On 2025-02-04 6:34 pm, Jason Gunthorpe wrote:
Instead use the virtual address and dma_map_single() like as->pd
uses. Introduce a small struct tegra_pt instead of void * to have some
clarity what is using this API and add compile safety during the
conversion.
Hmm, I'm not sure it's all that clear to have a major discrepancy
between how different levels of pagetable are referenced - I'd say
either use an explicit type for both, or just rework this as a u32**
along the same lines as the current patch #1.
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
drivers/iommu/tegra-smmu.c | 68 ++++++++++++++++++++------------------
1 file changed, 36 insertions(+), 32 deletions(-)
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 717bcd3b8de7dc..1e85141c80548d 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -51,13 +51,15 @@ struct tegra_smmu {
struct iommu_device iommu; /* IOMMU Core code handle */
};
+struct tegra_pt;
+
struct tegra_smmu_as {
struct iommu_domain domain;
struct tegra_smmu *smmu;
unsigned int use_count;
spinlock_t lock;
u32 *count;
- struct page **pts;
+ struct tegra_pt **pts;
u32 *pd;
dma_addr_t pd_dma;
unsigned id;
@@ -155,6 +157,10 @@ static inline u32 smmu_readl(struct tegra_smmu *smmu, unsigned long offset)
#define SMMU_PDE_ATTR (SMMU_PDE_READABLE | SMMU_PDE_WRITABLE | \
SMMU_PDE_NONSECURE)
+struct tegra_pt {
+ u32 val[SMMU_NUM_PTE];
+};
+
static unsigned int iova_pd_index(unsigned long iova)
{
return (iova >> SMMU_PDE_SHIFT) & (SMMU_NUM_PDE - 1);
@@ -564,11 +570,9 @@ static void tegra_smmu_set_pde(struct tegra_smmu_as *as, unsigned long iova,
smmu_flush(smmu);
}
-static u32 *tegra_smmu_pte_offset(struct page *pt_page, unsigned long iova)
+static u32 *tegra_smmu_pte_offset(struct tegra_pt *pt, unsigned long iova)
{
- u32 *pt = page_address(pt_page);
-
- return pt + iova_pt_index(iova);
+ return &pt->val[iova_pt_index(iova)];
}
static u32 *tegra_smmu_pte_lookup(struct tegra_smmu_as *as, unsigned long iova,
@@ -576,19 +580,19 @@ static u32 *tegra_smmu_pte_lookup(struct tegra_smmu_as *as, unsigned long iova,
{
unsigned int pd_index = iova_pd_index(iova);
struct tegra_smmu *smmu = as->smmu;
- struct page *pt_page;
+ struct tegra_pt *pt;
- pt_page = as->pts[pd_index];
- if (!pt_page)
+ pt = as->pts[pd_index];
+ if (!pt)
return NULL;
*dmap = smmu_pde_to_dma(smmu, as->pd[pd_index]);
- return tegra_smmu_pte_offset(pt_page, iova);
+ return tegra_smmu_pte_offset(pt, iova);
}
static u32 *as_get_pte(struct tegra_smmu_as *as, dma_addr_t iova,
- dma_addr_t *dmap, struct page *page)
+ dma_addr_t *dmap, struct tegra_pt *pt)
{
unsigned int pde = iova_pd_index(iova);
struct tegra_smmu *smmu = as->smmu;
@@ -596,21 +600,21 @@ static u32 *as_get_pte(struct tegra_smmu_as *as, dma_addr_t iova,
if (!as->pts[pde]) {
dma_addr_t dma;
- dma = dma_map_page(smmu->dev, page, 0, SMMU_SIZE_PT,
- DMA_TO_DEVICE);
+ dma = dma_map_single(smmu->dev, pt, SMMU_SIZE_PD,
SMMU_SIZE_PT (yeah they're numerically the same, but still...)
