[Patch Part3 V3 14/21] IOMMU/vt-d: introduce helper function dmar_walk_resources()

From: Jiang Liu
Date: Wed Jun 25 2014 - 05:05:17 EST

Introduce helper function dmar_walk_resources to walk resource entries
in DMAR table and ACPI buffer object returned by ACPI _DSM method
for IOMMU hot-plug.

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
---
drivers/iommu/dmar.c | 208 +++++++++++++++++++++++--------------------
drivers/iommu/intel-iommu.c | 4 +-
include/linux/dmar.h | 19 ++--
3 files changed, 122 insertions(+), 109 deletions(-)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 9a4f05e5b23f..8e3ae29b7008 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -43,6 +43,14 @@

#include "irq_remapping.h"

+typedef int (*dmar_res_handler_t)(struct acpi_dmar_header *, void *);
+struct dmar_res_callback {
+ dmar_res_handler_t cb[ACPI_DMAR_TYPE_RESERVED];
+ void *arg[ACPI_DMAR_TYPE_RESERVED];
+ bool ignore_unhandled;
+ bool print_entry;
+};
+
/*
* Assumptions:
* 1) The hotplug framework guarentees that DMAR unit will be hot-added
@@ -332,7 +340,7 @@ static struct notifier_block dmar_pci_bus_nb = {
* present in the platform
*/
static int __init
-dmar_parse_one_drhd(struct acpi_dmar_header *header)
+dmar_parse_one_drhd(struct acpi_dmar_header *header, void *arg)
{
struct acpi_dmar_hardware_unit *drhd;
struct dmar_drhd_unit *dmaru;
@@ -363,6 +371,10 @@ dmar_parse_one_drhd(struct acpi_dmar_header *header)
return ret;
}
dmar_register_drhd_unit(dmaru);
+
+ if (arg)
+ (*(int *)arg)++;
+
return 0;
}

@@ -375,7 +387,8 @@ static void dmar_free_drhd(struct dmar_drhd_unit *dmaru)
kfree(dmaru);
}

-static int __init dmar_parse_one_andd(struct acpi_dmar_header *header)
+static int __init dmar_parse_one_andd(struct acpi_dmar_header *header,
+ void *arg)
{
struct acpi_dmar_andd *andd = (void *)header;

@@ -397,7 +410,7 @@ static int __init dmar_parse_one_andd(struct acpi_dmar_header *header)

#ifdef CONFIG_ACPI_NUMA
static int __init
-dmar_parse_one_rhsa(struct acpi_dmar_header *header)
+dmar_parse_one_rhsa(struct acpi_dmar_header *header, void *arg)
{
struct acpi_dmar_rhsa *rhsa;
struct dmar_drhd_unit *drhd;
@@ -424,6 +437,8 @@ dmar_parse_one_rhsa(struct acpi_dmar_header *header)

return 0;
}
+#else
+#define dmar_parse_one_rhsa dmar_res_noop
#endif

static void __init
@@ -485,6 +500,52 @@ static int __init dmar_table_detect(void)
return (ACPI_SUCCESS(status) ? 1 : 0);
}

+static int dmar_walk_resources(struct acpi_dmar_header *start, size_t len,
+ struct dmar_res_callback *cb)
+{
+ int ret = 0;
+ struct acpi_dmar_header *iter, *next;
+ struct acpi_dmar_header *end = ((void *)start) + len;
+
+ for (iter = start; iter < end && ret == 0; iter = next) {
+ next = (void *)iter + iter->length;
+ if (iter->length == 0) {
+ /* Avoid looping forever on bad ACPI tables */
+ pr_debug(FW_BUG "Invalid 0-length structure\n");
+ break;
+ } else if (next > end) {
+ /* Avoid passing table end */
+ pr_warn(FW_BUG "record passes table end\n");
+ ret = -EINVAL;
+ break;
+ }
+
+ if (cb->print_entry)
+ dmar_table_print_dmar_entry(iter);
+
+ if (iter->type >= ACPI_DMAR_TYPE_RESERVED) {
+ /* continue for forward compatibility */
+ pr_debug("Unknown DMAR structure type %d\n",
+ iter->type);
+ } else if (cb->cb[iter->type]) {
+ ret = cb->cb[iter->type](iter, cb->arg[iter->type]);
+ } else if (!cb->ignore_unhandled) {
+ pr_warn("No handler for DMAR structure type %d\n",
+ iter->type);
+ ret = -EINVAL;
+ }
+ }
+
+ return ret;
+}
+
+static inline int dmar_walk_dmar_table(struct acpi_table_dmar *dmar,
+ struct dmar_res_callback *cb)
+{
+ return dmar_walk_resources((struct acpi_dmar_header *)(dmar + 1),
+ dmar->header.length - sizeof(*dmar), cb);
+}
+
/**
* parse_dmar_table - parses the DMA reporting table
*/
@@ -492,9 +553,18 @@ static int __init
parse_dmar_table(void)
{
struct acpi_table_dmar *dmar;
- struct acpi_dmar_header *entry_header;
int ret = 0;
int drhd_count = 0;
+ struct dmar_res_callback cb = {
+ .print_entry = true,
+ .ignore_unhandled = true,
+ .arg[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &drhd_count,
+ .cb[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &dmar_parse_one_drhd,
+ .cb[ACPI_DMAR_TYPE_RESERVED_MEMORY] = &dmar_parse_one_rmrr,
+ .cb[ACPI_DMAR_TYPE_ATSR] = &dmar_parse_one_atsr,
+ .cb[ACPI_DMAR_HARDWARE_AFFINITY] = &dmar_parse_one_rhsa,
+ .cb[ACPI_DMAR_TYPE_ANDD] = &dmar_parse_one_andd,
+ };

