Boris,
On 3/15/25 5:43 AM, Boris Brezillon wrote:
On Fri, 14 Mar 2025 14:38:56 -0300
Ariel D'Alessandro <ariel.dalessandro@xxxxxxxxxxxxx> wrote:
Currently, Panfrost only supports MMU configuration in "LEGACY" (as
Bifrost calls it) mode, a (modified) version of LPAE "Large Physical
Address Extension", which in Linux we've called "mali_lpae".
This commit adds support for conditionally enabling AARCH64_4K page
table format. To achieve that, a "GPU optional quirks" field was added
to `struct panfrost_features` with the related flag.
Note that, in order to enable AARCH64_4K mode, the GPU variant must have
the HW_FEATURE_AARCH64_MMU feature flag present.
Signed-off-by: Ariel D'Alessandro <ariel.dalessandro@xxxxxxxxxxxxx>
---
drivers/gpu/drm/panfrost/panfrost_device.h | 16 +++
drivers/gpu/drm/panfrost/panfrost_mmu.c | 136 +++++++++++++++++++--
drivers/gpu/drm/panfrost/panfrost_regs.h | 34 ++++++
3 files changed, 177 insertions(+), 9 deletions(-)
[snip]
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index 294f86b3c25e7..f24c23e1f67b8 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -26,6 +26,48 @@
#define mmu_write(dev, reg, data) writel(data, dev->iomem + reg)
#define mmu_read(dev, reg) readl(dev->iomem + reg)
[snip]
u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
{
int as;
@@ -618,6 +720,18 @@ struct panfrost_mmu *panfrost_mmu_ctx_create(struct panfrost_device *pfdev)
u32 va_bits = GPU_MMU_FEATURES_VA_BITS(pfdev->features.mmu_features);
u32 pa_bits = GPU_MMU_FEATURES_PA_BITS(pfdev->features.mmu_features);
struct panfrost_mmu *mmu;
+ enum io_pgtable_fmt fmt;
+
+ if (pfdev->comp->gpu_quirks & BIT(GPU_QUIRK_FORCE_AARCH64_PGTABLE)) {
+ if (!panfrost_has_hw_feature(pfdev, HW_FEATURE_AARCH64_MMU)) {
+ dev_err_once(pfdev->dev,
+ "AARCH64_4K page table not supported\n");
+ return ERR_PTR(-EINVAL);
+ }
+ fmt = ARM_64_LPAE_S1;
+ } else {
+ fmt = ARM_MALI_LPAE;
+ }
mmu = kzalloc(sizeof(*mmu), GFP_KERNEL);
if (!mmu)
@@ -642,16 +756,20 @@ struct panfrost_mmu *panfrost_mmu_ctx_create(struct panfrost_device *pfdev)
.iommu_dev = pfdev->dev,
};
- mmu->pgtbl_ops = alloc_io_pgtable_ops(ARM_MALI_LPAE, &mmu->pgtbl_cfg,
- mmu);
- if (!mmu->pgtbl_ops) {
- kfree(mmu);
- return ERR_PTR(-EINVAL);
- }
+ mmu->pgtbl_ops = alloc_io_pgtable_ops(fmt, &mmu->pgtbl_cfg, mmu);
+ if (!mmu->pgtbl_ops)
+ goto err_free_mmu;
+
+ if (panfrost_mmu_cfg_init(mmu, fmt))
+ goto err_free_mmu;
How about propagating the error returned by panfrost_mmu_cfg_init()
instead of assuming it's always -EINVAL on failure? Oh, and you need to
call free_io_pgtable_ops(), not just kfree().
Ah, totally, thanks for the heads up. Will fix in v3 right away.
--
Ariel D'Alessandro
Software Engineer
Collabora Ltd.
Platinum Building, St John's Innovation Park, Cambridge CB4 0DS, UK
Registered in England & Wales, no. 5513718
