blob: 0459e100b4e78990b1e07b126b7655082fae4591 [file] [log] [blame]
/*
* This file implements the DMA operations for NVLink devices. The NPU
* devices all point to the same iommu table as the parent PCI device.
*
* Copyright Alistair Popple, IBM Corporation 2015.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#include <linux/export.h>
#include <linux/pci.h>
#include <linux/memblock.h>
#include <linux/iommu.h>
#include <asm/iommu.h>
#include <asm/pnv-pci.h>
#include <asm/msi_bitmap.h>
#include <asm/opal.h>
#include "powernv.h"
#include "pci.h"
/*
* Other types of TCE cache invalidation are not functional in the
* hardware.
*/
static struct pci_dev *get_pci_dev(struct device_node *dn)
{
return PCI_DN(dn)->pcidev;
}
/* Given a NPU device get the associated PCI device. */
struct pci_dev *pnv_pci_get_gpu_dev(struct pci_dev *npdev)
{
struct device_node *dn;
struct pci_dev *gpdev;
/* Get assoicated PCI device */
dn = of_parse_phandle(npdev->dev.of_node, "ibm,gpu", 0);
if (!dn)
return NULL;
gpdev = get_pci_dev(dn);
of_node_put(dn);
return gpdev;
}
EXPORT_SYMBOL(pnv_pci_get_gpu_dev);
/* Given the real PCI device get a linked NPU device. */
struct pci_dev *pnv_pci_get_npu_dev(struct pci_dev *gpdev, int index)
{
struct device_node *dn;
struct pci_dev *npdev;
/* Get assoicated PCI device */
dn = of_parse_phandle(gpdev->dev.of_node, "ibm,npu", index);
if (!dn)
return NULL;
npdev = get_pci_dev(dn);
of_node_put(dn);
return npdev;
}
EXPORT_SYMBOL(pnv_pci_get_npu_dev);
#define NPU_DMA_OP_UNSUPPORTED() \
dev_err_once(dev, "%s operation unsupported for NVLink devices\n", \
__func__)
static void *dma_npu_alloc(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag,
struct dma_attrs *attrs)
{
NPU_DMA_OP_UNSUPPORTED();
return NULL;
}
static void dma_npu_free(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
struct dma_attrs *attrs)
{
NPU_DMA_OP_UNSUPPORTED();
}
static dma_addr_t dma_npu_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction direction,
struct dma_attrs *attrs)
{
NPU_DMA_OP_UNSUPPORTED();
return 0;
}
static int dma_npu_map_sg(struct device *dev, struct scatterlist *sglist,
int nelems, enum dma_data_direction direction,
struct dma_attrs *attrs)
{
NPU_DMA_OP_UNSUPPORTED();
return 0;
}
static int dma_npu_dma_supported(struct device *dev, u64 mask)
{
NPU_DMA_OP_UNSUPPORTED();
return 0;
}
static u64 dma_npu_get_required_mask(struct device *dev)
{
NPU_DMA_OP_UNSUPPORTED();
return 0;
}
struct dma_map_ops dma_npu_ops = {
.map_page = dma_npu_map_page,
.map_sg = dma_npu_map_sg,
.alloc = dma_npu_alloc,
.free = dma_npu_free,
.dma_supported = dma_npu_dma_supported,
.get_required_mask = dma_npu_get_required_mask,
};
/*
* Returns the PE assoicated with the PCI device of the given
* NPU. Returns the linked pci device if pci_dev != NULL.
*/
static struct pnv_ioda_pe *get_gpu_pci_dev_and_pe(struct pnv_ioda_pe *npe,
struct pci_dev **gpdev)
{
struct pnv_phb *phb;
struct pci_controller *hose;
struct pci_dev *pdev;
struct pnv_ioda_pe *pe;
struct pci_dn *pdn;
pdev = pnv_pci_get_gpu_dev(npe->pdev);
if (!pdev)
return NULL;
pdn = pci_get_pdn(pdev);
if (WARN_ON(!pdn || pdn->pe_number == IODA_INVALID_PE))
return NULL;
hose = pci_bus_to_host(pdev->bus);
phb = hose->private_data;
pe = &phb->ioda.pe_array[pdn->pe_number];
if (gpdev)
*gpdev = pdev;
return pe;
}
long pnv_npu_set_window(struct pnv_ioda_pe *npe, int num,
struct iommu_table *tbl)
{
struct pnv_phb *phb = npe->phb;
int64_t rc;
const unsigned long size = tbl->it_indirect_levels ?
tbl->it_level_size : tbl->it_size;
const __u64 start_addr = tbl->it_offset << tbl->it_page_shift;
const __u64 win_size = tbl->it_size << tbl->it_page_shift;
pe_info(npe, "Setting up window %llx..%llx pg=%lx\n",
start_addr, start_addr + win_size - 1,
IOMMU_PAGE_SIZE(tbl));
rc = opal_pci_map_pe_dma_window(phb->opal_id,
npe->pe_number,
npe->pe_number,
tbl->it_indirect_levels + 1,
__pa(tbl->it_base),
size << 3,
IOMMU_PAGE_SIZE(tbl));
if (rc) {
pe_err(npe, "Failed to configure TCE table, err %lld\n", rc);
return rc;
}
pnv_pci_ioda2_tce_invalidate_entire(phb, false);
/* Add the table to the list so its TCE cache will get invalidated */
pnv_pci_link_table_and_group(phb->hose->node, num,
tbl, &npe->table_group);
return 0;
}
long pnv_npu_unset_window(struct pnv_ioda_pe *npe, int num)
{
struct pnv_phb *phb = npe->phb;
int64_t rc;
pe_info(npe, "Removing DMA window\n");
rc = opal_pci_map_pe_dma_window(phb->opal_id, npe->pe_number,
npe->pe_number,
0/* levels */, 0/* table address */,
0/* table size */, 0/* page size */);
if (rc) {
pe_err(npe, "Unmapping failed, ret = %lld\n", rc);
return rc;
}
pnv_pci_ioda2_tce_invalidate_entire(phb, false);
pnv_pci_unlink_table_and_group(npe->table_group.tables[num],
&npe->table_group);
return 0;
}
/*
* Enables 32 bit DMA on NPU.
