Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1208 insertions, 0 deletions

diff --git a/drivers/misc/cxl/guest.c b/drivers/misc/cxl/guest.c
new file mode 100644
index 000000000..fb95a2d5c
--- /dev/null
+++ b/drivers/misc/cxl/guest.c
@@ -0,0 +1,1208 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2015 IBM Corp.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+#include <linux/delay.h>
+#include <linux/irqdomain.h>
+#include <linux/platform_device.h>
+
+#include "cxl.h"
+#include "hcalls.h"
+#include "trace.h"
+
+#define CXL_ERROR_DETECTED_EVENT	1
+#define CXL_SLOT_RESET_EVENT		2
+#define CXL_RESUME_EVENT		3
+
+static void pci_error_handlers(struct cxl_afu *afu,
+				int bus_error_event,
+				pci_channel_state_t state)
+{
+	struct pci_dev *afu_dev;
+	struct pci_driver *afu_drv;
+	const struct pci_error_handlers *err_handler;
+
+	if (afu->phb == NULL)
+		return;
+
+	list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {
+		afu_drv = to_pci_driver(afu_dev->dev.driver);
+		if (!afu_drv)
+			continue;
+
+		err_handler = afu_drv->err_handler;
+		switch (bus_error_event) {
+		case CXL_ERROR_DETECTED_EVENT:
+			afu_dev->error_state = state;
+
+			if (err_handler &&
+			    err_handler->error_detected)
+				err_handler->error_detected(afu_dev, state);
+			break;
+		case CXL_SLOT_RESET_EVENT:
+			afu_dev->error_state = state;
+
+			if (err_handler &&
+			    err_handler->slot_reset)
+				err_handler->slot_reset(afu_dev);
+			break;
+		case CXL_RESUME_EVENT:
+			if (err_handler &&
+			    err_handler->resume)
+				err_handler->resume(afu_dev);
+			break;
+		}
+	}
+}
+
+static irqreturn_t guest_handle_psl_slice_error(struct cxl_context *ctx, u64 dsisr,
+					u64 errstat)
+{
+	pr_devel("in %s\n", __func__);
+	dev_crit(&ctx->afu->dev, "PSL ERROR STATUS: 0x%.16llx\n", errstat);
+
+	return cxl_ops->ack_irq(ctx, 0, errstat);
+}
+
+static ssize_t guest_collect_vpd(struct cxl *adapter, struct cxl_afu *afu,
+			void *buf, size_t len)
+{
+	unsigned int entries, mod;
+	unsigned long **vpd_buf = NULL;
+	struct sg_list *le;
+	int rc = 0, i, tocopy;
+	u64 out = 0;
+
+	if (buf == NULL)
+		return -EINVAL;
+
+	/* number of entries in the list */
+	entries = len / SG_BUFFER_SIZE;
+	mod = len % SG_BUFFER_SIZE;
+	if (mod)
+		entries++;
+
+	if (entries > SG_MAX_ENTRIES) {
+		entries = SG_MAX_ENTRIES;
+		len = SG_MAX_ENTRIES * SG_BUFFER_SIZE;
+		mod = 0;
+	}
+
+	vpd_buf = kcalloc(entries, sizeof(unsigned long *), GFP_KERNEL);
+	if (!vpd_buf)
+		return -ENOMEM;
+
+	le = (struct sg_list *)get_zeroed_page(GFP_KERNEL);
+	if (!le) {
+		rc = -ENOMEM;
+		goto err1;
+	}
+
+	for (i = 0; i < entries; i++) {
+		vpd_buf[i] = (unsigned long *)get_zeroed_page(GFP_KERNEL);
+		if (!vpd_buf[i]) {
+			rc = -ENOMEM;
+			goto err2;
+		}
+		le[i].phys_addr = cpu_to_be64(virt_to_phys(vpd_buf[i]));
+		le[i].len = cpu_to_be64(SG_BUFFER_SIZE);
+		if ((i == (entries - 1)) && mod)
+			le[i].len = cpu_to_be64(mod);
+	}
+
+	if (adapter)
+		rc = cxl_h_collect_vpd_adapter(adapter->guest->handle,
+					virt_to_phys(le), entries, &out);
+	else
+		rc = cxl_h_collect_vpd(afu->guest->handle, 0,
+				virt_to_phys(le), entries, &out);
+	pr_devel("length of available (entries: %i), vpd: %#llx\n",
+		entries, out);
+
+	if (!rc) {
+		/*
+		 * hcall returns in 'out' the size of available VPDs.
+		 * It fills the buffer with as much data as possible.
