path: root/drivers/net/ethernet/ibm/ehea/ehea_qmr.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  linux/drivers/net/ethernet/ibm/ehea/ehea_qmr.c
 *
 *  eHEA ethernet device driver for IBM eServer System p
 *
 *  (C) Copyright IBM Corp. 2006
 *
 *  Authors:
 *       Christoph Raisch <raisch@de.ibm.com>
 *       Jan-Bernd Themann <themann@de.ibm.com>
 *       Thomas Klein <tklein@de.ibm.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/mm.h>
#include <linux/slab.h>
#include "ehea.h"
#include "ehea_phyp.h"
#include "ehea_qmr.h"

static struct ehea_bmap *ehea_bmap;

static void *hw_qpageit_get_inc(struct hw_queue *queue)
{
	void *retvalue = hw_qeit_get(queue);

	queue->current_q_offset += queue->pagesize;
	if (queue->current_q_offset > queue->queue_length) {
		queue->current_q_offset -= queue->pagesize;
		retvalue = NULL;
	} else if (((u64) retvalue) & (EHEA_PAGESIZE-1)) {
		pr_err("not on pageboundary\n");
		retvalue = NULL;
	}
	return retvalue;
}

static int hw_queue_ctor(struct hw_queue *queue, const u32 nr_of_pages,
			  const u32 pagesize, const u32 qe_size)
{
	int pages_per_kpage = PAGE_SIZE / pagesize;
	int i, k;

	if ((pagesize > PAGE_SIZE) || (!pages_per_kpage)) {
		pr_err("pagesize conflict! kernel pagesize=%d, ehea pagesize=%d\n",
		       (int)PAGE_SIZE, (int)pagesize);
		return -EINVAL;
	}

	queue->queue_length = nr_of_pages * pagesize;
	queue->queue_pages = kmalloc_array(nr_of_pages, sizeof(void *),
					   GFP_KERNEL);
	if (!queue->queue_pages)
		return -ENOMEM;

	/*
	 * allocate pages for queue:
	 * outer loop allocates whole kernel pages (page aligned) and
	 * inner loop divides a kernel page into smaller hea queue pages
	 */
	i = 0;
	while (i < nr_of_pages) {
		u8 *kpage = (u8 *)get_zeroed_page(GFP_KERNEL);
		if (!kpage)
			goto out_nomem;
		for (k = 0; k < pages_per_kpage && i < nr_of_pages; k++) {
			(queue->queue_pages)[i] = (struct ehea_page *)kpage;
			kpage += pagesize;
			i++;
		}
	}

	queue->current_q_offset = 0;
	queue->qe_size = qe_size;
	queue->pagesize = pagesize;
	queue->toggle_state = 1;

	return 0;
out_nomem:
	for (i = 0; i < nr_of_pages; i += pages_per_kpage) {
		if (!(queue->queue_pages)[i])
			break;
		free_page((unsigned long)(queue->queue_pages)[i]);
	}
	return -ENOMEM;
}

static void hw_queue_dtor(struct hw_queue *queue)
{
	int pages_per_kpage;
	int i, nr_pages;

	if (!queue || !queue->queue_pages)
		return;

	pages_per_kpage = PAGE_SIZE / queue->pagesize;

	nr_pages = queue->queue_length / queue->pagesize;

	for (i = 0; i < nr_pages; i += pages_per_kpage)
		free_page((unsigned long)(queue->queue_pages)[i]);

	kfree(queue->queue_pages);
}

struct ehea_cq *ehea_create_cq(struct ehea_adapter *adapter,
			       int nr_of_cqe, u64 eq_handle, u32 cq_token)
{
	struct ehea_cq *cq;
	u64 hret, rpage;
	u32 counter;
	int ret;
	void *vpage;

	cq = kzalloc(sizeof(*cq), GFP_KERNEL);
	if (!cq)
		goto out_nomem;

	cq->attr.max_nr_of_cqes = nr_of_cqe;
	cq->attr.cq_token = cq_token;
	cq->attr.eq_handle = eq_handle;

	cq->adapter = adapter;

	hret = ehea_h_alloc_resource_cq(adapter->handle, &cq->attr,
					&cq->fw_handle, &cq->epas);
	if (hret != H_SUCCESS) {
		pr_err("alloc_resource_cq failed\n");
		goto out_freemem;
	}

	ret = hw_queue_ctor(&cq->hw_queue, cq->attr.nr_pages,
			    EHEA_PAGESIZE, sizeof(struct ehea_cqe));
	if (ret)
		goto out_freeres;

	for (counter = 0; counter < cq->attr.nr_pages; counter++) {
		vpage = hw_qpageit_get_inc(&cq->hw_queue);
		if (!vpage) {
			pr_err("hw_qpageit_get_inc failed\n");
			goto out_kill_hwq;
		}

		rpage = __pa(vpage);
		hret = ehea_h_register_rpage(adapter->handle,
					     0, EHEA_CQ_REGISTER_ORIG,
					     cq->fw_handle, rpage, 1);
		if (hret < H_SUCCESS) {
			pr_err("register_rpage_cq failed ehea_cq=%p hret=%llx counter=%i act_pages=%i\n",
			       cq, hret, counter, cq->attr.nr_pages);
			goto out_kill_hwq;
		}

		if (counter == (cq->attr.nr_pages - 1)) {
			vpage = hw_qpageit_get_inc(&cq->hw_queue);

			if ((hret != H_SUCCESS) || (vpage)) {
				pr_err("registration of pages not complete hret=%llx\n",
				       hret);
				goto out_kill_hwq;
			}
		} else {
			if (hret != H_PAGE_REGISTERED) {
				pr_err("CQ: registration of page failed hret=%llx\n",
				       hret);
				goto out_kill_hwq