drivers/iommu/amd: Clean up iommu_pc_get_set_reg()

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@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Jörg Rödel <joro@8bytes.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: iommu@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/1487926102-13073-5-git-send-email-Suravee.Suthikulpanit@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 6130278c5d71bd08e925cc35007610bc32736938..ce65a47e2d0b0a792c3da04b184556b2a1c2b78a 100644 (file)
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -2763,22 +2763,25 @@ 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;