+		 */
+		if (out < len)
+			len = out;
+		rc = len;
+		if (out) {
+			for (i = 0; i < entries; i++) {
+				if (len < SG_BUFFER_SIZE)
+					tocopy = len;
+				else
+					tocopy = SG_BUFFER_SIZE;
+				memcpy(buf, vpd_buf[i], tocopy);
+				buf += tocopy;
+				len -= tocopy;
+			}
+		}
+	}
+err2:
+	for (i = 0; i < entries; i++) {
+		if (vpd_buf[i])
+			free_page((unsigned long) vpd_buf[i]);
+	}
+	free_page((unsigned long) le);
+err1:
+	kfree(vpd_buf);
+	return rc;
+}
+
+static int guest_get_irq_info(struct cxl_context *ctx, struct cxl_irq_info *info)
+{
+	return cxl_h_collect_int_info(ctx->afu->guest->handle, ctx->process_token, info);
+}
+
+static irqreturn_t guest_psl_irq(int irq, void *data)
+{
+	struct cxl_context *ctx = data;
+	struct cxl_irq_info irq_info;
+	int rc;
+
+	pr_devel("%d: received PSL interrupt %i\n", ctx->pe, irq);
+	rc = guest_get_irq_info(ctx, &irq_info);
+	if (rc) {
+		WARN(1, "Unable to get IRQ info: %i\n", rc);
+		return IRQ_HANDLED;
+	}
+
+	rc = cxl_irq_psl8(irq, ctx, &irq_info);
+	return rc;
+}
+
+static int afu_read_error_state(struct cxl_afu *afu, int *state_out)
+{
+	u64 state;
+	int rc = 0;
+
+	if (!afu)
+		return -EIO;
+
+	rc = cxl_h_read_error_state(afu->guest->handle, &state);
+	if (!rc) {
+		WARN_ON(state != H_STATE_NORMAL &&
+			state != H_STATE_DISABLE &&
+			state != H_STATE_TEMP_UNAVAILABLE &&
+			state != H_STATE_PERM_UNAVAILABLE);
+		*state_out = state & 0xffffffff;
+	}
+	return rc;
+}
+
+static irqreturn_t guest_slice_irq_err(int irq, void *data)
+{
+	struct cxl_afu *afu = data;
+	int rc;
+	u64 serr, afu_error, dsisr;
+
+	rc = cxl_h_get_fn_error_interrupt(afu->guest->handle, &serr);
+	if (rc) {
+		dev_crit(&afu->dev, "Couldn't read PSL_SERR_An: %d\n", rc);
+		return IRQ_HANDLED;
+	}
+	afu_error = cxl_p2n_read(afu, CXL_AFU_ERR_An);
+	dsisr = cxl_p2n_read(afu, CXL_PSL_DSISR_An);
+	cxl_afu_decode_psl_serr(afu, serr);
+	dev_crit(&afu->dev, "AFU_ERR_An: 0x%.16llx\n", afu_error);
+	dev_crit(&afu->dev, "PSL_DSISR_An: 0x%.16llx\n", dsisr);
+
+	rc = cxl_h_ack_fn_error_interrupt(afu->guest->handle, serr);
+	if (rc)
+		dev_crit(&afu->dev, "Couldn't ack slice error interrupt: %d\n",
+			rc);
+
+	return IRQ_HANDLED;
+}
+
+
+static int irq_alloc_range(struct cxl *adapter, int len, int *irq)
+{
+	int i, n;
+	struct irq_avail *cur;
+
+	for (i = 0; i < adapter->guest->irq_nranges; i++) {
+		cur = &adapter->guest->irq_avail[i];
+		n = bitmap_find_next_zero_area(cur->bitmap, cur->range,
+					0, len, 0);
+		if (n < cur->range) {
+			bitmap_set(cur->bitmap, n, len);
+			*irq = cur->offset + n;
+			pr_devel("guest: allocate IRQs %#x->%#x\n",
+				*irq, *irq + len - 1);
+
+			return 0;
+		}
+	}
+	return -ENOSPC;
+}
+
+static int irq_free_range(struct cxl *adapter, int irq, int len)
+{
+	int i, n;
+	struct irq_avail *cur;
+
+	if (len == 0)
+		return -ENOENT;
+
+	for (i = 0; i < adapter->guest->irq_nranges; i++) {
+		cur = &adapter->guest->irq_avail[i];
+		if (irq >= cur->offset &&
+			(irq + len) <= (cur->offset + cur->range)) {
+			n = irq - cur->offset;
+			bitmap_clear(cur->bitmap, n, len);
+			pr_devel("guest: release IRQs %#x->%#x\n",
+				irq, irq + len - 1);
+			return 0;
+		}
+	}
+	return -ENOENT;
+}
+
+static int guest_reset(struct cxl *adapter)
+{
+	struct cxl_afu *afu = NULL;
+	int i, rc;
+
+	pr_devel("Adapter reset request\n");
+	spin_lock(&adapter->afu_list_lock);
+	for (i = 0; i < adapter->slices; i++) {
+		if ((afu = adapter->afu[i])) {
+			pci_error_handlers(afu, CXL_ERROR_DETECTED_EVENT,
+					pci_channel_io_frozen);
+			cxl_context_detach_all(afu);
+		}
+	}
+
+	rc = cxl_h_reset_adapter(adapter->guest->handle);
+	for (i = 0; i < adapter->slices; i++) {
+		if (!rc && (afu = adapter->afu[i])) {
+			pci_error_handlers(afu, CXL_SLOT_RESET_EVENT,
+					pci_channel_io_normal);
+			pci_error_handlers(afu, CXL_RESUME_EVENT, 0);
+		}
+	}
+	spin_unlock(&adapter->afu_list_lock);
+	return rc;
+}
+
