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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/gpu/drm/drm_gem_shmem_helper.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/gpu/drm/drm_gem_shmem_helper.c')
-rw-r--r--drivers/gpu/drm/drm_gem_shmem_helper.c775
1 files changed, 775 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
new file mode 100644
index 000000000..b602cd72a
--- /dev/null
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -0,0 +1,775 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2018 Noralf Trønnes
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/shmem_fs.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/module.h>
+
+#ifdef CONFIG_X86
+#include <asm/set_memory.h>
+#endif
+
+#include <drm/drm.h>
+#include <drm/drm_device.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_gem_shmem_helper.h>
+#include <drm/drm_prime.h>
+#include <drm/drm_print.h>
+
+MODULE_IMPORT_NS(DMA_BUF);
+
+/**
+ * DOC: overview
+ *
+ * This library provides helpers for GEM objects backed by shmem buffers
+ * allocated using anonymous pageable memory.
+ *
+ * Functions that operate on the GEM object receive struct &drm_gem_shmem_object.
+ * For GEM callback helpers in struct &drm_gem_object functions, see likewise
+ * named functions with an _object_ infix (e.g., drm_gem_shmem_object_vmap() wraps
+ * drm_gem_shmem_vmap()). These helpers perform the necessary type conversion.
+ */
+
+static const struct drm_gem_object_funcs drm_gem_shmem_funcs = {
+ .free = drm_gem_shmem_object_free,
+ .print_info = drm_gem_shmem_object_print_info,
+ .pin = drm_gem_shmem_object_pin,
+ .unpin = drm_gem_shmem_object_unpin,
+ .get_sg_table = drm_gem_shmem_object_get_sg_table,
+ .vmap = drm_gem_shmem_object_vmap,
+ .vunmap = drm_gem_shmem_object_vunmap,
+ .mmap = drm_gem_shmem_object_mmap,
+ .vm_ops = &drm_gem_shmem_vm_ops,
+};
+
+static struct drm_gem_shmem_object *
+__drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private)
+{
+ struct drm_gem_shmem_object *shmem;
+ struct drm_gem_object *obj;
+ int ret = 0;
+
+ size = PAGE_ALIGN(size);
+
+ if (dev->driver->gem_create_object) {
+ obj = dev->driver->gem_create_object(dev, size);
+ if (IS_ERR(obj))
+ return ERR_CAST(obj);
+ shmem = to_drm_gem_shmem_obj(obj);
+ } else {
+ shmem = kzalloc(sizeof(*shmem), GFP_KERNEL);
+ if (!shmem)
+ return ERR_PTR(-ENOMEM);
+ obj = &shmem->base;
+ }
+
+ if (!obj->funcs)
+ obj->funcs = &drm_gem_shmem_funcs;
+
+ if (private) {
+ drm_gem_private_object_init(dev, obj, size);
+ shmem->map_wc = false; /* dma-buf mappings use always writecombine */
+ } else {
+ ret = drm_gem_object_init(dev, obj, size);
+ }
+ if (ret)
+ goto err_free;
+
+ ret = drm_gem_create_mmap_offset(obj);
+ if (ret)
+ goto err_release;
+
+ mutex_init(&shmem->pages_lock);
+ mutex_init(&shmem->vmap_lock);
+ INIT_LIST_HEAD(&shmem->madv_list);
+
+ if (!private) {
+ /*
+ * Our buffers are kept pinned, so allocating them
+ * from the MOVABLE zone is a really bad idea, and
+ * conflicts with CMA. See comments above new_inode()
+ * why this is required _and_ expected if you're
+ * going to pin these pages.
+ */
+ mapping_set_gfp_mask(obj->filp->f_mapping, GFP_HIGHUSER |
+ __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
+ }
+
+ return shmem;
+
+err_release:
+ drm_gem_object_release(obj);
+err_free:
+ kfree(obj);
+
+ return ERR_PTR(ret);
+}
+/**
+ * drm_gem_shmem_create - Allocate an object with the given size
+ * @dev: DRM device
+ * @size: Size of the object to allocate
+ *
+ * This function creates a shmem GEM object.
