diff mbox series

[v6,4/4] ARM: Add support for Hisilicon Kunpeng L3 cache controller

Message ID 20210201033601.1642-5-thunder.leizhen@huawei.com (mailing list archive)
State New, archived
Headers show
Series ARM: Add support for Hisilicon Kunpeng L3 cache controller | expand

Commit Message

Leizhen (ThunderTown) Feb. 1, 2021, 3:36 a.m. UTC 
Add support for the Hisilicon Kunpeng L3 cache controller as used with
Kunpeng506 and Kunpeng509 SoCs.

These Hisilicon SoCs support LPAE, so the physical addresses is wider than
32-bits, but the actual bit width does not exceed 36 bits. When the cache
operation is performed based on the address range, the upper 30 bits of
the physical address are recorded in registers L3_MAINT_START and
L3_MAINT_END, and ignore the lower 6 bits cacheline offset.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
 arch/arm/mm/Kconfig            |  10 ++
 arch/arm/mm/Makefile           |   1 +
 arch/arm/mm/cache-kunpeng-l3.c | 176 +++++++++++++++++++++++++++++++++
 3 files changed, 187 insertions(+)
 create mode 100644 arch/arm/mm/cache-kunpeng-l3.c

Comments

Arnd Bergmann Feb. 1, 2021, 8:31 a.m. UTC | #1 
On Mon, Feb 1, 2021 at 4:36 AM Zhen Lei <thunder.leizhen@huawei.com> wrote:
>
> Add support for the Hisilicon Kunpeng L3 cache controller as used with
> Kunpeng506 and Kunpeng509 SoCs.
>
> These Hisilicon SoCs support LPAE, so the physical addresses is wider than
> 32-bits, but the actual bit width does not exceed 36 bits. When the cache
> operation is performed based on the address range, the upper 30 bits of
> the physical address are recorded in registers L3_MAINT_START and
> L3_MAINT_END, and ignore the lower 6 bits cacheline offset.
>
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

If you add one more thing:

> +static void l3cache_maint_common(u32 range, u32 op_type)
> +{
> +       u32 reg;
> +
> +       reg = readl_relaxed(l3_ctrl_base + L3_MAINT_CTRL);
> +       reg &= ~(L3_MAINT_RANGE_MASK | L3_MAINT_TYPE_MASK);
> +       reg |= range | op_type;
> +       reg |= L3_MAINT_STATUS_START;
> +       writel(reg, l3_ctrl_base + L3_MAINT_CTRL);
> +
> +       /* Wait until the hardware maintenance operation is complete. */
> +       do {
> +               cpu_relax();
> +               reg = readl(l3_ctrl_base + L3_MAINT_CTRL);
> +       } while ((reg & L3_MAINT_STATUS_MASK) != L3_MAINT_STATUS_END);
> +}
> +
> +static void l3cache_maint_range(phys_addr_t start, phys_addr_t end, u32 op_type)
> +{
> +       start = start >> L3_CACHE_LINE_SHITF;
> +       end = ((end - 1) >> L3_CACHE_LINE_SHITF) + 1;
> +
> +       writel_relaxed(start, l3_ctrl_base + L3_MAINT_START);
> +       writel_relaxed(end, l3_ctrl_base + L3_MAINT_END);
> +
> +       l3cache_maint_common(L3_MAINT_RANGE_ADDR, op_type);
> +}

As mentioned, I'd like to see a code comment that explains the use
the of relaxed() vs non-relaxed MMIO accessors, as it will be impossible
for a reader to later understand why you picked a mix of the two,
and it also ensures that you have considered which one is the best
option to use here and that your explanation matches what you do.

Based on Russell's comments, I had expected that you would use
only relaxed accessors, plus explicit barriers if you change it, matching
what l2x0 does (l2x0 has to do it because of __l2c210_cache_sync(),
while you don't have a sync callback and don't need to).

