Messages in this thread | | | Subject | Re: [PATCH 06/10] irqchip/gic-v3-its: Allow use of pre-programmed LPI tables | From | Julien Thierry <> | Date | Mon, 24 Sep 2018 13:52:46 +0100 |
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On 21/09/18 20:59, Marc Zyngier wrote: > In order to cope with kexec and GICv3, let's try and spot when > we're booting with LPIs already enabled, and the tables already > programmed into the redistributors. > > This code is currently guarded by a predicate that is always false, > meaning this is not functionnal just yet. >
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > --- > drivers/irqchip/irq-gic-v3-its.c | 73 ++++++++++++++++++++++++++------ > 1 file changed, 61 insertions(+), 12 deletions(-) > > diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c > index c2f1138034fd..e29ce9f2ac8a 100644 > --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -52,6 +52,7 @@ > #define ITS_FLAGS_SAVE_SUSPEND_STATE (1ULL << 3) > > #define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0) > +#define RDIST_FLAGS_RD_TABLES_PREALLOCATED (1 << 1) > > static u32 lpi_id_bits; > > @@ -1628,18 +1629,32 @@ static void its_free_prop_table(struct page *prop_page) > > static int __init its_alloc_lpi_prop_table(void) > { > - struct page *page; > + if (gic_rdists->flags & RDIST_FLAGS_RD_TABLES_PREALLOCATED) { > + u64 val; > > - lpi_id_bits = min_t(u32, GICD_TYPER_ID_BITS(gic_rdists->gicd_typer), > - ITS_MAX_LPI_NRBITS); > - page = its_allocate_prop_table(GFP_NOWAIT); > - if (!page) { > - pr_err("Failed to allocate PROPBASE\n"); > - return -ENOMEM; > - } > + val = gicr_read_propbaser(gic_data_rdist_rd_base() + GICR_PROPBASER); > + lpi_id_bits = (val & GICR_PROPBASER_IDBITS_MASK) + 1; > > - gic_rdists->prop_table_pa = page_to_phys(page); > - gic_rdists->prop_table_va = page_address(page); > + gic_rdists->prop_table_pa = val & GENMASK_ULL(51, 12); > + gic_rdists->prop_table_va = memremap(gic_rdists->prop_table_pa, > + LPI_PROPBASE_SZ, > + MEMREMAP_WB); > + gic_reset_prop_table(gic_rdists->prop_table_va); > + } else { > + struct page *page; > + > + lpi_id_bits = min_t(u32, > + GICD_TYPER_ID_BITS(gic_rdists->gicd_typer), > + ITS_MAX_LPI_NRBITS); > + page = its_allocate_prop_table(GFP_NOWAIT); > + if (!page) { > + pr_err("Failed to allocate PROPBASE\n"); > + return -ENOMEM; > + } > + > + gic_rdists->prop_table_pa = page_to_phys(page); > + gic_rdists->prop_table_va = page_address(page); > + } > > pr_info("GICv3: using LPI property table @%pa\n", > &gic_rdists->prop_table_pa); > @@ -1948,10 +1963,27 @@ static void its_free_pending_table(struct page *pt) > free_pages((unsigned long)page_address(pt), get_order(LPI_PENDBASE_SZ)); > } > > +static bool enabled_lpis_allowed(void) > +{ > + return false; > +} > + > static int __init allocate_lpi_tables(void) > { > + u64 val; > int err, cpu; > > + /* > + * If LPIs are enabled while we run this from the boot CPU, > + * flag the RD tables as pre-allocated if the stars do align. > + */ > + val = readl_relaxed(gic_data_rdist_rd_base() + GICR_CTLR); > + if ((val & GICR_CTLR_ENABLE_LPIS) && enabled_lpis_allowed()) { > + gic_rdists->flags |= (RDIST_FLAGS_RD_TABLES_PREALLOCATED | > + RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING); > + pr_info("GICv3: Using preallocated redistributor tables\n"); > + } > + > err = its_alloc_lpi_prop_table(); > if (err) > return err; > @@ -1986,6 +2018,18 @@ static void its_cpu_init_lpis(void) > if (gic_data_rdist()->lpi_enabled) > return; > > + val = readl_relaxed(rbase + GICR_CTLR); > + if ((gic_rdists->flags & RDIST_FLAGS_RD_TABLES_PREALLOCATED) && > + (val & GICR_CTLR_ENABLE_LPIS)) { > + paddr = gicr_read_pendbaser(rbase + GICR_PENDBASER); > + paddr &= GENMASK_ULL(51, 16); > + > + its_free_pending_table(gic_data_rdist()->pend_page); > + gic_data_rdist()->pend_page = NULL; > + > + goto out; > + } > + > pend_page = gic_data_rdist()->pend_page; > paddr = page_to_phys(pend_page); > > @@ -2040,9 +2084,11 @@ static void its_cpu_init_lpis(void) > > /* Make sure the GIC has seen the above */ > dsb(sy); > +out: > gic_data_rdist()->lpi_enabled = true; > - pr_info("GICv3: CPU%d: using LPI pending table @%pa\n", > + pr_info("GICv3: CPU%d: using %s LPI pending table @%pa\n", > smp_processor_id(), > + gic_data_rdist()->pend_page ? "allocated" : "reserved", > &paddr); > } > > @@ -3535,8 +3581,11 @@ static int redist_disable_lpis(void) > * If coming via a CPU hotplug event, we don't need to disable > * LPIs before trying to re-enable them. They are already > * configured and all is well in the world. > + * > + * If running with preallocated tables, there is nothing to do. > */ > - if (gic_data_rdist()->lpi_enabled) > + if (gic_data_rdist()->lpi_enabled || > + (gic_rdists->flags & RDIST_FLAGS_RD_TABLES_PREALLOCATED)) > return 0; > > /* >
-- Julien Thierry
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