[PATCH v10 4/9] iommu/amd: Clean up iommu_pc_get_set_reg()

From: Suravee Suthikulpanit
Date: Wed Feb 15 2017 - 15:58:52 EST


From: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>

Clean up coding style and fix a bug in the 64-bit register read
logic since it overwrites the upper 32-bit when reading the lower 32-bit.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
drivers/iommu/amd_iommu_init.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 6799cf9..c7edc18 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -2760,22 +2760,25 @@ static int iommu_pc_get_set_reg_val(struct amd_iommu *iommu,
if (WARN_ON((fxn > 0x28) || (fxn & 7)))
return -ENODEV;

- offset = (u32)(((0x40|bank) << 12) | (cntr << 8) | fxn);
+ offset = (u32)(((0x40 | bank) << 12) | (cntr << 8) | fxn);

/* Limit the offset to the hw defined mmio region aperture */
- max_offset_lim = (u32)(((0x40|iommu->max_banks) << 12) |
+ max_offset_lim = (u32)(((0x40 | iommu->max_banks) << 12) |
(iommu->max_counters << 8) | 0x28);
if ((offset < MMIO_CNTR_REG_OFFSET) ||
(offset > max_offset_lim))
return -EINVAL;

if (is_write) {
- writel((u32)*value, iommu->mmio_base + offset);
- writel((*value >> 32), iommu->mmio_base + offset + 4);
+ u64 val = *value & GENMASK_ULL(47, 0);
+
+ writel((u32)val, iommu->mmio_base + offset);
+ writel((val >> 32), iommu->mmio_base + offset + 4);
} else {
*value = readl(iommu->mmio_base + offset + 4);
*value <<= 32;
- *value = readl(iommu->mmio_base + offset);
+ *value |= readl(iommu->mmio_base + offset);
+ *value &= GENMASK_ULL(47, 0);
}

return 0;
--
1.8.3.1