s390/ism: add device driver for internal shared memory

Add support for the Internal Shared Memory vPCI Adapter.
This driver implements the interfaces of the SMC-D protocol.

Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 623 insertions, 0 deletions

diff --git a/drivers/s390/net/ism_drv.c b/drivers/s390/net/ism_drv.c
new file mode 100644
index 000000000000..c0631895154e
--- /dev/null
+++ b/drivers/s390/net/ism_drv.c
@@ -0,0 +1,623 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ISM driver for s390.
+ *
+ * Copyright IBM Corp. 2018
+ */
+#define KMSG_COMPONENT "ism"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/pci.h>
+#include <linux/err.h>
+#include <net/smc.h>
+
+#include <asm/debug.h>
+
+#include "ism.h"
+
+MODULE_DESCRIPTION("ISM driver for s390");
+MODULE_LICENSE("GPL");
+
+#define PCI_DEVICE_ID_IBM_ISM 0x04ED
+#define DRV_NAME "ism"
+
+static const struct pci_device_id ism_device_table[] = {
+	{ PCI_VDEVICE(IBM, PCI_DEVICE_ID_IBM_ISM), 0 },
+	{ 0, }
+};
+MODULE_DEVICE_TABLE(pci, ism_device_table);
+
+static debug_info_t *ism_debug_info;
+
+static int ism_cmd(struct ism_dev *ism, void *cmd)
+{
+	struct ism_req_hdr *req = cmd;
+	struct ism_resp_hdr *resp = cmd;
+
+	memcpy_toio(ism->ctl + sizeof(*req), req + 1, req->len - sizeof(*req));
+	memcpy_toio(ism->ctl, req, sizeof(*req));
+
+	WRITE_ONCE(resp->ret, ISM_ERROR);
+
+	memcpy_fromio(resp, ism->ctl, sizeof(*resp));
+	if (resp->ret) {
+		debug_text_event(ism_debug_info, 0, "cmd failure");
+		debug_event(ism_debug_info, 0, resp, sizeof(*resp));
+		goto out;
+	}
+	memcpy_fromio(resp + 1, ism->ctl + sizeof(*resp),
+		      resp->len - sizeof(*resp));
+out:
+	return resp->ret;
+}
+
+static int ism_cmd_simple(struct ism_dev *ism, u32 cmd_code)
+{
+	union ism_cmd_simple cmd;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.request.hdr.cmd = cmd_code;
+	cmd.request.hdr.len = sizeof(cmd.request);
+
+	return ism_cmd(ism, &cmd);
+}
+
+static int query_info(struct ism_dev *ism)
+{
+	union ism_qi cmd;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.request.hdr.cmd = ISM_QUERY_INFO;
+	cmd.request.hdr.len = sizeof(cmd.request);
+
+	if (ism_cmd(ism, &cmd))
+		goto out;
+
+	debug_text_event(ism_debug_info, 3, "query info");
+	debug_event(ism_debug_info, 3, &cmd.response, sizeof(cmd.response));
+out:
+	return 0;
+}
+
+static int register_sba(struct ism_dev *ism)
+{
+	union ism_reg_sba cmd;
+	dma_addr_t dma_handle;
+	struct ism_sba *sba;
+
+	sba = dma_zalloc_coherent(&ism->pdev->dev, PAGE_SIZE,
+				  &dma_handle, GFP_KERNEL);
+	if (!sba)
+		return -ENOMEM;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.request.hdr.cmd = ISM_REG_SBA;
+	cmd.request.hdr.len = sizeof(cmd.request);
+	cmd.request.sba = dma_handle;
+
+	if (ism_cmd(ism, &cmd)) {
+		dma_free_coherent(&ism->pdev->dev, PAGE_SIZE, sba, dma_handle);
