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authorDavid S. Miller <davem@davemloft.net>2016-10-06 08:44:56 +0300
committerDavid S. Miller <davem@davemloft.net>2016-10-06 08:44:56 +0300
commit27f145e74c274fa6e40056f3a8d5dc3563bd7369 (patch)
tree8211bfaa3f0a1079db760f96f9d7ff277f996f62
parentcdd4f4c71047cdd28c13891e6e217765ea1c1bdc (diff)
parentaa7bde1a8b49391d34f17905a04c3acf7770283d (diff)
downloadlinux-27f145e74c274fa6e40056f3a8d5dc3563bd7369.tar.xz
Merge branch 'sparc-pcie-perf'
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>
-rw-r--r--arch/sparc/include/asm/hypervisor.h1
-rw-r--r--arch/sparc/kernel/pci_sun4v.c52
2 files changed, 42 insertions, 11 deletions
diff --git a/arch/sparc/include/asm/hypervisor.h b/arch/sparc/include/asm/hypervisor.h
index f5b6537306f0..666d5ba230d2 100644
--- a/arch/sparc/include/asm/hypervisor.h
+++ b/arch/sparc/include/asm/hypervisor.h
@@ -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) | \
diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c
index 61c6f935accc..db57d8acdc01 100644
--- a/arch/sparc/kernel/pci_sun4v.c
+++ b/arch/sparc/kernel/pci_sun4v.c
@@ -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;
}