+static int guest_alloc_one_irq(struct cxl *adapter)
+{
+	int irq;
+
+	spin_lock(&adapter->guest->irq_alloc_lock);
+	if (irq_alloc_range(adapter, 1, &irq))
+		irq = -ENOSPC;
+	spin_unlock(&adapter->guest->irq_alloc_lock);
+	return irq;
+}
+
+static void guest_release_one_irq(struct cxl *adapter, int irq)
+{
+	spin_lock(&adapter->guest->irq_alloc_lock);
+	irq_free_range(adapter, irq, 1);
+	spin_unlock(&adapter->guest->irq_alloc_lock);
+}
+
+static int guest_alloc_irq_ranges(struct cxl_irq_ranges *irqs,
+				struct cxl *adapter, unsigned int num)
+{
+	int i, try, irq;
+
+	memset(irqs, 0, sizeof(struct cxl_irq_ranges));
+
+	spin_lock(&adapter->guest->irq_alloc_lock);
+	for (i = 0; i < CXL_IRQ_RANGES && num; i++) {
+		try = num;
+		while (try) {
+			if (irq_alloc_range(adapter, try, &irq) == 0)
+				break;
+			try /= 2;
+		}
+		if (!try)
+			goto error;
+		irqs->offset[i] = irq;
+		irqs->range[i] = try;
+		num -= try;
+	}
+	if (num)
+		goto error;
+	spin_unlock(&adapter->guest->irq_alloc_lock);
+	return 0;
+
+error:
+	for (i = 0; i < CXL_IRQ_RANGES; i++)
+		irq_free_range(adapter, irqs->offset[i], irqs->range[i]);
+	spin_unlock(&adapter->guest->irq_alloc_lock);
+	return -ENOSPC;
+}
+
+static void guest_release_irq_ranges(struct cxl_irq_ranges *irqs,
+				struct cxl *adapter)
+{
+	int i;
+
+	spin_lock(&adapter->guest->irq_alloc_lock);
+	for (i = 0; i < CXL_IRQ_RANGES; i++)
+		irq_free_range(adapter, irqs->offset[i], irqs->range[i]);
+	spin_unlock(&adapter->guest->irq_alloc_lock);
+}
+
+static int guest_register_serr_irq(struct cxl_afu *afu)
+{
+	afu->err_irq_name = kasprintf(GFP_KERNEL, "cxl-%s-err",
+				      dev_name(&afu->dev));
+	if (!afu->err_irq_name)
+		return -ENOMEM;
+
+	if (!(afu->serr_virq = cxl_map_irq(afu->adapter, afu->serr_hwirq,
+				 guest_slice_irq_err, afu, afu->err_irq_name))) {
+		kfree(afu->err_irq_name);
+		afu->err_irq_name = NULL;
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void guest_release_serr_irq(struct cxl_afu *afu)
+{
+	cxl_unmap_irq(afu->serr_virq, afu);
+	cxl_ops->release_one_irq(afu->adapter, afu->serr_hwirq);
+	kfree(afu->err_irq_name);
+}
+
+static int guest_ack_irq(struct cxl_context *ctx, u64 tfc, u64 psl_reset_mask)
+{
+	return cxl_h_control_faults(ctx->afu->guest->handle, ctx->process_token,
+				tfc >> 32, (psl_reset_mask != 0));
+}
+
+static void disable_afu_irqs(struct cxl_context *ctx)
+{
+	irq_hw_number_t hwirq;
+	unsigned int virq;
+	int r, i;
+
+	pr_devel("Disabling AFU(%d) interrupts\n", ctx->afu->slice);
+	for (r = 0; r < CXL_IRQ_RANGES; r++) {
+		hwirq = ctx->irqs.offset[r];
+		for (i = 0; i < ctx->irqs.range[r]; hwirq++, i++) {
+			virq = irq_find_mapping(NULL, hwirq);
+			disable_irq(virq);
+		}
+	}
+}
+
+static void enable_afu_irqs(struct cxl_context *ctx)
+{
+	irq_hw_number_t hwirq;
+	unsigned int virq;
+	int r, i;
+
+	pr_devel("Enabling AFU(%d) interrupts\n", ctx->afu->slice);
+	for (r = 0; r < CXL_IRQ_RANGES; r++) {
+		hwirq = ctx->irqs.offset[r];
+		for (i = 0; i < ctx->irqs.range[r]; hwirq++, i++) {
+			virq = irq_find_mapping(NULL, hwirq);
+			enable_irq(virq);
+		}
+	}
+}
+
+static int _guest_afu_cr_readXX(int sz, struct cxl_afu *afu, int cr_idx,
+			u64 offset, u64 *val)
+{
+	unsigned long cr;
+	char c;
+	int rc = 0;
+
+	if (afu->crs_len < sz)
+		return -ENOENT;
+
+	if (unlikely(offset >= afu->crs_len))
+		return -ERANGE;
+
+	cr = get_zeroed_page(GFP_KERNEL);
+	if (!cr)
+		return -ENOMEM;
+
+	rc = cxl_h_get_config(afu->guest->handle, cr_idx, offset,
+			virt_to_phys((void *)cr), sz);
+	if (rc)
+		goto err;
+
+	switch (sz) {
+	case 1:
+		c = *((char *) cr);
+		*val = c;
+		break;
+	case 2:
+		*val = in_le16((u16 *)cr);
+		break;
+	case 4:
+		*val = in_le32((unsigned *)cr);
+		break;
+	case 8:
+		*val = in_le64((u64 *)cr);
+		break;
+	default:
+		WARN_ON(1);
+	}
+err:
+	free_page(cr);
+	return rc;
+}
+
+static int guest_afu_cr_read32(struct cxl_afu *afu, int cr_idx, u64 offset,
