diff mbox series

[3/5] genirq: Provide an IRQ affinity mask in non-SMP configs

Message ID 20220509034333.60017-4-samuel@sholland.org (mailing list archive)
State New, archived
Headers show
Series genirq/irqchip: RISC-V PLIC cleanup and optimization | expand

Commit Message

Samuel Holland May 9, 2022, 3:43 a.m. UTC 
IRQ affinity masks are not allocated in uniprocessor configurations.
This requires special case non-SMP code in drivers for irqchips which
have per-CPU enable or mask registers.

Since IRQ affinity is always the same in a uniprocessor configuration,
we can still provide the correct affinity mask without allocating one
per IRQ. We can reuse the system-wide cpu_possible_mask.

By returning a real cpumask from irq_data_get_affinity_mask even when
SMP is disabled, irqchip drivers which iterate over that mask will
automatically do the right thing.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---

 include/linux/irq.h | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

kernel test robot May 9, 2022, 7:52 a.m. UTC | #1 
Hi Samuel,

I love your patch! Yet something to improve:

[auto build test ERROR on tip/irq/core]
[also build test ERROR on soc/for-next linus/master v5.18-rc6 next-20220506]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/intel-lab-lkp/linux/commits/Samuel-Holland/genirq-irqchip-RISC-V-PLIC-cleanup-and-optimization/20220509-115510
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git ce4818957fdc5bca57fc2c92b0dfe109d26bcc47
config: mips-randconfig-r024-20220509 (https://download.01.org/0day-ci/archive/20220509/202205091545.QhhCDxVm-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project a385645b470e2d3a1534aae618ea56b31177639f)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install mips cross compiling tool for clang build
        # apt-get install binutils-mips-linux-gnu
        # https://github.com/intel-lab-lkp/linux/commit/4bca5b436c97eb2ee232dd23f262ebad05fa183c
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Samuel-Holland/genirq-irqchip-RISC-V-PLIC-cleanup-and-optimization/20220509-115510
        git checkout 4bca5b436c97eb2ee232dd23f262ebad05fa183c
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> kernel/irq/ipi.c:94:30: error: no member named 'affinity' in 'struct irq_common_data'
                   cpumask_copy(data->common->affinity, dest);
                                ~~~~~~~~~~~~  ^
   1 error generated.


