John,
Could you refresh this patch, since the file has changed locations,
and make some repairs based on feedback below?
attached a patch that could be possible update...
- Don
On 07/28/2011 05:13 PM, jharg93@xxxxxxxxx wrote:
The DMAR driver currently doesn't reserve the memory used for the IOMMU
registers. On one specific combination of cards on our system, the kernel
pci resource allocator was assigning a BAR to the same address as the IOMMU.
When the other driver did an ioremap, suddenly the IOMMU registers were no
longer valid.
Signed-off-by: Jordan Hargrave<Jordan_Hargrave@xxxxxxxx>
---
drivers/pci/dmar.c | 9 +++++++++
1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c
index 12e02bf..9650b9b 100644
--- a/drivers/pci/dmar.c
+++ b/drivers/pci/dmar.c
@@ -750,6 +750,10 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
iommu->seq_id = iommu_allocated++;
sprintf (iommu->name, "dmar%d", iommu->seq_id);
+ if (!request_mem_region(drhd->reg_base_addr, VTD_PAGE_SIZE, iommu->name)) {
+ printk(KERN_ERR "IOMMU: can't reserve memory\n");
+ goto error;
+ }
iommu->reg = ioremap(drhd->reg_base_addr, VTD_PAGE_SIZE);
if (!iommu->reg) {
printk(KERN_ERR "IOMMU: can't map the region\n");
probably want to introduce an err_release: at bottom of function that
does release_mem_region(), and set map_size to VTD_PAGE_SIZE here,
so it can be used in both ioremap() error checks in this function.
@@ -789,7 +793,12 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
cap_max_fault_reg_offset(iommu->cap));
map_size = VTD_PAGE_ALIGN(map_size);
if (map_size> VTD_PAGE_SIZE) {
+ release_mem_region(drhd->reg_base_addr, VTD_PAGE_SIZE);
need to do release after iounmap() below, not before it.
iounmap(iommu->reg);
+ if (!request_mem_region(drhd->reg_base_addr, map_size, iommu->name)) {
+ printk(KERN_ERR "IOMMU: can't reserve memory\n");
+ goto error;
+ }
iommu->reg = ioremap(drhd->reg_base_addr, map_size);
if (!iommu->reg) {
printk(KERN_ERR "IOMMU: can't map the region\n");
this is where you need an err_release goto as well
--- drivers/iommu/dmar.c.orig 2011-09-12 14:51:11.815394493 -0400
+++ drivers/iommu/dmar.c 2011-09-12 14:58:13.994299472 -0400
@@ -745,10 +745,16 @@ int alloc_iommu(struct dmar_drhd_unit *d
iommu->seq_id = iommu_allocated++;
sprintf (iommu->name, "dmar%d", iommu->seq_id);
- iommu->reg = ioremap(drhd->reg_base_addr, VTD_PAGE_SIZE);
+ map_size = VTD_PAGE_SIZE;
+ if (!request_mem_region(drhd->reg_base_addr, map_size, iommu->name)) {
+ printk(KERN_ERR "IOMMU: can't reserve memory\n");
+ goto error;
+ }
+
+ iommu->reg = ioremap(drhd->reg_base_addr, map_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);
@@ -785,10 +791,15 @@ int alloc_iommu(struct dmar_drhd_unit *d
map_size = VTD_PAGE_ALIGN(map_size);
if (map_size > VTD_PAGE_SIZE) {
iounmap(iommu->reg);
+ release_mem_region(drhd->reg_base_addr, VTD_PAGE_SIZE);
+ if (!request_mem_region(drhd->reg_base_addr, map_size, iommu->name)) {
+ printk(KERN_ERR "IOMMU: can't reserve memory\n");
+ goto error;
+ }
iommu->reg = ioremap(drhd->reg_base_addr, map_size);
if (!iommu->reg) {
printk(KERN_ERR "IOMMU: can't map the region\n");
- goto error;
+ goto err_release;
}
}
@@ -807,6 +818,8 @@ int alloc_iommu(struct dmar_drhd_unit *d
err_unmap:
iounmap(iommu->reg);
+ err_release:
+ release_mem_region(drhd->reg_base_addr, map_size);
error:
kfree(iommu);
return -1;