+			u32 *out)
+{
+	int rc;
+	u64 val;
+
+	rc = _guest_afu_cr_readXX(4, afu, cr_idx, offset, &val);
+	if (!rc)
+		*out = (u32) val;
+	return rc;
+}
+
+static int guest_afu_cr_read16(struct cxl_afu *afu, int cr_idx, u64 offset,
+			u16 *out)
+{
+	int rc;
+	u64 val;
+
+	rc = _guest_afu_cr_readXX(2, afu, cr_idx, offset, &val);
+	if (!rc)
+		*out = (u16) val;
+	return rc;
+}
+
+static int guest_afu_cr_read8(struct cxl_afu *afu, int cr_idx, u64 offset,
+			u8 *out)
+{
+	int rc;
+	u64 val;
+
+	rc = _guest_afu_cr_readXX(1, afu, cr_idx, offset, &val);
+	if (!rc)
+		*out = (u8) val;
+	return rc;
+}
+
+static int guest_afu_cr_read64(struct cxl_afu *afu, int cr_idx, u64 offset,
+			u64 *out)
+{
+	return _guest_afu_cr_readXX(8, afu, cr_idx, offset, out);
+}
+
+static int guest_afu_cr_write32(struct cxl_afu *afu, int cr, u64 off, u32 in)
+{
+	/* config record is not writable from guest */
+	return -EPERM;
+}
+
+static int guest_afu_cr_write16(struct cxl_afu *afu, int cr, u64 off, u16 in)
+{
+	/* config record is not writable from guest */
+	return -EPERM;
+}
+
+static int guest_afu_cr_write8(struct cxl_afu *afu, int cr, u64 off, u8 in)
+{
+	/* config record is not writable from guest */
+	return -EPERM;
+}
+
+static int attach_afu_directed(struct cxl_context *ctx, u64 wed, u64 amr)
+{
+	struct cxl_process_element_hcall *elem;
+	struct cxl *adapter = ctx->afu->adapter;
+	const struct cred *cred;
+	u32 pid, idx;
+	int rc, r, i;
+	u64 mmio_addr, mmio_size;
+	__be64 flags = 0;
+
+	/* Must be 8 byte aligned and cannot cross a 4096 byte boundary */
+	if (!(elem = (struct cxl_process_element_hcall *)
+			get_zeroed_page(GFP_KERNEL)))
+		return -ENOMEM;
+
+	elem->version = cpu_to_be64(CXL_PROCESS_ELEMENT_VERSION);
+	if (ctx->kernel) {
+		pid = 0;
+		flags |= CXL_PE_TRANSLATION_ENABLED;
+		flags |= CXL_PE_PRIVILEGED_PROCESS;
+		if (mfmsr() & MSR_SF)
+			flags |= CXL_PE_64_BIT;
+	} else {
+		pid = current->pid;
+		flags |= CXL_PE_PROBLEM_STATE;
+		flags |= CXL_PE_TRANSLATION_ENABLED;
+		if (!test_tsk_thread_flag(current, TIF_32BIT))
+			flags |= CXL_PE_64_BIT;
+		cred = get_current_cred();
+		if (uid_eq(cred->euid, GLOBAL_ROOT_UID))
+			flags |= CXL_PE_PRIVILEGED_PROCESS;
+		put_cred(cred);
+	}
+	elem->flags         = cpu_to_be64(flags);
+	elem->common.tid    = cpu_to_be32(0); /* Unused */
+	elem->common.pid    = cpu_to_be32(pid);
+	elem->common.csrp   = cpu_to_be64(0); /* disable */
+	elem->common.u.psl8.aurp0  = cpu_to_be64(0); /* disable */
+	elem->common.u.psl8.aurp1  = cpu_to_be64(0); /* disable */
+
+	cxl_prefault(ctx, wed);
+
+	elem->common.u.psl8.sstp0  = cpu_to_be64(ctx->sstp0);
+	elem->common.u.psl8.sstp1  = cpu_to_be64(ctx->sstp1);
+
+	/*
+	 * Ensure we have at least one interrupt allocated to take faults for
+	 * kernel contexts that may not have allocated any AFU IRQs at all:
+	 */
+	if (ctx->irqs.range[0] == 0) {
+		rc = afu_register_irqs(ctx, 0);
+		if (rc)
+			goto out_free;
+	}
+
+	for (r = 0; r < CXL_IRQ_RANGES; r++) {
+		for (i = 0; i < ctx->irqs.range[r]; i++) {
+			if (r == 0 && i == 0) {
+				elem->pslVirtualIsn = cpu_to_be32(ctx->irqs.offset[0]);
+			} else {
+				idx = ctx->irqs.offset[r] + i - adapter->guest->irq_base_offset;
+				elem->applicationVirtualIsnBitmap[idx / 8] |= 0x80 >> (idx % 8);
+			}
+		}
+	}
+	elem->common.amr = cpu_to_be64(amr);
+	elem->common.wed = cpu_to_be64(wed);
+
+	disable_afu_irqs(ctx);
+
+	rc = cxl_h_attach_process(ctx->afu->guest->handle, elem,
+				&ctx->process_token, &mmio_addr, &mmio_size);
+	if (rc == H_SUCCESS) {
+		if (ctx->master || !ctx->afu->pp_psa) {
+			ctx->psn_phys = ctx->afu->psn_phys;
+			ctx->psn_size = ctx->afu->adapter->ps_size;
+		} else {
+			ctx->psn_phys = mmio_addr;
+			ctx->psn_size = mmio_size;
+		}
+		if (ctx->afu->pp_psa && mmio_size &&
+			ctx->afu->pp_size == 0) {
+			/*
+			 * There's no property in the device tree to read the
+			 * pp_size. We only find out at the 1st attach.
