diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/misc/cxl/main.c | 383 |
1 files changed, 383 insertions, 0 deletions
diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c new file mode 100644 index 000000000..c1fbf6f58 --- /dev/null +++ b/drivers/misc/cxl/main.c @@ -0,0 +1,383 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright 2014 IBM Corp. + */ + +#include <linux/spinlock.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/mutex.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/mm.h> +#include <linux/of.h> +#include <linux/slab.h> +#include <linux/idr.h> +#include <linux/pci.h> +#include <linux/platform_device.h> +#include <linux/sched/task.h> + +#include <asm/cputable.h> +#include <asm/mmu.h> +#include <misc/cxl-base.h> + +#include "cxl.h" +#include "trace.h" + +static DEFINE_SPINLOCK(adapter_idr_lock); +static DEFINE_IDR(cxl_adapter_idr); + +uint cxl_verbose; +module_param_named(verbose, cxl_verbose, uint, 0600); +MODULE_PARM_DESC(verbose, "Enable verbose dmesg output"); + +const struct cxl_backend_ops *cxl_ops; + +int cxl_afu_slbia(struct cxl_afu *afu) +{ + unsigned long timeout = jiffies + (HZ * CXL_TIMEOUT); + + pr_devel("cxl_afu_slbia issuing SLBIA command\n"); + cxl_p2n_write(afu, CXL_SLBIA_An, CXL_TLB_SLB_IQ_ALL); + while (cxl_p2n_read(afu, CXL_SLBIA_An) & CXL_TLB_SLB_P) { + if (time_after_eq(jiffies, timeout)) { + dev_warn(&afu->dev, "WARNING: CXL AFU SLBIA timed out!\n"); + return -EBUSY; + } + /* If the adapter has gone down, we can assume that we + * will PERST it and that will invalidate everything. + */ + if (!cxl_ops->link_ok(afu->adapter, afu)) + return -EIO; + cpu_relax(); + } + return 0; +} + +static inline void _cxl_slbia(struct cxl_context *ctx, struct mm_struct *mm) +{ + unsigned long flags; + + if (ctx->mm != mm) + return; + + pr_devel("%s matched mm - card: %i afu: %i pe: %i\n", __func__, + ctx->afu->adapter->adapter_num, ctx->afu->slice, ctx->pe); + + spin_lock_irqsave(&ctx->sste_lock, flags); + trace_cxl_slbia(ctx); + memset(ctx->sstp, 0, ctx->sst_size); + spin_unlock_irqrestore(&ctx->sste_lock, flags); + mb(); + cxl_afu_slbia(ctx->afu); +} + +static inline void cxl_slbia_core(struct mm_struct *mm) +{ + struct cxl *adapter; + struct cxl_afu *afu; + struct cxl_context *ctx; + int card, slice, id; + + pr_devel("%s called\n", __func__); + + spin_lock(&adapter_idr_lock); + idr_for_each_entry(&cxl_adapter_idr, adapter, card) { + /* XXX: Make this lookup faster with link from mm to ctx */ + spin_lock(&adapter->afu_list_lock); + for (slice = 0; slice < adapter->slices; slice++) { + afu = adapter->afu[slice]; + if (!afu || !afu->enabled) + continue; + rcu_read_lock(); + idr_for_each_entry(&afu->contexts_idr, ctx, id) + _cxl_slbia(ctx, mm); + rcu_read_unlock(); + } + spin_unlock(&adapter->afu_list_lock); + } + spin_unlock(&adapter_idr_lock); +} + +static struct cxl_calls cxl_calls = { + .cxl_slbia = cxl_slbia_core, + .owner = THIS_MODULE, +}; + +int cxl_alloc_sst(struct cxl_context *ctx) +{ + unsigned long vsid; + u64 ea_mask, size, sstp0, sstp1; + + sstp0 = 0; + sstp1 = 0; + + ctx->sst_size = PAGE_SIZE; + ctx->sst_lru = 0; + ctx->sstp = (struct cxl_sste *)get_zeroed_page(GFP_KERNEL); + if (!ctx->sstp) { + pr_err("cxl_alloc_sst: Unable to allocate segment table\n"); + return -ENOMEM; + } + pr_devel("SSTP allocated at 0x%p\n", ctx->sstp); + + vsid = get_kernel_vsid((u64)ctx->sstp, mmu_kernel_ssize) << 12; + + sstp0 |= (u64)mmu_kernel_ssize << CXL_SSTP0_An_B_SHIFT; + sstp0 |= (SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp) << 50; + + size = (((u64)ctx->sst_size >> 8) - 1) << CXL_SSTP0_An_SegTableSize_SHIFT; + if (unlikely(size & ~CXL_SSTP0_An_SegTableSize_MASK)) { + WARN(1, "Impossible segment table size\n"); + return -EINVAL; + } + sstp0 |= size; + + if (mmu_kernel_ssize == MMU_SEGSIZE_256M) + ea_mask = 0xfffff00ULL; + else + ea_mask = 0xffffffff00ULL; + + sstp0 |= vsid >> (50-14); /* Top 14 bits of VSID */ + sstp1 |= (vsid << (64-(50-14))) & ~ea_mask; + sstp1 |= (u64)ctx->sstp & ea_mask; + sstp1 |= CXL_SSTP1_An_V; + + pr_devel("Looked up %#llx: slbfee. %#llx (ssize: %x, vsid: %#lx), copied to SSTP0: %#llx, SSTP1: %#llx\n", + (u64)ctx->sstp, (u64)ctx->sstp & ESID_MASK, mmu_kernel_ssize, vsid, sstp0, sstp1); + + /* Store calculated sstp hardware points for use later */ + ctx->sstp0 = sstp0; + ctx->sstp1 = sstp1; + + return 0; +} + +/* print buffer content as integers when debugging */ +void cxl_dump_debug_buffer(void *buf, size_t buf_len) +{ +#ifdef DEBUG + int i, *ptr; + + /* + * We want to regroup up to 4 integers per line, which means they + * need to be in the same pr_devel() statement + */ + ptr = (int *) buf; + for (i = 0; i * 4 < buf_len; i += 4) { + if ((i + 3) * 4 < buf_len) + pr_devel("%.8x %.8x %.8x %.8x\n", ptr[i], ptr[i + 1], + ptr[i + 2], ptr[i + 3]); + else if ((i + 2) * 4 < buf_len) + pr_devel("%.8x %.8x %.8x\n", ptr[i], ptr[i + 1], + ptr[i + 2]); + else if ((i + 1) * 4 < buf_len) + pr_devel("%.8x %.8x\n", ptr[i], ptr[i + 1]); + else + pr_devel("%.8x\n", ptr[i]); + } +#endif /* DEBUG */ +} + +/* Find a CXL adapter by it's number and increase it's refcount */ +struct cxl *get_cxl_adapter(int num) +{ + struct cxl *adapter; + + spin_lock(&adapter_idr_lock); + if ((adapter = idr_find(&cxl_adapter_idr, num))) + get_device(&adapter->dev); + spin_unlock(&adapter_idr_lock); + + return adapter; +} + +static int cxl_alloc_adapter_nr(struct cxl *adapter) +{ + int i; + + idr_preload(GFP_KERNEL); + spin_lock(&adapter_idr_lock); + i = idr_alloc(&cxl_adapter_idr, adapter, 0, 0, GFP_NOWAIT); + spin_unlock(&adapter_idr_lock); + idr_preload_end(); + if (i < 0) + return i; + + adapter->adapter_num = i; + + return 0; +} + +void cxl_remove_adapter_nr(struct cxl *adapter) +{ + idr_remove(&cxl_adapter_idr, adapter->adapter_num); +} + +struct cxl *cxl_alloc_adapter(void) +{ + struct cxl *adapter; + + if (!(adapter = kzalloc(sizeof(struct cxl), GFP_KERNEL))) + return NULL; + + spin_lock_init(&adapter->afu_list_lock); + + if (cxl_alloc_adapter_nr(adapter)) + goto err1; + + if (dev_set_name(&adapter->dev, "card%i", adapter->adapter_num)) + goto err2; + + /* start with context lock taken */ + atomic_set(&adapter->contexts_num, -1); + + return adapter; +err2: + cxl_remove_adapter_nr(adapter); +err1: + kfree(adapter); + return NULL; +} + +struct cxl_afu *cxl_alloc_afu(struct cxl *adapter, int slice) +{ + struct cxl_afu *afu; + + if (!