hdr in struct dmar_drhd_unit is used to point the DMAR hardware unit copied
at the end of struct dmar_drhd_unit. One zero-sized array may be more
elegant for this purpose.
This patch replace *hdr with hdr[0] in struct dmar_drhd_unit.
Besides this, this patch includes other two changes:
1. remove unnecessary type cast in dmar_table_detect()
2. type cast from acpi_dmar_header to acpi_dmar_hardware_unit directly
Signed-off-by: Wei Yang <richard.weiy...@gmail.com>
---
drivers/iommu/dmar.c | 15 ++++-----------
include/linux/dmar.h | 2 +-
2 files changed, 5 insertions(+), 12 deletions(-)
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 80e3c17..d6dd23f 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -292,8 +292,7 @@ static int dmar_pci_bus_add_dev(struct dmar_pci_notify_info
*info)
if (dmaru->include_all)
continue;
- drhd = container_of(dmaru->hdr,
- struct acpi_dmar_hardware_unit, header);
+ drhd = (struct acpi_dmar_hardware_unit *)dmaru->hdr;
ret = dmar_insert_dev_scope(info, (void *)(drhd + 1),
((void *)drhd) + drhd->header.length,
dmaru->segment,
@@ -390,7 +389,6 @@ static int dmar_parse_one_drhd(struct acpi_dmar_header
*header, void *arg)
* If header is allocated from slab by ACPI _DSM method, we need to
* copy the content because the memory buffer will be freed on return.
*/
- dmaru->hdr = (void *)(dmaru + 1);
memcpy(dmaru->hdr, header, header->length);
dmaru->reg_base_addr = drhd->address;
dmaru->segment = drhd->segment;
@@ -529,8 +527,7 @@ static int __init dmar_table_detect(void)
/* if we could find DMAR table, then there are DMAR devices */
status = acpi_get_table_with_size(ACPI_SIG_DMAR, 0,
- (struct acpi_table_header **)&dmar_tbl,
- &dmar_tbl_size);
+ &dmar_tbl, &dmar_tbl_size);
if (ACPI_SUCCESS(status) && !dmar_tbl) {
pr_warn("Unable to map DMAR\n");
@@ -663,9 +660,7 @@ dmar_find_matched_drhd_unit(struct pci_dev *dev)
rcu_read_lock();
for_each_drhd_unit(dmaru) {
- drhd = container_of(dmaru->hdr,
- struct acpi_dmar_hardware_unit,
- header);
+ drhd = (struct acpi_dmar_hardware_unit *)dmaru->hdr;
if (dmaru->include_all &&
drhd->segment == pci_domain_nr(dev->bus))
@@ -693,9 +688,7 @@ static void __init dmar_acpi_insert_dev_scope(u8
device_number,
struct acpi_dmar_pci_path *path;
for_each_drhd_unit(dmaru) {
- drhd = container_of(dmaru->hdr,
- struct acpi_dmar_hardware_unit,
- header);
+ drhd = (struct acpi_dmar_hardware_unit *)dmaru->hdr;
for (scope = (void *)(drhd + 1);
(unsigned long)scope < ((unsigned long)drhd) +
drhd->header.length;
diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index e9bc929..5f6da7e 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -52,7 +52,6 @@ struct dmar_dev_scope {
extern struct acpi_table_header *dmar_tbl;
struct dmar_drhd_unit {
struct list_head list; /* list of drhd units */
- struct acpi_dmar_header *hdr; /* ACPI header */
u64 reg_base_addr; /* register base address*/
struct dmar_dev_scope *devices;/* target device array */
int devices_cnt; /* target device count */
@@ -60,6 +59,7 @@ struct dmar_drhd_unit {
u8 ignored:1; /* ignore drhd */
u8 include_all:1;
struct intel_iommu *iommu;
+ struct acpi_dmar_header hdr[0];/* ACPI header */
};
struct dmar_pci_path {
--
2.5.0
