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-rw-r--r--drivers/iommu/amd/init.c104
1 files changed, 34 insertions, 70 deletions
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 5140c820bda6..7e66ddfa323f 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -406,6 +406,9 @@ static void iommu_set_device_table(struct amd_iommu *iommu)
BUG_ON(iommu->mmio_base == NULL);
+ if (is_kdump_kernel())
+ return;
+
entry = iommu_virt_to_phys(dev_table);
entry |= (dev_table_size >> 12) - 1;
memcpy_toio(iommu->mmio_base + MMIO_DEV_TABLE_OFFSET,
@@ -646,7 +649,10 @@ static inline int __init alloc_dev_table(struct amd_iommu_pci_seg *pci_seg)
static inline void free_dev_table(struct amd_iommu_pci_seg *pci_seg)
{
- iommu_free_pages(pci_seg->dev_table);
+ if (is_kdump_kernel())
+ memunmap((void *)pci_seg->dev_table);
+ else
+ iommu_free_pages(pci_seg->dev_table);
pci_seg->dev_table = NULL;
}
@@ -1117,15 +1123,12 @@ static void set_dte_bit(struct dev_table_entry *dte, u8 bit)
dte->data[i] |= (1UL << _bit);
}
-static bool __copy_device_table(struct amd_iommu *iommu)
+static bool __reuse_device_table(struct amd_iommu *iommu)
{
- u64 int_ctl, int_tab_len, entry = 0;
struct amd_iommu_pci_seg *pci_seg = iommu->pci_seg;
- struct dev_table_entry *old_devtb = NULL;
- u32 lo, hi, devid, old_devtb_size;
+ u32 lo, hi, old_devtb_size;
phys_addr_t old_devtb_phys;
- u16 dom_id, dte_v, irq_v;
- u64 tmp;
+ u64 entry;
/* Each IOMMU use separate device table with the same size */
lo = readl(iommu->mmio_base + MMIO_DEV_TABLE_OFFSET);
@@ -1150,66 +1153,20 @@ static bool __copy_device_table(struct amd_iommu *iommu)
pr_err("The address of old device table is above 4G, not trustworthy!\n");
return false;
}
- old_devtb = (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT) && is_kdump_kernel())
- ? (__force void *)ioremap_encrypted(old_devtb_phys,
- pci_seg->dev_table_size)
- : memremap(old_devtb_phys, pci_seg->dev_table_size, MEMREMAP_WB);
-
- if (!old_devtb)
- return false;
- pci_seg->old_dev_tbl_cpy = iommu_alloc_pages_sz(
- GFP_KERNEL | GFP_DMA32, pci_seg->dev_table_size);
+ /*
+ * Re-use the previous kernel's device table for kdump.
+ */
+ pci_seg->old_dev_tbl_cpy = iommu_memremap(old_devtb_phys, pci_seg->dev_table_size);
if (pci_seg->old_dev_tbl_cpy == NULL) {
- pr_err("Failed to allocate memory for copying old device table!\n");
- memunmap(old_devtb);
+ pr_err("Failed to remap memory for reusing old device table!\n");
return false;
}
- for (devid = 0; devid <= pci_seg->last_bdf; ++devid) {
- pci_seg->old_dev_tbl_cpy[devid] = old_devtb[devid];
- dom_id = old_devtb[devid].data[1] & DEV_DOMID_MASK;
- dte_v = old_devtb[devid].data[0] & DTE_FLAG_V;
-
- if (dte_v && dom_id) {
- pci_seg->old_dev_tbl_cpy[devid].data[0] = old_devtb[devid].data[0];
- pci_seg->old_dev_tbl_cpy[devid].data[1] = old_devtb[devid].data[1];
- /* Reserve the Domain IDs used by previous kernel */
- if (ida_alloc_range(&pdom_ids, dom_id, dom_id, GFP_ATOMIC) != dom_id) {
- pr_err("Failed to reserve domain ID 0x%x\n", dom_id);
- memunmap(old_devtb);
- return false;
- }
- /* If gcr3 table existed, mask it out */
- if (old_devtb[devid].data[0] & DTE_FLAG_GV) {
- tmp = (DTE_GCR3_30_15 | DTE_GCR3_51_31);
- pci_seg->old_dev_tbl_cpy[devid].data[1] &= ~tmp;
- tmp = (DTE_GCR3_14_12 | DTE_FLAG_GV);
- pci_seg->old_dev_tbl_cpy[devid].data[0] &= ~tmp;
