Commit 16e3613a authored by Marc Zyngier's avatar Marc Zyngier
Browse files

Merge branch irq/its-kexec-rt into irq/irqchip-next 



* irq/its-kexec-rt:
  : .
  : Series from Valentin Schneider, aiming at fixing the issues
  : the ITS driver has with PREEMPT_RT whilst trying to reserve
  : memory at early boot to support kexec.
  : .
  irqchip/gic-v3-its: Limit memreserve cpuhp state lifetime
  irqchip/gic-v3-its: Postpone LPI pending table freeing and memreserve
  irqchip/gic-v3-its: Give the percpu rdist struct its own flags field

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parents 0fcfb00b 835f442f

drivers/irqchip/irq-gic-v3-its.c

+75 −7
Original line number Diff line number Diff line
@@ -46,6 +46,10 @@ 
#define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING	(1 << 0)

#define RDIST_FLAGS_RD_TABLES_PREALLOCATED	(1 << 1)



#define RD_LOCAL_LPI_ENABLED                    BIT(0)

#define RD_LOCAL_PENDTABLE_PREALLOCATED         BIT(1)

#define RD_LOCAL_MEMRESERVE_DONE                BIT(2)



static u32 lpi_id_bits;



/*
@@ -3044,7 +3048,7 @@ static void its_cpu_init_lpis(void) 
	phys_addr_t paddr;

	u64 val, tmp;



	if (gic_data_rdist()->lpi_enabled)

	if (gic_data_rdist()->flags & RD_LOCAL_LPI_ENABLED)

		return;



	val = readl_relaxed(rbase + GICR_CTLR);
@@ -3063,15 +3067,13 @@ static void its_cpu_init_lpis(void) 
		paddr &= GENMASK_ULL(51, 16);



		WARN_ON(!gic_check_reserved_range(paddr, LPI_PENDBASE_SZ));

		its_free_pending_table(gic_data_rdist()->pend_page);

		gic_data_rdist()->pend_page = NULL;

		gic_data_rdist()->flags |= RD_LOCAL_PENDTABLE_PREALLOCATED;



		goto out;

	}



	pend_page = gic_data_rdist()->pend_page;

	paddr = page_to_phys(pend_page);

	WARN_ON(gic_reserve_range(paddr, LPI_PENDBASE_SZ));



	/* set PROPBASE */

	val = (gic_rdists->prop_table_pa |
@@ -3158,10 +3160,11 @@ static void its_cpu_init_lpis(void) 
	/* Make sure the GIC has seen the above */

	dsb(sy);

out:

	gic_data_rdist()->lpi_enabled = true;

	gic_data_rdist()->flags |= RD_LOCAL_LPI_ENABLED;

	pr_info("GICv3: CPU%d: using %s LPI pending table @%pa\n",

		smp_processor_id(),

		gic_data_rdist()->pend_page ? "allocated" : "reserved",

		gic_data_rdist()->flags & RD_LOCAL_PENDTABLE_PREALLOCATED ?

		"reserved" : "allocated",

		&paddr);

}
@@ -5138,7 +5141,7 @@ static int redist_disable_lpis(void) 
	 *

	 * If running with preallocated tables, there is nothing to do.

	 */

	if (gic_data_rdist()->lpi_enabled ||

	if ((gic_data_rdist()->flags & RD_LOCAL_LPI_ENABLED) ||

	    (gic_rdists->flags & RDIST_FLAGS_RD_TABLES_PREALLOCATED))

		return 0;
@@ -5200,6 +5203,51 @@ int its_cpu_init(void) 
	return 0;

}



static void rdist_memreserve_cpuhp_cleanup_workfn(struct work_struct *work)

{

	cpuhp_remove_state_nocalls(gic_rdists->cpuhp_memreserve_state);

	gic_rdists->cpuhp_memreserve_state = CPUHP_INVALID;

}



static DECLARE_WORK(rdist_memreserve_cpuhp_cleanup_work,

		    rdist_memreserve_cpuhp_cleanup_workfn);



static int its_cpu_memreserve_lpi(unsigned int cpu)

{

	struct page *pend_page;

	int ret = 0;



	/* This gets to run exactly once per CPU */

	if (gic_data_rdist()->flags & RD_LOCAL_MEMRESERVE_DONE)

		return 0;



	pend_page = gic_data_rdist()->pend_page;

	if (WARN_ON(!pend_page)) {

		ret = -ENOMEM;

		goto out;

	}

	/*

	 * If the pending table was pre-programmed, free the memory we

	 * preemptively allocated. Otherwise, reserve that memory for

	 * later kexecs.

	 */

	if (gic_data_rdist()->flags & RD_LOCAL_PENDTABLE_PREALLOCATED) {

		its_free_pending_table(pend_page);

		gic_data_rdist()->pend_page = NULL;

	} else {

		phys_addr_t paddr = page_to_phys(pend_page);

		WARN_ON(gic_reserve_range(paddr, LPI_PENDBASE_SZ));

	}



out:

	/* Last CPU being brought up gets to issue the cleanup */

	if (cpumask_equal(&cpus_booted_once_mask, cpu_possible_mask))

		schedule_work(&rdist_memreserve_cpuhp_cleanup_work);



	gic_data_rdist()->flags |= RD_LOCAL_MEMRESERVE_DONE;

	return ret;

}



static const struct of_device_id its_device_id[] = {

	{	.compatible	= "arm,gic-v3-its",	},

	{},
@@ -5383,6 +5431,26 @@ static void __init its_acpi_probe(void) 
static void __init its_acpi_probe(void) { }

#endif



int __init its_lpi_memreserve_init(void)

{

	int state;



	if (!efi_enabled(EFI_CONFIG_TABLES))

		return 0;



	gic_rdists->cpuhp_memreserve_state = CPUHP_INVALID;

	state = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,

				  "irqchip/arm/gicv3/memreserve:online",

				  its_cpu_memreserve_lpi,

				  NULL);

	if (state < 0)

		return state;



	gic_rdists->cpuhp_memreserve_state = state;



	return 0;

}



int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,

		    struct irq_domain *parent_domain)

{

drivers/irqchip/irq-gic-v3.c

+1 −0
Original line number Diff line number Diff line
@@ -1802,6 +1802,7 @@ static int __init gic_init_bases(void __iomem *dist_base, 
	if (gic_dist_supports_lpis()) {

		its_init(handle, &gic_data.rdists, gic_data.domain);

		its_cpu_init();

		its_lpi_memreserve_init();

	} else {

		if (IS_ENABLED(CONFIG_ARM_GIC_V2M))

			gicv2m_init(handle, gic_data.domain);

include/linux/irqchip/arm-gic-v3.h

+3 −1
Original line number Diff line number Diff line
@@ -615,7 +615,7 @@ struct rdists { 
		void __iomem	*rd_base;

		struct page	*pend_page;

		phys_addr_t	phys_base;

		bool		lpi_enabled;

		u64             flags;

		cpumask_t	*vpe_table_mask;

		void		*vpe_l1_base;

	} __percpu		*rdist;
@@ -624,6 +624,7 @@ struct rdists { 
	u64			flags;

	u32			gicd_typer;

	u32			gicd_typer2;

	int                     cpuhp_memreserve_state;

	bool			has_vlpis;

	bool			has_rvpeid;

	bool			has_direct_lpi;
@@ -632,6 +633,7 @@ struct rdists { 


struct irq_domain;

struct fwnode_handle;

int __init its_lpi_memreserve_init(void);

int its_cpu_init(void);

int its_init(struct fwnode_handle *handle, struct rdists *rdists,

	     struct irq_domain *domain);