+		return -EIO;
+	}
+
+	ism->sba = sba;
+	ism->sba_dma_addr = dma_handle;
+
+	return 0;
+}
+
+static int register_ieq(struct ism_dev *ism)
+{
+	union ism_reg_ieq cmd;
+	dma_addr_t dma_handle;
+	struct ism_eq *ieq;
+
+	ieq = dma_zalloc_coherent(&ism->pdev->dev, PAGE_SIZE,
+				  &dma_handle, GFP_KERNEL);
+	if (!ieq)
+		return -ENOMEM;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.request.hdr.cmd = ISM_REG_IEQ;
+	cmd.request.hdr.len = sizeof(cmd.request);
+	cmd.request.ieq = dma_handle;
+	cmd.request.len = sizeof(*ieq);
+
+	if (ism_cmd(ism, &cmd)) {
+		dma_free_coherent(&ism->pdev->dev, PAGE_SIZE, ieq, dma_handle);
+		return -EIO;
+	}
+
+	ism->ieq = ieq;
+	ism->ieq_idx = -1;
+	ism->ieq_dma_addr = dma_handle;
+
+	return 0;
+}
+
+static int unregister_sba(struct ism_dev *ism)
+{
+	if (!ism->sba)
+		return 0;
+
+	if (ism_cmd_simple(ism, ISM_UNREG_SBA))
+		return -EIO;
+
+	dma_free_coherent(&ism->pdev->dev, PAGE_SIZE,
+			  ism->sba, ism->sba_dma_addr);
+
+	ism->sba = NULL;
+	ism->sba_dma_addr = 0;
+
+	return 0;
+}
+
+static int unregister_ieq(struct ism_dev *ism)
+{
+	if (!ism->ieq)
+		return 0;
+
+	if (ism_cmd_simple(ism, ISM_UNREG_IEQ))
+		return -EIO;
+
+	dma_free_coherent(&ism->pdev->dev, PAGE_SIZE,
+			  ism->ieq, ism->ieq_dma_addr);
+
+	ism->ieq = NULL;
+	ism->ieq_dma_addr = 0;
+
+	return 0;
+}
+
+static int ism_read_local_gid(struct ism_dev *ism)
+{
+	union ism_read_gid cmd;
+	int ret;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.request.hdr.cmd = ISM_READ_GID;
+	cmd.request.hdr.len = sizeof(cmd.request);
+
+	ret = ism_cmd(ism, &cmd);
+	if (ret)
+		goto out;
+
+	ism->smcd->local_gid = cmd.response.gid;
+out:
+	return ret;
+}
+
+static int ism_query_rgid(struct smcd_dev *smcd, u64 rgid, u32 vid_valid,
+			  u32 vid)
+{
+	struct ism_dev *ism = smcd->priv;
+	union ism_query_rgid cmd;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.request.hdr.cmd = ISM_QUERY_RGID;
+	cmd.request.hdr.len = sizeof(cmd.request);
+
+	cmd.request.rgid = rgid;
+	cmd.request.vlan_valid = vid_valid;
+	cmd.request.vlan_id = vid;
+
+	return ism_cmd(ism, &cmd);
+}
+
+static void ism_free_dmb(struct ism_dev *ism, struct smcd_dmb *dmb)
+{
+	clear_bit(dmb->sba_idx, ism->sba_bitmap);
+	dma_free_coherent(&ism->pdev->dev, dmb->dmb_len,
+			  dmb->cpu_addr, dmb->dma_addr);
+}
+
+static int ism_alloc_dmb(struct ism_dev *ism, struct smcd_dmb *dmb)
+{
+	unsigned long bit;
+
+	if (PAGE_ALIGN(dmb->dmb_len) > dma_get_max_seg_size(&ism->pdev->dev))
+		return -EINVAL;
+
+	if (!dmb->sba_idx) {
+		bit = find_next_zero_bit(ism->sba_bitmap, ISM_NR_DMBS,
+					 ISM_DMB_BIT_OFFSET);
+		if (bit == ISM_NR_DMBS)
+			return -ENOMEM;
+
+		dmb->sba_idx = bit;
+	}
+	if (dmb->sba_idx < ISM_DMB_BIT_OFFSET ||
+	    test_and_set_bit(dmb->sba_idx, ism->sba_bitmap))
+		return -EINVAL;
+
+	dmb->cpu_addr = dma_zalloc_coherent(&ism->pdev->dev, dmb->dmb_len,
