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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/ntb/msi.c | |
| download | linux-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 'drivers/ntb/msi.c')
| -rw-r--r-- | drivers/ntb/msi.c | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/drivers/ntb/msi.c b/drivers/ntb/msi.c new file mode 100644 index 000000000..6817d504c --- /dev/null +++ b/drivers/ntb/msi.c @@ -0,0 +1,344 @@ +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) + +#include <linux/irq.h> +#include <linux/module.h> +#include <linux/ntb.h> +#include <linux/msi.h> +#include <linux/pci.h> + +struct ntb_msi { + u64 base_addr; + u64 end_addr; + + void (*desc_changed)(void *ctx); + + u32 __iomem *peer_mws[]; +}; + +/** + * ntb_msi_init() - Initialize the MSI context + * @ntb: NTB device context + * + * This function must be called before any other ntb_msi function. + * It initializes the context for MSI operations and maps + * the peer memory windows. + * + * This function reserves the last N outbound memory windows (where N + * is the number of peers). + * + * Return: Zero on success, otherwise a negative error number. + */ +int ntb_msi_init(struct ntb_dev *ntb, + void (*desc_changed)(void *ctx)) +{ + phys_addr_t mw_phys_addr; + resource_size_t mw_size; + int peer_widx; + int peers; + int ret; + int i; + + peers = ntb_peer_port_count(ntb); + if (peers <= 0) + return -EINVAL; + + ntb->msi = devm_kzalloc(&ntb->dev, struct_size(ntb->msi, peer_mws, peers), + GFP_KERNEL); + if (!ntb->msi) + return -ENOMEM; + + ntb->msi->desc_changed = desc_changed; + + for (i = 0; i < peers; i++) { + peer_widx = ntb_peer_mw_count(ntb) - 1 - i; + + ret = ntb_peer_mw_get_addr(ntb, peer_widx, &mw_phys_addr, + &mw_size); + if (ret) + goto unroll; + + ntb->msi->peer_mws[i] = devm_ioremap(&ntb->dev, mw_phys_addr, + mw_size); + if (!ntb->msi->peer_mws[i]) { + ret = -EFAULT; + goto unroll; + } + } + + return 0; + +unroll: + for (i = 0; i < peers; i++) + if (ntb->msi->peer_mws[i]) + devm_iounmap(&ntb->dev, ntb->msi->peer_mws[i]); + + devm_kfree(&ntb->dev, ntb->msi); + ntb->msi = NULL; + return ret; +} +EXPORT_SYMBOL(ntb_msi_init); + +/** + * ntb_msi_setup_mws() - Initialize the MSI inbound memory windows + * @ntb: NTB device context + * + * This function sets up the required inbound memory windows. It should be + * called from a work function after a link up event. + * + * Over the entire network, this function will reserves the last N + * inbound memory windows for each peer (where N is the number of peers). + * + * ntb_msi_init() must be called before this function. + * + * Return: Zero on success, otherwise a negative error number. + */ +int ntb_msi_setup_mws(struct ntb_dev *ntb) +{ + struct msi_desc *desc; + u64 addr; + int peer, peer_widx; + resource_size_t addr_align, size_align, size_max; + resource_size_t mw_size = SZ_32K; + resource_size_t mw_min_size = mw_size; + int i; + int ret; + + if (!ntb->msi) + return -EINVAL; + + scoped_guard (msi_descs_lock, &ntb->pdev->dev) { + desc = msi_first_desc(&ntb->pdev->dev, MSI_DESC_ASSOCIATED); + addr = desc->msg.address_lo + ((uint64_t)desc->msg.address_hi << 32); + } + + for (peer = 0; peer < ntb_peer_port_count(ntb); peer++) { + peer_widx = ntb_peer_highest_mw_idx(ntb, peer); + if (peer_widx < 0) + return peer_widx; + + ret = ntb_mw_get_align(ntb, peer, peer_widx, &addr_align, + NULL, NULL); + if (ret) + return ret; + + addr &= ~(addr_align - 1); + } + + for (peer = 0; peer < ntb_peer_port_count(ntb); peer++) { + peer_widx = ntb_peer_highest_mw_idx(ntb, peer); + if (peer_widx < 0) { + ret = peer_widx; + goto error_out; + } + + ret = ntb_mw_get_align(ntb, peer, peer_widx, NULL, + &size_align, &size_max); + if (ret) + goto error_out; + + mw_size = round_up(mw_size, size_align); + mw_size = max(mw_size, size_max); + if (mw_size < mw_min_size) + mw_min_size = mw_size; + + ret = ntb_mw_set_trans(ntb, peer, peer_widx, + addr, mw_size); + if (ret) + goto error_out; + } + + ntb->msi->base_addr = addr; + ntb->msi->end_addr = addr + mw_min_size; + + return 0; + +error_out: + for (i = 0; i < peer; i++) { + peer_widx = ntb_peer_highest_mw_idx(ntb, peer); + if (peer_widx < 0) + continue; + + ntb_mw_clear_trans(ntb, i, peer_widx); + } + + return ret; +} +EXPORT_SYMBOL(ntb_msi_setup_mws); + +/** + * ntb_msi_clear_mws() - Clear all inbound memory windows + * @ntb: NTB device context + * + * This function tears down the resources used by ntb_msi_setup_mws(). + */ +void ntb_msi_clear_mws(struct