drm/msm/a6xx: Use the DMA API for GMU memory objects

The GMU has very few memory allocations and uses a flat memory space so
there is no good reason to go out of our way to bypass the DMA APIs which
were basically designed for this exact scenario.

v7: Check return value of dma_set_mask_and_coherent
v4: Use dma_alloc_wc()
v3: Set the dma mask correctly and use dma_addr_t for the iova type
v2: Pass force_dma false to of_dma_configure to require that the DMA
region be set up and return error from of_dma_configure to fail probe.

Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index 748cd379065f1103240ecf4dd4af72d635f63318..c4e71abbdd537632dcdc6276676c0521a310e29e 100644 (file)
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -2,6 +2,7 @@
 /* Copyright (c) 2017-2019 The Linux Foundation. All rights reserved. */
 
 #include <linux/clk.h>
+#include <linux/dma-mapping.h>
 #include <linux/interconnect.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_opp.h>
@@ -920,21 +921,10 @@ int a6xx_gmu_stop(struct a6xx_gpu *a6xx_gpu)
 
 static void a6xx_gmu_memory_free(struct a6xx_gmu *gmu, struct a6xx_gmu_bo *bo)
 {
-       int count, i;
-       u64 iova;
-
        if (IS_ERR_OR_NULL(bo))
                return;
 
-       count = bo->size >> PAGE_SHIFT;
-       iova = bo->iova;
-
-       for (i = 0; i < count; i++, iova += PAGE_SIZE) {
-               iommu_unmap(gmu->domain, iova, PAGE_SIZE);
-               __free_pages(bo->pages[i], 0);
-       }
-
-       kfree(bo->pages);
+       dma_free_wc(gmu->dev, bo->size, bo->virt, bo->iova);
        kfree(bo);
 }
 
@@ -942,7 +932,6 @@ static struct a6xx_gmu_bo *a6xx_gmu_memory_alloc(struct a6xx_gmu *gmu,
                size_t size)
 {
        struct a6xx_gmu_bo *bo;
-       int ret, count, i;
 
        bo = kzalloc(sizeof(*bo), GFP_KERNEL);
        if (!bo)
@@ -950,86 +939,14 @@ static struct a6xx_gmu_bo *a6xx_gmu_memory_alloc(struct a6xx_gmu *gmu,
 
        bo->size = PAGE_ALIGN(size);
 
-       count = bo->size >> PAGE_SHIFT;
+       bo->virt = dma_alloc_wc(gmu->dev, bo->size, &bo->iova, GFP_KERNEL);
 
-       bo->pages = kcalloc(count, sizeof(struct page *), GFP_KERNEL);
-       if (!bo->pages) {
+       if (!bo->virt) {
                kfree(bo);
                return ERR_PTR(-ENOMEM);
        }
 
