Re: [PATCH V13 07/13] irqchip/loongson-pch-msi: Add ACPI init support

[Jianmin Lv <lvjianmin@loongson.cn>]

On 2022/6/29 下午9:15, Marc Zyngier wrote:
> On Mon, 27 Jun 2022 12:39:51 +0100,
> Jianmin Lv <lvjianmin@loongson.cn> wrote:
>>
>> From: Huacai Chen <chenhuacai@loongson.cn>
>>
>> We are preparing to add new Loongson (based on LoongArch, not compatible
>> with old MIPS-based Loongson) support. LoongArch use ACPI other than DT
>> as its boot protocol, so add ACPI init support.
> 
> Same rant about the content-less paragraph, which I asked you to drop
> a few version ago.
> 

Ok, I only dropped it for the patch that you reviewed in previous 
version, without handling other similar patches. I'll drop it for all 
similar patch in next version.


>>
>> PCH-PIC/PCH-MSI stands for "Interrupt Controller" that described in
>> Section 5 of "Loongson 7A1000 Bridge User Manual". For more information
>> please refer Documentation/loongarch/irq-chip-model.rst.
>>
>> For systems with two chipsets, there are two related msi irqdomains,
>> each of which has the same node id as its parent irqdomain. So we
>> use a structure to mantain the relation of node and it's parent
>> irqdomain as pch irqdomin, and add a pci_segment field to it for
>> matching the pci segment of a pci device when setting msi irqdomain
>> for the device.
>>
>> struct acpi_vector_group {
>>          int node;
>>          int pci_segment;
>>          struct irq_domain *parent;
>> };
>>
>> The field 'pci_segment' and 'node' are initialized from MCFG, and
>> the parent irqdomain will set field 'parent' by matching same
>> 'node'.
>>
>> Co-developed-by: Jianmin Lv <lvjianmin@loongson.cn>
>> Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
>> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
>> ---
>>   arch/loongarch/include/asm/irq.h       |   7 +-
>>   arch/loongarch/kernel/irq.c            |  30 ++++++-
>>   drivers/irqchip/irq-loongson-pch-msi.c | 147 +++++++++++++++++++++++----------
>>   3 files changed, 138 insertions(+), 46 deletions(-)
>>
>> diff --git a/arch/loongarch/include/asm/irq.h b/arch/loongarch/include/asm/irq.h
>> index a444dc6..367aa44 100644
>> --- a/arch/loongarch/include/asm/irq.h
>> +++ b/arch/loongarch/include/asm/irq.h
>> @@ -50,9 +50,11 @@ static inline bool on_irq_stack(int cpu, unsigned long sp)
>>   
>>   struct acpi_vector_group {
>>   	int node;
>> +	int pci_segment;
>>   	struct irq_domain *parent;
>>   };
>>   extern struct acpi_vector_group pch_group[MAX_IO_PICS];
>> +extern struct acpi_vector_group msi_group[MAX_IO_PICS];
>>   
>>   #define CORES_PER_EIO_NODE	4
>>   
>> @@ -112,9 +114,8 @@ struct irq_domain *htvec_acpi_init(struct irq_domain *parent,
>>   					struct acpi_madt_ht_pic *acpi_htvec);
>>   int pch_lpc_acpi_init(struct irq_domain *parent,
>>   					struct acpi_madt_lpc_pic *acpi_pchlpc);
>> -struct irq_domain *pch_msi_acpi_init(struct irq_domain *parent,
>> -					struct acpi_madt_msi_pic *acpi_pchmsi);
>>   int find_pch_pic(u32 gsi);
>> +struct fwnode_handle *get_pch_msi_handle(int pci_segment);
>>   
>>   extern struct acpi_madt_lio_pic *acpi_liointc;
>>   extern struct acpi_madt_eio_pic *acpi_eiointc[MAX_IO_PICS];
>> @@ -127,7 +128,7 @@ struct irq_domain *pch_msi_acpi_init(struct irq_domain *parent,
>>   extern struct irq_domain *cpu_domain;
>>   extern struct irq_domain *liointc_domain;
>>   extern struct fwnode_handle *pch_lpc_handle;
>> -extern struct irq_domain *pch_msi_domain[MAX_IO_PICS];
>> +extern struct fwnode_handle *pch_msi_handle[MAX_IO_PICS];
>>   extern struct fwnode_handle *pch_pic_handle[MAX_IO_PICS];
>>   
>>   extern irqreturn_t loongson3_ipi_interrupt(int irq, void *dev);
>> diff --git a/arch/loongarch/kernel/irq.c b/arch/loongarch/kernel/irq.c
>> index f2115be..82bc6c7 100644
>> --- a/arch/loongarch/kernel/irq.c
>> +++ b/arch/loongarch/kernel/irq.c
>> @@ -27,8 +27,8 @@
>>   
>>   struct irq_domain *cpu_domain;
>>   struct irq_domain *liointc_domain;
>> -struct irq_domain *pch_msi_domain[MAX_IO_PICS];
>>   struct acpi_vector_group pch_group[MAX_IO_PICS];
>> +struct acpi_vector_group msi_group[MAX_IO_PICS];
>>   
>>   /*
>>    * 'what should we do if we get a hw irq event on an illegal vector'.
>> @@ -55,6 +55,33 @@ int arch_show_interrupts(struct seq_file *p, int prec)
>>   	return 0;
>>   }
>>   
>> +static int early_pci_mcfg_parse(struct acpi_table_header *header)
> 
> Shouldn't this be __init as well?
> 

