[PATCH v6 11/29] iommu/amd: Expose [set|get]_dev_entry_bit()

From: Ricardo Neri
Date: Thu May 05 2022 - 19:58:46 EST


These functions are used to check and set specific bits in a Device Table
Entry. For instance, they can be used to modify the setting of the NMIPass
field.

Currently, these functions are used only for ACPI-specified devices.
However, an interrupt is to be allocated with NMI as delivery mode, the
Device Table Entry needs modified accordingly in irq_remapping_alloc().

As a first step expose these two functions. No functional changes.

Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: "Ravi V. Shankar" <ravi.v.shankar@xxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: x86@xxxxxxxxxx
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx>
---
Changes since v5:
* Introduced this patch

Changes since v4:
* N/A

Changes since v3:
* N/A

Changes since v2:
* N/A

Changes since v1:
* N/A
---
drivers/iommu/amd/amd_iommu.h | 3 +++
drivers/iommu/amd/init.c | 4 ++--
2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
index 1ab31074f5b3..9f3d1564c84e 100644
--- a/drivers/iommu/amd/amd_iommu.h
+++ b/drivers/iommu/amd/amd_iommu.h
@@ -128,4 +128,7 @@ static inline void amd_iommu_apply_ivrs_quirks(void) { }

extern void amd_iommu_domain_set_pgtable(struct protection_domain *domain,
u64 *root, int mode);
+
+extern void set_dev_entry_bit(u16 devid, u8 bit);
+extern int get_dev_entry_bit(u16 devid, u8 bit);
#endif
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index b4a798c7b347..823e76b284f1 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -914,7 +914,7 @@ static void iommu_enable_gt(struct amd_iommu *iommu)
}

/* sets a specific bit in the device table entry. */
-static void set_dev_entry_bit(u16 devid, u8 bit)
+void set_dev_entry_bit(u16 devid, u8 bit)
{
int i = (bit >> 6) & 0x03;
int _bit = bit & 0x3f;
@@ -922,7 +922,7 @@ static void set_dev_entry_bit(u16 devid, u8 bit)
amd_iommu_dev_table[devid].data[i] |= (1UL << _bit);
}

-static int get_dev_entry_bit(u16 devid, u8 bit)
+int get_dev_entry_bit(u16 devid, u8 bit)
{
int i = (bit >> 6) & 0x03;
int _bit = bit & 0x3f;
--
2.17.1