      Arnd
Leizhen (ThunderTown) Feb. 1, 2021, 11:38 a.m. UTC | #2 
On 2021/2/1 16:31, Arnd Bergmann wrote:
> On Mon, Feb 1, 2021 at 4:36 AM Zhen Lei <thunder.leizhen@huawei.com> wrote:
>>
>> Add support for the Hisilicon Kunpeng L3 cache controller as used with
>> Kunpeng506 and Kunpeng509 SoCs.
>>
>> These Hisilicon SoCs support LPAE, so the physical addresses is wider than
>> 32-bits, but the actual bit width does not exceed 36 bits. When the cache
>> operation is performed based on the address range, the upper 30 bits of
>> the physical address are recorded in registers L3_MAINT_START and
>> L3_MAINT_END, and ignore the lower 6 bits cacheline offset.
>>
>> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> 
> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
> 
> If you add one more thing:
> 
>> +static void l3cache_maint_common(u32 range, u32 op_type)
>> +{
>> +       u32 reg;
>> +
>> +       reg = readl_relaxed(l3_ctrl_base + L3_MAINT_CTRL);
>> +       reg &= ~(L3_MAINT_RANGE_MASK | L3_MAINT_TYPE_MASK);
>> +       reg |= range | op_type;
>> +       reg |= L3_MAINT_STATUS_START;
>> +       writel(reg, l3_ctrl_base + L3_MAINT_CTRL);
>> +
>> +       /* Wait until the hardware maintenance operation is complete. */
>> +       do {
>> +               cpu_relax();
>> +               reg = readl(l3_ctrl_base + L3_MAINT_CTRL);
>> +       } while ((reg & L3_MAINT_STATUS_MASK) != L3_MAINT_STATUS_END);
>> +}
>> +
>> +static void l3cache_maint_range(phys_addr_t start, phys_addr_t end, u32 op_type)
>> +{
>> +       start = start >> L3_CACHE_LINE_SHITF;
>> +       end = ((end - 1) >> L3_CACHE_LINE_SHITF) + 1;
>> +
>> +       writel_relaxed(start, l3_ctrl_base + L3_MAINT_START);
>> +       writel_relaxed(end, l3_ctrl_base + L3_MAINT_END);
>> +
>> +       l3cache_maint_common(L3_MAINT_RANGE_ADDR, op_type);
>> +}
> 
> As mentioned, I'd like to see a code comment that explains the use
> the of relaxed() vs non-relaxed MMIO accessors, as it will be impossible
> for a reader to later understand why you picked a mix of the two,
> and it also ensures that you have considered which one is the best
> option to use here and that your explanation matches what you do.

OK, I'll test the performance and add the comment.

> 
> Based on Russell's comments, I had expected that you would use
> only relaxed accessors, plus explicit barriers if you change it, matching
> what l2x0 does (l2x0 has to do it because of __l2c210_cache_sync(),
> while you don't have a sync callback and don't need to).

I might have been a little conservative, I'll change all of them to _relaxed and then test it. Thanks.

> 
>       Arnd
> 
> .
>
diff mbox series

Patch

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 02692fbe2db5c59..d2082503de053d2 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -1070,6 +1070,16 @@  config CACHE_XSC3L2
 	help
 	  This option enables the L2 cache on XScale3.
 
+config CACHE_KUNPENG_L3
+	bool "Enable the Hisilicon Kunpeng L3 cache controller"
+	depends on ARCH_KUNPENG50X && OF
+	default y
+	select OUTER_CACHE
+	help
+	  This option enables the Kunpeng L3 cache controller on Hisilicon
+	  Kunpeng506 and Kunpeng509 SoCs. It supports a maximum of 36-bit
+	  physical addresses.
+
 config ARM_L1_CACHE_SHIFT_6
 	bool
 	default y if CPU_V7
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 3510503bc5e688b..ececc5489e353eb 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -112,6 +112,7 @@  obj-$(CONFIG_CACHE_L2X0_PMU)	+= cache-l2x0-pmu.o
 obj-$(CONFIG_CACHE_XSC3L2)	+= cache-xsc3l2.o
 obj-$(CONFIG_CACHE_TAUROS2)	+= cache-tauros2.o
 obj-$(CONFIG_CACHE_UNIPHIER)	+= cache-uniphier.o
+obj-$(CONFIG_CACHE_KUNPENG_L3)	+= cache-kunpeng-l3.o
 
