[PATCH 1/2] iommu/core: stop converting bytes to page order

[Ohad Ben-Cohen]

Express sizes in bytes rather than in page order, to eliminate the
size->order->size conversions we have whenever the IOMMU API is calling
the low level drivers' map/unmap methods.

Adopt all existing drivers.

Signed-off-by: Ohad Ben-Cohen <ohad@xxxxxxxxxx>
---
 drivers/iommu/amd_iommu.c   |   13 +++++--------
 drivers/iommu/intel-iommu.c |   11 ++++-------
 drivers/iommu/iommu.c       |    8 +++++---
 drivers/iommu/msm_iommu.c   |   19 +++++++------------
 drivers/iommu/omap-iommu.c  |   14 +++++---------
 include/linux/iommu.h       |    6 +++---
 6 files changed, 29 insertions(+), 42 deletions(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 764e3da..32d502e 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2702,9 +2702,8 @@ static int amd_iommu_attach_device(struct
iommu_domain *dom,
 }

 static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova,
-			 phys_addr_t paddr, int gfp_order, int iommu_prot)
+			 phys_addr_t paddr, size_t page_size, int iommu_prot)
 {
-	unsigned long page_size = 0x1000UL << gfp_order;
 	struct protection_domain *domain = dom->priv;
 	int prot = 0;
 	int ret;
@@ -2721,13 +2720,11 @@ static int amd_iommu_map(struct iommu_domain
*dom, unsigned long iova,
 	return ret;
 }

-static int amd_iommu_unmap(struct iommu_domain *dom, unsigned long iova,
-			   int gfp_order)
+static size_t amd_iommu_unmap(struct iommu_domain *dom, unsigned long iova,
+			   size_t page_size)
 {
 	struct protection_domain *domain = dom->priv;
-	unsigned long page_size, unmap_size;
-
-	page_size  = 0x1000UL << gfp_order;
+	size_t unmap_size;

 	mutex_lock(&domain->api_lock);
 	unmap_size = iommu_unmap_page(domain, iova, page_size);
@@ -2735,7 +2732,7 @@ static int amd_iommu_unmap(struct iommu_domain
*dom, unsigned long iova,

 	domain_flush_tlb_pde(domain);

-	return get_order(unmap_size);
+	return unmap_size;
 }

 static phys_addr_t amd_iommu_iova_to_phys(struct iommu_domain *dom,
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 2d53c3d..96a9bd4 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3821,12 +3821,11 @@ static void intel_iommu_detach_device(struct
iommu_domain *domain,

 static int intel_iommu_map(struct iommu_domain *domain,
 			   unsigned long iova, phys_addr_t hpa,
-			   int gfp_order, int iommu_prot)
+			   size_t size, int iommu_prot)
 {
 	struct dmar_domain *dmar_domain = domain->priv;
 	u64 max_addr;
 	int prot = 0;
-	size_t size;
 	int ret;

 	if (iommu_prot & IOMMU_READ)
@@ -3836,7 +3835,6 @@ static int intel_iommu_map(struct iommu_domain *domain,
 	if ((iommu_prot & IOMMU_CACHE) && dmar_domain->iommu_snooping)
 		prot |= DMA_PTE_SNP;

-	size     = PAGE_SIZE << gfp_order;
 	max_addr = iova + size;
 	if (dmar_domain->max_addr < max_addr) {
 		u64 end;
@@ -3859,11 +3857,10 @@ static int intel_iommu_map(struct iommu_domain *domain,
 	return ret;
 }

-static int intel_iommu_unmap(struct iommu_domain *domain,
-			     unsigned long iova, int gfp_order)
+static size_t intel_iommu_unmap(struct iommu_domain *domain,
+			     unsigned long iova, size_t size)
 {
 	struct dmar_domain *dmar_domain = domain->priv;
-	size_t size = PAGE_SIZE << gfp_order;

 	dma_pte_clear_range(dmar_domain, iova >> VTD_PAGE_SHIFT,
 			    (iova + size - 1) >> VTD_PAGE_SHIFT);
@@ -3871,7 +3868,7 @@ static int intel_iommu_unmap(struct iommu_domain *domain,
 	if (dmar_domain->max_addr == iova + size)
 		dmar_domain->max_addr = iova;

-	return gfp_order;
+	return size;
 }

 static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 63ca9ba..5d042e8 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -168,13 +168,13 @@ int iommu_map(struct iommu_domain *domain,
unsigned long iova,

 	BUG_ON(!IS_ALIGNED(iova | paddr, size));

-	return domain->ops->map(domain, iova, paddr, gfp_order, prot);
+	return domain->ops->map(domain, iova, paddr, size, prot);
 }
 EXPORT_SYMBOL_GPL(iommu_map);

 int iommu_unmap(struct iommu_domain *domain, unsigned long iova, int gfp_order)
 {
-	size_t size;
+	size_t size, unmapped;

 	if (unlikely(domain->ops->unmap == NULL))
 		return -ENODEV;
@@ -183,7 +183,9 @@ int iommu_unmap(struct iommu_domain *domain,
unsigned long iova, int gfp_order)