-       for (i = 0; i < count; i++) {
-               bo->pages[i] = alloc_page(GFP_KERNEL);
-               if (!bo->pages[i])
-                       goto err;
-       }
-
-       bo->iova = gmu->uncached_iova_base;
-
-       for (i = 0; i < count; i++) {
-               ret = iommu_map(gmu->domain,
-                       bo->iova + (PAGE_SIZE * i),
-                       page_to_phys(bo->pages[i]), PAGE_SIZE,
-                       IOMMU_READ | IOMMU_WRITE);
-
-               if (ret) {
-                       DRM_DEV_ERROR(gmu->dev, "Unable to map GMU buffer object\n");
-
-                       for (i = i - 1 ; i >= 0; i--)
-                               iommu_unmap(gmu->domain,
-                                       bo->iova + (PAGE_SIZE * i),
-                                       PAGE_SIZE);
-
-                       goto err;
-               }
-       }
-
-       bo->virt = vmap(bo->pages, count, VM_IOREMAP,
-               pgprot_writecombine(PAGE_KERNEL));
-       if (!bo->virt)
-               goto err;
-
-       /* Align future IOVA addresses on 1MB boundaries */
-       gmu->uncached_iova_base += ALIGN(size, SZ_1M);
-
        return bo;
-
-err:
-       for (i = 0; i < count; i++) {
-               if (bo->pages[i])
-                       __free_pages(bo->pages[i], 0);
-       }
-
-       kfree(bo->pages);
-       kfree(bo);
-
-       return ERR_PTR(-ENOMEM);
-}
-
-static int a6xx_gmu_memory_probe(struct a6xx_gmu *gmu)
-{
-       int ret;
-
-       /*
-        * The GMU address space is hardcoded to treat the range
-        * 0x60000000 - 0x80000000 as un-cached memory. All buffers shared
-        * between the GMU and the CPU will live in this space
-        */
-       gmu->uncached_iova_base = 0x60000000;
-
-
-       gmu->domain = iommu_domain_alloc(&platform_bus_type);
-       if (!gmu->domain)
-               return -ENODEV;
-
-       ret = iommu_attach_device(gmu->domain, gmu->dev);
-
-       if (ret) {
-               iommu_domain_free(gmu->domain);
-               gmu->domain = NULL;
-       }
-
-       return ret;
 }
 
 /* Return the 'arc-level' for the given frequency */
@@ -1289,10 +1206,6 @@ void a6xx_gmu_remove(struct a6xx_gpu *a6xx_gpu)
 
        a6xx_gmu_memory_free(gmu, gmu->hfi);
 
-       iommu_detach_device(gmu->domain, gmu->dev);
-
-       iommu_domain_free(gmu->domain);
-
        free_irq(gmu->gmu_irq, gmu);
        free_irq(gmu->hfi_irq, gmu);
 
@@ -1313,7 +1226,15 @@ int a6xx_gmu_init(struct a6xx_gpu *a6xx_gpu, struct device_node *node)
 
        gmu->dev = &pdev->dev;
 
-       of_dma_configure(gmu->dev, node, true);
+       /* Pass force_dma false to require the DT to set the dma region */
+       ret = of_dma_configure(gmu->dev, node, false);
+       if (ret)
+               return ret;
+
+       /* Set the mask after the of_dma_configure() */
+       ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(31));
+       if (ret)
+               return ret;
 
        /* Fow now, don't do anything fancy until we get our feet under us */
        gmu->idle_level = GMU_IDLE_STATE_ACTIVE;
@@ -1325,11 +1246,6 @@ int a6xx_gmu_init(struct a6xx_gpu *a6xx_gpu, struct device_node *node)
        if (ret)
                goto err_put_device;
 
-       /* Set up the IOMMU context bank */
-       ret = a6xx_gmu_memory_probe(gmu);
-       if (ret)
-               goto err_put_device;
-
        /* Allocate memory for for the HFI queues */
        gmu->hfi = a6xx_gmu_memory_alloc(gmu, SZ_16K);
        if (IS_ERR(gmu->hfi))
@@ -1375,11 +1291,6 @@ err_mmio:
 err_memory:
        a6xx_gmu_memory_free(gmu, gmu->hfi);
 
-       if (gmu->domain) {
-               iommu_detach_device(gmu->domain, gmu->dev);
-
-               iommu_domain_free(gmu->domain);
-       }
        ret = -ENODEV;
 
 err_put_device:

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
index 2af91ed7ed0ca498f992453118b565cf4cfb4d39..4af65a36d5ca6efdadbe2295c1083e1287542bea 100644 (file)
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
@@ -12,8 +12,7 @@
 struct a6xx_gmu_bo {
        void *virt;
        size_t size;
-       u64 iova;
-       struct page **pages;
+       dma_addr_t iova;
 };
 
 /*
@@ -49,9 +48,6 @@ struct a6xx_gmu {
        int hfi_irq;
        int gmu_irq;
 
-       struct iommu_domain *domain;
-       u64 uncached_iova_base;
-
        struct device *gxpd;
 
        int idle_level;