From 5186322bc7c89596a437a11d8e57ac647f55b271 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <marc.zyngier@arm.com>
Date: Tue, 26 Jun 2018 11:21:11 +0100
Subject: [PATCH] irqchip/gic-v3-its: Use pre-programmed redistributor tables
 with kdump kernels

mainline inclusion
from 4.20-rc1
commit: c6e2ccb66d0c3b4fffc59932585e9f709ad59003
category: kdump
bugzilla: 5272
CVE: NA

This 10 patches is used for secondary kernel using LPI.

[PATCH 01/10] irqchip/gic-v3-its: Change initialization ordering for LPIs
[PATCH 02/10] irqchip/gic-v3-its: Simplify LPI_PENDBASE_SZ usage
[PATCH 03/10] irqchip/gic-v3-its: Split property table clearing from allocation
[PATCH 04/10] irqchip/gic-v3-its: Move pending table allocation to init time
[PATCH 05/10] irqchip/gic-v3-its: Keep track of property table's PA and VA
[PATCH 06/10] irqchip/gic-v3-its: Allow use of pre-programmed LPI tables
[PATCH 07/10] irqchip/gic-v3-its: Use pre-programmed redistributor tables with kdump kernels
[PATCH 08/10] irqchip/gic-v3-its: Check that all RDs have the same property table
[PATCH 09/10] irqchip/gic-v3-its: Register LPI tables with EFI config table
[PATCH 10/10] irqchip/gic-v3-its: Allow use of LPI tables in reserved memory

--------------------------------------

If using a kdump kernel, and that we cannot disable LPIs to install
our own tables, let's switch to using the already allocated tables.

This means that we'll change some of the initial kernel's memory,
but at least we'll be able to have LPIs in this secondary kernel.

Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
Tested-by: Lei Zhang <zhang.lei@jp.fujitsu.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 6a9066411cbc..83d5573f56e9 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -19,6 +19,7 @@
 #include <linux/acpi_iort.h>
 #include <linux/bitmap.h>
 #include <linux/cpu.h>
+#include <linux/crash_dump.h>
 #include <linux/delay.h>
 #include <linux/dma-iommu.h>
 #include <linux/interrupt.h>
@@ -1963,8 +1964,15 @@ static void its_free_pending_table(struct page *pt)
 	free_pages((unsigned long)page_address(pt), get_order(LPI_PENDBASE_SZ));
 }
 
+/*
+ * Booting with kdump and LPIs enabled is generally fine.
+ */
 static bool enabled_lpis_allowed(void)
 {
+	/* Allow a kdump kernel */
+	if (is_kdump_kernel())
+		return true;
+
 	return false;
 }
 
-- 
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