+ *
+ * Returns:
+ * A struct drm_gem_shmem_object * on success or an ERR_PTR()-encoded negative
+ * error code on failure.
+ */
+struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size)
+{
+ return __drm_gem_shmem_create(dev, size, false);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_create);
+
+/**
+ * drm_gem_shmem_free - Free resources associated with a shmem GEM object
+ * @shmem: shmem GEM object to free
+ *
+ * This function cleans up the GEM object state and frees the memory used to
+ * store the object itself.
+ */
+void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem)
+{
+ struct drm_gem_object *obj = &shmem->base;
+
+ WARN_ON(shmem->vmap_use_count);
+
+ if (obj->import_attach) {
+ drm_prime_gem_destroy(obj, shmem->sgt);
+ } else {
+ if (shmem->sgt) {
+ dma_unmap_sgtable(obj->dev->dev, shmem->sgt,
+ DMA_BIDIRECTIONAL, 0);
+ sg_free_table(shmem->sgt);
+ kfree(shmem->sgt);
+ }
+ if (shmem->pages)
+ drm_gem_shmem_put_pages(shmem);
+ }
+
+ WARN_ON(shmem->pages_use_count);
+
+ drm_gem_object_release(obj);
+ mutex_destroy(&shmem->pages_lock);
+ mutex_destroy(&shmem->vmap_lock);
+ kfree(shmem);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_free);
+
+static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem)
+{
+ struct drm_gem_object *obj = &shmem->base;
+ struct page **pages;
+
+ if (shmem->pages_use_count++ > 0)
+ return 0;
+
+ pages = drm_gem_get_pages(obj);
+ if (IS_ERR(pages)) {
+ DRM_DEBUG_KMS("Failed to get pages (%ld)\n", PTR_ERR(pages));
+ shmem->pages_use_count = 0;
+ return PTR_ERR(pages);
+ }
+
+ /*
+ * TODO: Allocating WC pages which are correctly flushed is only
+ * supported on x86. Ideal solution would be a GFP_WC flag, which also
+ * ttm_pool.c could use.
+ */
+#ifdef CONFIG_X86
+ if (shmem->map_wc)
+ set_pages_array_wc(pages, obj->size >> PAGE_SHIFT);
+#endif
+
+ shmem->pages = pages;
+
+ return 0;
+}
+
+/*
+ * drm_gem_shmem_get_pages - Allocate backing pages for a shmem GEM object
+ * @shmem: shmem GEM object
+ *
+ * This function makes sure that backing pages exists for the shmem GEM object
+ * and increases the use count.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
+{
+ int ret;
+
+ WARN_ON(shmem->base.import_attach);
+
+ ret = mutex_lock_interruptible(&shmem->pages_lock);
+ if (ret)
+ return ret;
+ ret = drm_gem_shmem_get_pages_locked(shmem);
+ mutex_unlock(&shmem->pages_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_gem_shmem_get_pages);
+
+static void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem)
+{
+ struct drm_gem_object *obj = &shmem->base;
+
+ if (WARN_ON_ONCE(!shmem->pages_use_count))
+ return;
+
+ if (--shmem->pages_use_count > 0)
+ return;
+
+#ifdef CONFIG_X86
+ if (shmem->map_wc)
+ set_pages_array_wb(shmem->pages, obj->size >> PAGE_SHIFT);
+#endif
+
+ drm_gem_put_pages(obj, shmem->pages,
+ shmem->pages_mark_dirty_on_put,
+ shmem->pages_mark_accessed_on_put);
+ shmem->pages = NULL;
+}
+
+/*
+ * drm_gem_shmem_put_pages - Decrease use count on the backing pages for a shmem GEM object
+ * @shmem: shmem GEM object
+ *
+ * This function decreases the use count and puts the backing pages when use drops to zero.
