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From:   Sebastian Reichel <sebastian.reichel@collabora.com>
To:     Marc Zyngier <maz@kernel.org>, Heiko Stuebner <heiko@sntech.de>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Peng Fan <peng.fan@nxp.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Peter Geis <pgwipeout@gmail.com>,
        XiaoDong Huang <derrick.huang@rock-chips.com>,
        Kever Yang <kever.yang@rock-chips.com>,
        linux-rockchip@lists.infradead.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Sebastian Reichel <sebastian.reichel@collabora.com>,
        kernel@collabora.com
Subject: [PATCH v2 1/2] irqchip/gic-v3: Add Rockchip 3588001 errata workaround
Date:   Mon, 17 Apr 2023 17:00:37 +0200
Message-Id: <20230417150038.51698-2-sebastian.reichel@collabora.com>
In-Reply-To: <20230417150038.51698-1-sebastian.reichel@collabora.com>
References: <20230417150038.51698-1-sebastian.reichel@collabora.com>
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Rockchip RK3588/RK3588s GIC600 integration is not cache coherent. Thus
even though the GIC600 itself supports the sharability feature, it may
not be used. Rockchip assigned Errata ID #3588001 for this issue.

The RK3588's GIC600 IP is using ARM's ID in the IIDR register
(0x0201743b), so it cannot be used to apply the quirk. Thus I used the
machine compatible instead.

I named the flag ITS_FLAGS_BROKEN_SHAREABILITY to be vendor agnostic,
since apparently similar integration design errors exist in other
platforms and they can reuse the same flag.

Co-developed-by: XiaoDong Huang <derrick.huang@rock-chips.com>
Signed-off-by: XiaoDong Huang <derrick.huang@rock-chips.com>
Co-developed-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Co-developed-by: Lucas Tanure <lucas.tanure@collabora.com>
Signed-off-by: Lucas Tanure <lucas.tanure@collabora.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
 Documentation/arm64/silicon-errata.rst |  3 +++
 arch/arm64/Kconfig                     | 10 ++++++++++
 drivers/irqchip/irq-gic-v3-its.c       | 25 +++++++++++++++++++++++++
 3 files changed, 38 insertions(+)

diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst
index ec5f889d7681..46d06ed3e4f4 100644
--- a/Documentation/arm64/silicon-errata.rst
+++ b/Documentation/arm64/silicon-errata.rst
@@ -205,6 +205,9 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | Qualcomm Tech. | Kryo4xx Gold    | N/A             | ARM64_ERRATUM_1286807       |
 +----------------+-----------------+-----------------+-----------------------------+
++----------------+-----------------+-----------------+-----------------------------+
+| Rockchip       | RK3588          | #3588001        | ROCKCHIP_ERRATUM_3588001    |
++----------------+-----------------+-----------------+-----------------------------+
 
 +----------------+-----------------+-----------------+-----------------------------+
 | Fujitsu        | A64FX           | E#010001        | FUJITSU_ERRATUM_010001      |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 1023e896d46b..640619459648 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1150,6 +1150,16 @@ config NVIDIA_CARMEL_CNP_ERRATUM
 
 	  If unsure, say Y.
 
+config ROCKCHIP_ERRATUM_3588001
+	bool "Rockchip 3588001: GIC600 can not support shareable attribute"
+	default y
+	help
+	  The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite
+	  and thus is not cache coherent. This means, that the GIC600 may not use
+	  the sharability feature even though it is supported by the IP itself.
+
+	  If unsure, say Y.
+
 config SOCIONEXT_SYNQUACER_PREITS
 	bool "Socionext Synquacer: Workaround for GICv3 pre-ITS"
 	default y
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 586271b8aa39..0701d0b67690 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -42,6 +42,7 @@
 #define ITS_FLAGS_CMDQ_NEEDS_FLUSHING		(1ULL << 0)
 #define ITS_FLAGS_WORKAROUND_CAVIUM_22375	(1ULL << 1)
 #define ITS_FLAGS_WORKAROUND_CAVIUM_23144	(1ULL << 2)
+#define ITS_FLAGS_BROKEN_SHAREABILITY		(1ULL << 3)
 