+			 * Compared to bare-metal, it is too late and we
+			 * should really lock here. However, on powerVM,
+			 * pp_size is really only used to display in /sys.
+			 * Being discussed with pHyp for their next release.
+			 */
+			ctx->afu->pp_size = mmio_size;
+		}
+		/* from PAPR: process element is bytes 4-7 of process token */
+		ctx->external_pe = ctx->process_token & 0xFFFFFFFF;
+		pr_devel("CXL pe=%i is known as %i for pHyp, mmio_size=%#llx",
+			ctx->pe, ctx->external_pe, ctx->psn_size);
+		ctx->pe_inserted = true;
+		enable_afu_irqs(ctx);
+	}
+
+out_free:
+	free_page((u64)elem);
+	return rc;
+}
+
+static int guest_attach_process(struct cxl_context *ctx, bool kernel, u64 wed, u64 amr)
+{
+	pr_devel("in %s\n", __func__);
+
+	ctx->kernel = kernel;
+	if (ctx->afu->current_mode == CXL_MODE_DIRECTED)
+		return attach_afu_directed(ctx, wed, amr);
+
+	/* dedicated mode not supported on FW840 */
+
+	return -EINVAL;
+}
+
+static int detach_afu_directed(struct cxl_context *ctx)
+{
+	if (!ctx->pe_inserted)
+		return 0;
+	if (cxl_h_detach_process(ctx->afu->guest->handle, ctx->process_token))
+		return -1;
+	return 0;
+}
+
+static int guest_detach_process(struct cxl_context *ctx)
+{
+	pr_devel("in %s\n", __func__);
+	trace_cxl_detach(ctx);
+
+	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
+		return -EIO;
+
+	if (ctx->afu->current_mode == CXL_MODE_DIRECTED)
+		return detach_afu_directed(ctx);
+
+	return -EINVAL;
+}
+
+static void guest_release_afu(struct device *dev)
+{
+	struct cxl_afu *afu = to_cxl_afu(dev);
+
+	pr_devel("%s\n", __func__);
+
+	idr_destroy(&afu->contexts_idr);
+
+	kfree(afu->guest);
+	kfree(afu);
+}
+
+ssize_t cxl_guest_read_afu_vpd(struct cxl_afu *afu, void *buf, size_t len)
+{
+	return guest_collect_vpd(NULL, afu, buf, len);
+}
+
+#define ERR_BUFF_MAX_COPY_SIZE PAGE_SIZE
+static ssize_t guest_afu_read_err_buffer(struct cxl_afu *afu, char *buf,
+					loff_t off, size_t count)
+{
+	void *tbuf = NULL;
+	int rc = 0;
+
+	tbuf = (void *) get_zeroed_page(GFP_KERNEL);
+	if (!tbuf)
+		return -ENOMEM;
+
+	rc = cxl_h_get_afu_err(afu->guest->handle,
+			       off & 0x7,
+			       virt_to_phys(tbuf),
+			       count);
+	if (rc)
+		goto err;
+
+	if (count > ERR_BUFF_MAX_COPY_SIZE)
+		count = ERR_BUFF_MAX_COPY_SIZE - (off & 0x7);
+	memcpy(buf, tbuf, count);
+err:
+	free_page((u64)tbuf);
+
+	return rc;
+}
+
+static int guest_afu_check_and_enable(struct cxl_afu *afu)
+{
+	return 0;
+}
+
+static bool guest_support_attributes(const char *attr_name,
+				     enum cxl_attrs type)
+{
+	switch (type) {
+	case CXL_ADAPTER_ATTRS:
+		if ((strcmp(attr_name, "base_image") == 0) ||
+			(strcmp(attr_name, "load_image_on_perst") == 0) ||
+			(strcmp(attr_name, "perst_reloads_same_image") == 0) ||
+			(strcmp(attr_name, "image_loaded") == 0))
+			return false;
+		break;
+	case CXL_AFU_MASTER_ATTRS:
+		if ((strcmp(attr_name, "pp_mmio_off") == 0))
+			return false;
+		break;
+	case CXL_AFU_ATTRS:
+		break;
+	default:
+		break;
+	}
+
+	return true;
+}
+
+static int activate_afu_directed(struct cxl_afu *afu)
+{
+	int rc;
+
+	dev_info(&afu->dev, "Activating AFU(%d) directed mode\n", afu->slice);
+
+	afu->current_mode = CXL_MODE_DIRECTED;
+
+	afu->num_procs = afu->max_procs_virtualised;
+
+	if ((rc = cxl_chardev_m_afu_add(afu)))
+		return rc;
+
+	if ((rc = cxl_sysfs_afu_m_add(afu)))
+		goto err;
+
+	if ((rc = cxl_chardev_s_afu_add(afu)))
+		goto err1;
+
+	return 0;
+err1:
+	cxl_sysfs_afu_m_remove(afu);
+err:
+	cxl_chardev_afu_remove(afu);
+	return rc;
+}
+
+static int guest_afu_activate_mode(struct cxl_afu *afu, int mode)
+{
+	if (!mode)
+		return 0;