vim +94 kernel/irq/ipi.c

d17bf24e695290 Qais Yousef     2015-12-08   13  
d17bf24e695290 Qais Yousef     2015-12-08   14  /**
d17bf24e695290 Qais Yousef     2015-12-08   15   * irq_reserve_ipi() - Setup an IPI to destination cpumask
d17bf24e695290 Qais Yousef     2015-12-08   16   * @domain:	IPI domain
3b35e7e6daef5a Randy Dunlap    2021-08-10   17   * @dest:	cpumask of CPUs which can receive the IPI
d17bf24e695290 Qais Yousef     2015-12-08   18   *
d17bf24e695290 Qais Yousef     2015-12-08   19   * Allocate a virq that can be used to send IPI to any CPU in dest mask.
d17bf24e695290 Qais Yousef     2015-12-08   20   *
3b35e7e6daef5a Randy Dunlap    2021-08-10   21   * Return: Linux IRQ number on success or error code on failure
d17bf24e695290 Qais Yousef     2015-12-08   22   */
7cec18a3906b52 Matt Redfearn   2016-04-25   23  int irq_reserve_ipi(struct irq_domain *domain,
d17bf24e695290 Qais Yousef     2015-12-08   24  			     const struct cpumask *dest)
d17bf24e695290 Qais Yousef     2015-12-08   25  {
d17bf24e695290 Qais Yousef     2015-12-08   26  	unsigned int nr_irqs, offset;
d17bf24e695290 Qais Yousef     2015-12-08   27  	struct irq_data *data;
d17bf24e695290 Qais Yousef     2015-12-08   28  	int virq, i;
d17bf24e695290 Qais Yousef     2015-12-08   29  
d17bf24e695290 Qais Yousef     2015-12-08   30  	if (!domain ||!irq_domain_is_ipi(domain)) {
d17bf24e695290 Qais Yousef     2015-12-08   31  		pr_warn("Reservation on a non IPI domain\n");
7cec18a3906b52 Matt Redfearn   2016-04-25   32  		return -EINVAL;
d17bf24e695290 Qais Yousef     2015-12-08   33  	}
d17bf24e695290 Qais Yousef     2015-12-08   34  
d17bf24e695290 Qais Yousef     2015-12-08   35  	if (!cpumask_subset(dest, cpu_possible_mask)) {
d17bf24e695290 Qais Yousef     2015-12-08   36  		pr_warn("Reservation is not in possible_cpu_mask\n");
7cec18a3906b52 Matt Redfearn   2016-04-25   37  		return -EINVAL;
d17bf24e695290 Qais Yousef     2015-12-08   38  	}
d17bf24e695290 Qais Yousef     2015-12-08   39  
d17bf24e695290 Qais Yousef     2015-12-08   40  	nr_irqs = cpumask_weight(dest);
d17bf24e695290 Qais Yousef     2015-12-08   41  	if (!nr_irqs) {
d17bf24e695290 Qais Yousef     2015-12-08   42  		pr_warn("Reservation for empty destination mask\n");
7cec18a3906b52 Matt Redfearn   2016-04-25   43  		return -EINVAL;
d17bf24e695290 Qais Yousef     2015-12-08   44  	}
d17bf24e695290 Qais Yousef     2015-12-08   45  
d17bf24e695290 Qais Yousef     2015-12-08   46  	if (irq_domain_is_ipi_single(domain)) {
d17bf24e695290 Qais Yousef     2015-12-08   47  		/*
d17bf24e695290 Qais Yousef     2015-12-08   48  		 * If the underlying implementation uses a single HW irq on
d17bf24e695290 Qais Yousef     2015-12-08   49  		 * all cpus then we only need a single Linux irq number for
d17bf24e695290 Qais Yousef     2015-12-08   50  		 * it. We have no restrictions vs. the destination mask. The
d17bf24e695290 Qais Yousef     2015-12-08   51  		 * underlying implementation can deal with holes nicely.
d17bf24e695290 Qais Yousef     2015-12-08   52  		 */
d17bf24e695290 Qais Yousef     2015-12-08   53  		nr_irqs = 1;
d17bf24e695290 Qais Yousef     2015-12-08   54  		offset = 0;
d17bf24e695290 Qais Yousef     2015-12-08   55  	} else {
d17bf24e695290 Qais Yousef     2015-12-08   56  		unsigned int next;
d17bf24e695290 Qais Yousef     2015-12-08   57  
d17bf24e695290 Qais Yousef     2015-12-08   58  		/*
c5f48c0a7aa1a8 Ingo Molnar     2018-12-03   59  		 * The IPI requires a separate HW irq on each CPU. We require
d17bf24e695290 Qais Yousef     2015-12-08   60  		 * that the destination mask is consecutive. If an
d17bf24e695290 Qais Yousef     2015-12-08   61  		 * implementation needs to support holes, it can reserve
d17bf24e695290 Qais Yousef     2015-12-08   62  		 * several IPI ranges.
d17bf24e695290 Qais Yousef     2015-12-08   63  		 */
d17bf24e695290 Qais Yousef     2015-12-08   64  		offset = cpumask_first(dest);
d17bf24e695290 Qais Yousef     2015-12-08   65  		/*
d17bf24e695290 Qais Yousef     2015-12-08   66  		 * Find a hole and if found look for another set bit after the
d17bf24e695290 Qais Yousef     2015-12-08   67  		 * hole. For now we don't support this scenario.
d17bf24e695290 Qais Yousef     2015-12-08   68  		 */
d17bf24e695290 Qais Yousef     2015-12-08   69  		next = cpumask_next_zero(offset, dest);
d17bf24e695290 Qais Yousef     2015-12-08   70  		if (next < nr_cpu_ids)
d17bf24e695290 Qais Yousef     2015-12-08   71  			next = cpumask_next(next, dest);
d17bf24e695290 Qais Yousef     2015-12-08   72  		if (next < nr_cpu_ids) {
d17bf24e695290 Qais Yousef     2015-12-08   73  			pr_warn("Destination mask has holes\n");
