Hi Shimoda-san,
On Wed, Oct 9, 2019 at 10:27 AM Yoshihiro Shimoda
<[email protected]> wrote:
> Since we will have changed memory mapping of the IPMMU in the future,
> this patch uses ipmmu_features values instead of a macro to
> calculate context registers offset. No behavior change.
>
> Signed-off-by: Yoshihiro Shimoda <[email protected]>
Thanks for your patch!
> --- a/drivers/iommu/ipmmu-vmsa.c
> +++ b/drivers/iommu/ipmmu-vmsa.c
> @@ -50,6 +50,8 @@ struct ipmmu_features {
> bool twobit_imttbcr_sl0;
> bool reserved_context;
> bool cache_snoop;
> + u32 ctx_offset_base;
> + u32 ctx_offset_stride;
> };
>
> struct ipmmu_vmsa_device {
> @@ -99,8 +101,6 @@ static struct ipmmu_vmsa_device *to_ipmmu(struct device
> *dev)
>
> #define IM_NS_ALIAS_OFFSET 0x800
>
> -#define IM_CTX_SIZE 0x40
> -
> #define IMCTR 0x0000
> #define IMCTR_TRE (1 << 17)
> #define IMCTR_AFE (1 << 16)
> @@ -253,18 +253,25 @@ static void ipmmu_write(struct ipmmu_vmsa_device *mmu,
> unsigned int offset,
> iowrite32(data, mmu->base + offset);
> }
>
> +static u32 ipmmu_ctx_reg(struct ipmmu_vmsa_device *mmu, unsigned int
> context_id,
> + unsigned int reg)
> +{
> + return mmu->features->ctx_offset_base +
> + context_id * mmu->features->ctx_offset_stride + reg;
> +}
> +
> static u32 ipmmu_ctx_read_root(struct ipmmu_vmsa_domain *domain,
> unsigned int reg)
> {
> return ipmmu_read(domain->mmu->root,
> - domain->context_id * IM_CTX_SIZE + reg);
> + ipmmu_ctx_reg(domain->mmu, domain->context_id,
> reg));
For consistency:
ipmmu_ctx_reg(domain->mmu->root, ...)
but in practice the features for domain->mmu and domain->mmu->root are
identical anyway.
> }
>
> static void ipmmu_ctx_write_root(struct ipmmu_vmsa_domain *domain,
> unsigned int reg, u32 data)
> {
> ipmmu_write(domain->mmu->root,
> - domain->context_id * IM_CTX_SIZE + reg, data);
> + ipmmu_ctx_reg(domain->mmu, domain->context_id, reg),
> data);
Likewise:
ipmmu_ctx_reg(domain->mmu->root, ...)?
I find these ipmmu_{read,write}() a bit hard too read, with passing the
mmu to both ipmmu_{read,write}() and ipmmu_ctx_reg().
What do you think about providing two helpers ipmmu_ctx_{read,write}(),
so all users can just use e.g.
ipmmu_ctx_write(mmu, context_id, reg, data);
instead of
ipmmu_write(mmu, ipmmu_ctx_reg(mmu, context_id, reg), data);
?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
