From: Tushar Dave <tushar.n.dave@oracle.com>
Date: Fri, 21 Apr 2017 17:49:31 +0000 (-0700)
Subject: SPARC64: Introduce IOMMU BYPASS method
X-Git-Tag: v4.1.12-106.0.20170720_1900~80
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=6b8533ad05451fc27cf39cc890a6ce6c4dc2d5e9;p=users%2Fjedix%2Flinux-maple.git

SPARC64: Introduce IOMMU BYPASS method

This change adds IOMMU BYPASS HV API that will allow PCIe devices to
bypass IOMMU during DMA map/unmap.

Orabug: 25573557

Reviewed-by: chris hyser <chris.hyser@oracle.com>
Signed-off-by: Tushar Dave <tushar.n.dave@oracle.com>
Signed-off-by: Allen Pais <allen.pais@oracle.com>
---

diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c
index db968b72702e..0da3b11b98af 100644
--- a/arch/sparc/kernel/pci_sun4v.c
+++ b/arch/sparc/kernel/pci_sun4v.c
@@ -361,6 +361,40 @@ static void dma_4v_free_coherent(struct device *dev, size_t size, void *cpu,
 		free_pages((unsigned long)cpu, order);
 }
 
+static dma_addr_t dma_4v_map_page_bypass(struct device *dev, struct page *page,
+					 unsigned long offset, size_t sz,
+					 enum dma_data_direction direction,
+					 struct dma_attrs *attrs)
+{
+	struct pci_pbm_info *pbm;
+	unsigned long devhandle;
+	unsigned long ra;
+	unsigned long prot;
+	unsigned long dma_addr;
+
+	if (unlikely(direction == DMA_NONE))
+		goto bad;
+
+	prot = HV_PCI_MAP_ATTR_READ;
+	if (direction != DMA_TO_DEVICE)
+		prot |= HV_PCI_MAP_ATTR_WRITE;
+
+	/* VPCI maj=2, min=[0,1] or greater supports relax ordering */
+	if (dma_get_attr(DMA_ATTR_WEAK_ORDERING, attrs) && vpci_major >= 2)
+		prot |= HV_PCI_MAP_ATTR_RELAXED_ORDER;
+
+	pbm = dev->archdata.host_controller;
+	devhandle = pbm->devhandle;
+	ra = __pa(page_address(page) + offset);
+	if (pci_sun4v_iommu_getbypass(devhandle, ra, prot, &dma_addr))
+		goto bad;
+
+	return dma_addr;
+
+bad:
+	return DMA_ERROR_CODE;
+}
+
 static dma_addr_t dma_4v_map_page(struct device *dev, struct page *page,
 				  unsigned long offset, size_t sz,
 				  enum dma_data_direction direction,
@@ -484,6 +518,45 @@ static void dma_4v_unmap_page(struct device *dev, dma_addr_t bus_addr,
 	iommu_tbl_range_free(tbl, bus_addr, npages, IOMMU_ERROR_CODE);
 }
 
+static int dma_4v_map_sg_bypass(struct device *dev, struct scatterlist *sglist,
+				int nelems, enum dma_data_direction direction,
+				struct dma_attrs *attrs)
+{
+	struct pci_pbm_info *pbm;
+	unsigned long devhandle;
+	unsigned long ra;
+	unsigned long prot;
+	unsigned long dma_addr;
+	struct scatterlist *s;
+	int i;
+
+	if (unlikely(direction == DMA_NONE))
+		goto bad;
+
+	prot = HV_PCI_MAP_ATTR_READ;
+	if (direction != DMA_TO_DEVICE)
+		prot |= HV_PCI_MAP_ATTR_WRITE;
+
+	/* VPCI maj=2, min=[0,1] or greater supports relax ordering */
+	if (dma_get_attr(DMA_ATTR_WEAK_ORDERING, attrs) && vpci_major >= 2)
+		prot |= HV_PCI_MAP_ATTR_RELAXED_ORDER;
+
+	pbm = dev->archdata.host_controller;
+	devhandle = pbm->devhandle;
+	for_each_sg(sglist, s, nelems, i) {
+		ra = (unsigned long)SG_ENT_PHYS_ADDRESS(s);
+		if (pci_sun4v_iommu_getbypass(devhandle, ra, prot, &dma_addr))
+			goto bad;
+		s->dma_address = dma_addr;
+		s->dma_length = s->length;
+	}
+
+	return nelems;
+
+bad:
+	return 0;
+}
+
 static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
 			 int nelems, enum dma_data_direction direction,
 			 struct dma_attrs *attrs)
diff --git a/arch/sparc/kernel/pci_sun4v.h b/arch/sparc/kernel/pci_sun4v.h
index c87db0a89149..ea5e5290c203 100644
--- a/arch/sparc/kernel/pci_sun4v.h
+++ b/arch/sparc/kernel/pci_sun4v.h
@@ -18,6 +18,10 @@ unsigned long pci_sun4v_iommu_getmap(unsigned long devhandle,
 				     unsigned long tsbid,
 				     unsigned long *io_attributes,
 				     unsigned long *real_address);
+unsigned long pci_sun4v_iommu_getbypass(unsigned long dev_hdl,
+					unsigned long ra,
+					unsigned long attr,
+					unsigned long *io_addr_p);
 unsigned long pci_sun4v_config_get(unsigned long devhandle,
 				   unsigned long pci_device,
 				   unsigned long config_offset,
diff --git a/arch/sparc/kernel/pci_sun4v_asm.S b/arch/sparc/kernel/pci_sun4v_asm.S
index 55eb534e4613..5ba5b551dbde 100644
--- a/arch/sparc/kernel/pci_sun4v_asm.S
+++ b/arch/sparc/kernel/pci_sun4v_asm.S
@@ -56,6 +56,22 @@ ENTRY(pci_sun4v_iommu_getmap)
 	 mov	%o0, %o0
 ENDPROC(pci_sun4v_iommu_getmap)
 
+	/* %o0: devhandle
+	 * %o1: r_addr
+	 * %o2: io_attributes
+	 * %o3: &io_addr
+	 *
+	 * returns: %o0: status
+	 */
+ENTRY(pci_sun4v_iommu_getbypass)
+	mov	HV_FAST_PCI_IOMMU_GETBYPASS, %o5
+	ta	HV_FAST_TRAP
+	brz,a	%o0, 1f
+	 stx	%o1, [%o3]
+1:	retl
+	 nop
+ENDPROC(pci_sun4v_iommu_getbypass)
+
 	/* %o0: devhandle
 	 * %o1:	pci_device
 	 * %o2:	pci_config_offset