+ DMA_TO_DEVICE);
if (dma_mapping_error(smmu->dev, dma)) {
- __iommu_free_pages(page, 0);
+ iommu_free_page(pt);
return NULL;
}
if (!smmu_dma_addr_valid(smmu, dma)) {
dma_unmap_page(smmu->dev, dma, SMMU_SIZE_PT,
DMA_TO_DEVICE);
All the unmaps should be converted to _single as well (and in patch #1)
- the APIs are not officially interchangeable.
Thanks,
Robin.
- __iommu_free_pages(page, 0);
+ iommu_free_page(pt);
return NULL;
}
- as->pts[pde] = page;
+ as->pts[pde] = pt;
tegra_smmu_set_pde(as, iova, SMMU_MK_PDE(dma, SMMU_PDE_ATTR |
SMMU_PDE_NEXT));
@@ -633,7 +637,7 @@ static void tegra_smmu_pte_get_use(struct tegra_smmu_as *as, unsigned long iova)
static void tegra_smmu_pte_put_use(struct tegra_smmu_as *as, unsigned long iova)
{
unsigned int pde = iova_pd_index(iova);
- struct page *page = as->pts[pde];
+ struct tegra_pt *pt = as->pts[pde];
/*
* When no entries in this page table are used anymore, return the
@@ -646,7 +650,7 @@ static void tegra_smmu_pte_put_use(struct tegra_smmu_as *as, unsigned long iova)
tegra_smmu_set_pde(as, iova, 0);
dma_unmap_page(smmu->dev, pte_dma, SMMU_SIZE_PT, DMA_TO_DEVICE);
- __iommu_free_pages(page, 0);
+ iommu_free_page(pt);
as->pts[pde] = NULL;
}
}
@@ -666,16 +670,16 @@ static void tegra_smmu_set_pte(struct tegra_smmu_as *as, unsigned long iova,
smmu_flush(smmu);
}
-static struct page *as_get_pde_page(struct tegra_smmu_as *as,
- unsigned long iova, gfp_t gfp,
- unsigned long *flags)
+static struct tegra_pt *as_get_pde_page(struct tegra_smmu_as *as,
+ unsigned long iova, gfp_t gfp,
+ unsigned long *flags)
{
unsigned int pde = iova_pd_index(iova);
- struct page *page = as->pts[pde];
+ struct tegra_pt *pt = as->pts[pde];
/* at first check whether allocation needs to be done at all */
- if (page)
- return page;
+ if (pt)
+ return pt;
/*
* In order to prevent exhaustion of the atomic memory pool, we
@@ -685,7 +689,7 @@ static struct page *as_get_pde_page(struct tegra_smmu_as *as,
if (gfpflags_allow_blocking(gfp))
spin_unlock_irqrestore(&as->lock, *flags);
- page = __iommu_alloc_pages(gfp | __GFP_DMA, 0);
+ pt = iommu_alloc_page(gfp | __GFP_DMA);
if (gfpflags_allow_blocking(gfp))
spin_lock_irqsave(&as->lock, *flags);
@@ -696,13 +700,13 @@ static struct page *as_get_pde_page(struct tegra_smmu_as *as,
* if allocation succeeded and the allocation failure isn't fatal.
*/
if (as->pts[pde]) {
- if (page)
- __iommu_free_pages(page, 0);
+ if (pt)
+ iommu_free_page(pt);
- page = as->pts[pde];
+ pt = as->pts[pde];
}
- return page;
+ return pt;
}
static int
@@ -712,15 +716,15 @@ __tegra_smmu_map(struct iommu_domain *domain, unsigned long iova,
{
struct tegra_smmu_as *as = to_smmu_as(domain);
dma_addr_t pte_dma;
- struct page *page;
+ struct tegra_pt *pt;
u32 pte_attrs;
u32 *pte;
- page = as_get_pde_page(as, iova, gfp, flags);
- if (!page)
+ pt = as_get_pde_page(as, iova, gfp, flags);
+ if (!pt)
return -ENOMEM;
- pte = as_get_pte(as, iova, &pte_dma, page);
+ pte = as_get_pte(as, iova, &pte_dma, pt);
if (!pte)
return -ENOMEM;