/*
* Do it again, earlier dmar_tbl mapping could be mapped with
@@ -519,50 +589,10 @@ parse_dmar_table(void)

pr_info("Host address width %d\n", dmar->width + 1);

- entry_header = (struct acpi_dmar_header *)(dmar + 1);
- while (((unsigned long)entry_header) <
- (((unsigned long)dmar) + dmar_tbl->length)) {
- /* Avoid looping forever on bad ACPI tables */
- if (entry_header->length == 0) {
- pr_warn("Invalid 0-length structure\n");
- ret = -EINVAL;
- break;
- }
-
- dmar_table_print_dmar_entry(entry_header);
-
- switch (entry_header->type) {
- case ACPI_DMAR_TYPE_HARDWARE_UNIT:
- drhd_count++;
- ret = dmar_parse_one_drhd(entry_header);
- break;
- case ACPI_DMAR_TYPE_RESERVED_MEMORY:
- ret = dmar_parse_one_rmrr(entry_header);
- break;
- case ACPI_DMAR_TYPE_ATSR:
- ret = dmar_parse_one_atsr(entry_header);
- break;
- case ACPI_DMAR_HARDWARE_AFFINITY:
-#ifdef CONFIG_ACPI_NUMA
- ret = dmar_parse_one_rhsa(entry_header);
-#endif
- break;
- case ACPI_DMAR_TYPE_ANDD:
- ret = dmar_parse_one_andd(entry_header);
- break;
- default:
- pr_warn("Unknown DMAR structure type %d\n",
- entry_header->type);
- ret = 0; /* for forward compatibility */
- break;
- }
- if (ret)
- break;
-
- entry_header = ((void *)entry_header + entry_header->length);
- }
- if (drhd_count == 0)
+ ret = dmar_walk_dmar_table(dmar, &cb);
+ if (ret == 0 && drhd_count == 0)
pr_warn(FW_BUG "No DRHD structure found in DMAR table\n");
+
return ret;
}

@@ -761,76 +791,60 @@ static void warn_invalid_dmar(u64 addr, const char *message)
dmi_get_system_info(DMI_PRODUCT_VERSION));
}

-static int __init check_zero_address(void)
+static int __ref
+dmar_validate_one_drhd(struct acpi_dmar_header *entry, void *arg)
{
- struct acpi_table_dmar *dmar;
- struct acpi_dmar_header *entry_header;
struct acpi_dmar_hardware_unit *drhd;
+ void __iomem *addr;
+ u64 cap, ecap;

- dmar = (struct acpi_table_dmar *)dmar_tbl;
- entry_header = (struct acpi_dmar_header *)(dmar + 1);
-
- while (((unsigned long)entry_header) <
- (((unsigned long)dmar) + dmar_tbl->length)) {
- /* Avoid looping forever on bad ACPI tables */
- if (entry_header->length == 0) {
- pr_warn("Invalid 0-length structure\n");
- return 0;
- }
-
- if (entry_header->type == ACPI_DMAR_TYPE_HARDWARE_UNIT) {
- void __iomem *addr;
- u64 cap, ecap;
-
- drhd = (void *)entry_header;
- if (!drhd->address) {
- warn_invalid_dmar(0, "");
- goto failed;
- }
+ drhd = (void *)entry;
+ if (!drhd->address) {
+ warn_invalid_dmar(0, "");
+ return -EINVAL;
+ }