(afu = kzalloc(sizeof(struct cxl_afu), GFP_KERNEL))) + return NULL; + + afu->adapter = adapter; + afu->dev.parent = &adapter->dev; + afu->dev.release = cxl_ops->release_afu; + afu->slice = slice; + idr_init(&afu->contexts_idr); + mutex_init(&afu->contexts_lock); + spin_lock_init(&afu->afu_cntl_lock); + atomic_set(&afu->configured_state, -1); + afu->prefault_mode = CXL_PREFAULT_NONE; + afu->irqs_max = afu->adapter->user_irqs; + + return afu; +} + +int cxl_afu_select_best_mode(struct cxl_afu *afu) +{ + if (afu->modes_supported & CXL_MODE_DIRECTED) + return cxl_ops->afu_activate_mode(afu, CXL_MODE_DIRECTED); + + if (afu->modes_supported & CXL_MODE_DEDICATED) + return cxl_ops->afu_activate_mode(afu, CXL_MODE_DEDICATED); + + dev_warn(&afu->dev, "No supported programming modes available\n"); + /* We don't fail this so the user can inspect sysfs */ + return 0; +} + +int cxl_adapter_context_get(struct cxl *adapter) +{ + int rc; + + rc = atomic_inc_unless_negative(&adapter->contexts_num); + return rc ? 0 : -EBUSY; +} + +void cxl_adapter_context_put(struct cxl *adapter) +{ + atomic_dec_if_positive(&adapter->contexts_num); +} + +int cxl_adapter_context_lock(struct cxl *adapter) +{ + int rc; + /* no active contexts -> contexts_num == 0 */ + rc = atomic_cmpxchg(&adapter->contexts_num, 0, -1); + return rc ? -EBUSY : 0; +} + +void cxl_adapter_context_unlock(struct cxl *adapter) +{ + int val = atomic_cmpxchg(&adapter->contexts_num, -1, 0); + + /* + * contexts lock taken -> contexts_num == -1 + * If not true then show a warning and force reset the lock. + * This will happen when context_unlock was requested without + * doing a context_lock. + */ + if (val != -1) { + atomic_set(&adapter->contexts_num, 0); + WARN(1, "Adapter context unlocked with %d active contexts", + val); + } +} + +static int __init init_cxl(void) +{ + int rc = 0; + + if (!tlbie_capable) + return -EINVAL; + + if ((rc = cxl_file_init())) + return rc; + + cxl_debugfs_init(); + + /* + * we don't register the callback on P9. slb callack is only + * used for the PSL8 MMU and CX4. + */ + if (cxl_is_power8()) { + rc = register_cxl_calls(&cxl_calls); + if (rc) + goto err; + } + + if (cpu_has_feature(CPU_FTR_HVMODE)) { + cxl_ops = &cxl_native_ops; + rc = pci_register_driver(&cxl_pci_driver); + } +#ifdef CONFIG_PPC_PSERIES + else { + cxl_ops = &cxl_guest_ops; + rc = platform_driver_register(&cxl_of_driver); + } +#endif + if (rc) + goto err1; + + return 0; +err1: + if (cxl_is_power8()) + unregister_cxl_calls(&cxl_calls); +err: + cxl_debugfs_exit(); + cxl_file_exit(); + + return rc; +} + +static void exit_cxl(void) +{ + if (cpu_has_feature(CPU_FTR_HVMODE)) + pci_unregister_driver(&cxl_pci_driver); +#ifdef CONFIG_PPC_PSERIES + else + platform_driver_unregister(&cxl_of_driver); +#endif + + cxl_debugfs_exit(); + cxl_file_exit(); + if (cxl_is_power8()) + unregister_cxl_calls(&cxl_calls); + idr_destroy(&cxl_adapter_idr); +} + +module_init(init_cxl); +module_exit(exit_cxl); + +MODULE_DESCRIPTION("IBM Coherent Accelerator"); +MODULE_AUTHOR("Ian Munsie <imunsie@au1.ibm.com>"); +MODULE_LICENSE("GPL"); |