On 26/03/2021 11:29, Hanjun Guo wrote:
On 2021/3/25 18:10, LeoLiu-oc wrote:
Some ACPI devices need to issue dma requests to access the reserved memory area.BIOS uses the device scope type ACPI_NAMESPACE_DEVICE in RMRR to report these ACPI devices. This patch add support for detecting ACPI devices in RMRR and in order to distinguish it from PCI device, some interface functions are modified.
What kind of devices need this feature, I know LSI 3408 raid card needs this, do you have other devices and it's not PCI device?
This patch was submitted to mainline kernel but not accepted by upstream maintainer whose reason is "As I explained in the previous reply, RMRRs were added as work around for certain legacy device and we have been working hard to fix those legacy devices so that RMRR are no longer needed. Any new use case of RMRR is not encouraged".
I agree, it's the bug of the device itself :)
VT-D 1.3/2.5/3.0 Spec have this case's specification, We think this Intel driver should support this case too.
https://lkml.org/lkml/2020/10/10/56 Signed-off-by: LeoLiu-oc LeoLiu-oc@zhaoxin.com
drivers/iommu/dmar.c | 75 +++++++++++++++++++++---------------- drivers/iommu/intel-iommu.c | 24 +++++++++++- include/linux/dmar.h | 11 +++++- 3 files changed, 75 insertions(+), 35 deletions(-)
I'm not against to accept this patch for openEuler kernel if you have the solid use cases.
We run this on zhaoxin X86 paltform.
There are some MCUS on our platforms that read and write data to the system memory.
During this process, the MCU is invisible to the host kernel. And the MCU needs to report through ACPI_NAMESPACE_DEVICE in RMRR.
Sincerely TonyWWangoc
Thanks Hanjun
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c index 3f0c2c1ef0cb..9a07bcad38e5 100644 --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -226,7 +226,7 @@ static bool dmar_match_pci_path(struct dmar_pci_notify_info *info, int bus, }
/* Return: > 0 if match found, 0 if no match found, < 0 if error happens */ -int dmar_insert_dev_scope(struct dmar_pci_notify_info *info, +int dmar_pci_insert_dev_scope(struct dmar_pci_notify_info *info, void *start, void*end, u16 segment, struct dmar_dev_scope *devices, int devices_cnt) @@ -315,7 +315,7 @@ static int dmar_pci_bus_add_dev(struct dmar_pci_notify_info *info)
drhd = container_of(dmaru->hdr, struct acpi_dmar_hardware_unit, header); - ret = dmar_insert_dev_scope(info, (void *)(drhd + 1), + ret = dmar_pci_insert_dev_scope(info, (void *)(drhd + 1), ((void *)drhd) + drhd->header.length, dmaru->segment, dmaru->devices, dmaru->devices_cnt); @@ -707,47 +707,58 @@ dmar_find_matched_drhd_unit(struct pci_dev *dev) return dmaru; }
-static void __init dmar_acpi_insert_dev_scope(u8 device_number, - struct acpi_device *adev) +/* Return: > 0 if match found, 0 if no match found */ +bool dmar_acpi_insert_dev_scope(u8 device_number, + struct acpi_device *adev, + void *start, void *end, + struct dmar_dev_scope *devices, + int devices_cnt) { - struct dmar_drhd_unit *dmaru; - struct acpi_dmar_hardware_unit *drhd; struct acpi_dmar_device_scope *scope; struct device *tmp; int i; struct acpi_dmar_pci_path *path;
+ for (; start < end; start += scope->length) { + scope = start; + if (scope->entry_type != ACPI_DMAR_SCOPE_TYPE_NAMESPACE) + continue; + if (scope->enumeration_id != device_number) + continue; + path = (void *)(scope + 1); + for_each_dev_scope(devices, devices_cnt, i, tmp) + if (tmp == NULL) { + devices[i].bus = scope->bus; + devices[i].devfn = PCI_DEVFN(path->device, path->function); + rcu_assign_pointer(devices[i].dev, + get_device(&adev->dev)); + return true; + } + WARN_ON(i >= devices_cnt); + } + return false; +}
+static int dmar_acpi_bus_add_dev(u8 device_number, struct acpi_device *adev) +{ + struct dmar_drhd_unit *dmaru; + struct acpi_dmar_hardware_unit *drhd; + int ret;
for_each_drhd_unit(dmaru) { drhd = container_of(dmaru->hdr, struct acpi_dmar_hardware_unit, header);
- for (scope = (void *)(drhd + 1); - (unsigned long)scope < ((unsigned long)drhd) + drhd->header.length; - scope = ((void *)scope) + scope->length) { - if (scope->entry_type != ACPI_DMAR_SCOPE_TYPE_NAMESPACE) - continue; - if (scope->enumeration_id != device_number) - continue;
