Whilst Midgard's MEMATTR follows a similar principle to the VMSA MAIR,
the actual attribute values differ, so although it currently appears to
work to some degree, we probably shouldn't be using our standard stage 1
MAIR for that. Instead, generate a reasonable MEMATTR with attribute
values borrowed from the kbase driver; at this point we'll be overriding
or ignoring pretty much all of the LPAE config, so just implement these
Mali details in a dedicated allocator instead of pretending to subclass
the standard VMSA format.
Signed-off-by: Robin Murphy <robin.mur...@arm.com>
---
drivers/iommu/io-pgtable-arm.c | 53 +++++++++++++++++++++++++---------
1 file changed, 40 insertions(+), 13 deletions(-)
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 161a7d56264d..9e35cd991f06 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -167,6 +167,9 @@
#define ARM_MALI_LPAE_TTBR_READ_INNER BIT(2)
#define ARM_MALI_LPAE_TTBR_SHARE_OUTER BIT(4)
+#define ARM_MALI_LPAE_MEMATTR_IMP_DEF 0x88ULL
+#define ARM_MALI_LPAE_MEMATTR_WRITE_ALLOC 0x8DULL
+
/* IOPTE accessors */
#define iopte_deref(pte,d) __va(iopte_to_paddr(pte, d))
@@ -1013,27 +1016,51 @@ arm_32_lpae_alloc_pgtable_s2(struct io_pgtable_cfg
*cfg, void *cookie)
static struct io_pgtable *
arm_mali_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie)
{
- struct io_pgtable *iop;
+ struct arm_lpae_io_pgtable *data;
+
+ /* No quirks for Mali (hopefully) */
+ if (cfg->quirks)
+ return NULL;
if (cfg->ias != 48 || cfg->oas > 40)
return NULL;
cfg->pgsize_bitmap &= (SZ_4K | SZ_2M | SZ_1G);
- iop = arm_64_lpae_alloc_pgtable_s1(cfg, cookie);
- if (iop) {
- u64 mair, ttbr;
- /* Copy values as union fields overlap */
- mair = cfg->arm_lpae_s1_cfg.mair[0];
- ttbr = cfg->arm_lpae_s1_cfg.ttbr[0];
+ data = arm_lpae_alloc_pgtable(cfg);
+ if (!data)
+ return NULL;
- cfg->arm_mali_lpae_cfg.memattr = mair;
- cfg->arm_mali_lpae_cfg.transtab = ttbr |
- ARM_MALI_LPAE_TTBR_READ_INNER |
- ARM_MALI_LPAE_TTBR_ADRMODE_TABLE;
- }
+ /*
+ * MEMATTR: Mali has no actual notion of a non-cacheable type, so the
+ * best we can do is mimic the out-of-tree driver and hope that the
+ * "implementation-defined caching policy" is good enough. Similarly,
+ * we'll use it for the sake of a valid attribute for our 'device'
+ * index, although callers should never request that in practice.
+ */
+ cfg->arm_mali_lpae_cfg.memattr =
+ (ARM_MALI_LPAE_MEMATTR_IMP_DEF
+ << ARM_LPAE_MAIR_ATTR_SHIFT(ARM_LPAE_MAIR_ATTR_IDX_NC)) |
+ (ARM_MALI_LPAE_MEMATTR_WRITE_ALLOC
+ << ARM_LPAE_MAIR_ATTR_SHIFT(ARM_LPAE_MAIR_ATTR_IDX_CACHE)) |
+ (ARM_MALI_LPAE_MEMATTR_IMP_DEF
+ << ARM_LPAE_MAIR_ATTR_SHIFT(ARM_LPAE_MAIR_ATTR_IDX_DEV));
- return iop;
+ data->pgd = __arm_lpae_alloc_pages(data->pgd_size, GFP_KERNEL, cfg);
+ if (!data->pgd)
+ goto out_free_data;
+
+ /* Ensure the empty pgd is visible before TRANSTAB can be written */
+ wmb();
+
+ cfg->arm_mali_lpae_cfg.transtab = virt_to_phys(data->pgd) |
+ ARM_MALI_LPAE_TTBR_READ_INNER |
+ ARM_MALI_LPAE_TTBR_ADRMODE_TABLE;
+ return &data->iop;
+
+out_free_data:
+ kfree(data);
+ return NULL;
}
struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns = {
--
2.21.0.dirty
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