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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/dma/ioat/dca.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/dma/ioat/dca.c')
| -rw-r--r-- | drivers/dma/ioat/dca.c | 333 |
1 files changed, 333 insertions, 0 deletions
diff --git a/drivers/dma/ioat/dca.c b/drivers/dma/ioat/dca.c new file mode 100644 index 000000000..5d3c0ae6b --- /dev/null +++ b/drivers/dma/ioat/dca.c @@ -0,0 +1,333 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Intel I/OAT DMA Linux driver + * Copyright(c) 2007 - 2009 Intel Corporation. + */ + +#include <linux/kernel.h> +#include <linux/pci.h> +#include <linux/smp.h> +#include <linux/interrupt.h> +#include <linux/dca.h> + +#include <asm/cpuid/api.h> + +/* either a kernel change is needed, or we need something like this in kernel */ +#ifndef CONFIG_SMP +#include <asm/smp.h> +#undef cpu_physical_id +#define cpu_physical_id(cpu) (cpuid_ebx(1) >> 24) +#endif + +#include "dma.h" +#include "registers.h" + +/* + * Bit 7 of a tag map entry is the "valid" bit, if it is set then bits 0:6 + * contain the bit number of the APIC ID to map into the DCA tag. If the valid + * bit is not set, then the value must be 0 or 1 and defines the bit in the tag. + */ +#define DCA_TAG_MAP_VALID 0x80 + +#define DCA3_TAG_MAP_BIT_TO_INV 0x80 +#define DCA3_TAG_MAP_BIT_TO_SEL 0x40 +#define DCA3_TAG_MAP_LITERAL_VAL 0x1 + +#define DCA_TAG_MAP_MASK 0xDF + +/* expected tag map bytes for I/OAT ver.2 */ +#define DCA2_TAG_MAP_BYTE0 0x80 +#define DCA2_TAG_MAP_BYTE1 0x0 +#define DCA2_TAG_MAP_BYTE2 0x81 +#define DCA2_TAG_MAP_BYTE3 0x82 +#define DCA2_TAG_MAP_BYTE4 0x82 + +/* + * "Legacy" DCA systems do not implement the DCA register set in the + * I/OAT device. Software needs direct support for their tag mappings. + */ + +#define APICID_BIT(x) (DCA_TAG_MAP_VALID | (x)) +#define IOAT_TAG_MAP_LEN 8 + +/* pack PCI B/D/F into a u16 */ +static inline u16 dcaid_from_pcidev(struct pci_dev *pci) +{ + return pci_dev_id(pci); +} + +static int dca_enabled_in_bios(struct pci_dev *pdev) +{ + /* CPUID level 9 returns DCA configuration */ + /* Bit 0 indicates DCA enabled by the BIOS */ + u32 eax; + int res; + + eax = cpuid_eax(CPUID_LEAF_DCA); + res = eax & BIT(0); + if (!res) + dev_dbg(&pdev->dev, "DCA is disabled in BIOS\n"); + + return res; +} + +int system_has_dca_enabled(struct pci_dev *pdev) +{ + if (boot_cpu_has(X86_FEATURE_DCA)) + return dca_enabled_in_bios(pdev); + + dev_dbg(&pdev->dev, "boot cpu doesn't have X86_FEATURE_DCA\n"); + return 0; +} + +struct ioat_dca_slot { + struct pci_dev *pdev; /* requester device */ + u16 rid; /* requester id, as used by IOAT */ +}; + +#define IOAT_DCA_MAX_REQ 6 +#define IOAT3_DCA_MAX_REQ 2 + +struct ioat_dca_priv { + void __iomem *iobase; + void __iomem *dca_base; + int max_requesters; + int requester_count; + u8 tag_map[IOAT_TAG_MAP_LEN]; + struct ioat_dca_slot req_slots[]; +}; + +static int ioat_dca_dev_managed(struct dca_provider *dca, + struct device *dev) +{ + struct ioat_dca_priv *ioatdca = dca_priv(dca); + struct pci_dev *pdev; + int i; + + pdev = to_pci_dev(dev); + for (i = 0; i < ioatdca->max_requesters; i++) { + if (ioatdca->req_slots[i].pdev == pdev) + return 1; + } + return 0; +} + +static int ioat_dca_add_requester(struct dca_provider *dca, struct device *dev) +{ + struct ioat_dca_priv *ioatdca = dca_priv(dca); + struct pci_dev *pdev; + int i; + u16 id; + u16 global_req_table; + + /* This implementation only supports PCI-Express */ + if (!dev_is_pci(dev)) + return -ENODEV; + pdev = to_pci_dev(dev); + id = dcaid_from_pcidev(pdev); + + if (ioatdca->requester_count == ioatdca->max_requesters) + return -ENODEV; + + for (i = 0; i < ioatdca->max_requesters; i++) { + if (ioatdca->req_slots[i].pdev == NULL) { + /* found an empty slot */ + ioatdca->requester_count++; + ioatdca->req_slots[i].pdev = pdev; + ioatdca->req_slots[i].rid = id; + global_req_table = + readw(ioatdca->dca_base + IOAT3_DCA_GREQID_OFFSET); + writel(id | IOAT_DCA_GREQID_VALID, + ioatdca->iobase + global_req_table + (i * 4)); + return i; + } + } + /* Error, ioatdma->requester_count is out of whack */ + return -EFAULT; +} + +static int ioat_dca_remove_requester(struct dca_provider *dca, + struct device *dev) +{ + struct ioat_dca_priv *ioatdca = dca_priv(dca); + struct pci_dev *pdev; + int i; + u16 global_req_table; + + /* This implementation only supports PCI-Express */ + if (!dev_is_pci(dev)) + return -ENODEV; + pdev = to_pci_dev(dev); + + for (i = 0; i < ioatdca->max_requesters; i++) { + if (ioatdca->req_slots[i].pdev == pdev) { + global_req_table = + readw(ioatdca->dca_base + IOAT3_DCA_GREQID_OFFSET); + writel(0, ioatdca->iobase + global_req_table + (i * 4)); + ioatdca->req_slots[i].pdev = NULL; + ioatdca->req_slots[i].rid = 0; + ioatdca->requester_count--; + return i; + } + } + return -ENODEV; +} + +static u8 ioat_dca_get_tag(struct dca_provider *dca, + struct device *dev, + int cpu) +{ + u8 tag; + + struct ioat_dca_priv *ioatdca = dca_priv(dca); + int i, apic_id, bit, value; + u8 entry; + + tag = 0; + apic_id = cpu_physical_id(cpu); + + for (i = 0; i < IOAT_TAG_MAP_LEN; i++) { + entry = ioatdca->tag_map[i]; + if (entry & DCA3_TAG_MAP_BIT_TO_SEL) { + bit = entry & + ~(DCA3_TAG_MAP_BIT_TO_SEL | DCA3_TAG_MAP_BIT_TO_INV); + value = (apic_id & (1 << bit)) ? 1 : 0; + } else if (entry & DCA3_TAG_MAP_BIT_TO_INV) { + bit = entry & ~DCA3_TAG_MAP_BIT_TO_INV; + value = (apic_id & (1 << bit)) ? 0 : 1; + } else { + value = (entry & DCA3_TAG_MAP_LITERAL_VAL) ? 