+					    &dmb->dma_addr, GFP_KERNEL |
+					    __GFP_NOWARN | __GFP_NOMEMALLOC |
+					    __GFP_COMP | __GFP_NORETRY);
+	if (!dmb->cpu_addr)
+		clear_bit(dmb->sba_idx, ism->sba_bitmap);
+
+	return dmb->cpu_addr ? 0 : -ENOMEM;
+}
+
+static int ism_register_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb)
+{
+	struct ism_dev *ism = smcd->priv;
+	union ism_reg_dmb cmd;
+	int ret;
+
+	ret = ism_alloc_dmb(ism, dmb);
+	if (ret)
+		goto out;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.request.hdr.cmd = ISM_REG_DMB;
+	cmd.request.hdr.len = sizeof(cmd.request);
+
+	cmd.request.dmb = dmb->dma_addr;
+	cmd.request.dmb_len = dmb->dmb_len;
+	cmd.request.sba_idx = dmb->sba_idx;
+	cmd.request.vlan_valid = dmb->vlan_valid;
+	cmd.request.vlan_id = dmb->vlan_id;
+	cmd.request.rgid = dmb->rgid;
+
+	ret = ism_cmd(ism, &cmd);
+	if (ret) {
+		ism_free_dmb(ism, dmb);
+		goto out;
+	}
+	dmb->dmb_tok = cmd.response.dmb_tok;
+out:
+	return ret;
+}
+
+static int ism_unregister_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb)
+{
+	struct ism_dev *ism = smcd->priv;
+	union ism_unreg_dmb cmd;
+	int ret;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.request.hdr.cmd = ISM_UNREG_DMB;
+	cmd.request.hdr.len = sizeof(cmd.request);
+
+	cmd.request.dmb_tok = dmb->dmb_tok;
+
+	ret = ism_cmd(ism, &cmd);
+	if (ret)
+		goto out;
+
+	ism_free_dmb(ism, dmb);
+out:
+	return ret;
+}
+
+static int ism_add_vlan_id(struct smcd_dev *smcd, u64 vlan_id)
+{
+	struct ism_dev *ism = smcd->priv;
+	union ism_set_vlan_id cmd;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.request.hdr.cmd = ISM_ADD_VLAN_ID;
+	cmd.request.hdr.len = sizeof(cmd.request);
+
+	cmd.request.vlan_id = vlan_id;
+
+	return ism_cmd(ism, &cmd);
+}
+
+static int ism_del_vlan_id(struct smcd_dev *smcd, u64 vlan_id)
+{
+	struct ism_dev *ism = smcd->priv;
+	union ism_set_vlan_id cmd;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.request.hdr.cmd = ISM_DEL_VLAN_ID;
+	cmd.request.hdr.len = sizeof(cmd.request);
+
+	cmd.request.vlan_id = vlan_id;
+
+	return ism_cmd(ism, &cmd);
+}
+
+static int ism_set_vlan_required(struct smcd_dev *smcd)
+{
+	return ism_cmd_simple(smcd->priv, ISM_SET_VLAN);
+}
+
+static int ism_reset_vlan_required(struct smcd_dev *smcd)
+{
+	return ism_cmd_simple(smcd->priv, ISM_RESET_VLAN);
+}
+
+static int ism_signal_ieq(struct smcd_dev *smcd, u64 rgid, u32 trigger_irq,
+			  u32 event_code, u64 info)
+{
+	struct ism_dev *ism = smcd->priv;
+	union ism_sig_ieq cmd;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.request.hdr.cmd = ISM_SIGNAL_IEQ;
+	cmd.request.hdr.len = sizeof(cmd.request);
+
+	cmd.request.rgid = rgid;
+	cmd.request.trigger_irq = trigger_irq;
+	cmd.request.event_code = event_code;
+	cmd.request.info = info;
+
+	return ism_cmd(ism, &cmd);
+}
+