+ */
+void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem)
+{
+ mutex_lock(&shmem->pages_lock);
+ drm_gem_shmem_put_pages_locked(shmem);
+ mutex_unlock(&shmem->pages_lock);
+}
+EXPORT_SYMBOL(drm_gem_shmem_put_pages);
+
+/**
+ * drm_gem_shmem_pin - Pin backing pages for a shmem GEM object
+ * @shmem: shmem GEM object
+ *
+ * This function makes sure the backing pages are pinned in memory while the
+ * buffer is exported.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem)
+{
+ WARN_ON(shmem->base.import_attach);
+
+ return drm_gem_shmem_get_pages(shmem);
+}
+EXPORT_SYMBOL(drm_gem_shmem_pin);
+
+/**
+ * drm_gem_shmem_unpin - Unpin backing pages for a shmem GEM object
+ * @shmem: shmem GEM object
+ *
+ * This function removes the requirement that the backing pages are pinned in
+ * memory.
+ */
+void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem)
+{
+ WARN_ON(shmem->base.import_attach);
+
+ drm_gem_shmem_put_pages(shmem);
+}
+EXPORT_SYMBOL(drm_gem_shmem_unpin);
+
+static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem,
+ struct iosys_map *map)
+{
+ struct drm_gem_object *obj = &shmem->base;
+ int ret = 0;
+
+ if (shmem->vmap_use_count++ > 0) {
+ iosys_map_set_vaddr(map, shmem->vaddr);
+ return 0;
+ }
+
+ if (obj->import_attach) {
+ ret = dma_buf_vmap(obj->import_attach->dmabuf, map);
+ if (!ret) {
+ if (WARN_ON(map->is_iomem)) {
+ dma_buf_vunmap(obj->import_attach->dmabuf, map);
+ ret = -EIO;
+ goto err_put_pages;
+ }
+ shmem->vaddr = map->vaddr;
+ }
+ } else {
+ pgprot_t prot = PAGE_KERNEL;
+
+ ret = drm_gem_shmem_get_pages(shmem);
+ if (ret)
+ goto err_zero_use;
+
+ if (shmem->map_wc)
+ prot = pgprot_writecombine(prot);
+ shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT,
+ VM_MAP, prot);
+ if (!shmem->vaddr)
+ ret = -ENOMEM;
+ else
+ iosys_map_set_vaddr(map, shmem->vaddr);
+ }
+
+ if (ret) {
+ DRM_DEBUG_KMS("Failed to vmap pages, error %d\n", ret);
+ goto err_put_pages;
+ }
+
+ return 0;
+
+err_put_pages:
+ if (!obj->import_attach)
+ drm_gem_shmem_put_pages(shmem);
+err_zero_use:
+ shmem->vmap_use_count = 0;
+
+ return ret;
+}
+
+/*
+ * drm_gem_shmem_vmap - Create a virtual mapping for a shmem GEM object
+ * @shmem: shmem GEM object
+ * @map: Returns the kernel virtual address of the SHMEM GEM object's backing
+ * store.
+ *
+ * This function makes sure that a contiguous kernel virtual address mapping
+ * exists for the buffer backing the shmem GEM object. It hides the differences
+ * between dma-buf imported and natively allocated objects.
+ *
+ * Acquired mappings should be cleaned up by calling drm_gem_shmem_vunmap().
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem,
+ struct iosys_map *map)
+{
+ int ret;
+
+ ret = mutex_lock_interruptible(&shmem->vmap_lock);
+ if (ret)
+ return ret;
+ ret = drm_gem_shmem_vmap_locked(shmem, map);
+ mutex_unlock(&shmem->vmap_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_gem_shmem_vmap);
+
+static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
+ struct iosys_map *map)
+{
+ struct drm_gem_object *obj = &shmem->base;
+
+ if (WARN_ON_ONCE(!shmem->vmap_use_count))
+ return;
+
+ if (--shmem->vmap_use_count > 0)
+ return;
+
+ if (obj->import_attach) {
+ dma_buf_vunmap(obj->import_attach->dmabuf, map);
+ } else {
+ vunmap(shmem->vaddr);
+ drm_gem_shmem_put_pages(shmem);
+ }
+
+ shmem->vaddr = NULL;
+}
+
+/*
+ * drm_gem_shmem_vunmap - Unmap a virtual mapping for a shmem GEM object
+ * @shmem: shmem GEM object
+ * @map: Kernel virtual address where the SHMEM GEM object was mapped
+ *
+ * This function cleans up a kernel virtual address mapping acquired by
+ * drm_gem_shmem_vmap(). The mapping is only removed when the use count drops to
+ * zero.