1 : 0; + } + tag |= (value << i); + } + + return tag; +} + +static const struct dca_ops ioat_dca_ops = { + .add_requester = ioat_dca_add_requester, + .remove_requester = ioat_dca_remove_requester, + .get_tag = ioat_dca_get_tag, + .dev_managed = ioat_dca_dev_managed, +}; + +static int ioat_dca_count_dca_slots(void *iobase, u16 dca_offset) +{ + int slots = 0; + u32 req; + u16 global_req_table; + + global_req_table = readw(iobase + dca_offset + IOAT3_DCA_GREQID_OFFSET); + if (global_req_table == 0) + return 0; + + do { + req = readl(iobase + global_req_table + (slots * sizeof(u32))); + slots++; + } while ((req & IOAT_DCA_GREQID_LASTID) == 0); + + return slots; +} + +static inline int dca3_tag_map_invalid(u8 *tag_map) +{ + /* + * If the tag map is not programmed by the BIOS the default is: + * 0x80 0x80 0x80 0x80 0x80 0x00 0x00 0x00 + * + * This an invalid map and will result in only 2 possible tags + * 0x1F and 0x00. 0x00 is an invalid DCA tag so we know that + * this entire definition is invalid. + */ + return ((tag_map[0] == DCA_TAG_MAP_VALID) && + (tag_map[1] == DCA_TAG_MAP_VALID) && + (tag_map[2] == DCA_TAG_MAP_VALID) && + (tag_map[3] == DCA_TAG_MAP_VALID) && + (tag_map[4] == DCA_TAG_MAP_VALID)); +} + +struct dca_provider *ioat_dca_init(struct pci_dev *pdev, void __iomem *iobase) +{ + struct dca_provider *dca; + struct ioat_dca_priv *ioatdca; + int slots; + int i; + int err; + u16 dca_offset; + u16 csi_fsb_control; + u16 pcie_control; + u8 bit; + + union { + u64 full; + struct { + u32 low; + u32 high; + }; + } tag_map; + + if (!system_has_dca_enabled(pdev)) + return NULL; + + dca_offset = readw(iobase + IOAT_DCAOFFSET_OFFSET); + if (dca_offset == 0) + return NULL; + + slots = ioat_dca_count_dca_slots(iobase, dca_offset); + if (slots == 0) + return NULL; + + dca = alloc_dca_provider(&ioat_dca_ops, + struct_size(ioatdca, req_slots, slots)); + if (!dca) + return NULL; + + ioatdca = dca_priv(dca); + ioatdca->iobase = iobase; + ioatdca->dca_base = iobase + dca_offset; + ioatdca->max_requesters = slots; + + /* some bios might not know to turn these on */ + csi_fsb_control = readw(ioatdca->dca_base + IOAT3_CSI_CONTROL_OFFSET); + if ((csi_fsb_control & IOAT3_CSI_CONTROL_PREFETCH) == 0) { + csi_fsb_control |= IOAT3_CSI_CONTROL_PREFETCH; + writew(csi_fsb_control, + ioatdca->dca_base + IOAT3_CSI_CONTROL_OFFSET); + } + pcie_control = readw(ioatdca->dca_base + IOAT3_PCI_CONTROL_OFFSET); + if ((pcie_control & IOAT3_PCI_CONTROL_MEMWR) == 0) { + pcie_control |= IOAT3_PCI_CONTROL_MEMWR; + writew(pcie_control, + ioatdca->dca_base + IOAT3_PCI_CONTROL_OFFSET); + } + + + /* TODO version, compatibility and configuration checks */ + + /* copy out the APIC to DCA tag map */ + tag_map.low = + readl(ioatdca->dca_base + IOAT3_APICID_TAG_MAP_OFFSET_LOW); + tag_map.high = + readl(ioatdca->dca_base + IOAT3_APICID_TAG_MAP_OFFSET_HIGH); + for (i = 0; i < 8; i++) { + bit = tag_map.full >> (8 * i); + ioatdca->tag_map[i] = bit & DCA_TAG_MAP_MASK; + } + + if (dca3_tag_map_invalid(ioatdca->tag_map)) { + add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK); + pr_warn_once("%s %s: APICID_TAG_MAP set incorrectly by BIOS, disabling DCA\n", + dev_driver_string(&pdev->dev), + dev_name(&pdev->dev)); + free_dca_provider(dca); + return NULL; + } + + err = register_dca_provider(dca, &pdev->dev); + if (err) { + free_dca_provider(dca); + return NULL; + } + + return dca; +} |