+static unsigned int max_bytes(unsigned int start, unsigned int len,
+			      unsigned int boundary)
+{
+	return min(boundary - (start & (boundary - 1)), len);
+}
+
+static int ism_move(struct smcd_dev *smcd, u64 dmb_tok, unsigned int idx,
+		    bool sf, unsigned int offset, void *data, unsigned int size)
+{
+	struct ism_dev *ism = smcd->priv;
+	unsigned int bytes;
+	u64 dmb_req;
+	int ret;
+
+	while (size) {
+		bytes = max_bytes(offset, size, PAGE_SIZE);
+		dmb_req = ISM_CREATE_REQ(dmb_tok, idx, size == bytes ? sf : 0,
+					 offset);
+
+		ret = __ism_move(ism, dmb_req, data, bytes);
+		if (ret)
+			return ret;
+
+		size -= bytes;
+		data += bytes;
+		offset += bytes;
+	}
+
+	return 0;
+}
+
+static void ism_handle_event(struct ism_dev *ism)
+{
+	struct smcd_event *entry;
+
+	while ((ism->ieq_idx + 1) != READ_ONCE(ism->ieq->header.idx)) {
+		if (++(ism->ieq_idx) == ARRAY_SIZE(ism->ieq->entry))
+			ism->ieq_idx = 0;
+
+		entry = &ism->ieq->entry[ism->ieq_idx];
+		debug_event(ism_debug_info, 2, entry, sizeof(*entry));
+		smcd_handle_event(ism->smcd, entry);
+	}
+}
+
+static irqreturn_t ism_handle_irq(int irq, void *data)
+{
+	struct ism_dev *ism = data;
+	unsigned long bit, end;
+	unsigned long *bv;
+
+	bv = (void *) &ism->sba->dmb_bits[ISM_DMB_WORD_OFFSET];
+	end = sizeof(ism->sba->dmb_bits) * BITS_PER_BYTE - ISM_DMB_BIT_OFFSET;
+
+	spin_lock(&ism->lock);
+	ism->sba->s = 0;
+	barrier();
+	for (bit = 0;;) {
+		bit = find_next_bit_inv(bv, end, bit);
+		if (bit >= end)
+			break;
+
+		clear_bit_inv(bit, bv);
+		barrier();
+		smcd_handle_irq(ism->smcd, bit + ISM_DMB_BIT_OFFSET);
+		ism->sba->dmbe_mask[bit + ISM_DMB_BIT_OFFSET] = 0;
+	}
+
+	if (ism->sba->e) {
+		ism->sba->e = 0;
+		barrier();
+		ism_handle_event(ism);
+	}
+	spin_unlock(&ism->lock);
+	return IRQ_HANDLED;
+}
+
+static const struct smcd_ops ism_ops = {
+	.query_remote_gid = ism_query_rgid,
+	.register_dmb = ism_register_dmb,
+	.unregister_dmb = ism_unregister_dmb,
+	.add_vlan_id = ism_add_vlan_id,
+	.del_vlan_id = ism_del_vlan_id,
+	.set_vlan_required = ism_set_vlan_required,
+	.reset_vlan_required = ism_reset_vlan_required,
+	.signal_event = ism_signal_ieq,
+	.move_data = ism_move,
+};
+
+static int ism_dev_init(struct ism_dev *ism)
+{
+	struct pci_dev *pdev = ism->pdev;
+	int ret;
+
+	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
+	if (ret <= 0)
+		goto out;
+
+	ret = request_irq(pci_irq_vector(pdev, 0), ism_handle_irq, 0,
+			  pci_name(pdev), ism);
+	if (ret)
+		goto free_vectors;
+
+	ret = register_sba(ism);
+	if (ret)
+		goto free_irq;
+
+	ret = register_ieq(ism);
+	if (ret)
+		goto unreg_sba;
+
+	ret = ism_read_local_gid(ism);
+	if (ret)
+		goto unreg_ieq;
+
+	ret = smcd_register_dev(ism->smcd);
+	if (ret)
+		goto unreg_ieq;
+
+	query_info(ism);
+	return 0;
+
+unreg_ieq:
+	unregister_ieq(ism);
+unreg_sba:
+	unregister_sba(ism);
+free_irq:
