[PATCH v4 6/7] iommu/mediatek: Get rid of the pgtlock

From: Yong Wu
Date: Tue Oct 15 2019 - 23:34:21 EST


Now we have tlb_lock for the HW tlb flush, then pgtable code hasn't
needed the external "pgtlock" for a while. this patch remove the
"pgtlock".

Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
---
drivers/iommu/mtk_iommu.c | 25 +++----------------------
1 file changed, 3 insertions(+), 22 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 0e5f41f..c2b7ed5 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -101,8 +101,6 @@
#define MTK_M4U_TO_PORT(id) ((id) & 0x1f)

struct mtk_iommu_domain {
- spinlock_t pgtlock; /* lock for page table */
-
struct io_pgtable_cfg cfg;
struct io_pgtable_ops *iop;

@@ -295,8 +293,6 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom)
{
struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();

- spin_lock_init(&dom->pgtlock);
-
dom->cfg = (struct io_pgtable_cfg) {
.quirks = IO_PGTABLE_QUIRK_ARM_NS |
IO_PGTABLE_QUIRK_NO_PERMS |
@@ -395,18 +391,13 @@ static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova,
{
struct mtk_iommu_domain *dom = to_mtk_domain(domain);
struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();
- unsigned long flags;
- int ret;

/* The "4GB mode" M4U physically can not use the lower remap of Dram. */
if (data->enable_4GB)
paddr |= BIT_ULL(32);

- spin_lock_irqsave(&dom->pgtlock, flags);
- ret = dom->iop->map(dom->iop, iova, paddr, size, prot);
- spin_unlock_irqrestore(&dom->pgtlock, flags);
-
- return ret;
+ /* Synchronize with the tlb_lock */
+ return dom->iop->map(dom->iop, iova, paddr, size, prot);
}

static size_t mtk_iommu_unmap(struct iommu_domain *domain,
@@ -414,14 +405,8 @@ static size_t mtk_iommu_unmap(struct iommu_domain *domain,
struct iommu_iotlb_gather *gather)
{
struct mtk_iommu_domain *dom = to_mtk_domain(domain);
- unsigned long flags;
- size_t unmapsz;
-
- spin_lock_irqsave(&dom->pgtlock, flags);
- unmapsz = dom->iop->unmap(dom->iop, iova, size, gather);
- spin_unlock_irqrestore(&dom->pgtlock, flags);

- return unmapsz;
+ return dom->iop->unmap(dom->iop, iova, size, gather);
}

static void mtk_iommu_flush_iotlb_all(struct iommu_domain *domain)
@@ -447,13 +432,9 @@ static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
{
struct mtk_iommu_domain *dom = to_mtk_domain(domain);
struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();
- unsigned long flags;
phys_addr_t pa;

- spin_lock_irqsave(&dom->pgtlock, flags);
pa = dom->iop->iova_to_phys(dom->iop, iova);
- spin_unlock_irqrestore(&dom->pgtlock, flags);
-
if (data->enable_4GB && pa >= MTK_IOMMU_4GB_MODE_REMAP_BASE)
pa &= ~BIT_ULL(32);

--
1.9.1