vphb.c
/*
* Copyright 2014 IBM Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/pci.h>
#include <misc/cxl.h>
#include "cxl.h"
static int cxl_dma_set_mask(struct pci_dev *pdev, u64 dma_mask)
{
if (dma_mask < DMA_BIT_MASK(64)) {
pr_info("%s only 64bit DMA supported on CXL", __func__);
return -EIO;
}
*(pdev->dev.dma_mask) = dma_mask;
return 0;
}
static int cxl_pci_probe_mode(struct pci_bus *bus)
{
return PCI_PROBE_NORMAL;
}
static int cxl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
{
return -ENODEV;
}
static void cxl_teardown_msi_irqs(struct pci_dev *pdev)
{
/*
* MSI should never be set but need still need to provide this call
* back.
*/
}
static bool cxl_pci_enable_device_hook(struct pci_dev *dev)
{
struct pci_controller *phb;
struct cxl_afu *afu;
struct cxl_context *ctx;
phb = pci_bus_to_host(dev->bus);
afu = (struct cxl_afu *)phb->private_data;
if (!cxl_adapter_link_ok(afu->adapter)) {
dev_warn(&dev->dev, "%s: Device link is down, refusing to enable AFU\n", __func__);
return false;
}
set_dma_ops(&dev->dev, &dma_direct_ops);
set_dma_offset(&dev->dev, PAGE_OFFSET);
/*
* Allocate a context to do cxl things too. If we eventually do real
* DMA ops, we'll need a default context to attach them to
*/
ctx = cxl_dev_context_init(dev);
if (!ctx)
return false;
dev->dev.archdata.cxl_ctx = ctx;
return (cxl_afu_check_and_enable(afu) == 0);
}
static void cxl_pci_disable_device(struct pci_dev *dev)
{
struct cxl_context *ctx = cxl_get_context(dev);
if (ctx) {
if (ctx->status == STARTED) {
dev_err(&dev->dev, "Default context started\n");
return;
}
dev->dev.archdata.cxl_ctx = NULL;
cxl_release_context(ctx);
}
}
static resource_size_t cxl_pci_window_alignment(struct pci_bus *bus,
unsigned long type)
{
return 1;
}
static void cxl_pci_reset_secondary_bus(struct pci_dev *dev)
{
/* Should we do an AFU reset here ? */
}
static int cxl_pcie_cfg_record(u8 bus, u8 devfn)
{
return (bus << 8) + devfn;
}
static unsigned long cxl_pcie_cfg_addr(struct pci_controller* phb,
u8 bus, u8 devfn, int offset)
{
int record = cxl_pcie_cfg_record(bus, devfn);
return (unsigned long)phb->cfg_addr + ((unsigned long)phb->cfg_data * record) + offset;
}
static int cxl_pcie_config_info(struct pci_bus *bus, unsigned int devfn,
int offset, int len,
volatile void __iomem **ioaddr,
u32 *mask, int *shift)
{
struct pci_controller *phb;
struct cxl_afu *afu;
unsigned long addr;
phb = pci_bus_to_host(bus);
if (phb == NULL)
return PCIBIOS_DEVICE_NOT_FOUND;
afu = (struct cxl_afu *)phb->private_data;
if (cxl_pcie_cfg_record(bus->number, devfn) > afu->crs_num)
return PCIBIOS_DEVICE_NOT_FOUND;
if (offset >= (unsigned long)phb->cfg_data)
return PCIBIOS_BAD_REGISTER_NUMBER;
addr = cxl_pcie_cfg_addr(phb, bus->number, devfn, offset);
*ioaddr = (void *)(addr & ~0x3ULL);
*shift = ((addr & 0x3) * 8);
switch (len) {
case 1:
*mask = 0xff;
break;
case 2:
*mask = 0xffff;
break;
default:
*mask = 0xffffffff;
break;
}
return 0;
}
static inline bool cxl_config_link_ok(struct pci_bus *bus)
{
struct pci_controller *phb;
struct cxl_afu *afu;
/* Config space IO is based on phb->cfg_addr, which is based on
* afu_desc_mmio. This isn't safe to read/write when the link
* goes down, as EEH tears down MMIO space.
*
* Check if the link is OK before proceeding.