+ *
+ * This function hides the differences between dma-buf imported and natively
+ * allocated objects.
+ */
+void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem,
+ struct iosys_map *map)
+{
+ mutex_lock(&shmem->vmap_lock);
+ drm_gem_shmem_vunmap_locked(shmem, map);
+ mutex_unlock(&shmem->vmap_lock);
+}
+EXPORT_SYMBOL(drm_gem_shmem_vunmap);
+
+static struct drm_gem_shmem_object *
+drm_gem_shmem_create_with_handle(struct drm_file *file_priv,
+ struct drm_device *dev, size_t size,
+ uint32_t *handle)
+{
+ struct drm_gem_shmem_object *shmem;
+ int ret;
+
+ shmem = drm_gem_shmem_create(dev, size);
+ if (IS_ERR(shmem))
+ return shmem;
+
+ /*
+ * Allocate an id of idr table where the obj is registered
+ * and handle has the id what user can see.
+ */
+ ret = drm_gem_handle_create(file_priv, &shmem->base, handle);
+ /* drop reference from allocate - handle holds it now. */
+ drm_gem_object_put(&shmem->base);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return shmem;
+}
+
+/* Update madvise status, returns true if not purged, else
+ * false or -errno.
+ */
+int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv)
+{
+ mutex_lock(&shmem->pages_lock);
+
+ if (shmem->madv >= 0)
+ shmem->madv = madv;
+
+ madv = shmem->madv;
+
+ mutex_unlock(&shmem->pages_lock);
+
+ return (madv >= 0);
+}
+EXPORT_SYMBOL(drm_gem_shmem_madvise);
+
+void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem)
+{
+ struct drm_gem_object *obj = &shmem->base;
+ struct drm_device *dev = obj->dev;
+
+ WARN_ON(!drm_gem_shmem_is_purgeable(shmem));
+
+ dma_unmap_sgtable(dev->dev, shmem->sgt, DMA_BIDIRECTIONAL, 0);
+ sg_free_table(shmem->sgt);
+ kfree(shmem->sgt);
+ shmem->sgt = NULL;
+
+ drm_gem_shmem_put_pages_locked(shmem);
+
+ shmem->madv = -1;
+
+ drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping);
+ drm_gem_free_mmap_offset(obj);
+
+ /* Our goal here is to return as much of the memory as
+ * is possible back to the system as we are called from OOM.
+ * To do this we must instruct the shmfs to drop all of its
+ * backing pages, *now*.
+ */
+ shmem_truncate_range(file_inode(obj->filp), 0, (loff_t)-1);
+
+ invalidate_mapping_pages(file_inode(obj->filp)->i_mapping, 0, (loff_t)-1);
+}
+EXPORT_SYMBOL(drm_gem_shmem_purge_locked);
+
+bool drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem)
+{
+ if (!mutex_trylock(&shmem->pages_lock))
+ return false;
+ drm_gem_shmem_purge_locked(shmem);
+ mutex_unlock(&shmem->pages_lock);
+
+ return true;
+}
+EXPORT_SYMBOL(drm_gem_shmem_purge);
+
+/**
+ * drm_gem_shmem_dumb_create - Create a dumb shmem buffer object
+ * @file: DRM file structure to create the dumb buffer for
+ * @dev: DRM device
+ * @args: IOCTL data
+ *
+ * This function computes the pitch of the dumb buffer and rounds it up to an
+ * integer number of bytes per pixel. Drivers for hardware that doesn't have
+ * any additional restrictions on the pitch can directly use this function as
+ * their &drm_driver.dumb_create callback.