+	free_irq(pci_irq_vector(pdev, 0), ism);
+free_vectors:
+	pci_free_irq_vectors(pdev);
+out:
+	return ret;
+}
+
+static int ism_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct ism_dev *ism;
+	int ret;
+
+	ism = kzalloc(sizeof(*ism), GFP_KERNEL);
+	if (!ism)
+		return -ENOMEM;
+
+	spin_lock_init(&ism->lock);
+	dev_set_drvdata(&pdev->dev, ism);
+	ism->pdev = pdev;
+
+	ret = pci_enable_device_mem(pdev);
+	if (ret)
+		goto err;
+
+	ret = pci_request_mem_regions(pdev, DRV_NAME);
+	if (ret)
+		goto err_disable;
+
+	ism->ctl = pci_iomap(pdev, 2, 0);
+	if (!ism->ctl)
+		goto err_resource;
+
+	ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
+	if (ret)
+		goto err_unmap;
+
+	pci_set_dma_seg_boundary(pdev, SZ_1M - 1);
+	pci_set_dma_max_seg_size(pdev, SZ_1M);
+	pci_set_master(pdev);
+
+	ism->smcd = smcd_alloc_dev(&pdev->dev, dev_name(&pdev->dev), &ism_ops,
+				   ISM_NR_DMBS);
+	if (!ism->smcd)
+		goto err_unmap;
+
+	ism->smcd->priv = ism;
+	ret = ism_dev_init(ism);
+	if (ret)
+		goto err_free;
+
+	return 0;
+
+err_free:
+	smcd_free_dev(ism->smcd);
+err_unmap:
+	pci_iounmap(pdev, ism->ctl);
+err_resource:
+	pci_release_mem_regions(pdev);
+err_disable:
+	pci_disable_device(pdev);
+err:
+	kfree(ism);
+	dev_set_drvdata(&pdev->dev, NULL);
+	return ret;
+}
+
+static void ism_dev_exit(struct ism_dev *ism)
+{
+	struct pci_dev *pdev = ism->pdev;
+
+	smcd_unregister_dev(ism->smcd);
+	unregister_ieq(ism);
+	unregister_sba(ism);
+	free_irq(pci_irq_vector(pdev, 0), ism);
+	pci_free_irq_vectors(pdev);
+}
+
+static void ism_remove(struct pci_dev *pdev)
+{
+	struct ism_dev *ism = dev_get_drvdata(&pdev->dev);
+
+	ism_dev_exit(ism);
+
+	smcd_free_dev(ism->smcd);
+	pci_iounmap(pdev, ism->ctl);
+	pci_release_mem_regions(pdev);
+	pci_disable_device(pdev);
+	dev_set_drvdata(&pdev->dev, NULL);
+	kfree(ism);
+}
+
+static int ism_suspend(struct device *dev)
+{
+	struct ism_dev *ism = dev_get_drvdata(dev);
+
+	ism_dev_exit(ism);
+	return 0;
+}
+
+static int ism_resume(struct device *dev)
+{
+	struct ism_dev *ism = dev_get_drvdata(dev);
+
+	return ism_dev_init(ism);
+}
+
+static SIMPLE_DEV_PM_OPS(ism_pm_ops, ism_suspend, ism_resume);
+
+static struct pci_driver ism_driver = {
+	.name	  = DRV_NAME,
+	.id_table = ism_device_table,
+	.probe	  = ism_probe,
+	.remove	  = ism_remove,
+	.driver	  = {
+		.pm = &ism_pm_ops,
+	},
+};
+
+static int __init ism_init(void)
+{
+	int ret;
+
+	ism_debug_info = debug_register("ism", 2, 1, 16);
+	if (!ism_debug_info)
+		return -ENODEV;
+
+	debug_register_view(ism_debug_info, &debug_hex_ascii_view);
+	ret = pci_register_driver(&ism_driver);
+	if (ret)
+		debug_unregister(ism_debug_info);
+
+	return ret;
+}
+
+static void __exit ism_exit(void)
+{
+	pci_unregister_driver(&ism_driver);
+	debug_unregister(ism_debug_info);
+}
+
+module_init(ism_init);
+module_exit(ism_exit);