- }
- }
-
- irq_v = old_devtb[devid].data[2] & DTE_IRQ_REMAP_ENABLE;
- int_ctl = old_devtb[devid].data[2] & DTE_IRQ_REMAP_INTCTL_MASK;
- int_tab_len = old_devtb[devid].data[2] & DTE_INTTABLEN_MASK;
- if (irq_v && (int_ctl || int_tab_len)) {
- if ((int_ctl != DTE_IRQ_REMAP_INTCTL) ||
- (int_tab_len != DTE_INTTABLEN_512 &&
- int_tab_len != DTE_INTTABLEN_2K)) {
- pr_err("Wrong old irq remapping flag: %#x\n", devid);
- memunmap(old_devtb);
- return false;
- }
-
- pci_seg->old_dev_tbl_cpy[devid].data[2] = old_devtb[devid].data[2];
- }
- }
- memunmap(old_devtb);
-
return true;
}
-static bool copy_device_table(void)
+static bool reuse_device_table(void)
{
struct amd_iommu *iommu;
struct amd_iommu_pci_seg *pci_seg;
@@ -1217,17 +1174,17 @@ static bool copy_device_table(void)
if (!amd_iommu_pre_enabled)
return false;
- pr_warn("Translation is already enabled - trying to copy translation structures\n");
+ pr_warn("Translation is already enabled - trying to reuse translation structures\n");
/*
* All IOMMUs within PCI segment shares common device table.
- * Hence copy device table only once per PCI segment.
+ * Hence reuse device table only once per PCI segment.
*/
for_each_pci_segment(pci_seg) {
for_each_iommu(iommu) {
if (pci_seg->id != iommu->pci_seg->id)
continue;
- if (!__copy_device_table(iommu))
+ if (!__reuse_device_table(iommu))
return false;
break;
}
@@ -2906,8 +2863,8 @@ static void early_enable_iommu(struct amd_iommu *iommu)
* This function finally enables all IOMMUs found in the system after
* they have been initialized.
*
- * Or if in kdump kernel and IOMMUs are all pre-enabled, try to copy
- * the old content of device table entries. Not this case or copy failed,
+ * Or if in kdump kernel and IOMMUs are all pre-enabled, try to reuse
+ * the old content of device table entries. Not this case or reuse failed,
* just continue as normal kernel does.
*/
static void early_enable_iommus(void)
@@ -2915,18 +2872,25 @@ static void early_enable_iommus(void)
struct amd_iommu *iommu;
struct amd_iommu_pci_seg *pci_seg;
- if (!copy_device_table()) {
+ if (!reuse_device_table()) {
/*
- * If come here because of failure in copying device table from old
+ * If come here because of failure in reusing device table from old
* kernel with all IOMMUs enabled, print error message and try to
* free allocated old_dev_tbl_cpy.
*/
- if (amd_iommu_pre_enabled)
- pr_err("Failed to copy DEV table from previous kernel.\n");
+ if (amd_iommu_pre_enabled) {
+ pr_err("Failed to reuse DEV table from previous kernel.\n");
+ /*
+ * Bail out early if unable to remap/reuse DEV table from
+ * previous kernel if SNP enabled as IOMMU commands will
+ * time out without DEV table and cause kdump boot panic.
+ */
+ BUG_ON(check_feature(FEATURE_SNP));
+ }
for_each_pci_segment(pci_seg) {
if (pci_seg->old_dev_tbl_cpy != NULL) {
- iommu_free_pages(pci_seg->old_dev_tbl_cpy);
+ memunmap((void *)pci_seg->old_dev_tbl_cpy);
pci_seg->old_dev_tbl_cpy = NULL;
}
}
@@ -2936,7 +2900,7 @@ static void early_enable_iommus(void)
early_enable_iommu(iommu);
}
} else {
- pr_info("Copied DEV table from previous kernel.\n");
+ pr_info("Reused DEV table from previous kernel.\n");
for_each_pci_segment(pci_seg) {
iommu_free_pages(pci_seg->dev_table);
generated by cgit (git 2.34.1) at 2025-11-01 08:31:37 +0000