+ *
+ * For hardware with additional restrictions, drivers can adjust the fields
+ * set up by userspace before calling into this function.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev,
+ struct drm_mode_create_dumb *args)
+{
+ u32 min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
+ struct drm_gem_shmem_object *shmem;
+
+ if (!args->pitch || !args->size) {
+ args->pitch = min_pitch;
+ args->size = PAGE_ALIGN(args->pitch * args->height);
+ } else {
+ /* ensure sane minimum values */
+ if (args->pitch < min_pitch)
+ args->pitch = min_pitch;
+ if (args->size < args->pitch * args->height)
+ args->size = PAGE_ALIGN(args->pitch * args->height);
+ }
+
+ shmem = drm_gem_shmem_create_with_handle(file, dev, args->size, &args->handle);
+
+ return PTR_ERR_OR_ZERO(shmem);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_dumb_create);
+
+static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf)
+{
+ struct vm_area_struct *vma = vmf->vma;
+ struct drm_gem_object *obj = vma->vm_private_data;
+ struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
+ loff_t num_pages = obj->size >> PAGE_SHIFT;
+ vm_fault_t ret;
+ struct page *page;
+ pgoff_t page_offset;
+
+ /* We don't use vmf->pgoff since that has the fake offset */
+ page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
+
+ mutex_lock(&shmem->pages_lock);
+
+ if (page_offset >= num_pages ||
+ WARN_ON_ONCE(!shmem->pages) ||
+ shmem->madv < 0) {
+ ret = VM_FAULT_SIGBUS;
+ } else {
+ page = shmem->pages[page_offset];
+
+ ret = vmf_insert_pfn(vma, vmf->address, page_to_pfn(page));
+ }
+
+ mutex_unlock(&shmem->pages_lock);
+
+ return ret;
+}
+
+static void drm_gem_shmem_vm_open(struct vm_area_struct *vma)
+{
+ struct drm_gem_object *obj = vma->vm_private_data;
+ struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
+
+ WARN_ON(shmem->base.import_attach);
+
+ mutex_lock(&shmem->pages_lock);
+
+ /*
+ * We should have already pinned the pages when the buffer was first
+ * mmap'd, vm_open() just grabs an additional reference for the new
+ * mm the vma is getting copied into (ie. on fork()).
+ */
+ if (!WARN_ON_ONCE(!shmem->pages_use_count))
+ shmem->pages_use_count++;
+
+ mutex_unlock(&shmem->pages_lock);
+
+ drm_gem_vm_open(vma);
+}
+
+static void drm_gem_shmem_vm_close(struct vm_area_struct *vma)
+{
+ struct drm_gem_object *obj = vma->vm_private_data;
+ struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
+
+ drm_gem_shmem_put_pages(shmem);
+ drm_gem_vm_close(vma);
+}
+
+const struct vm_operations_struct drm_gem_shmem_vm_ops = {
+ .fault = drm_gem_shmem_fault,
+ .open = drm_gem_shmem_vm_open,
+ .close = drm_gem_shmem_vm_close,
+};
+EXPORT_SYMBOL_GPL(drm_gem_shmem_vm_ops);
+
+/**
+ * drm_gem_shmem_mmap - Memory-map a shmem GEM object
+ * @shmem: shmem GEM object
+ * @vma: VMA for the area to be mapped
+ *
+ * This function implements an augmented version of the GEM DRM file mmap
+ * operation for shmem objects.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct *vma)
+{
+ struct drm_gem_object *obj = &shmem->base;
+ int ret;
+
+ if (obj->import_attach) {
+ /* Drop the reference drm_gem_mmap_obj() acquired.*/
+ drm_gem_object_put(obj);
+ vma->vm_private_data = NULL;
+
+ return dma_buf_mmap(obj->dma_buf, vma, 0);
+ }
+
+ ret = drm_gem_shmem_get_pages(shmem);
+ if (ret)
+ return ret;
+
+ vma->vm_flags |= VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
+ vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
+ if (shmem->map_wc)
+ vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_mmap);
+
+/**
+ * drm_gem_shmem_print_info() - Print &drm_gem_shmem_object info for debugfs
+ * @shmem: shmem GEM object
+ * @p: DRM printer
+ * @indent: Tab indentation level
+ */
+void drm_gem_shmem_print_info(const struct drm_gem_shmem_object *shmem,
+ struct drm_printer *p, unsigned int indent)
+{
+ drm_printf_indent(p, indent, "pages_use_count=%u\n", shmem->pages_use_count);
+ drm_printf_indent(p, indent, "vmap_use_count=%u\n", shmem->vmap_use_count);
+ drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr);
+}
+EXPORT_SYMBOL(drm_gem_shmem_print_info);
+
+/**
+ * drm_gem_shmem_get_sg_table - Provide a scatter/gather table of pinned
+ * pages for a shmem GEM object
+ * @shmem: shmem GEM object
+ *
+ * This function exports a scatter/gather table suitable for PRIME usage by
+ * calling the standard DMA mapping API.
