Although there is a runtime WARN_ON() when NR_IPR > max SGI, it had better
do the check during built time, and associate these related code together.
Signed-off-by: Pingfan Liu <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Jason Cooper <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Mark Rutland <[email protected]>
To: [email protected]
Cc: [email protected]
---
arch/arm64/kernel/smp.c | 2 ++
drivers/irqchip/irq-gic-v3.c | 2 +-
drivers/irqchip/irq-gic.c | 2 +-
include/linux/irqchip/arm-gic-common.h | 2 ++
4 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 18e9727..9fc383c 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -33,6 +33,7 @@
#include <linux/kernel_stat.h>
#include <linux/kexec.h>
#include <linux/kvm_host.h>
+#include <linux/irqchip/arm-gic-common.h>
#include <asm/alternative.h>
#include <asm/atomic.h>
@@ -76,6 +77,7 @@ enum ipi_msg_type {
IPI_WAKEUP,
NR_IPI
};
+static_assert(NR_IPI <= MAX_SGI_NUM);
static int ipi_irq_base __read_mostly;
static int nr_ipi __read_mostly = NR_IPI;
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 16fecc0..ee13f85 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -1162,7 +1162,7 @@ static void __init gic_smp_init(void)
gic_starting_cpu, NULL);
/* Register all 8 non-secure SGIs */
- base_sgi = __irq_domain_alloc_irqs(gic_data.domain, -1, 8,
+ base_sgi = __irq_domain_alloc_irqs(gic_data.domain, -1, MAX_SGI_NUM,
NUMA_NO_NODE, &sgi_fwspec,
false, NULL);
if (WARN_ON(base_sgi <= 0))
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 6053245..07d36de 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -845,7 +845,7 @@ static __init void gic_smp_init(void)
"irqchip/arm/gic:starting",
gic_starting_cpu, NULL);
- base_sgi = __irq_domain_alloc_irqs(gic_data[0].domain, -1, 8,
+ base_sgi = __irq_domain_alloc_irqs(gic_data[0].domain, -1, MAX_SGI_NUM,
NUMA_NO_NODE, &sgi_fwspec,
false, NULL);
if (WARN_ON(base_sgi <= 0))
diff --git a/include/linux/irqchip/arm-gic-common.h b/include/linux/irqchip/arm-gic-common.h
index fa8c045..7e45a9f 100644
--- a/include/linux/irqchip/arm-gic-common.h
+++ b/include/linux/irqchip/arm-gic-common.h
@@ -16,6 +16,8 @@
(GICD_INT_DEF_PRI << 8) |\
GICD_INT_DEF_PRI)
+#define MAX_SGI_NUM 8
+
enum gic_type {
GIC_V2,
GIC_V3,
--
2.7.5
On 2020-12-08 09:21, Pingfan Liu wrote:
> Although there is a runtime WARN_ON() when NR_IPR > max SGI, it had
> better
> do the check during built time, and associate these related code
> together.
>
> Signed-off-by: Pingfan Liu <[email protected]>
> Cc: Catalin Marinas <[email protected]>
> Cc: Will Deacon <[email protected]>
> Cc: Thomas Gleixner <[email protected]>
> Cc: Jason Cooper <[email protected]>
> Cc: Marc Zyngier <[email protected]>
> Cc: Mark Rutland <[email protected]>
> To: [email protected]
> Cc: [email protected]
> ---
> arch/arm64/kernel/smp.c | 2 ++
> drivers/irqchip/irq-gic-v3.c | 2 +-
> drivers/irqchip/irq-gic.c | 2 +-
> include/linux/irqchip/arm-gic-common.h | 2 ++
> 4 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> index 18e9727..9fc383c 100644
> --- a/arch/arm64/kernel/smp.c
> +++ b/arch/arm64/kernel/smp.c
> @@ -33,6 +33,7 @@
> #include <linux/kernel_stat.h>
> #include <linux/kexec.h>
> #include <linux/kvm_host.h>
> +#include <linux/irqchip/arm-gic-common.h>
>
> #include <asm/alternative.h>
> #include <asm/atomic.h>
> @@ -76,6 +77,7 @@ enum ipi_msg_type {
> IPI_WAKEUP,
> NR_IPI
> };
> +static_assert(NR_IPI <= MAX_SGI_NUM);
I am trying *very hard* to remove dependencies between the architecture
code and random drivers, so this kind of check really is
counter-productive.