+	if (!(mode & afu->modes_supported))
+		return -EINVAL;
+
+	if (mode == CXL_MODE_DIRECTED)
+		return activate_afu_directed(afu);
+
+	if (mode == CXL_MODE_DEDICATED)
+		dev_err(&afu->dev, "Dedicated mode not supported\n");
+
+	return -EINVAL;
+}
+
+static int deactivate_afu_directed(struct cxl_afu *afu)
+{
+	dev_info(&afu->dev, "Deactivating AFU(%d) directed mode\n", afu->slice);
+
+	afu->current_mode = 0;
+	afu->num_procs = 0;
+
+	cxl_sysfs_afu_m_remove(afu);
+	cxl_chardev_afu_remove(afu);
+
+	cxl_ops->afu_reset(afu);
+
+	return 0;
+}
+
+static int guest_afu_deactivate_mode(struct cxl_afu *afu, int mode)
+{
+	if (!mode)
+		return 0;
+	if (!(mode & afu->modes_supported))
+		return -EINVAL;
+
+	if (mode == CXL_MODE_DIRECTED)
+		return deactivate_afu_directed(afu);
+	return 0;
+}
+
+static int guest_afu_reset(struct cxl_afu *afu)
+{
+	pr_devel("AFU(%d) reset request\n", afu->slice);
+	return cxl_h_reset_afu(afu->guest->handle);
+}
+
+static int guest_map_slice_regs(struct cxl_afu *afu)
+{
+	if (!(afu->p2n_mmio = ioremap(afu->guest->p2n_phys, afu->guest->p2n_size))) {
+		dev_err(&afu->dev, "Error mapping AFU(%d) MMIO regions\n",
+			afu->slice);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+static void guest_unmap_slice_regs(struct cxl_afu *afu)
+{
+	if (afu->p2n_mmio)
+		iounmap(afu->p2n_mmio);
+}
+
+static int afu_update_state(struct cxl_afu *afu)
+{
+	int rc, cur_state;
+
+	rc = afu_read_error_state(afu, &cur_state);
+	if (rc)
+		return rc;
+
+	if (afu->guest->previous_state == cur_state)
+		return 0;
+
+	pr_devel("AFU(%d) update state to %#x\n", afu->slice, cur_state);
+
+	switch (cur_state) {
+	case H_STATE_NORMAL:
+		afu->guest->previous_state = cur_state;
+		break;
+
+	case H_STATE_DISABLE:
+		pci_error_handlers(afu, CXL_ERROR_DETECTED_EVENT,
+				pci_channel_io_frozen);
+
+		cxl_context_detach_all(afu);
+		if ((rc = cxl_ops->afu_reset(afu)))
+			pr_devel("reset hcall failed %d\n", rc);
+
+		rc = afu_read_error_state(afu, &cur_state);
+		if (!rc && cur_state == H_STATE_NORMAL) {
+			pci_error_handlers(afu, CXL_SLOT_RESET_EVENT,
+					pci_channel_io_normal);
+			pci_error_handlers(afu, CXL_RESUME_EVENT, 0);
+		}
+		afu->guest->previous_state = 0;
+		break;
+
+	case H_STATE_TEMP_UNAVAILABLE:
+		afu->guest->previous_state = cur_state;
+		break;
+
+	case H_STATE_PERM_UNAVAILABLE:
+		dev_err(&afu->dev, "AFU is in permanent error state\n");
+		pci_error_handlers(afu, CXL_ERROR_DETECTED_EVENT,
+				pci_channel_io_perm_failure);
+		afu->guest->previous_state = cur_state;
+		break;
+
+	default:
+		pr_err("Unexpected AFU(%d) error state: %#x\n",
+		       afu->slice, cur_state);
+		return -EINVAL;
+	}
+
+	return rc;
+}
+
+static void afu_handle_errstate(struct work_struct *work)
+{
+	struct cxl_afu_guest *afu_guest =
+		container_of(to_delayed_work(work), struct cxl_afu_guest, work_err);
+
+	if (!afu_update_state(afu_guest->parent) &&
+	    afu_guest->previous_state == H_STATE_PERM_UNAVAILABLE)
+		return;
+
+	if (afu_guest->handle_err)
+		schedule_delayed_work(&afu_guest->work_err,
+				      msecs_to_jiffies(3000));
+}
+
+static bool guest_link_ok(struct cxl *cxl, struct cxl_afu *afu)
+{
+	int state;
+
+	if (afu && (!afu_read_error_state(afu, &state))) {
+		if (state == H_STATE_NORMAL)
+			return true;
+	}
+
+	return false;
+}
+
+static int afu_properties_look_ok(struct cxl_afu *afu)
+{
+	if (afu->pp_irqs < 0) {
+		dev_err(&afu->dev, "Unexpected per-process minimum interrupt value\n");
+		return -EINVAL;
+	}
+
+	if (afu->max_procs_virtualised < 1) {