7cec18a3906b52 Matt Redfearn   2016-04-25   74  			return -EINVAL;
d17bf24e695290 Qais Yousef     2015-12-08   75  		}
d17bf24e695290 Qais Yousef     2015-12-08   76  	}
d17bf24e695290 Qais Yousef     2015-12-08   77  
06ee6d571f0e35 Thomas Gleixner 2016-07-04   78  	virq = irq_domain_alloc_descs(-1, nr_irqs, 0, NUMA_NO_NODE, NULL);
d17bf24e695290 Qais Yousef     2015-12-08   79  	if (virq <= 0) {
d17bf24e695290 Qais Yousef     2015-12-08   80  		pr_warn("Can't reserve IPI, failed to alloc descs\n");
7cec18a3906b52 Matt Redfearn   2016-04-25   81  		return -ENOMEM;
d17bf24e695290 Qais Yousef     2015-12-08   82  	}
d17bf24e695290 Qais Yousef     2015-12-08   83  
d17bf24e695290 Qais Yousef     2015-12-08   84  	virq = __irq_domain_alloc_irqs(domain, virq, nr_irqs, NUMA_NO_NODE,
eb0dc47ab6810c Vincent Stehle  2016-07-18   85  				       (void *) dest, true, NULL);
d17bf24e695290 Qais Yousef     2015-12-08   86  
d17bf24e695290 Qais Yousef     2015-12-08   87  	if (virq <= 0) {
d17bf24e695290 Qais Yousef     2015-12-08   88  		pr_warn("Can't reserve IPI, failed to alloc hw irqs\n");
d17bf24e695290 Qais Yousef     2015-12-08   89  		goto free_descs;
d17bf24e695290 Qais Yousef     2015-12-08   90  	}
d17bf24e695290 Qais Yousef     2015-12-08   91  
d17bf24e695290 Qais Yousef     2015-12-08   92  	for (i = 0; i < nr_irqs; i++) {
d17bf24e695290 Qais Yousef     2015-12-08   93  		data = irq_get_irq_data(virq + i);
d17bf24e695290 Qais Yousef     2015-12-08  @94  		cpumask_copy(data->common->affinity, dest);
d17bf24e695290 Qais Yousef     2015-12-08   95  		data->common->ipi_offset = offset;
4589f450fb285a Matt Redfearn   2016-04-21   96  		irq_set_status_flags(virq + i, IRQ_NO_BALANCING);
d17bf24e695290 Qais Yousef     2015-12-08   97  	}
d17bf24e695290 Qais Yousef     2015-12-08   98  	return virq;
d17bf24e695290 Qais Yousef     2015-12-08   99  
d17bf24e695290 Qais Yousef     2015-12-08  100  free_descs:
d17bf24e695290 Qais Yousef     2015-12-08  101  	irq_free_descs(virq, nr_irqs);
7cec18a3906b52 Matt Redfearn   2016-04-25  102  	return -EBUSY;
d17bf24e695290 Qais Yousef     2015-12-08  103  }
d17bf24e695290 Qais Yousef     2015-12-08  104
Samuel Holland May 10, 2022, 4:20 a.m. UTC | #2 
On 5/9/22 2:52 AM, kernel test robot wrote:
> Hi Samuel,
> 
> I love your patch! Yet something to improve:
> 
> [auto build test ERROR on tip/irq/core]
> [also build test ERROR on soc/for-next linus/master v5.18-rc6 next-20220506]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Samuel-Holland/genirq-irqchip-RISC-V-PLIC-cleanup-and-optimization/20220509-115510
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git ce4818957fdc5bca57fc2c92b0dfe109d26bcc47
> config: mips-randconfig-r024-20220509 (https://download.01.org/0day-ci/archive/20220509/202205091545.QhhCDxVm-lkp@intel.com/config)
> compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project a385645b470e2d3a1534aae618ea56b31177639f)
> reproduce (this is a W=1 build):
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # install mips cross compiling tool for clang build
>         # apt-get install binutils-mips-linux-gnu
>         # https://github.com/intel-lab-lkp/linux/commit/4bca5b436c97eb2ee232dd23f262ebad05fa183c
>         git remote add linux-review https://github.com/intel-lab-lkp/linux
>         git fetch --no-tags linux-review Samuel-Holland/genirq-irqchip-RISC-V-PLIC-cleanup-and-optimization/20220509-115510
>         git checkout 4bca5b436c97eb2ee232dd23f262ebad05fa183c
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All errors (new ones prefixed by >>):
> 
>>> kernel/irq/ipi.c:94:30: error: no member named 'affinity' in 'struct irq_common_data'
>                    cpumask_copy(data->common->affinity, dest);
>                                 ~~~~~~~~~~~~  ^
>    1 error generated.

I think the fix here is to make GENERIC_IRQ_IPI also depend on SMP. I will add a
patch doing this for v2.

Regards,
Samuel
diff mbox series

Patch

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 48ac33ca3703..d716e882c020 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -151,7 +151,9 @@  struct irq_common_data {
 #endif
 	void			*handler_data;
 	struct msi_desc		*msi_desc;
+#ifdef CONFIG_SMP
 	cpumask_var_t		affinity;
+#endif
 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
 	cpumask_var_t		effective_affinity;
 #endif
@@ -879,7 +881,11 @@  static inline int irq_data_get_node(struct irq_data *d)
 
 static inline struct cpumask *irq_data_get_affinity_mask(struct irq_data *d)
 {
+#ifdef CONFIG_SMP
 	return d->common->affinity;
+#else
+	return &__cpu_possible_mask;
+#endif
 }
 
 static inline struct cpumask *irq_get_affinity_mask(int irq)