+ *
+ * Drivers who need to acquire an scatter/gather table for objects need to call
+ * drm_gem_shmem_get_pages_sgt() instead.
+ *
+ * Returns:
+ * A pointer to the scatter/gather table of pinned pages or error pointer on failure.
+ */
+struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_shmem_object *shmem)
+{
+ struct drm_gem_object *obj = &shmem->base;
+
+ WARN_ON(shmem->base.import_attach);
+
+ return drm_prime_pages_to_sg(obj->dev, shmem->pages, obj->size >> PAGE_SHIFT);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_get_sg_table);
+
+/**
+ * drm_gem_shmem_get_pages_sgt - Pin pages, dma map them, and return a
+ * scatter/gather table for a shmem GEM object.
+ * @shmem: shmem GEM object
+ *
+ * This function returns a scatter/gather table suitable for driver usage. If
+ * the sg table doesn't exist, the pages are pinned, dma-mapped, and a sg
+ * table created.
+ *
+ * This is the main function for drivers to get at backing storage, and it hides
+ * and difference between dma-buf imported and natively allocated objects.
+ * drm_gem_shmem_get_sg_table() should not be directly called by drivers.
+ *
+ * Returns:
+ * A pointer to the scatter/gather table of pinned pages or errno on failure.
+ */
+struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem)
+{
+ struct drm_gem_object *obj = &shmem->base;
+ int ret;
+ struct sg_table *sgt;
+
+ if (shmem->sgt)
+ return shmem->sgt;
+
+ WARN_ON(obj->import_attach);
+
+ ret = drm_gem_shmem_get_pages(shmem);
+ if (ret)
+ return ERR_PTR(ret);
+
+ sgt = drm_gem_shmem_get_sg_table(shmem);
+ if (IS_ERR(sgt)) {
+ ret = PTR_ERR(sgt);
+ goto err_put_pages;
+ }
+ /* Map the pages for use by the h/w. */
+ ret = dma_map_sgtable(obj->dev->dev, sgt, DMA_BIDIRECTIONAL, 0);
+ if (ret)
+ goto err_free_sgt;
+
+ shmem->sgt = sgt;
+
+ return sgt;
+
+err_free_sgt:
+ sg_free_table(sgt);
+ kfree(sgt);
+err_put_pages:
+ drm_gem_shmem_put_pages(shmem);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_get_pages_sgt);
+
+/**
+ * drm_gem_shmem_prime_import_sg_table - Produce a shmem GEM object from
+ * another driver's scatter/gather table of pinned pages
+ * @dev: Device to import into
+ * @attach: DMA-BUF attachment
+ * @sgt: Scatter/gather table of pinned pages
+ *
+ * This function imports a scatter/gather table exported via DMA-BUF by
+ * another driver. Drivers that use the shmem helpers should set this as their
+ * &drm_driver.gem_prime_import_sg_table callback.
+ *
+ * Returns:
+ * A pointer to a newly created GEM object or an ERR_PTR-encoded negative
+ * error code on failure.
+ */
+struct drm_gem_object *
+drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,
+ struct dma_buf_attachment *attach,
+ struct sg_table *sgt)
+{
+ size_t size = PAGE_ALIGN(attach->dmabuf->size);
+ struct drm_gem_shmem_object *shmem;
+
+ shmem = __drm_gem_shmem_create(dev, size, true);
+ if (IS_ERR(shmem))
+ return ERR_CAST(shmem);
+
+ shmem->sgt = sgt;
+
+ DRM_DEBUG_PRIME("size = %zu\n", size);
+
+ return &shmem->base;
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_sg_table);
+
+MODULE_DESCRIPTION("DRM SHMEM memory-management helpers");
+MODULE_IMPORT_NS(DMA_BUF);
+MODULE_LICENSE("GPL v2");