On 28/10/2019 15:09, Steven Price wrote:
[...]
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -822,15 +822,13 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct
io_pgtable_cfg *cfg,
/* Ensure the empty pgd is visible before any actual TTBR write */
wmb();
- /* TTBRs */
- cfg->arm_v7s_cfg.ttbr[0] = virt_to_phys(data->pgd) |
- ARM_V7S_TTBR_S | ARM_V7S_TTBR_NOS |
- (cfg->coherent_walk ?
- (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) |
- ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA)) :
- (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_NC) |
- ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_NC)));
- cfg->arm_v7s_cfg.ttbr[1] = 0;
+ /* TTBR */
+ cfg->arm_v7s_cfg.ttbr = virt_to_phys(data->pgd) | ARM_V7S_TTBR_S |
+ (cfg->coherent_walk ? (ARM_V7S_TTBR_NOS |
+ ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) |
+ ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA)) :
+ (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_NC) |
+ ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_NC)));
ARM_V7S_TTBR_NOS seems to have sneaked into the cfg->coherent_walk
condition here - which you haven't mentioned in the commit log, so it
doesn't look like it should be in this commit.
Ah, yes, it's taken a while to remember whether this was something
important that got muddled up in rebasing, but it's actually just
trivial cleanup. For !coherent_walk, the non-cacheable output attribute
makes shareable accesses implicitly outer-shareable, so setting TTBR.NOS
for that case actually does nothing except look misleading. Thus this is
essentially just a cosmetic change included in the reformatting for
clarity and consistency with the LPAE version. I'll call that out in the
commit message, thanks for spotting!
Robin.
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