在acpi_iort_init->iort_init_platform_devices 中会遍历iort_table 中的node,然后调用iort_add_smmu_platform_device 将irq 资源添加给device,最终会在smmu的probe函数中使用这里添加的irq资源.
static int __init iort_add_smmu_platform_device(struct acpi_iort_node *node)
{
struct fwnode_handle *fwnode;
struct platform_device *pdev;
struct resource *r;
enum dev_dma_attr attr;
int ret, count;
const struct iort_iommu_config *ops = iort_get_iommu_cfg(node);
if (!ops)
return -ENODEV;
pdev = platform_device_alloc(ops->name, PLATFORM_DEVID_AUTO);
if (!pdev)
return PTR_ERR(pdev);
count = ops->iommu_count_resources(node);
r = kcalloc(count, sizeof(*r), GFP_KERNEL);
if (!r) {
ret = -ENOMEM;
goto dev_put;
}
ops->iommu_init_resources(r, node);
ret = platform_device_add_resources(pdev, r, count);
/*
* Resources are duplicated in platform_device_add_resources,
* free their allocated memory
*/
kfree(r);
if (ret)
goto dev_put;
/*
* Add a copy of IORT node pointer to platform_data to
* be used to retrieve IORT data information.
*/
ret = platform_device_add_data(pdev, &node, sizeof(node));
if (ret)
goto dev_put;
/*
* We expect the dma masks to be equivalent for
* all SMMUs set-ups
*/
pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
fwnode = iort_get_fwnode(node);
if (!fwnode) {
ret = -ENODEV;
goto dev_put;
}
pdev->dev.fwnode = fwnode;
attr = ops->iommu_is_coherent(node) ?
DEV_DMA_COHERENT : DEV_DMA_NON_COHERENT;
/* Configure DMA for the page table walker */
acpi_dma_configure(&pdev->dev, attr);
ret = platform_device_add(pdev);
if (ret)
goto dma_deconfigure;
return 0;
dma_deconfigure:
acpi_dma_deconfigure(&pdev->dev);
dev_put:
platform_device_put(pdev);
return ret;
}
在iort_add_smmu_platform_device 中首先通过iort_get_iommu_cfg 得到iort_iommu_config *ops
static const struct iort_iommu_config iort_arm_smmu_v3_cfg __initconst = {
.name = "arm-smmu-v3",
.iommu_is_coherent = arm_smmu_v3_is_coherent,
.iommu_count_resources = arm_smmu_v3_count_resources,
.iommu_init_resources = arm_smmu_v3_init_resources
};
static __init
const struct iort_iommu_config *iort_get_iommu_cfg(struct acpi_iort_node *node)
{
switch (node->type) {
case ACPI_IORT_NODE_SMMU_V3:
return &iort_arm_smmu_v3_cfg;
case ACPI_IORT_NODE_SMMU:
return &iort_arm_smmu_cfg;
default:
return NULL;
}
}
根据node->type,决定用smmu还是smmuv3,我们这里以ACPI_IORT_NODE_SMMU_V3为例,所以返回iort_arm_smmu_v3_cfg
然后通过 pdev = platform_device_alloc(ops->name, PLATFORM_DEVID_AUTO);
申请一个platform_device *pdev。
然后调用count = ops->iommu_count_resources(node);来计算resource的数量,由于是smmuv3,因此调用arm_smmu_v3_count_resources
static int __init arm_smmu_v3_count_resources(struct acpi_iort_node *node)
{
struct acpi_iort_smmu_v3 *smmu;
/* Always present mem resource */
int num_res = 1;
/* Retrieve SMMUv3 specific data */
smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
if (smmu->event_gsiv)
num_res++;
if (smmu->pri_gsiv)
num_res++;
if (smmu->gerr_gsiv)
num_res++;
if (smmu->sync_gsiv)
num_res++;
return num_res;
}
从arm_smmu_v3_count_resources 中可以看出资源总共有四种event_gsiv/pri_gsiv/gerr_gsiv/sync_gsiv,这些信息是存在是存在platfrom_data中的,这个可以参考之前的博文.