 #define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING	(1 << 0)
 #define RDIST_FLAGS_RD_TABLES_PREALLOCATED	(1 << 1)
@@ -2359,6 +2360,13 @@ static int its_setup_baser(struct its_node *its, struct its_baser *baser,
 	its_write_baser(its, baser, val);
 	tmp = baser->val;
 
+	if (its->flags & ITS_FLAGS_BROKEN_SHAREABILITY) {
+		if (tmp & GITS_BASER_SHAREABILITY_MASK)
+			tmp &= ~GITS_BASER_SHAREABILITY_MASK;
+		else
+			gic_flush_dcache_to_poc(base, PAGE_ORDER_TO_SIZE(order));
+	}
+
 	if ((val ^ tmp) & GITS_BASER_SHAREABILITY_MASK) {
 		/*
 		 * Shareability didn't stick. Just use
@@ -3055,6 +3063,7 @@ static u64 its_clear_vpend_valid(void __iomem *vlpi_base, u64 clr, u64 set)
 
 static void its_cpu_init_lpis(void)
 {
+	struct its_node *its = list_first_entry(&its_nodes, struct its_node, entry);
 	void __iomem *rbase = gic_data_rdist_rd_base();
 	struct page *pend_page;
 	phys_addr_t paddr;
@@ -3096,6 +3105,9 @@ static void its_cpu_init_lpis(void)
 	gicr_write_propbaser(val, rbase + GICR_PROPBASER);
 	tmp = gicr_read_propbaser(rbase + GICR_PROPBASER);
 
+	if (its->flags & ITS_FLAGS_BROKEN_SHAREABILITY)
+		tmp &= ~GICR_PROPBASER_SHAREABILITY_MASK;
+
 	if ((tmp ^ val) & GICR_PROPBASER_SHAREABILITY_MASK) {
 		if (!(tmp & GICR_PROPBASER_SHAREABILITY_MASK)) {
 			/*
@@ -3120,6 +3132,9 @@ static void its_cpu_init_lpis(void)
 	gicr_write_pendbaser(val, rbase + GICR_PENDBASER);
 	tmp = gicr_read_pendbaser(rbase + GICR_PENDBASER);
 
+	if (its->flags & ITS_FLAGS_BROKEN_SHAREABILITY)
+		tmp &= ~GICR_PENDBASER_SHAREABILITY_MASK;
+
 	if (!(tmp & GICR_PENDBASER_SHAREABILITY_MASK)) {
 		/*
 		 * The HW reports non-shareable, we must remove the
@@ -4765,6 +4780,13 @@ static void its_enable_quirks(struct its_node *its)
 	u32 iidr = readl_relaxed(its->base + GITS_IIDR);
 
 	gic_enable_quirks(iidr, its_quirks, its);
+
+#ifdef CONFIG_ROCKCHIP_ERRATUM_3588001
+	if (of_machine_is_compatible("rockchip,rk3588")) {
+		its->flags |= ITS_FLAGS_BROKEN_SHAREABILITY;
+		pr_info("GIC: enabling workaround for Rockchip #3588001\n");
+	}
+#endif
 }
 
 static int its_save_disable(void)
@@ -5096,6 +5118,9 @@ static int __init its_probe_one(struct resource *res,
 	gits_write_cbaser(baser, its->base + GITS_CBASER);
 	tmp = gits_read_cbaser(its->base + GITS_CBASER);
 
+	if (its->flags & ITS_FLAGS_BROKEN_SHAREABILITY)
+		tmp &= ~GITS_CBASER_SHAREABILITY_MASK;
+
 	if ((tmp ^ baser) & GITS_CBASER_SHAREABILITY_MASK) {
 		if (!(tmp & GITS_CBASER_SHAREABILITY_MASK)) {
 			/*
-- 
2.39.2