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 0000000000..c1fbf6f588
--- /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");