Re: [PATCH v3] irqchip: gic-v3: Extend collection table

[wangwudi]

Hi Marc,

A gentle ping.

Thanks,
Wudi

在 2023/7/14 17:57, wangwudi 写道:
> 
> 
> -----邮件原件-----
> 发件人: wangwudi 
> 发送时间: 2023年6月21日 18:02
> 收件人: linux-kernel@xxxxxxxxxxxxxxx
> 抄送: liaochang (A) <liaochang1@xxxxxxxxxx>; wangwudi <wangwudi@xxxxxxxxxxxxx>; Thomas Gleixner <tglx@xxxxxxxxxxxxx>; Marc Zyngier <maz@xxxxxxxxxx>
> 主题: [PATCH v3] irqchip: gic-v3: Extend collection table
> 
> Only single level table is supported to the collection table, and only one page is allocated.
> 
> Extend collection table to support more CPUs:
> 1. Recalculate the page number of collection table based on the number of CPUs.
> 2. Add 2 level tables to collection table when HCC field is zero.
> 3. Add GITS_TYPER_CIDBITS macros.
> 
> It is noticed in an internal simulation research:
> - the page_size of collection table is 4 KB
> - the entry_size of collection table is 16 Byte
> - with 512 CPUs
> 
> And I don't find a have a GIC500 platform to test this path. 
> 
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Marc Zyngier <maz@xxxxxxxxxx>
> Signed-off-by: wangwudi <wangwudi@xxxxxxxxxxxxx>
> ---
> 
> ChangeLog:
> v1-->v2:
> 1. Support 2 level table.
> 2. Rewrite the commit log.
> v2-->v3
> 1. Fixed the error when HCC is field is not zero.
> 2. Modifiy the commit log.
> 
>  drivers/irqchip/irq-gic-v3-its.c   | 67 +++++++++++++++++++++++++++++++-------
>  include/linux/irqchip/arm-gic-v3.h |  3 ++
>  2 files changed, 58 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 0ec2b1e1df75..c37e010fd50c 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -126,6 +126,7 @@ struct its_node {
>  #define is_v4(its)		(!!((its)->typer & GITS_TYPER_VLPIS))
>  #define is_v4_1(its)		(!!((its)->typer & GITS_TYPER_VMAPP))
>  #define device_ids(its)		(FIELD_GET(GITS_TYPER_DEVBITS, (its)->typer) + 1)
> +#define collection_ids(its)	(FIELD_GET(GITS_TYPER_CIDBITS, (its)->typer) + 1)
>  
>  #define ITS_ITT_ALIGN		SZ_256
>  
> @@ -2626,6 +2627,10 @@ static int its_alloc_tables(struct its_node *its)
>  			indirect = its_parse_indirect_baser(its, baser, &order,
>  							    ITS_MAX_VPEID_BITS);
>  			break;
> +		case GITS_BASER_TYPE_COLLECTION:
> +			indirect = its_parse_indirect_baser(its, baser, &order,
> +							    order_base_2(num_possible_cpus()));
> +			break;
>  		}
>  
>  		err = its_setup_baser(its, baser, cache, shr, order, indirect); @@ -3230,18 +3235,6 @@ static void its_cpu_init_collection(struct its_node *its)
>  	its_send_invall(its, &its->collections[cpu]);  }
>  
> -static void its_cpu_init_collections(void) -{
> -	struct its_node *its;
> -
> -	raw_spin_lock(&its_lock);
> -
> -	list_for_each_entry(its, &its_nodes, entry)
> -		its_cpu_init_collection(its);
> -
> -	raw_spin_unlock(&its_lock);
> -}
> -
>  static struct its_device *its_find_device(struct its_node *its, u32 dev_id)  {
>  	struct its_device *its_dev = NULL, *tmp; @@ -3316,6 +3309,56 @@ static bool its_alloc_table_entry(struct its_node *its,
>  	return true;
>  }
>  
> +static bool its_alloc_collection_table(struct its_node *its, struct 
> +its_baser *baser) {
> +	int cpu = smp_processor_id();
> +	int cpu_ids = 16;
> +
> +	if (its->typer & GITS_TYPER_CIL)
> +		cpu_ids = collection_ids(its);
> +
> +	if (!(ilog2(cpu) < cpu_ids)) {
> +		pr_warn("ITS: CPU%d out of Collection ID range for %dbits", cpu, cpu_ids);
> +		return false;
> +	}
> +
> +	if (!its_alloc_table_entry(its, baser, cpu)) {
> +		pr_warn("ITS: CPU%d failed to allocate collection l2 table", cpu);
> +		return false;
> +	}
> +
> +	return true;
> +}
> +
> +static bool its_cpu_init_collections(void) {
> +	struct its_node *its;
> +	struct its_baser *baser;
> +	void __iomem *base;
> +
> +	raw_spin_lock(&its_lock);
> +
> +	list_for_each_entry(its, &its_nodes, entry) {
> +		base = its->base;
> +		if (!GITS_TYPER_HCC(gic_read_typer(base + GITS_TYPER))) {
> +			baser = its_get_baser(its, GITS_BASER_TYPE_COLLECTION);
> +			if (!baser) {
> +				raw_spin_unlock(&its_lock);
> +				return false;
> +			}
> +
> +			if (!its_alloc_collection_table(its, baser)) {
> +				raw_spin_unlock(&its_lock);
> +				return false;
> +			}
> +		}
> +
> +		its_cpu_init_collection(its);
> +	}
> +	raw_spin_unlock(&its_lock);
> +	return true;
> +}
> +
>  static bool its_alloc_device_table(struct its_node *its, u32 dev_id)  {
>  	struct its_baser *baser;
> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
> index 728691365464..35e83da8961f 100644
> --- a/include/linux/irqchip/arm-gic-v3.h
> +++ b/include/linux/irqchip/arm-gic-v3.h
> @@ -400,6 +400,9 @@
>  #define GITS_TYPER_PTA			(1UL << 19)
>  #define GITS_TYPER_HCC_SHIFT		24
>  #define GITS_TYPER_HCC(r)		(((r) >> GITS_TYPER_HCC_SHIFT) & 0xff)
> +#define GITS_TYPER_CIDBITS_SHIFT	32
> +#define GITS_TYPER_CIDBITS		GENMASK_ULL(35, 32)
> +#define GITS_TYPER_CIL			(1ULL << 36)
>  #define GITS_TYPER_VMOVP		(1ULL << 37)
>  #define GITS_TYPER_VMAPP		(1ULL << 40)
>  #define GITS_TYPER_SVPET		GENMASK_ULL(42, 41)
> --
> 2.7.4
>