ntb_dev *ntb) +{ + int peer; + int peer_widx; + + for (peer = 0; peer < ntb_peer_port_count(ntb); peer++) { + peer_widx = ntb_peer_highest_mw_idx(ntb, peer); + if (peer_widx < 0) + continue; + + ntb_mw_clear_trans(ntb, peer, peer_widx); + } +} +EXPORT_SYMBOL(ntb_msi_clear_mws); + +struct ntb_msi_devres { + struct ntb_dev *ntb; + struct msi_desc *entry; + struct ntb_msi_desc *msi_desc; +}; + +static int ntb_msi_set_desc(struct ntb_dev *ntb, struct msi_desc *entry, + struct ntb_msi_desc *msi_desc) +{ + u64 addr; + + addr = entry->msg.address_lo + + ((uint64_t)entry->msg.address_hi << 32); + + if (addr < ntb->msi->base_addr || addr >= ntb->msi->end_addr) { + dev_warn_once(&ntb->dev, + "IRQ %d: MSI Address not within the memory window (%llx, [%llx %llx])\n", + entry->irq, addr, ntb->msi->base_addr, + ntb->msi->end_addr); + return -EFAULT; + } + + msi_desc->addr_offset = addr - ntb->msi->base_addr; + msi_desc->data = entry->msg.data; + + return 0; +} + +static void ntb_msi_write_msg(struct msi_desc *entry, void *data) +{ + struct ntb_msi_devres *dr = data; + + WARN_ON(ntb_msi_set_desc(dr->ntb, entry, dr->msi_desc)); + + if (dr->ntb->msi->desc_changed) + dr->ntb->msi->desc_changed(dr->ntb->ctx); +} + +static void ntbm_msi_callback_release(struct device *dev, void *res) +{ + struct ntb_msi_devres *dr = res; + + dr->entry->write_msi_msg = NULL; + dr->entry->write_msi_msg_data = NULL; +} + +static int ntbm_msi_setup_callback(struct ntb_dev *ntb, struct msi_desc *entry, + struct ntb_msi_desc *msi_desc) +{ + struct ntb_msi_devres *dr; + + dr = devres_alloc(ntbm_msi_callback_release, + sizeof(struct ntb_msi_devres), GFP_KERNEL); + if (!dr) + return -ENOMEM; + + dr->ntb = ntb; + dr->entry = entry; + dr->msi_desc = msi_desc; + + devres_add(&ntb->dev, dr); + + dr->entry->write_msi_msg = ntb_msi_write_msg; + dr->entry->write_msi_msg_data = dr; + + return 0; +} + +/** + * ntbm_msi_request_threaded_irq() - allocate an MSI interrupt + * @ntb: NTB device context + * @handler: Function to be called when the IRQ occurs + * @thread_fn: Function to be called in a threaded interrupt context. NULL + * for clients which handle everything in @handler + * @name: An ascii name for the claiming device, dev_name(dev) if NULL + * @dev_id: A cookie passed back to the handler function + * @msi_desc: MSI descriptor data which triggers the interrupt + * + * This function assigns an interrupt handler to an unused + * MSI interrupt and returns the descriptor used to trigger + * it. The descriptor can then be sent to a peer to trigger + * the interrupt. + * + * The interrupt resource is managed with devres so it will + * be automatically freed when the NTB device is torn down. + * + * If an IRQ allocated with this function needs to be freed + * separately, ntbm_free_irq() must be used. + * + * Return: IRQ number assigned on success, otherwise a negative error number. + */ +int ntbm_msi_request_threaded_irq(struct ntb_dev *ntb, irq_handler_t handler, + irq_handler_t thread_fn, + const char *name, void *dev_id, + struct ntb_msi_desc *msi_desc) +{ + struct device *dev = &ntb->pdev->dev; + struct msi_desc *entry; + int ret; + + if (!ntb->msi) + return -EINVAL; + + guard(msi_descs_lock)(dev); + msi_for_each_desc(entry, dev, MSI_DESC_ASSOCIATED) { + if (irq_has_action(entry->irq)) + continue; + + ret = devm_request_threaded_irq(&ntb->dev, entry->irq, handler, + thread_fn, 0, name, dev_id); + if (ret) + continue; + + if (ntb_msi_set_desc(ntb, entry, msi_desc)) { + devm_free_irq(&ntb->dev, entry->irq, dev_id); + continue; + } + + ret = ntbm_msi_setup_callback(ntb, entry, msi_desc); + if (ret) { + devm_free_irq(&ntb->dev, entry->irq, dev_id); + return ret; + } + return entry->irq; + } + return -ENODEV; +} +EXPORT_SYMBOL(ntbm_msi_request_threaded_irq); + +/** + * ntb_msi_peer_trigger() - Trigger an interrupt handler on a peer + * @ntb: NTB device context + * @peer: Peer index + * @desc: MSI descriptor data which triggers the interrupt + * + * This function triggers an interrupt on a peer. It requires + * the descriptor structure to have been passed from that peer + * by some other means. + * + * Return: Zero on success, otherwise a negative error number. + */ +int ntb_msi_peer_trigger(struct ntb_dev *ntb, int peer, + struct ntb_msi_desc *desc) +{ + int idx; + + if (!ntb->msi) + return -EINVAL; + + idx = desc->addr_offset / sizeof(*ntb->msi->peer_mws[peer]); + + iowrite32(desc->data, &ntb->msi->peer_mws[peer][idx]); + + return 0; +} +EXPORT_SYMBOL(ntb_msi_peer_trigger); |