*/
static void pnv_npu_dma_set_32(struct pnv_ioda_pe *npe)
{
struct pci_dev *gpdev;
struct pnv_ioda_pe *gpe;
int64_t rc;
/*
* Find the assoicated PCI devices and get the dma window
* information from there.
*/
if (!npe->pdev || !(npe->flags & PNV_IODA_PE_DEV))
return;
gpe = get_gpu_pci_dev_and_pe(npe, &gpdev);
if (!gpe)
return;
rc = pnv_npu_set_window(npe, 0, gpe->table_group.tables[0]);
/*
* We don't initialise npu_pe->tce32_table as we always use
* dma_npu_ops which are nops.
*/
set_dma_ops(&npe->pdev->dev, &dma_npu_ops);
}
/*
* Enables bypass mode on the NPU. The NPU only supports one
* window per link, so bypass needs to be explicitly enabled or
* disabled. Unlike for a PHB3 bypass and non-bypass modes can't be
* active at the same time.
*/
static int pnv_npu_dma_set_bypass(struct pnv_ioda_pe *npe)
{
struct pnv_phb *phb = npe->phb;
int64_t rc = 0;
phys_addr_t top = memblock_end_of_DRAM();
if (phb->type != PNV_PHB_NPU || !npe->pdev)
return -EINVAL;
rc = pnv_npu_unset_window(npe, 0);
if (rc != OPAL_SUCCESS)
return rc;
/* Enable the bypass window */
top = roundup_pow_of_two(top);
dev_info(&npe->pdev->dev, "Enabling bypass for PE %d\n",
npe->pe_number);
rc = opal_pci_map_pe_dma_window_real(phb->opal_id,
npe->pe_number, npe->pe_number,
0 /* bypass base */, top);
if (rc == OPAL_SUCCESS)
pnv_pci_ioda2_tce_invalidate_entire(phb, false);
return rc;
}
void pnv_npu_try_dma_set_bypass(struct pci_dev *gpdev, bool bypass)
{
int i;
struct pnv_phb *phb;
struct pci_dn *pdn;
struct pnv_ioda_pe *npe;
struct pci_dev *npdev;
for (i = 0; ; ++i) {
npdev = pnv_pci_get_npu_dev(gpdev, i);
if (!npdev)
break;
pdn = pci_get_pdn(npdev);
if (WARN_ON(!pdn || pdn->pe_number == IODA_INVALID_PE))
return;
phb = pci_bus_to_host(npdev->bus)->private_data;
/* We only do bypass if it's enabled on the linked device */
npe = &phb->ioda.pe_array[pdn->pe_number];
if (bypass) {
dev_info(&npdev->dev,
"Using 64-bit DMA iommu bypass\n");
pnv_npu_dma_set_bypass(npe);
} else {
dev_info(&npdev->dev, "Using 32-bit DMA via iommu\n");
pnv_npu_dma_set_32(npe);
}
}
}
/* Switch ownership from platform code to external user (e.g. VFIO) */
void pnv_npu_take_ownership(struct pnv_ioda_pe *npe)
{
struct pnv_phb *phb = npe->phb;
int64_t rc;
/*
* Note: NPU has just a single TVE in the hardware which means that
* while used by the kernel, it can have either 32bit window or
* DMA bypass but never both. So we deconfigure 32bit window only
* if it was enabled at the moment of ownership change.
*/
if (npe->table_group.tables[0]) {
pnv_npu_unset_window(npe, 0);
return;
}
/* Disable bypass */
rc = opal_pci_map_pe_dma_window_real(phb->opal_id,
npe->pe_number, npe->pe_number,
0 /* bypass base */, 0);
if (rc) {
pe_err(npe, "Failed to disable bypass, err %lld\n", rc);
return;
}
pnv_pci_ioda2_tce_invalidate_entire(npe->phb, false);
}
struct pnv_ioda_pe *pnv_pci_npu_setup_iommu(struct pnv_ioda_pe *npe)
{
struct pnv_phb *phb = npe->phb;
struct pci_bus *pbus = phb->hose->bus;
struct pci_dev *npdev, *gpdev = NULL, *gptmp;
struct pnv_ioda_pe *gpe = get_gpu_pci_dev_and_pe(npe, &gpdev);
if (!gpe || !gpdev)
return NULL;
list_for_each_entry(npdev, &pbus->devices, bus_list) {
gptmp = pnv_pci_get_gpu_dev(npdev);
if (gptmp != gpdev)
continue;
pe_info(gpe, "Attached NPU %s\n", dev_name(&npdev->dev));
iommu_group_add_device(gpe->table_group.group, &npdev->dev);
}
return gpe;
}