AGPCMD, mcmd);
+ }
+}
+
+/*
+ * Fully configure and enable an AGP 3.0 host bridge and all the devices
+ * lying behind it.
+ */
+int agp_3_5_enable(struct agp_bridge_data *bridge)
+{
+ struct pci_dev *td = bridge->dev, *dev = NULL;
+ u8 mcapndx;
+ u32 isoch;
+ u32 tstatus, mstatus, ncapid;
+ u32 mmajor;
+ u16 mpstat;
+ struct agp_3_5_dev *dev_list, *cur;
+ struct list_head *head, *pos;
+ unsigned int ndevs = 0;
+ int ret = 0;
+
+ /* Extract some power-on defaults from the target */
+ pci_read_config_dword(td, bridge->capndx+AGPSTAT, &tstatus);
+ isoch = (tstatus >> 17) & 0x1;
+ if (isoch == 0) /* isoch xfers not available, bail out. */
+ return -ENODEV;
+
+ /*
+ * Allocate a head for our AGP 3.5 device list
+ * (multiple AGP v3 devices are allowed behind a single bridge).
+ */
+ if ((dev_list = kmalloc(sizeof(*dev_list), GFP_KERNEL)) == NULL) {
+ ret = -ENOMEM;
+ goto get_out;
+ }
+ head = &dev_list->list;
+ INIT_LIST_HEAD(head);
+
+ /* Find all AGP devices, and add them to dev_list. */
+ for_each_pci_dev(dev) {
+ mcapndx = pci_find_capability(dev, PCI_CAP_ID_AGP);
+ if (mcapndx == 0)
+ continue;
+
+ switch ((dev->class >>8) & 0xff00) {
+ case 0x0600: /* Bridge */
+ /* Skip bridges. We should call this function for each one. */
+ continue;
+
+ case 0x0001: /* Unclassified device */
+ /* Don't know what this is, but log it for investigation. */
+ if (mcapndx != 0) {
+ dev_info(&td->dev, "wacky, found unclassified AGP device %s [%04x/%04x]\n",
+ pci_name(dev),
+ dev->vendor, dev->device);
+ }
+ continue;
+
+ case 0x0300: /* Display controller */
+ case 0x0400: /* Multimedia controller */
+ if ((cur = kmalloc(sizeof(*cur), GFP_KERNEL)) == NULL) {
+ ret = -ENOMEM;
+ goto free_and_exit;
+ }
+ cur->dev = dev;
+
+ pos = &cur->list;
+ list_add(pos, head);
+ ndevs++;
+ continue;
+
+ default:
+ continue;
+ }
+ }
+
+ /*
+ * Take an initial pass through the devices lying behind our host
+ * bridge. Make sure each one is actually an AGP 3.0 device, otherwise
+ * exit with an error message. Along the way store the AGP 3.0
+ * cap_ptr for each device
+ */
+ list_for_each(pos, head) {
+ cur = list_entry(pos, struct agp_3_5_dev, list);
+ dev = cur->dev;
+
+ pci_read_config_word(dev, PCI_STATUS, &mpstat);
+ if ((mpstat & PCI_STATUS_CAP_LIST) == 0)
+ continue;
+
+ pci_read_config_byte(dev, PCI_CAPABILITY_LIST, &mcapndx);
+ if (mcapndx != 0) {
+ do {
+ pci_read_config_dword(dev, mcapndx, &ncapid);
+ if ((ncapid & 0xff) != 2)
+ mcapndx = (ncapid >> 8) & 0xff;
+ }
+ while (((ncapid & 0xff) != 2) && (mcapndx != 0));
+ }
+
+ if (mcapndx == 0) {
+ dev_err(&td->dev, "woah! Non-AGP device %s on "
+ "secondary bus of AGP 3.5 bridge!\n",
+ pci_name(dev));
+ ret = -ENODEV;
+ goto free_and_exit;
+ }
+
+ mmajor = (ncapid >> AGP_MAJOR_VERSION_SHIFT) & 0xf;
+ if (mmajor < 3) {
+ dev_err(&td->dev, "woah! AGP 2.0 device %s on "
+ "secondary bus of AGP 3.5 bridge operating "
+ "with AGP 3.0 electricals!\n", pci_name(dev));
+ ret = -ENODEV;
+ goto free_and_exit;
+ }
+
+ cur->capndx = mcapndx;
+
+ pci_read_config_dword(dev, cur->capndx+AGPSTAT, &mstatus);
+
+ if (((mstatus >> 3) & 0x1) == 0) {
+ dev_err(&td->dev, "woah! AGP 3.x device %s not "
+ "operating in AGP 3.x mode on secondary bus "
+ "of AGP 3.5 bridge operating with AGP 3.0 "
+ "electricals!\n", pci_name(dev));
+ ret = -ENODEV;
+ goto free_and_exit;
+ }
+ }
+
+ /*
+ * Call functions to divide target resources amongst the AGP 3.0
+ * masters. This process is dramatically different depending on
+ * whether isochronous transfers are supported.
+ */
+ if (isoch) {
+ ret = agp_3_5_isochronous_node_enable(bridge, dev_list, ndevs);
+ if (ret) {
+ dev_info(&td->dev, "something bad happened setting "
+ "up isochronous xfers; falling back to "
+ "non-isochronous xfer mode\n");
+ } else {
+ goto free_and_exit;
+ }
+ }
+ agp_3_5_nonisochronous_node_enable(bridge, dev_list, ndevs);
+
+free_and_exit:
+ /* Be sure to free the dev_list */
+ for (pos=head->next; pos!=head; ) {
+ cur = list_entry(pos, struct agp_3_5_dev, list);
+
+ pos = pos->next;
+ kfree(cur);
+ }
+ kfree(dev_list);
+
+get_out:
+ return ret;
+}