+		dev_err(&afu->dev, "Unexpected max number of processes virtualised value\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int cxl_guest_init_afu(struct cxl *adapter, int slice, struct device_node *afu_np)
+{
+	struct cxl_afu *afu;
+	bool free = true;
+	int rc;
+
+	pr_devel("in %s - AFU(%d)\n", __func__, slice);
+	if (!(afu = cxl_alloc_afu(adapter, slice)))
+		return -ENOMEM;
+
+	if (!(afu->guest = kzalloc(sizeof(struct cxl_afu_guest), GFP_KERNEL))) {
+		kfree(afu);
+		return -ENOMEM;
+	}
+
+	if ((rc = dev_set_name(&afu->dev, "afu%i.%i",
+					  adapter->adapter_num,
+					  slice)))
+		goto err1;
+
+	adapter->slices++;
+
+	if ((rc = cxl_of_read_afu_handle(afu, afu_np)))
+		goto err1;
+
+	if ((rc = cxl_ops->afu_reset(afu)))
+		goto err1;
+
+	if ((rc = cxl_of_read_afu_properties(afu, afu_np)))
+		goto err1;
+
+	if ((rc = afu_properties_look_ok(afu)))
+		goto err1;
+
+	if ((rc = guest_map_slice_regs(afu)))
+		goto err1;
+
+	if ((rc = guest_register_serr_irq(afu)))
+		goto err2;
+
+	/*
+	 * After we call this function we must not free the afu directly, even
+	 * if it returns an error!
+	 */
+	if ((rc = cxl_register_afu(afu)))
+		goto err_put_dev;
+
+	if ((rc = cxl_sysfs_afu_add(afu)))
+		goto err_del_dev;
+
+	/*
+	 * pHyp doesn't expose the programming models supported by the
+	 * AFU. pHyp currently only supports directed mode. If it adds
+	 * dedicated mode later, this version of cxl has no way to
+	 * detect it. So we'll initialize the driver, but the first
+	 * attach will fail.
+	 * Being discussed with pHyp to do better (likely new property)
+	 */
+	if (afu->max_procs_virtualised == 1)
+		afu->modes_supported = CXL_MODE_DEDICATED;
+	else
+		afu->modes_supported = CXL_MODE_DIRECTED;
+
+	if ((rc = cxl_afu_select_best_mode(afu)))
+		goto err_remove_sysfs;
+
+	adapter->afu[afu->slice] = afu;
+
+	afu->enabled = true;
+
+	/*
+	 * wake up the cpu periodically to check the state
+	 * of the AFU using "afu" stored in the guest structure.
+	 */
+	afu->guest->parent = afu;
+	afu->guest->handle_err = true;
+	INIT_DELAYED_WORK(&afu->guest->work_err, afu_handle_errstate);
+	schedule_delayed_work(&afu->guest->work_err, msecs_to_jiffies(1000));
+
+	if ((rc = cxl_pci_vphb_add(afu)))
+		dev_info(&afu->dev, "Can't register vPHB\n");
+
+	return 0;
+
+err_remove_sysfs:
+	cxl_sysfs_afu_remove(afu);
+err_del_dev:
+	device_del(&afu->dev);
+err_put_dev:
+	put_device(&afu->dev);
+	free = false;
+	guest_release_serr_irq(afu);
+err2:
+	guest_unmap_slice_regs(afu);
+err1:
+	if (free) {
+		kfree(afu->guest);
+		kfree(afu);
+	}
+	return rc;
+}
+
+void cxl_guest_remove_afu(struct cxl_afu *afu)
+{
+	if (!afu)
+		return;
+
+	/* flush and stop pending job */
+	afu->guest->handle_err = false;
+	flush_delayed_work(&afu->guest->work_err);
+
+	cxl_pci_vphb_remove(afu);
+	cxl_sysfs_afu_remove(afu);
+
+	spin_lock(&afu->adapter->afu_list_lock);
+	afu->adapter->afu[afu->slice] = NULL;
+	spin_unlock(&afu->adapter->afu_list_lock);
+
+	cxl_context_detach_all(afu);
+	cxl_ops->afu_deactivate_mode(afu, afu->current_mode);
+	guest_release_serr_irq(afu);
+	guest_unmap_slice_regs(afu);
+
+	device_unregister(&afu->dev);
+}
+
+static void free_adapter(struct cxl *adapter)
+{
+	struct irq_avail *cur;
+	int i;
+
+	if (adapter->guest) {
+		if (adapter->guest->irq_avail) {
+			for (i = 0; i < adapter->guest->irq_nranges; i++) {
+				cur = &adapter->guest->irq_avail[i];
+				bitmap_free(cur->bitmap);
+			}
+			kfree(adapter->guest->irq_avail);
+		}
+		kfree(adapter->guest->status);
+		kfree(adapter->guest);
+	}
+	cxl_remove_adapter_nr(adapter);
+	kfree(adapter);
+}
+
+static int properties_look_ok(struct cxl *adapter)
+{
+	/* The absence of this property means that the operational
+	 * status is unknown or okay