回到iort_add_smmu_platform_device中继续调用ops->iommu_init_resources(r, node);来初始resource
static void __init arm_smmu_v3_init_resources(struct resource *res,
struct acpi_iort_node *node)
{
struct acpi_iort_smmu_v3 *smmu;
int num_res = 0;
/* Retrieve SMMUv3 specific data */
smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
res[num_res].start = smmu->base_address;
res[num_res].end = smmu->base_address + SZ_128K - 1;
res[num_res].flags = IORESOURCE_MEM;
num_res++;
if (smmu->event_gsiv)
acpi_iort_register_irq(smmu->event_gsiv, "eventq",
ACPI_EDGE_SENSITIVE,
&res[num_res++]);
if (smmu->pri_gsiv)
acpi_iort_register_irq(smmu->pri_gsiv, "priq",
ACPI_EDGE_SENSITIVE,
&res[num_res++]);
if (smmu->gerr_gsiv)
acpi_iort_register_irq(smmu->gerr_gsiv, "gerror",
ACPI_EDGE_SENSITIVE,
&res[num_res++]);
if (smmu->sync_gsiv)
acpi_iort_register_irq(smmu->sync_gsiv, "cmdq-sync",
ACPI_EDGE_SENSITIVE,
&res[num_res++]);
}
在arm_smmu_v3_init_resources 中会对res中的num_res 的start/end/flags 来赋值,这里的flag赋值的是IORESOURCE_MEM
然后调用acpi_iort_register_irq 来准备irq
static void __init acpi_iort_register_irq(int hwirq, const char *name,
int trigger,
struct resource *res)
{
int irq = acpi_register_gsi(NULL, hwirq, trigger,
ACPI_ACTIVE_HIGH);
if (irq <= 0) {
pr_err("could not register gsi hwirq %d name [%s]\n", hwirq,
name);
return;
}
res->start = irq;
res->end = irq;
res->flags = IORESOURCE_IRQ;
res->name = name;
}
这里继续对res赋值,注意这里的flags已经被换成IORESOURCE_IRQ了.
回到iort_add_smmu_platform_device中然后通过platform_device_add_resources 来添加资源
int platform_device_add_resources(struct platform_device *pdev,
const struct resource *res, unsigned int num)
{
struct resource *r = NULL;
if (res) {
r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
if (!r)
return -ENOMEM;
}
kfree(pdev->resource);
pdev->resource = r;
pdev->num_resources = num;
return 0;
}
这样我们在arm_smmu_device_probe 函数中就可以通过platform_get_irq_byname 来得到中断号
irq = platform_get_irq_byname(pdev, "eventq");
int platform_get_irq_byname(struct platform_device *dev, const char *name)
{
struct resource *r;
if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
int ret;
ret = of_irq_get_byname(dev->dev.of_node, name);
if (ret > 0 || ret == -EPROBE_DEFER)
return ret;
}
r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
return r ? r->start : -ENXIO;
}
由于我们用的是acpi因此直接调用platform_get_resource_byname,注意这里的type是IORESOURCE_IRQ
struct resource *platform_get_resource_byname(struct platform_device *dev,
unsigned int type,
const char *name)
{
int i;
for (i = 0; i < dev->num_resources; i++) {
struct resource *r = &dev->resource[i];
if (unlikely(!r->name))
continue;
if (type == resource_type(r) && !strcmp(r->name, name))
return r;
}
return NULL;
}
从platform_get_resource_byname 中可见会遍历dev->resource,然后比较type和name相等的话,就认为已经匹配到了,而dev->resource 就是前面分析的是通过platform_device_add_resources 来添加的.
static int __init iort_add_smmu_platform_device(struct acpi_iort_node *node)
{
struct fwnode_handle *fwnode;
struct platform_device *pdev;
struct resource *r;
enum dev_dma_attr attr;
int ret, count;
const struct iort_iommu_config *ops = iort_get_iommu_cfg(node);
if (!ops)
return -ENODEV;
pdev = platform_device_alloc(ops->name, PLATFORM_DEVID_AUTO);
if (!pdev)
return PTR_ERR(pdev);
count = ops->iommu_count_resources(node);
r = kcalloc(count, sizeof(*r), GFP_KERNEL);
if (!r) {
ret = -ENOMEM;
goto dev_put;
}
ops->iommu_init_resources(r, node);
ret = platform_device_add_resources(pdev, r, count);
/*
* Resources are duplicated in platform_device_add_resources,
* free their allocated memory
*/
kfree(r);
if (ret)
goto dev_put;
/*
* Add a copy of IORT node pointer to platform_data to
* be used to retrieve IORT data information.
*/
ret = platform_device_add_data(pdev, &node, sizeof(node));
if (ret)
goto dev_put;
/*
* We expect the dma masks to be equivalent for
* all SMMUs set-ups
*/
pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
fwnode = iort_get_fwnode(node);
if (!fwnode) {
ret = -ENODEV;
goto dev_put;
}
pdev->dev.fwnode = fwnode;
attr = ops->iommu_is_coherent(node) ?