- addr = early_ioremap(drhd->address, VTD_PAGE_SIZE);
- if (!addr ) {
- printk("IOMMU: can't validate: %llx\n", drhd->address);
- goto failed;
- }
- cap = dmar_readq(addr + DMAR_CAP_REG);
- ecap = dmar_readq(addr + DMAR_ECAP_REG);
- early_iounmap(addr, VTD_PAGE_SIZE);
- if (cap == (uint64_t)-1 && ecap == (uint64_t)-1) {
- warn_invalid_dmar(drhd->address,
- " returns all ones");
- goto failed;
- }
- }
+ addr = early_ioremap(drhd->address, VTD_PAGE_SIZE);
+ if (!addr) {
+ pr_warn("IOMMU: can't validate: %llx\n", drhd->address);
+ return -EINVAL;
+ }
+ cap = dmar_readq(addr + DMAR_CAP_REG);
+ ecap = dmar_readq(addr + DMAR_ECAP_REG);
+ early_iounmap(addr, VTD_PAGE_SIZE);

- entry_header = ((void *)entry_header + entry_header->length);
+ if (cap == (uint64_t)-1 && ecap == (uint64_t)-1) {
+ warn_invalid_dmar(drhd->address, " returns all ones");
+ return -EINVAL;
}
- return 1;

-failed:
return 0;
}

int __init detect_intel_iommu(void)
{
int ret;
+ struct dmar_res_callback validate_drhd_cb = {
+ .cb[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &dmar_validate_one_drhd,
+ .ignore_unhandled = true,
+ };

down_write(&dmar_global_lock);
ret = dmar_table_detect();
if (ret)
- ret = check_zero_address();
- {
- if (ret && !no_iommu && !iommu_detected && !dmar_disabled) {
- iommu_detected = 1;
- /* Make sure ACS will be enabled */
- pci_request_acs();
- }
+ ret = !dmar_walk_dmar_table((struct acpi_table_dmar *)dmar_tbl,
+ &validate_drhd_cb);
+ if (ret && !no_iommu && !iommu_detected && !dmar_disabled) {
+ iommu_detected = 1;
+ /* Make sure ACS will be enabled */
+ pci_request_acs();
+ }

#ifdef CONFIG_X86
- if (ret)
- x86_init.iommu.iommu_init = intel_iommu_init;
+ if (ret)
+ x86_init.iommu.iommu_init = intel_iommu_init;
#endif
- }
+
early_acpi_os_unmap_memory((void __iomem *)dmar_tbl, dmar_tbl_size);
dmar_tbl = NULL;
up_write(&dmar_global_lock);
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 91dc85f63c41..531049f70d96 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3674,7 +3674,7 @@ static inline void init_iommu_pm_ops(void) {}
#endif /* CONFIG_PM */


-int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header)
+int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header, void *arg)
{
struct acpi_dmar_reserved_memory *rmrr;
struct dmar_rmrr_unit *rmrru;
@@ -3700,7 +3700,7 @@ int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header)
return 0;
}

-int __init dmar_parse_one_atsr(struct acpi_dmar_header *hdr)
+int __init dmar_parse_one_atsr(struct acpi_dmar_header *hdr, void *arg)
{
struct acpi_dmar_atsr *atsr;
struct dmar_atsr_unit *atsru;
diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index 1deece46a0ca..fac8ca34f9a8 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -115,22 +115,21 @@ extern int dmar_remove_dev_scope(struct dmar_pci_notify_info *info,
extern int detect_intel_iommu(void);
extern int enable_drhd_fault_handling(void);

+static inline int dmar_res_noop(struct acpi_dmar_header *hdr, void *arg)
+{
+ return 0;
+}
+
#ifdef CONFIG_INTEL_IOMMU
extern int iommu_detected, no_iommu;
extern int intel_iommu_init(void);
-extern int dmar_parse_one_rmrr(struct acpi_dmar_header *header);
-extern int dmar_parse_one_atsr(struct acpi_dmar_header *header);
+extern int dmar_parse_one_rmrr(struct acpi_dmar_header *header, void *arg);
+extern int dmar_parse_one_atsr(struct acpi_dmar_header *header, void *arg);
extern int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info);
#else /* !CONFIG_INTEL_IOMMU: */
static inline int intel_iommu_init(void) { return -ENODEV; }
-static inline int dmar_parse_one_rmrr(struct acpi_dmar_header *header)
-{
- return 0;
-}
-static inline int dmar_parse_one_atsr(struct acpi_dmar_header *header)
-{
- return 0;
-}
+#define dmar_parse_one_rmrr dmar_res_noop
+#define dmar_parse_one_atsr dmar_res_noop
static inline int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info)
{
return 0;
--
1.7.10.4

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