- path = (void *)(scope + 1); - pr_info("ACPI device "%s" under DMAR at %llx as %02x:%02x.%d\n", - dev_name(&adev->dev), dmaru->reg_base_addr, - scope->bus, path->device, path->function); - for_each_dev_scope(dmaru->devices, dmaru->devices_cnt, i, tmp) - if (tmp == NULL) { - dmaru->devices[i].bus = scope->bus; - dmaru->devices[i].devfn = PCI_DEVFN(path->device, - path->function); - rcu_assign_pointer(dmaru->devices[i].dev, - get_device(&adev->dev)); - return; - } - BUG_ON(i >= dmaru->devices_cnt); - } + ret = dmar_acpi_insert_dev_scope(device_number, adev, (void *)(drhd+1), + ((void *)drhd)+drhd->header.length, + dmaru->devices, dmaru->devices_cnt); + if (ret) + break; } - pr_warn("No IOMMU scope found for ANDD enumeration ID %d (%s)\n", - device_number, dev_name(&adev->dev)); + if (ret > 0) + ret = dmar_rmrr_add_acpi_dev(device_number, adev); + return ret; }
static int __init dmar_acpi_dev_scope_init(void) @@ -776,7 +787,7 @@ static int __init dmar_acpi_dev_scope_init(void) andd->device_name); continue; } - dmar_acpi_insert_dev_scope(andd->device_number, adev); + dmar_acpi_bus_add_dev(andd->device_number, adev); } } return 0; diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index f51ae0086786..18e0be8e05a5 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -4512,6 +4512,26 @@ int dmar_find_matched_atsr_unit(struct pci_dev *dev) return ret; }
+int dmar_rmrr_add_acpi_dev(u8 device_number, struct acpi_device *adev) +{ + int ret; + struct dmar_rmrr_unit *rmrru; + struct acpi_dmar_reserved_memory *rmrr;
+ list_for_each_entry(rmrru, &dmar_rmrr_units, list) { + rmrr = container_of(rmrru->hdr, + struct acpi_dmar_reserved_memory, + header); + ret = dmar_acpi_insert_dev_scope(device_number, adev, (void *)(rmrr + 1), + ((void *)rmrr) + rmrr->header.length, + rmrru->devices, rmrru->devices_cnt); + if (ret) + break; + } + pr_info("Add acpi_dev:%s to rmrru->devices\n", dev_name(&adev->dev)); + return 0; +}
int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info) { int ret = 0; @@ -4527,7 +4547,7 @@ int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info) rmrr = container_of(rmrru->hdr, struct acpi_dmar_reserved_memory, header); if (info->event == BUS_NOTIFY_ADD_DEVICE) { - ret = dmar_insert_dev_scope(info, (void *)(rmrr + 1), + ret = dmar_pci_insert_dev_scope(info, (void *)(rmrr + 1), ((void *)rmrr) + rmrr->header.length, rmrr->segment, rmrru->devices, rmrru->devices_cnt); @@ -4545,7 +4565,7 @@ int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info)
atsr = container_of(atsru->hdr, struct acpi_dmar_atsr, header); if (info->event == BUS_NOTIFY_ADD_DEVICE) { - ret = dmar_insert_dev_scope(info, (void *)(atsr + 1), + ret = dmar_pci_insert_dev_scope(info, (void *)(atsr + 1), (void *)atsr + atsr->header.length, atsr->segment, atsru->devices, atsru->devices_cnt); diff --git a/include/linux/dmar.h b/include/linux/dmar.h index 843a41ba7e28..68de8732d8d4 100644 --- a/include/linux/dmar.h +++ b/include/linux/dmar.h @@ -117,10 +117,13 @@ extern int dmar_parse_dev_scope(void *start, void *end, int *cnt, struct dmar_dev_scope **devices, u16 segment); extern void *dmar_alloc_dev_scope(void *start, void *end, int *cnt); extern void dmar_free_dev_scope(struct dmar_dev_scope **devices, int *cnt); -extern int dmar_insert_dev_scope(struct dmar_pci_notify_info *info, +extern int dmar_pci_insert_dev_scope(struct dmar_pci_notify_info *info, void *start, void*end, u16 segment, struct dmar_dev_scope *devices, int devices_cnt); +extern bool dmar_acpi_insert_dev_scope(u8 device_number, + struct acpi_device *adev, void *start, void *end, + struct dmar_dev_scope *devices, int devices_cnt); extern int dmar_remove_dev_scope(struct dmar_pci_notify_info *info, u16 segment, struct dmar_dev_scope *devices, int count); @@ -143,6 +146,7 @@ extern int dmar_parse_one_atsr(struct acpi_dmar_header *header, void *arg); extern int dmar_check_one_atsr(struct acpi_dmar_header *hdr, void *arg); extern int dmar_release_one_atsr(struct acpi_dmar_header *hdr, void *arg); extern int dmar_iommu_hotplug(struct dmar_drhd_unit *dmaru, bool insert); +extern int dmar_rmrr_add_acpi_dev(u8 device_number, struct acpi_device *adev); 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; } @@ -152,6 +156,11 @@ static inline int intel_iommu_init(void) { return -ENODEV; } #define dmar_check_one_atsr dmar_res_noop #define dmar_release_one_atsr dmar_res_noop
+static inline int dmar_rmrr_add_acpi_dev(u8 device_number, struct acpi_device *adev) +{ + return 0; +}
static inline int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info) { return 0;
.