Driver code should not have to know the number of IPIs, because there is
no requirement that all IPIs should map 1:1 to SGIs. Conflating the two
is already wrong, and I really don't want to add more of that.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
On Tue, Dec 8, 2020 at 5:31 PM Marc Zyngier <[email protected]> wrote:
>
> On 2020-12-08 09:21, Pingfan Liu wrote:
> > Although there is a runtime WARN_ON() when NR_IPR > max SGI, it had
> > better
> > do the check during built time, and associate these related code
> > together.
> >
> > Signed-off-by: Pingfan Liu <[email protected]>
> > Cc: Catalin Marinas <[email protected]>
> > Cc: Will Deacon <[email protected]>
> > Cc: Thomas Gleixner <[email protected]>
> > Cc: Jason Cooper <[email protected]>
> > Cc: Marc Zyngier <[email protected]>
> > Cc: Mark Rutland <[email protected]>
> > To: [email protected]
> > Cc: [email protected]
> > ---
> > arch/arm64/kernel/smp.c | 2 ++
> > drivers/irqchip/irq-gic-v3.c | 2 +-
> > drivers/irqchip/irq-gic.c | 2 +-
> > include/linux/irqchip/arm-gic-common.h | 2 ++
> > 4 files changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> > index 18e9727..9fc383c 100644
> > --- a/arch/arm64/kernel/smp.c
> > +++ b/arch/arm64/kernel/smp.c
> > @@ -33,6 +33,7 @@
> > #include <linux/kernel_stat.h>
> > #include <linux/kexec.h>
> > #include <linux/kvm_host.h>
> > +#include <linux/irqchip/arm-gic-common.h>
> >
> > #include <asm/alternative.h>
> > #include <asm/atomic.h>
> > @@ -76,6 +77,7 @@ enum ipi_msg_type {
> > IPI_WAKEUP,
> > NR_IPI
> > };
> > +static_assert(NR_IPI <= MAX_SGI_NUM);
>
> I am trying *very hard* to remove dependencies between the architecture
> code and random drivers, so this kind of check really is
> counter-productive.
>
> Driver code should not have to know the number of IPIs, because there is
> no requirement that all IPIs should map 1:1 to SGIs. Conflating the two
Just curious about this. Is there an IPI which is not implemented by
SGI? Or mapping several IPIs to a single SGI, and scatter out due to a
global variable value?
Thanks,
Pingfan
> is already wrong, and I really don't want to add more of that.
>
> Thanks,
>
> M.
> --
> Jazz is not dead. It just smells funny...
On Tue, Dec 8, 2020 at 5:51 PM Marc Zyngier <[email protected]> wrote:
>
> On 2020-12-08 09:43, Pingfan Liu wrote:
> > On Tue, Dec 8, 2020 at 5:31 PM Marc Zyngier <[email protected]> wrote:
> >>
> >> On 2020-12-08 09:21, Pingfan Liu wrote:
> >> > Although there is a runtime WARN_ON() when NR_IPR > max SGI, it had
> >> > better
> >> > do the check during built time, and associate these related code
> >> > together.
> >> >
> >> > Signed-off-by: Pingfan Liu <[email protected]>
> >> > Cc: Catalin Marinas <[email protected]>
> >> > Cc: Will Deacon <[email protected]>
> >> > Cc: Thomas Gleixner <[email protected]>
> >> > Cc: Jason Cooper <[email protected]>
> >> > Cc: Marc Zyngier <[email protected]>
> >> > Cc: Mark Rutland <[email protected]>
> >> > To: [email protected]
> >> > Cc: [email protected]
> >> > ---
> >> > arch/arm64/kernel/smp.c | 2 ++
> >> > drivers/irqchip/irq-gic-v3.c | 2 +-
> >> > drivers/irqchip/irq-gic.c | 2 +-
> >> > include/linux/irqchip/arm-gic-common.h | 2 ++
> >> > 4 files changed, 6 insertions(+), 2 deletions(-)
> >> >
> >> > diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> >> > index 18e9727..9fc383c 100644
> >> > --- a/arch/arm64/kernel/smp.c
> >> > +++ b/arch/arm64/kernel/smp.c
> >> > @@ -33,6 +33,7 @@
> >> > #include <linux/kernel_stat.h>
> >> > #include <linux/kexec.h>
> >> > #include <linux/kvm_host.h>
> >> > +#include <linux/irqchip/arm-gic-common.h>
> >> >
> >> > #include <asm/alternative.h>
> >> > #include <asm/atomic.h>
> >> > @@ -76,6 +77,7 @@ enum ipi_msg_type {
> >> > IPI_WAKEUP,
> >> > NR_IPI
> >> > };
> >> > +static_assert(NR_IPI <= MAX_SGI_NUM);
> >>
> >> I am trying *very hard* to remove dependencies between the
> >> architecture
> >> code and random drivers, so this kind of check really is
> >> counter-productive.