Yes, thanks, it should be __init too.


>> +{
>> +	struct acpi_table_mcfg *mcfg;
>> +	struct acpi_mcfg_allocation *mptr;
>> +	int i, n;
>> +
>> +	if (header->length < sizeof(struct acpi_table_mcfg))
>> +		return -EINVAL;
>> +
>> +	n = (header->length - sizeof(struct acpi_table_mcfg)) /
>> +					sizeof(struct acpi_mcfg_allocation);
>> +	mcfg = (struct acpi_table_mcfg *)header;
>> +	mptr = (struct acpi_mcfg_allocation *) &mcfg[1];
>> +
>> +	for (i = 0; i < n; i++, mptr++) {
>> +		msi_group[i].pci_segment = mptr->pci_segment;
>> +		msi_group[i].node = (mptr->address >> 44) & 0xf;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +void __init init_msi_parent_group(void)
>> +{
>> +	acpi_table_parse(ACPI_SIG_MCFG, early_pci_mcfg_parse);
>> +}
>> +
>>   void __init init_IRQ(void)
>>   {
>>   	int i;
>> @@ -68,6 +95,7 @@ void __init init_IRQ(void)
>>   	clear_csr_ecfg(ECFG0_IM);
>>   	clear_csr_estat(ESTATF_IP);
>>   
>> +	init_msi_parent_group();
> 
> The changes in this file should be a separate patch, as it is
> completely independent.
> 

Ok, I'll put it in a separate patch.


>>   	irqchip_init();
>>   #ifdef CONFIG_SMP
>>   	ipi_irq = EXCCODE_IPI - EXCCODE_INT_START;
>> diff --git a/drivers/irqchip/irq-loongson-pch-msi.c b/drivers/irqchip/irq-loongson-pch-msi.c
>> index e3801c4..5db4a68 100644
>> --- a/drivers/irqchip/irq-loongson-pch-msi.c
>> +++ b/drivers/irqchip/irq-loongson-pch-msi.c
>> @@ -15,14 +15,30 @@
>>   #include <linux/pci.h>
>>   #include <linux/slab.h>
>>   
>> +static int nr_pics;
>> +
>>   struct pch_msi_data {
>>   	struct mutex	msi_map_lock;
>>   	phys_addr_t	doorbell;
>>   	u32		irq_first;	/* The vector number that MSIs starts */
>>   	u32		num_irqs;	/* The number of vectors for MSIs */
>>   	unsigned long	*msi_map;
>> +	struct fwnode_handle *domain_handle;
>>   };
>>   
>> +static struct pch_msi_data *pch_msi_priv[2];
> 
> What is this '2'?
> 

Yes, I should use MAX_IO_PICS, thanks.


>> +
>> +struct fwnode_handle *get_pch_msi_handle(int pci_segment)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < MAX_IO_PICS; i++) {
>> +		if (msi_group[i].pci_segment == pci_segment)
> 
> AFAICT, this driver is supposed to compile on MIPS too. Clearly, you
> haven't bothered checking that it was still building:
> 
> drivers/irqchip/irq-loongson-pch-msi.c: In function ‘get_pch_msi_handle’:
> drivers/irqchip/irq-loongson-pch-msi.c:35:18: error: ‘MAX_IO_PICS’ undeclared (first use in this function)
>     35 |  for (i = 0; i < MAX_IO_PICS; i++) {
>        |                  ^~~~~~~~~~~
> drivers/irqchip/irq-loongson-pch-msi.c:35:18: note: each undeclared identifier is reported only once for each function it appears in
> drivers/irqchip/irq-loongson-pch-msi.c:36:7: error: ‘msi_group’ undeclared (first use in this function); did you mean ‘task_group’?
>     36 |   if (msi_group[i].pci_segment == pci_segment)
>        |       ^~~~~~~~~
>        |       task_group
> 
> I've stopped here.


So sorry for that, I got it, I'll fix them and test on both of LoongArch 
and MIPS machine.

> 
> 	M.
>