*/
phb = pci_bus_to_host(bus);
if (phb == NULL)
return false;
afu = (struct cxl_afu *)phb->private_data;
return cxl_adapter_link_ok(afu->adapter);
}
static int cxl_pcie_read_config(struct pci_bus *bus, unsigned int devfn,
int offset, int len, u32 *val)
{
volatile void __iomem *ioaddr;
int shift, rc;
u32 mask;
rc = cxl_pcie_config_info(bus, devfn, offset, len, &ioaddr,
&mask, &shift);
if (rc)
return rc;
if (!cxl_config_link_ok(bus))
return PCIBIOS_DEVICE_NOT_FOUND;
/* Can only read 32 bits */
*val = (in_le32(ioaddr) >> shift) & mask;
return PCIBIOS_SUCCESSFUL;
}
static int cxl_pcie_write_config(struct pci_bus *bus, unsigned int devfn,
int offset, int len, u32 val)
{
volatile void __iomem *ioaddr;
u32 v, mask;
int shift, rc;
rc = cxl_pcie_config_info(bus, devfn, offset, len, &ioaddr,
&mask, &shift);
if (rc)
return rc;
if (!cxl_config_link_ok(bus))
return PCIBIOS_DEVICE_NOT_FOUND;
/* Can only write 32 bits so do read-modify-write */
mask <<= shift;
val <<= shift;
v = (in_le32(ioaddr) & ~mask) || (val & mask);
out_le32(ioaddr, v);
return PCIBIOS_SUCCESSFUL;
}
static struct pci_ops cxl_pcie_pci_ops =
{
.read = cxl_pcie_read_config,
.write = cxl_pcie_write_config,
};
static struct pci_controller_ops cxl_pci_controller_ops =
{
.probe_mode = cxl_pci_probe_mode,
.enable_device_hook = cxl_pci_enable_device_hook,
.disable_device = cxl_pci_disable_device,
.release_device = cxl_pci_disable_device,
.window_alignment = cxl_pci_window_alignment,
.reset_secondary_bus = cxl_pci_reset_secondary_bus,
.setup_msi_irqs = cxl_setup_msi_irqs,
.teardown_msi_irqs = cxl_teardown_msi_irqs,
.dma_set_mask = cxl_dma_set_mask,
};
int cxl_pci_vphb_add(struct cxl_afu *afu)
{
struct pci_dev *phys_dev;
struct pci_controller *phb, *phys_phb;
phys_dev = to_pci_dev(afu->adapter->dev.parent);
phys_phb = pci_bus_to_host(phys_dev->bus);
/* Alloc and setup PHB data structure */
phb = pcibios_alloc_controller(phys_phb->dn);
if (!phb)
return -ENODEV;
/* Setup parent in sysfs */
phb->parent = &phys_dev->dev;
/* Setup the PHB using arch provided callback */
phb->ops = &cxl_pcie_pci_ops;
phb->cfg_addr = afu->afu_desc_mmio + afu->crs_offset;
phb->cfg_data = (void *)(u64)afu->crs_len;
phb->private_data = afu;
phb->controller_ops = cxl_pci_controller_ops;
/* Scan the bus */
pcibios_scan_phb(phb);
if (phb->bus == NULL)
return -ENXIO;
/* Claim resources. This might need some rework as well depending
* whether we are doing probe-only or not, like assigning unassigned
* resources etc...
*/
pcibios_claim_one_bus(phb->bus);
/* Add probed PCI devices to the device model */
pci_bus_add_devices(phb->bus);
afu->phb = phb;
return 0;
}
void cxl_pci_vphb_reconfigure(struct cxl_afu *afu)
{
/* When we are reconfigured, the AFU's MMIO space is unmapped
* and remapped. We need to reflect this in the PHB's view of
* the world.
*/
afu->phb->cfg_addr = afu->afu_desc_mmio + afu->crs_offset;
}
void cxl_pci_vphb_remove(struct cxl_afu *afu)
{
struct pci_controller *phb;
/* If there is no configuration record we won't have one of these */
if (!afu || !afu->phb)
return;
phb = afu->phb;
pci_remove_root_bus(phb->bus);
}
struct cxl_afu *cxl_pci_to_afu(struct pci_dev *dev)
{
struct pci_controller *phb;
phb = pci_bus_to_host(dev->bus);
return (struct cxl_afu *)phb->private_data;
}
EXPORT_SYMBOL_GPL(cxl_pci_to_afu);
unsigned int cxl_pci_to_cfg_record(struct pci_dev *dev)
{
return cxl_pcie_cfg_record(dev->bus->number, dev->devfn);
}
EXPORT_SYMBOL_GPL(cxl_pci_to_cfg_record);