> >>
> >> Driver code should not have to know the number of IPIs, because there
> >> is
> >> no requirement that all IPIs should map 1:1 to SGIs. Conflating the
> >> two
> >
> > Just curious about this. Is there an IPI which is not implemented by
> > SGI? Or mapping several IPIs to a single SGI, and scatter out due to a
> > global variable value?
>
> We currently have a single NS SGI left, and I'd like to move some of the
> non-critical IPIs over to dispatching mechanism (the two "CPU stop" IPIs
> definitely are candidate for merging). That's not implemented yet, but
> I don't see a need to add checks that would otherwise violate this
> IPI/SGI distinction.
Got it. Thanks for your detailed explanation.
Regards,
Pingfan
On 2020-12-08 09:43, Pingfan Liu wrote:
> On Tue, Dec 8, 2020 at 5:31 PM Marc Zyngier <[email protected]> wrote:
>>
>> On 2020-12-08 09:21, Pingfan Liu wrote:
>> > Although there is a runtime WARN_ON() when NR_IPR > max SGI, it had
>> > better
>> > do the check during built time, and associate these related code
>> > together.
>> >
>> > Signed-off-by: Pingfan Liu <[email protected]>
>> > Cc: Catalin Marinas <[email protected]>
>> > Cc: Will Deacon <[email protected]>
>> > Cc: Thomas Gleixner <[email protected]>
>> > Cc: Jason Cooper <[email protected]>
>> > Cc: Marc Zyngier <[email protected]>
>> > Cc: Mark Rutland <[email protected]>
>> > To: [email protected]
>> > Cc: [email protected]
>> > ---
>> > arch/arm64/kernel/smp.c | 2 ++
>> > drivers/irqchip/irq-gic-v3.c | 2 +-
>> > drivers/irqchip/irq-gic.c | 2 +-
>> > include/linux/irqchip/arm-gic-common.h | 2 ++
>> > 4 files changed, 6 insertions(+), 2 deletions(-)
>> >
>> > diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
>> > index 18e9727..9fc383c 100644
>> > --- a/arch/arm64/kernel/smp.c
>> > +++ b/arch/arm64/kernel/smp.c
>> > @@ -33,6 +33,7 @@
>> > #include <linux/kernel_stat.h>
>> > #include <linux/kexec.h>
>> > #include <linux/kvm_host.h>
>> > +#include <linux/irqchip/arm-gic-common.h>
>> >
>> > #include <asm/alternative.h>
>> > #include <asm/atomic.h>
>> > @@ -76,6 +77,7 @@ enum ipi_msg_type {
>> > IPI_WAKEUP,
>> > NR_IPI
>> > };
>> > +static_assert(NR_IPI <= MAX_SGI_NUM);
>>
>> I am trying *very hard* to remove dependencies between the
>> architecture
>> code and random drivers, so this kind of check really is
>> counter-productive.
>>
>> Driver code should not have to know the number of IPIs, because there
>> is
>> no requirement that all IPIs should map 1:1 to SGIs. Conflating the
>> two
>
> Just curious about this. Is there an IPI which is not implemented by
> SGI? Or mapping several IPIs to a single SGI, and scatter out due to a
> global variable value?
We currently have a single NS SGI left, and I'd like to move some of the
non-critical IPIs over to dispatching mechanism (the two "CPU stop" IPIs
definitely are candidate for merging). That's not implemented yet, but
I don't see a need to add checks that would otherwise violate this
IPI/SGI distinction.
Thanks,
M.
--
Jazz is not dead. It just smells funny...