From: Laurentiu Tudor <laurentiu.tu...@nxp.com>

In preparation for dropping the existing "coherent" dma mem declaration
APIs, replace the current dma_declare_coherent_memory() based mechanism
with the creation of a genalloc pool that will be used in the OHCI
subsystem as replacement for the DMA APIs.

For context, see thread here: https://lkml.org/lkml/2019/4/22/357

Signed-off-by: Laurentiu Tudor <laurentiu.tu...@nxp.com>
---
 drivers/usb/host/ohci-sm501.c | 60 +++++++++++++++++++----------------
 1 file changed, 33 insertions(+), 27 deletions(-)

diff --git a/drivers/usb/host/ohci-sm501.c b/drivers/usb/host/ohci-sm501.c
index c26228c25f99..8b829eca04ab 100644
--- a/drivers/usb/host/ohci-sm501.c
+++ b/drivers/usb/host/ohci-sm501.c
@@ -16,6 +16,7 @@
 #include <linux/jiffies.h>
 #include <linux/platform_device.h>
 #include <linux/dma-mapping.h>
+#include <linux/genalloc.h>
 #include <linux/sm501.h>
 #include <linux/sm501-regs.h>
 
@@ -110,40 +111,18 @@ static int ohci_hcd_sm501_drv_probe(struct 
platform_device *pdev)
                goto err0;
        }
 
-       /* The sm501 chip is equipped with local memory that may be used
-        * by on-chip devices such as the video controller and the usb host.
-        * This driver uses dma_declare_coherent_memory() to make sure
-        * usb allocations with dma_alloc_coherent() allocate from
-        * this local memory. The dma_handle returned by dma_alloc_coherent()
-        * will be an offset starting from 0 for the first local memory byte.
-        *
-        * So as long as data is allocated using dma_alloc_coherent() all is
-        * fine. This is however not always the case - buffers may be allocated
-        * using kmalloc() - so the usb core needs to be told that it must copy
-        * data into our local memory if the buffers happen to be placed in
-        * regular memory. The HCD_LOCAL_MEM flag does just that.
-        */
-
-       retval = dma_declare_coherent_memory(dev, mem->start,
-                                        mem->start - mem->parent->start,
-                                        resource_size(mem));
-       if (retval) {
-               dev_err(dev, "cannot declare coherent memory\n");
-               goto err1;
-       }
-
        /* allocate, reserve and remap resources for registers */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (res == NULL) {
                dev_err(dev, "no resource definition for registers\n");
                retval = -ENOENT;
-               goto err2;
+               goto err1;
        }
 
        hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
        if (!hcd) {
                retval = -ENOMEM;
-               goto err2;
+               goto err1;
        }
 
        hcd->rsrc_start = res->start;
@@ -164,6 +143,36 @@ static int ohci_hcd_sm501_drv_probe(struct platform_device 
*pdev)
 
        ohci_hcd_init(hcd_to_ohci(hcd));
 
+       /* The sm501 chip is equipped with local memory that may be used
+        * by on-chip devices such as the video controller and the usb host.
+        * This driver uses genalloc so that usb allocations with
+        * gen_pool_dma_alloc() allocate from this local memory. The dma_handle
+        * returned by gen_pool_dma_alloc() will be an offset starting from 0
+        * for the first local memory byte.
+        *
+        * So as long as data is allocated using gen_pool_dma_alloc() all is
+        * fine. This is however not always the case - buffers may be allocated
+        * using kmalloc() - so the usb core needs to be told that it must copy
+        * data into our local memory if the buffers happen to be placed in
+        * regular memory. The HCD_LOCAL_MEM flag does just that.
+        */
+
+       hcd->localmem_pool = devm_gen_pool_create(dev, PAGE_SHIFT,
+                                                 dev_to_node(dev),
+                                                 "ohci-sm501");
+       if (IS_ERR(hcd->localmem_pool)) {
+               retval = PTR_ERR(hcd->localmem_pool);
+               goto err5;
+       }
+       retval = gen_pool_add_virt(hcd->localmem_pool,
+                                  (unsigned long)mem->start -
+                                       mem->parent->start,
+                                  mem->start, resource_size(mem),
+                                  dev_to_node(dev));
+       if (retval < 0) {
+               dev_err(dev, "failed to add to pool: %d\n", retval);
+               goto err5;
+       }
        retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
        if (retval)
                goto err5;
@@ -181,8 +190,6 @@ static int ohci_hcd_sm501_drv_probe(struct platform_device 
*pdev)
        release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
 err3:
        usb_put_hcd(hcd);
-err2:
-       dma_release_declared_memory(dev);
 err1:
        release_mem_region(mem->start, resource_size(mem));
 err0:
@@ -197,7 +204,6 @@ static int ohci_hcd_sm501_drv_remove(struct platform_device 
*pdev)
        usb_remove_hcd(hcd);
        release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
        usb_put_hcd(hcd);
-       dma_release_declared_memory(&pdev->dev);
        mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
        if (mem)
                release_mem_region(mem->start, resource_size(mem));
-- 
2.17.1

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