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Merge branch 'sparc-pcie-perf'

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Chris Hyser says:

====================
sparc64: PCIe performance enhancements

Ver 2 is redone for 4.8 where commit 00085f1efa387a8ce100e3734920f7639c80caa3
changed DMA attributes from struct pointer to unsigned long.

This set of patches initiates a series of PCIe performance enhancement patch
submittals.

Patch 1/2 enables version 2 of the SPARC sun4v IOMMU I/O address translation
services need for subsequent enhancements.

Patch 2/2 allows drivers to specify DMA_ATTR_WEAK_ORDERING via DMA attributes
to the SPARC DMA mapping routines enabling "relaxed ordering" for the buffer
being mapped.

[Still relevant write-up]
PCI-Express Relaxed Ordering and the Sun SPARC Enterprise M-class Servers
https://blogs.oracle.com/olympus/entry/relaxed_ordering
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2016-10-06 01:44:56 -04:00
commit 27f145e74c
2 changed files with 42 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/sparc/include/asm/hypervisor.h
View File

@ -1744,6 +1744,7 @@ unsigned long sun4v_vintr_set_target(unsigned long dev_handle,
#define HV_PCI_MAP_ATTR_READ 0x01
#define HV_PCI_MAP_ATTR_WRITE 0x02
#define HV_PCI_MAP_ATTR_RELAXED_ORDER 0x04
#define HV_PCI_DEVICE_BUILD(b,d,f) \
((((b) & 0xff) << 16) | \

52
arch/sparc/kernel/pci_sun4v.c
View File

@ -30,8 +30,19 @@
#define DRIVER_NAME "pci_sun4v"
#define PFX DRIVER_NAME ": "
static unsigned long vpci_major = 1;
static unsigned long vpci_minor = 1;
static unsigned long vpci_major;
static unsigned long vpci_minor;
struct vpci_version {
unsigned long major;
unsigned long minor;
};
/* Ordered from largest major to lowest */
static struct vpci_version vpci_versions[] = {
{ .major = 2, .minor = 0 },
{ .major = 1, .minor = 1 },
};
#define PGLIST_NENTS (PAGE_SIZE / sizeof(u64))
@ -67,6 +78,10 @@ static long iommu_batch_flush(struct iommu_batch *p)
u64 *pglist = p->pglist;
unsigned long npages = p->npages;
/* VPCI maj=1, min=[0,1] only supports read and write */
if (vpci_major < 2)
prot &= (HV_PCI_MAP_ATTR_READ | HV_PCI_MAP_ATTR_WRITE);
while (npages != 0) {
long num;
@ -133,6 +148,7 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size,
unsigned long attrs)
{
unsigned long flags, order, first_page, npages, n;
unsigned long prot = 0;
struct iommu *iommu;
struct page *page;
void *ret;
@ -146,6 +162,9 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size,
npages = size >> IO_PAGE_SHIFT;
if (attrs & DMA_ATTR_WEAK_ORDERING)
prot = HV_PCI_MAP_ATTR_RELAXED_ORDER;
nid = dev->archdata.numa_node;
page = alloc_pages_node(nid, gfp, order);
if (unlikely(!page))
@ -169,7 +188,7 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size,
local_irq_save(flags);
iommu_batch_start(dev,
(HV_PCI_MAP_ATTR_READ |
(HV_PCI_MAP_ATTR_READ | prot |
HV_PCI_MAP_ATTR_WRITE),
entry);
@ -266,6 +285,9 @@ static dma_addr_t dma_4v_map_page(struct device *dev, struct page *page,
if (direction != DMA_TO_DEVICE)
prot |= HV_PCI_MAP_ATTR_WRITE;
if (attrs & DMA_ATTR_WEAK_ORDERING)
prot |= HV_PCI_MAP_ATTR_RELAXED_ORDER;
local_irq_save(flags);
iommu_batch_start(dev, prot, entry);
@ -344,6 +366,9 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
if (direction != DMA_TO_DEVICE)
prot |= HV_PCI_MAP_ATTR_WRITE;
if (attrs & DMA_ATTR_WEAK_ORDERING)
prot |= HV_PCI_MAP_ATTR_RELAXED_ORDER;
outs = s = segstart = &sglist[0];
outcount = 1;
incount = nelems;
@ -907,22 +932,27 @@ static int pci_sun4v_probe(struct platform_device *op)
struct device_node *dp;
struct iommu *iommu;
u32 devhandle;
int i, err;
int i, err = -ENODEV;
dp = op->dev.of_node;
if (!hvapi_negotiated++) {
err = sun4v_hvapi_register(HV_GRP_PCI,
vpci_major,
&vpci_minor);
for (i = 0; i < ARRAY_SIZE(vpci_versions); i++) {
vpci_major = vpci_versions[i].major;
vpci_minor = vpci_versions[i].minor;
err = sun4v_hvapi_register(HV_GRP_PCI, vpci_major,
&vpci_minor);
if (!err)
break;
}
if (err) {
printk(KERN_ERR PFX "Could not register hvapi, "
"err=%d\n", err);
pr_err(PFX "Could not register hvapi, err=%d\n", err);
return err;
}
printk(KERN_INFO PFX "Registered hvapi major[%lu] minor[%lu]\n",
vpci_major, vpci_minor);
pr_info(PFX "Registered hvapi major[%lu] minor[%lu]\n",
vpci_major, vpci_minor);
dma_ops = &sun4v_dma_ops;
}