+	 */
+	if (strlen(adapter->guest->status) &&
+	    strcmp(adapter->guest->status, "okay")) {
+		pr_err("ABORTING:Bad operational status of the device\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+ssize_t cxl_guest_read_adapter_vpd(struct cxl *adapter, void *buf, size_t len)
+{
+	return guest_collect_vpd(adapter, NULL, buf, len);
+}
+
+void cxl_guest_remove_adapter(struct cxl *adapter)
+{
+	pr_devel("in %s\n", __func__);
+
+	cxl_sysfs_adapter_remove(adapter);
+
+	cxl_guest_remove_chardev(adapter);
+	device_unregister(&adapter->dev);
+}
+
+static void release_adapter(struct device *dev)
+{
+	free_adapter(to_cxl_adapter(dev));
+}
+
+struct cxl *cxl_guest_init_adapter(struct device_node *np, struct platform_device *pdev)
+{
+	struct cxl *adapter;
+	bool free = true;
+	int rc;
+
+	if (!(adapter = cxl_alloc_adapter()))
+		return ERR_PTR(-ENOMEM);
+
+	if (!(adapter->guest = kzalloc(sizeof(struct cxl_guest), GFP_KERNEL))) {
+		free_adapter(adapter);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	adapter->slices = 0;
+	adapter->guest->pdev = pdev;
+	adapter->dev.parent = &pdev->dev;
+	adapter->dev.release = release_adapter;
+	dev_set_drvdata(&pdev->dev, adapter);
+
+	/*
+	 * Hypervisor controls PSL timebase initialization (p1 register).
+	 * On FW840, PSL is initialized.
+	 */
+	adapter->psl_timebase_synced = true;
+
+	if ((rc = cxl_of_read_adapter_handle(adapter, np)))
+		goto err1;
+
+	if ((rc = cxl_of_read_adapter_properties(adapter, np)))
+		goto err1;
+
+	if ((rc = properties_look_ok(adapter)))
+		goto err1;
+
+	if ((rc = cxl_guest_add_chardev(adapter)))
+		goto err1;
+
+	/*
+	 * After we call this function we must not free the adapter directly,
+	 * even if it returns an error!
+	 */
+	if ((rc = cxl_register_adapter(adapter)))
+		goto err_put_dev;
+
+	if ((rc = cxl_sysfs_adapter_add(adapter)))
+		goto err_del_dev;
+
+	/* release the context lock as the adapter is configured */
+	cxl_adapter_context_unlock(adapter);
+
+	return adapter;
+
+err_del_dev:
+	device_del(&adapter->dev);
+err_put_dev:
+	put_device(&adapter->dev);
+	free = false;
+	cxl_guest_remove_chardev(adapter);
+err1:
+	if (free)
+		free_adapter(adapter);
+	return ERR_PTR(rc);
+}
+
+void cxl_guest_reload_module(struct cxl *adapter)
+{
+	struct platform_device *pdev;
+
+	pdev = adapter->guest->pdev;
+	cxl_guest_remove_adapter(adapter);
+
+	cxl_of_probe(pdev);
+}
+
+const struct cxl_backend_ops cxl_guest_ops = {
+	.module = THIS_MODULE,
+	.adapter_reset = guest_reset,
+	.alloc_one_irq = guest_alloc_one_irq,
+	.release_one_irq = guest_release_one_irq,
+	.alloc_irq_ranges = guest_alloc_irq_ranges,
+	.release_irq_ranges = guest_release_irq_ranges,
+	.setup_irq = NULL,
+	.handle_psl_slice_error = guest_handle_psl_slice_error,
+	.psl_interrupt = guest_psl_irq,
+	.ack_irq = guest_ack_irq,
+	.attach_process = guest_attach_process,
+	.detach_process = guest_detach_process,
+	.update_ivtes = NULL,
+	.support_attributes = guest_support_attributes,
+	.link_ok = guest_link_ok,
+	.release_afu = guest_release_afu,
+	.afu_read_err_buffer = guest_afu_read_err_buffer,
+	.afu_check_and_enable = guest_afu_check_and_enable,
+	.afu_activate_mode = guest_afu_activate_mode,
+	.afu_deactivate_mode = guest_afu_deactivate_mode,
+	.afu_reset = guest_afu_reset,
+	.afu_cr_read8 = guest_afu_cr_read8,
+	.afu_cr_read16 = guest_afu_cr_read16,
+	.afu_cr_read32 = guest_afu_cr_read32,
+	.afu_cr_read64 = guest_afu_cr_read64,
+	.afu_cr_write8 = guest_afu_cr_write8,
+	.afu_cr_write16 = guest_afu_cr_write16,
+	.afu_cr_write32 = guest_afu_cr_write32,
+	.read_adapter_vpd = cxl_guest_read_adapter_vpd,
+};