staging: gasket: page table: remove code for "no dma_ops"

Remove code with TODOs on it for working around apparent problems
previously seen in a qemu environment where dma_ops was not set
correctly.  There is no user of this in the current code.

Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 8 insertions, 55 deletions

diff --git a/drivers/staging/gasket/gasket_core.c b/drivers/staging/gasket/gasket_core.c
index f44805c38159..859a6df9e12d 100644
--- a/drivers/staging/gasket/gasket_core.c
+++ b/drivers/staging/gasket/gasket_core.c
@@ -916,7 +916,7 @@ static int gasket_enable_dev(
                         &gasket_dev->bar_data[
                                 driver_desc->page_table_bar_index],
                         &driver_desc->page_table_configs[tbl_idx],
-                        gasket_dev->dev, gasket_dev->pci_dev, true);
+                        gasket_dev->dev, gasket_dev->pci_dev);
                 if (ret) {
                         dev_err(gasket_dev->dev,
                                 "Couldn't init page table %d: %d\n",
diff --git a/drivers/staging/gasket/gasket_page_table.c b/drivers/staging/gasket/gasket_page_table.c
index 32f1c1e10c7e..722839603f20 100644
--- a/drivers/staging/gasket/gasket_page_table.c
+++ b/drivers/staging/gasket/gasket_page_table.c
@@ -212,12 +212,6 @@ struct gasket_page_table {
          * gasket_mmap function, so user_virt belongs in the driver anyhow.
          */
         struct gasket_coherent_page_entry *coherent_pages;
-
-        /*
-         * Whether the page table uses arch specific dma_ops or
-         * whether the driver is supplying its own.
-         */
-        bool dma_ops;
 };
 
 /* Mapping declarations */
@@ -290,7 +284,7 @@ int gasket_page_table_init(
         struct gasket_page_table **ppg_tbl,
         const struct gasket_bar_data *bar_data,
         const struct gasket_page_table_config *page_table_config,
-        struct device *device, struct pci_dev *pci_dev, bool has_dma_ops)
+        struct device *device, struct pci_dev *pci_dev)
 {
         ulong bytes;
         struct gasket_page_table *pg_tbl;
@@ -353,7 +347,6 @@ int gasket_page_table_init(
                 bar_data->virt_base[page_table_config->extended_reg]);
         pg_tbl->device = device;
         pg_tbl->pci_dev = pci_dev;
-        pg_tbl->dma_ops = has_dma_ops;
 
         dev_dbg(device, "Page table initialized successfully\n");
 
@@ -760,33 +753,6 @@ static int gasket_map_extended_pages(
 }
 
 /*
- * TODO: dma_map_page() is not plugged properly when running under qemu. i.e.
- * dma_ops are not set properly, which causes the kernel to assert.
- *
- * This temporary hack allows the driver to work on qemu, but need to be fixed:
- * - either manually set the dma_ops for the architecture (which incidentally
- * can't be done in an out-of-tree module) - or get qemu to fill the device tree
- * properly so as linux plug the proper dma_ops or so as the driver can detect
- * that it is runnig on qemu
- */
-static inline dma_addr_t _no_op_dma_map_page(
-        struct device *dev, struct page *page, size_t offset, size_t size,
-        enum dma_data_direction dir)
-{
-        /*
-         * struct dma_map_ops *ops = get_dma_ops(dev);
-         * dma_addr_t addr;
-         *
-         * kmemcheck_mark_initialized(page_address(page) + offset, size);
-         * BUG_ON(!valid_dma_direction(dir));
-         * addr = ops->map_page(dev, page, offset, size, dir, NULL);
-         * debug_dma_map_page(dev, page, offset, size, dir, addr, false);
-         */
-
-        return page_to_phys(page);
-}
-
-/*
  * Get and map last level page table buffers.
  * @pg_tbl: Gasket page table pointer.
  * @ptes: Array of page table entries to describe this mapping, one per
@@ -856,16 +822,9 @@ static int gasket_perform_mapping(
                         ptes[i].offset = offset;
 
                         /* Map the page into DMA space. */
-                        if (pg_tbl->dma_ops) {
-                                /* hook in to kernel map functions */
-                                ptes[i].dma_addr = dma_map_page(pg_tbl->device,
-                                        page, 0, PAGE_SIZE, DMA_BIDIRECTIONAL);
-                        } else {
-                                ptes[i].dma_addr = _no_op_dma_map_page(
-                                        pg_tbl->device, page, 0, PAGE_SIZE,
-                                        DMA_BIDIRECTIONAL);
-                        }
-
+                        ptes[i].dma_addr =
+                                dma_map_page(pg_tbl->device, page, 0, PAGE_SIZE,
+                                             DMA_BIDIRECTIONAL);
                         dev_dbg(pg_tbl->device,
                                 "%s i %d pte %p pfn %p -> mapped %llx\n",
                                 __func__, i, &ptes[i],
@@ -1042,13 +1001,8 @@ static int gasket_alloc_extended_subtable(
         }
 
         /* Map the page into DMA space. */
-        if (pg_tbl->dma_ops) {
-                pte->dma_addr = dma_map_page(pg_tbl->device, pte->page, 0,
-                        PAGE_SIZE, DMA_BIDIRECTIONAL);
-        } else {
-                pte->dma_addr = _no_op_dma_map_page(pg_tbl->device, pte->page,
-                        0, PAGE_SIZE, DMA_BIDIRECTIONAL);
-        }
+        pte->dma_addr = dma_map_page(pg_tbl->device, pte->page, 0, PAGE_SIZE,
+                                     DMA_BIDIRECTIONAL);
         /* Wait until the page is mapped. */
         mb();
 
diff --git a/drivers/staging/gasket/gasket_page_table.h b/drivers/staging/gasket/gasket_page_table.h
index 0e8afdb8c113..765588649365 100644
--- a/drivers/staging/gasket/gasket_page_table.h
+++ b/drivers/staging/gasket/gasket_page_table.h
@@ -37,7 +37,6 @@ struct gasket_page_table;
  *                 translation table.
  * @device: Device structure for the underlying device. Only used for logging.
  * @pci_dev: PCI system descriptor for the underlying device.
- * @bool has_dma_ops: Whether the page table uses arch specific dma_ops or
  * whether the driver will supply its own.
  *
  * Description: Allocates and initializes data to track address translation -
@@ -51,7 +50,7 @@ int gasket_page_table_init(
         struct gasket_page_table **ppg_tbl,
         const struct gasket_bar_data *bar_data,
         const struct gasket_page_table_config *page_table_config,
-        struct device *device, struct pci_dev *pci_dev, bool dma_ops);
+        struct device *device, struct pci_dev *pci_dev);
 
 /*
  * Deallocate and cleanup page table data.