From: Julien Thierry <julien.thierry@arm.com>
To: Marc Zyngier <marc.zyngier@arm.com>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Jeremy Linton <jeremy.linton@arm.com>,
Jeffrey Hugo <jhugo@codeaurora.org>,
Thomas Gleixner <tglx@linutronix.de>,
Jason Cooper <jason@lakedaemon.net>
Subject: Re: [PATCH 06/10] irqchip/gic-v3-its: Allow use of pre-programmed LPI tables
Date: Mon, 24 Sep 2018 13:52:46 +0100 [thread overview]
Message-ID: <e3c26829-ad1e-7b4f-1fef-b32222bb1692@arm.com> (raw)
In-Reply-To: <20180921195954.21574-7-marc.zyngier@arm.com>
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
next prev parent reply other threads:[~2018-09-24 12:52 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-21 19:59 [PATCH 00/10] GICv3 support for kexec/kdump on EFI systems Marc Zyngier
2018-09-21 19:59 ` [PATCH 01/10] irqchip/gic-v3-its: Change initialization ordering for LPIs Marc Zyngier
2018-09-24 10:49 ` Julien Thierry
2018-09-21 19:59 ` [PATCH 02/10] irqchip/gic-v3-its: Consolidate LPI_PENDBASE_SZ usage Marc Zyngier
2018-09-24 10:33 ` Suzuki K Poulose
2018-09-24 10:50 ` Julien Thierry
2018-09-24 10:54 ` Suzuki K Poulose
2018-09-24 10:55 ` Julien Thierry
2018-09-26 10:28 ` Marc Zyngier
2018-09-21 19:59 ` [PATCH 03/10] irqchip/gic-v3-its: Split property table clearing from allocation Marc Zyngier
2018-09-21 19:59 ` [PATCH 04/10] irqchip/gic-v3-its: Move pending table allocation to init time Marc Zyngier
2018-09-24 11:58 ` Julien Thierry
2018-09-26 10:39 ` Marc Zyngier
2018-09-21 19:59 ` [PATCH 05/10] irqchip/gic-v3-its: Keep track of property table's PA and VA Marc Zyngier
2018-09-21 19:59 ` [PATCH 06/10] irqchip/gic-v3-its: Allow use of pre-programmed LPI tables Marc Zyngier
2018-09-24 12:52 ` Julien Thierry [this message]
2018-09-21 19:59 ` [PATCH 07/10] irqchip/gic-v3-its: Use pre-programmed redistributor tables with kdump kernels Marc Zyngier
2018-09-21 19:59 ` [PATCH 08/10] irqchip/gic-v3-its: Check that all RDs have the same property table Marc Zyngier
2018-09-21 19:59 ` [PATCH 09/10] irqchip/gic-v3-its: Register LPI tables with EFI config table Marc Zyngier
2018-09-21 19:59 ` [PATCH 10/10] irqchip/gic-v3-its: Allow use of LPI tables in reserved memory Marc Zyngier
2018-09-25 18:48 ` [PATCH 00/10] GICv3 support for kexec/kdump on EFI systems Jeremy Linton
2018-09-27 9:55 ` Bhupesh Sharma
2018-09-27 13:01 ` Zhang, Lei
2018-09-27 21:10 ` Richard Ruigrok
2018-09-28 10:33 ` Marc Zyngier
[not found] ` <CACiNFG5r2Czfy_kXA2PPQa=xdyzq0vUgoQZ=XNME4d_h=O1oBw@mail.gmail.com>
2019-02-01 9:15 ` Marc Zyngier
2019-02-02 3:05 ` Xulin Sun
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