/*
* Thunderbolt driver - NHI driver
*
* The NHI (native host interface) is the pci device that allows us to send and
* receive frames from the thunderbolt bus.
*
* Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
* Copyright (C) 2018, Intel Corporation
*/
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/delay.h>
#include "nhi.h"
#include "nhi_regs.h"
#include "tb.h"
#define RING_TYPE(ring) ((ring)->is_tx ? "TX ring" : "RX ring")
/*
* Used to enable end-to-end workaround for missing RX packets. Do not
* use this ring for anything else.
*/
#define RING_E2E_UNUSED_HOPID 2
#define RING_FIRST_USABLE_HOPID TB_PATH_MIN_HOPID
/*
* Minimal number of vectors when we use MSI-X. Two for control channel
* Rx/Tx and the rest four are for cross domain DMA paths.
*/
#define MSIX_MIN_VECS 6
#define MSIX_MAX_VECS 16
#define NHI_MAILBOX_TIMEOUT 500 /* ms */
static int ring_interrupt_index(struct tb_ring *ring)
{
int bit = ring->hop;
if (!ring->is_tx)
bit += ring->nhi->hop_count;
return bit;
}
/**
* ring_interrupt_active() - activate/deactivate interrupts for a single ring
*
* ring->nhi->lock must be held.
*/
static void ring_interrupt_active(struct tb_ring *ring, bool active)
{
int reg = REG_RING_INTERRUPT_BASE +
ring_interrupt_index(ring) / 32 * 4;
int bit = ring_interrupt_index(ring) & 31;
int mask = 1 << bit;
u32 old, new;
if (ring->irq > 0) {
u32 step, shift, ivr, misc;
void __iomem *ivr_base;
int index;
if (ring->is_tx)
index = ring->hop;
else
index = ring->hop + ring->nhi->hop_count;
/*
* Ask the hardware to clear interrupt status bits automatically
* since we already know which interrupt was triggered.
*/
misc = ioread32(ring->nhi->iobase + REG_DMA_MISC);
if (!(misc & REG_DMA_MISC_INT_AUTO_CLEAR)) {
misc |= REG_DMA_MISC_INT_AUTO_CLEAR;
iowrite32(misc, ring->nhi->iobase + REG_DMA_MISC);
}
ivr_base = ring->nhi->iobase + REG_INT_VEC_ALLOC_BASE;
step = index / REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
shift = index % REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
ivr = ioread32(ivr_base + step);
ivr &= ~(REG_INT_VEC_ALLOC_MASK << shift);
if (active)
ivr |= ring->vector << shift;
iowrite32(ivr, ivr_base + step);
}
old = ioread32(ring->nhi->iobase + reg);
if (active)
new = old | mask;
else
new = old & ~mask;
dev_dbg(&ring->nhi->pdev->dev,
"%s interrupt at register %#x bit %d (%#x -> %#x)\n",
active ? "enabling" : "disabling", reg, bit, old, new);
if (new == old)
dev_WARN(&ring->nhi->pdev->dev,
"interrupt for %s %d is already %s\n",
RING_TYPE(ring),