Intel-iommu initialization doesn't currently reserve the memory used
for the IOMMU registers. This can allow the pci resource allocator
to assign a device BAR to the same address as the IOMMU registers.
This can cause some not so nice side affects when the driver
ioremap's that region.
Signed-off-by: Donald Dutile <ddut...@redhat.com>
v2: missed a release-mem after an iounmap() in v1, which
caused the additional changes to add the phys_addr
and variable register region size to be stored in the
intel_iommu struct
---
drivers/iommu/dmar.c | 35 +++++++++++++++++++++++++++--------
include/linux/intel-iommu.h | 3 ++-
2 files changed, 29 insertions(+), 9 deletions(-)
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 35c1e17..0747c7f 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -581,7 +581,7 @@ int __init detect_intel_iommu(void)
int alloc_iommu(struct dmar_drhd_unit *drhd)
{
struct intel_iommu *iommu;
- int map_size;
+ resource_size_t map_size;
u32 ver;
static int iommu_allocated = 0;
int agaw = 0;
@@ -599,10 +599,17 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
iommu->seq_id = iommu_allocated++;
sprintf (iommu->name, "dmar%d", iommu->seq_id);
- iommu->reg = ioremap(drhd->reg_base_addr, VTD_PAGE_SIZE);
+ iommu->reg_phys = drhd->reg_base_addr;
+ iommu->reg_size = VTD_PAGE_SIZE;
+ if (!request_mem_region(iommu->reg_phys, iommu->reg_size, iommu->name))
{
+ printk(KERN_ERR "IOMMU: can't reserve memory\n");
+ goto error;
+ }
+
+ iommu->reg = ioremap(iommu->reg_phys, iommu->reg_size);
if (!iommu->reg) {
printk(KERN_ERR "IOMMU: can't map the region\n");
- goto error;
+ goto err_release;
}
iommu->cap = dmar_readq(iommu->reg + DMAR_CAP_REG);
iommu->ecap = dmar_readq(iommu->reg + DMAR_ECAP_REG);
@@ -635,19 +642,26 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
map_size = max_t(int, ecap_max_iotlb_offset(iommu->ecap),
cap_max_fault_reg_offset(iommu->cap));
map_size = VTD_PAGE_ALIGN(map_size);
- if (map_size > VTD_PAGE_SIZE) {
+ if (map_size > iommu->reg_size) {
iounmap(iommu->reg);
- iommu->reg = ioremap(drhd->reg_base_addr, map_size);
+ release_mem_region(iommu->reg_phys, iommu->reg_size);
+ iommu->reg_size = map_size;
+ if (!request_mem_region(iommu->reg_phys, iommu->reg_size,
+ iommu->name)) {
+ printk(KERN_ERR "IOMMU: can't reserve memory\n");
+ goto error;
+ }
+ iommu->reg = ioremap(iommu->reg_phys, iommu->reg_size);
if (!iommu->reg) {
printk(KERN_ERR "IOMMU: can't map the region\n");
- goto error;
+ goto err_release;
}
}
ver = readl(iommu->reg + DMAR_VER_REG);
pr_info("IOMMU %d: reg_base_addr %llx ver %d:%d cap %llx ecap %llx\n",
iommu->seq_id,
- (unsigned long long)drhd->reg_base_addr,
+ (unsigned long long)iommu->reg_phys,
DMAR_VER_MAJOR(ver), DMAR_VER_MINOR(ver),
(unsigned long long)iommu->cap,
(unsigned long long)iommu->ecap);
@@ -659,6 +673,8 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
err_unmap:
iounmap(iommu->reg);
+ err_release:
+ release_mem_region(iommu->reg_phys, iommu->reg_size);
error:
kfree(iommu);
return -1;
@@ -671,8 +687,11 @@ void free_iommu(struct intel_iommu *iommu)
free_dmar_iommu(iommu);
- if (iommu->reg)
+ if (iommu->reg) {
iounmap(iommu->reg);
+ release_mem_region(iommu->reg_phys, iommu->reg_size);
+ }
+
kfree(iommu);
}
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index e6ca56d..c6d132b 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -308,6 +308,8 @@ enum {
struct intel_iommu {
void __iomem *reg; /* Pointer to hardware regs, virtual addr */
+ resource_size_t reg_phys;
+ resource_size_t reg_size;
u64 cap;
u64 ecap;
u32 gcmd; /* Holds TE, EAFL. Don't need SRTP, SFL, WBF */
@@ -360,7 +362,6 @@ extern void qi_flush_dev_iotlb(struct intel_iommu *iommu,
u16 sid, u16 qdep,
u64 addr, unsigned mask);
extern int qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu);
-
extern int dmar_ir_support(void);
#endif
--
1.7.1
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