Re: [PATCH] ACPI/IORT: Update SMMUv3 DeviceID support

[Nicolin Chen <nicolinc@nvidia.com>]

On Wed, Sep 28, 2022 at 08:21:26PM +0100, Robin Murphy wrote:
> External email: Use caution opening links or attachments
> 
> 
> IORT E.e now allows SMMUv3 nodes to describe the DeviceID for MSIs
> independently of wired GSIVs, where the previous oddly-restrictive
> definition meant that an SMMU without PRI support had to provide a
> DeviceID even if it didn't support MSIs either. Support this, with
> the usual temporary flag definition while the real one is making
> its way through ACPICA.
> 
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>

All the indentations in this patch are using white spaces vs. tabs,
so it fails at git-apply. I manually fixed them and tested the PATCH
by applying a small revision hack to the IORT binaries:

---------
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 3269a888fb7a..5a4eef7b937c 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -333,8 +333,20 @@ void __iomem __ref
 		return NULL;
 	}
 
-	if (!acpi_permanent_mmap)
-		return __acpi_map_table((unsigned long)phys, size);
+	if (!acpi_permanent_mmap) {
+		virt = __acpi_map_table((unsigned long)phys, size);
+		if (!strncmp((char *)virt, "IORT", 4)) {
+			u8 *tmp = virt;
+			int i = 0x30;
+			while (i < size) {
+				if (tmp[i] == 0x4) /* SMMUv3 */
+					tmp[i + 3] = 0x5; /* Revision */
+				i += tmp[i + 1]; /* next node */
+				continue;
+			}
+		}
+		return virt;
+	}
 
 	mutex_lock(&acpi_ioremap_lock);
 	/* Check if there's a suitable mapping already. */
---------

Once the indentations are fixed,

Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>

Thanks!
Nicolin

> ---
>  drivers/acpi/arm64/iort.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index ca2aed86b540..51bc3c1d8d42 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -402,6 +402,10 @@ static struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
>         return NULL;
>  }
> 
> +#ifndef ACPI_IORT_SMMU_V3_DEVICEID_VALID
> +#define ACPI_IORT_SMMU_V3_DEVICEID_VALID (1 << 4)
> +#endif
> +
>  static int iort_get_id_mapping_index(struct acpi_iort_node *node)
>  {
>         struct acpi_iort_smmu_v3 *smmu;
> @@ -418,12 +422,16 @@ static int iort_get_id_mapping_index(struct acpi_iort_node *node)
> 
>                 smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
>                 /*
> -                * ID mapping index is only ignored if all interrupts are
> -                * GSIV based
> +                * Until IORT E.e (node rev. 5), the ID mapping index was
> +                * defined to be valid unless all interrupts are GSIV-based.
>                  */
> -               if (smmu->event_gsiv && smmu->pri_gsiv && smmu->gerr_gsiv
> -                   && smmu->sync_gsiv)
> +               if (node->revision < 5) {
> +                       if (smmu->event_gsiv && smmu->pri_gsiv &&
> +                           smmu->gerr_gsiv && smmu->sync_gsiv)
> +                               return -EINVAL;
> +               } else if (!(smmu->flags & ACPI_IORT_SMMU_V3_DEVICEID_VALID)) {
>                         return -EINVAL;
> +               }
> 
>                 if (smmu->id_mapping_index >= node->mapping_count) {
>                         pr_err(FW_BUG "[node %p type %d] ID mapping index overflows valid mappings\n",
> --
> 2.36.1.dirty
> 

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