DEV_DMA_COHERENT : DEV_DMA_NON_COHERENT;
/* Configure DMA for the page table walker */
acpi_dma_configure(&pdev->dev, attr);
ret = platform_device_add(pdev);
if (ret)
goto dma_deconfigure;
return 0;
dma_deconfigure:
acpi_dma_deconfigure(&pdev->dev);
dev_put:
platform_device_put(pdev);
return ret;
}
在iort_add_smmu_platform_device 中首先通过iort_get_iommu_cfg 得到iort_iommu_config *ops
static const struct iort_iommu_config iort_arm_smmu_v3_cfg __initconst = {
.name = "arm-smmu-v3",
.iommu_is_coherent = arm_smmu_v3_is_coherent,
.iommu_count_resources = arm_smmu_v3_count_resources,
.iommu_init_resources = arm_smmu_v3_init_resources
};
static __init
const struct iort_iommu_config *iort_get_iommu_cfg(struct acpi_iort_node *node)
{
switch (node->type) {
case ACPI_IORT_NODE_SMMU_V3:
return &iort_arm_smmu_v3_cfg;
case ACPI_IORT_NODE_SMMU:
return &iort_arm_smmu_cfg;
default:
return NULL;
}
}
根据node->type,决定用smmu还是smmuv3,我们这里以ACPI_IORT_NODE_SMMU_V3为例,所以返回iort_arm_smmu_v3_cfg
然后通过 pdev = platform_device_alloc(ops->name, PLATFORM_DEVID_AUTO);
申请一个platform_device *pdev。
然后调用count = ops->iommu_count_resources(node);来计算resource的数量,由于是smmuv3,因此调用arm_smmu_v3_count_resources
static int __init arm_smmu_v3_count_resources(struct acpi_iort_node *node)
{
struct acpi_iort_smmu_v3 *smmu;
/* Always present mem resource */
int num_res = 1;
/* Retrieve SMMUv3 specific data */
smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
if (smmu->event_gsiv)
num_res++;
if (smmu->pri_gsiv)
num_res++;
if (smmu->gerr_gsiv)
num_res++;
if (smmu->sync_gsiv)
num_res++;
return num_res;
}
从arm_smmu_v3_count_resources 中可以看出资源总共有四种event_gsiv/pri_gsiv/gerr_gsiv/sync_gsiv,这些信息是存在是存在platfrom_data中的,这个可以参考之前的博文.
回到iort_add_smmu_platform_device中继续调用ops->iommu_init_resources(r, node);来初始resource
static void __init arm_smmu_v3_init_resources(struct resource *res,
struct acpi_iort_node *node)
{
struct acpi_iort_smmu_v3 *smmu;
int num_res = 0;
/* Retrieve SMMUv3 specific data */
smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
res[num_res].start = smmu->base_address;
res[num_res].end = smmu->base_address + SZ_128K - 1;
res[num_res].flags = IORESOURCE_MEM;
num_res++;
if (smmu->event_gsiv)
acpi_iort_register_irq(smmu->event_gsiv, "eventq",
ACPI_EDGE_SENSITIVE,
&res[num_res++]);
if (smmu->pri_gsiv)
acpi_iort_register_irq(smmu->pri_gsiv, "priq",
ACPI_EDGE_SENSITIVE,
&res[num_res++]);
if (smmu->gerr_gsiv)
acpi_iort_register_irq(smmu->gerr_gsiv, "gerror",
ACPI_EDGE_SENSITIVE,
&res[num_res++]);
if (smmu->sync_gsiv)
acpi_iort_register_irq(smmu->sync_gsiv, "cmdq-sync",
ACPI_EDGE_SENSITIVE,
&res[num_res++]);
}
在arm_smmu_v3_init_resources 中会对res中的num_res 的start/end/flags 来赋值,这里的flag赋值的是IORESOURCE_MEM
然后调用acpi_iort_register_irq 来准备irq
static void __init acpi_iort_register_irq(int hwirq, const char *name,
int trigger,
struct resource *res)
{
int irq = acpi_register_gsi(NULL, hwirq, trigger,
ACPI_ACTIVE_HIGH);
if (irq <= 0) {
pr_err("could not register gsi hwirq %d name [%s]\n", hwirq,
name);
return;
}
res->start = irq;
res->end = irq;
res->flags = IORESOURCE_IRQ;
res->name = name;
}
这里继续对res赋值,注意这里的flags已经被换成IORESOURCE_IRQ了.
回到iort_add_smmu_platform_device中然后通过platform_device_add_resources 来添加资源
int platform_device_add_resources(struct platform_device *pdev,
const struct resource *res, unsigned int num)
{
struct resource *r = NULL;
if (res) {
r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
if (!r)
return -ENOMEM;
}
kfree(pdev->resource);
pdev->resource = r;
pdev->num_resources = num;
return 0;
}
这样我们在arm_smmu_device_probe 函数中就可以通过platform_get_irq_byname 来得到中断号
irq = platform_get_irq_byname(pdev, "eventq");
int platform_get_irq_byname(struct platform_device *dev, const char *name)
{
struct resource *r;
if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
int ret;
ret = of_irq_get_byname(dev->dev.of_node, name);
if (ret > 0 || ret == -EPROBE_DEFER)
return ret;
}
r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
return r ? r->start : -ENXIO;
}
由于我们用的是acpi因此直接调用platform_get_resource_byname,注意这里的type是IORESOURCE_IRQ
struct resource *platform_get_resource_byname(struct platform_device *dev,
unsigned int type,
const char *name)
{
int i;
for (i = 0; i < dev->num_resources; i++) {
struct resource *r = &dev->resource[i];
if (unlikely(!r->name))
continue;
if (type == resource_type(r) && !strcmp(r->name, name))
return r;
}
return NULL;
}
从platform_get_resource_byname 中可见会遍历dev->resource,然后比较type和name相等的话,就认为已经匹配到了,而dev->resource 就是前面分析的是通过platform_device_add_resources 来添加的.
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