 	BUG_ON(!IS_ALIGNED(iova, size));

-	return domain->ops->unmap(domain, iova, gfp_order);
+	unmapped = domain->ops->unmap(domain, iova, size);
+
+	return get_order(unmapped);
 }
 EXPORT_SYMBOL_GPL(iommu_unmap);

diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
index 5865dd2..13718d9 100644
--- a/drivers/iommu/msm_iommu.c
+++ b/drivers/iommu/msm_iommu.c
@@ -352,7 +352,7 @@ fail:
 }

 static int msm_iommu_map(struct iommu_domain *domain, unsigned long va,
-			 phys_addr_t pa, int order, int prot)
+			 phys_addr_t pa, size_t len, int prot)
 {
 	struct msm_priv *priv;
 	unsigned long flags;
@@ -363,7 +363,6 @@ static int msm_iommu_map(struct iommu_domain
*domain, unsigned long va,
 	unsigned long *sl_pte;
 	unsigned long sl_offset;
 	unsigned int pgprot;
-	size_t len = 0x1000UL << order;
 	int ret = 0, tex, sh;

 	spin_lock_irqsave(&msm_iommu_lock, flags);
@@ -463,8 +462,8 @@ fail:
 	return ret;
 }

-static int msm_iommu_unmap(struct iommu_domain *domain, unsigned long va,
-			    int order)
+static size_t msm_iommu_unmap(struct iommu_domain *domain, unsigned long va,
+			    size_t len)
 {
 	struct msm_priv *priv;
 	unsigned long flags;
@@ -474,7 +473,6 @@ static int msm_iommu_unmap(struct iommu_domain
*domain, unsigned long va,
 	unsigned long *sl_table;
 	unsigned long *sl_pte;
 	unsigned long sl_offset;
-	size_t len = 0x1000UL << order;
 	int i, ret = 0;

 	spin_lock_irqsave(&msm_iommu_lock, flags);
@@ -544,15 +542,12 @@ static int msm_iommu_unmap(struct iommu_domain
*domain, unsigned long va,

 	ret = __flush_iotlb(domain);

-	/*
-	 * the IOMMU API requires us to return the order of the unmapped
-	 * page (on success).
-	 */
-	if (!ret)
-		ret = order;
 fail:
 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
-	return ret;
+
+	/* the IOMMU API requires us to return how many bytes were unmapped */
+	len = ret ? 0 : len;
+	return len;
 }

 static phys_addr_t msm_iommu_iova_to_phys(struct iommu_domain *domain,
diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index 9ee2c38..1bb2971 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -1019,12 +1019,11 @@ static void iopte_cachep_ctor(void *iopte)
 }

 static int omap_iommu_map(struct iommu_domain *domain, unsigned long da,
-			 phys_addr_t pa, int order, int prot)
+			 phys_addr_t pa, size_t bytes, int prot)
 {
 	struct omap_iommu_domain *omap_domain = domain->priv;
 	struct omap_iommu *oiommu = omap_domain->iommu_dev;
 	struct device *dev = oiommu->dev;
-	size_t bytes = PAGE_SIZE << order;
 	struct iotlb_entry e;
 	int omap_pgsz;
 	u32 ret, flags;
@@ -1049,19 +1048,16 @@ static int omap_iommu_map(struct iommu_domain
*domain, unsigned long da,
 	return ret;
 }

-static int omap_iommu_unmap(struct iommu_domain *domain, unsigned long da,
-			    int order)
+static size_t omap_iommu_unmap(struct iommu_domain *domain, unsigned long da,
+			    size_t size)
 {
 	struct omap_iommu_domain *omap_domain = domain->priv;
 	struct omap_iommu *oiommu = omap_domain->iommu_dev;
 	struct device *dev = oiommu->dev;
-	size_t unmap_size;

-	dev_dbg(dev, "unmapping da 0x%lx order %d\n", da, order);
+	dev_dbg(dev, "unmapping da 0x%lx size %u\n", da, size);

-	unmap_size = iopgtable_clear_entry(oiommu, da);
-
-	return unmap_size ? get_order(unmap_size) : -EINVAL;
+	return iopgtable_clear_entry(oiommu, da);
 }

 static int
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 710291f..6b6ed21 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -54,9 +54,9 @@ struct iommu_ops {
 	int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
 	void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
 	int (*map)(struct iommu_domain *domain, unsigned long iova,
-		   phys_addr_t paddr, int gfp_order, int prot);
-	int (*unmap)(struct iommu_domain *domain, unsigned long iova,
-		     int gfp_order);
+		   phys_addr_t paddr, size_t size, int prot);
+	size_t (*unmap)(struct iommu_domain *domain, unsigned long iova,
+		     size_t size);
 	phys_addr_t (*iova_to_phys)(struct iommu_domain *domain,
 				    unsigned long iova);
 	int (*domain_has_cap)(struct iommu_domain *domain,
-- 
1.7.4.1