 KASAN_SANITIZE_kasan_init.o	:= n
 obj-$(CONFIG_KASAN)		+= kasan_init.o
diff --git a/arch/arm/mm/cache-kunpeng-l3.c b/arch/arm/mm/cache-kunpeng-l3.c
new file mode 100644
index 000000000000000..4a9e47150a446ed
--- /dev/null
+++ b/arch/arm/mm/cache-kunpeng-l3.c
@@ -0,0 +1,176 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 Hisilicon Limited.
+ */
+
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+
+#include <asm/cacheflush.h>
+
+#define L3_CACHE_LINE_SHITF		6
+
+#define L3_CTRL				0x0
+#define L3_CTRL_ENABLE			(1U << 0)
+#define L3_CTRL_DISABLE			(0U << 0)
+
+#define L3_AUCTRL			0x4
+#define L3_AUCTRL_EVENT_EN		BIT(23)
+#define L3_AUCTRL_ECC_EN		BIT(8)
+
+#define L3_MAINT_CTRL			0x20
+#define L3_MAINT_RANGE_MASK		GENMASK(3, 3)
+#define L3_MAINT_RANGE_ALL		(0U << 3)
+#define L3_MAINT_RANGE_ADDR		(1U << 3)
+#define L3_MAINT_TYPE_MASK		GENMASK(2, 1)
+#define L3_MAINT_TYPE_CLEAN		(1U << 1)
+#define L3_MAINT_TYPE_INV		(2U << 1)
+#define L3_MAINT_TYPE_FLUSH		(3U << 1)
+#define L3_MAINT_STATUS_MASK		GENMASK(0, 0)
+#define L3_MAINT_STATUS_START		(1U << 0)
+#define L3_MAINT_STATUS_END		(0U << 0)
+
+#define L3_MAINT_START			0x24
+#define L3_MAINT_END			0x28
+
+static DEFINE_RAW_SPINLOCK(l3cache_lock);
+static void __iomem *l3_ctrl_base;
+
+
+static void l3cache_maint_common(u32 range, u32 op_type)
+{
+	u32 reg;
+
+	reg = readl_relaxed(l3_ctrl_base + L3_MAINT_CTRL);
+	reg &= ~(L3_MAINT_RANGE_MASK | L3_MAINT_TYPE_MASK);
+	reg |= range | op_type;
+	reg |= L3_MAINT_STATUS_START;
+	writel(reg, l3_ctrl_base + L3_MAINT_CTRL);
+
+	/* Wait until the hardware maintenance operation is complete. */
+	do {
+		cpu_relax();
+		reg = readl(l3_ctrl_base + L3_MAINT_CTRL);
+	} while ((reg & L3_MAINT_STATUS_MASK) != L3_MAINT_STATUS_END);
+}
+
+static void l3cache_maint_range(phys_addr_t start, phys_addr_t end, u32 op_type)
+{
+	start = start >> L3_CACHE_LINE_SHITF;
+	end = ((end - 1) >> L3_CACHE_LINE_SHITF) + 1;
+
+	writel_relaxed(start, l3_ctrl_base + L3_MAINT_START);
+	writel_relaxed(end, l3_ctrl_base + L3_MAINT_END);
+
+	l3cache_maint_common(L3_MAINT_RANGE_ADDR, op_type);
+}
+
+static inline void l3cache_flush_all_nolock(void)
+{
+	l3cache_maint_common(L3_MAINT_RANGE_ALL, L3_MAINT_TYPE_FLUSH);
+}
+
+static void l3cache_flush_all(void)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&l3cache_lock, flags);
+	l3cache_flush_all_nolock();
+	raw_spin_unlock_irqrestore(&l3cache_lock, flags);
+}
+
+static void l3cache_inv_range(phys_addr_t start, phys_addr_t end)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&l3cache_lock, flags);
+	l3cache_maint_range(start, end, L3_MAINT_TYPE_INV);
+	raw_spin_unlock_irqrestore(&l3cache_lock, flags);
+}
+
+static void l3cache_clean_range(phys_addr_t start, phys_addr_t end)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&l3cache_lock, flags);
+	l3cache_maint_range(start, end, L3_MAINT_TYPE_CLEAN);
+	raw_spin_unlock_irqrestore(&l3cache_lock, flags);
+}
+
+static void l3cache_flush_range(phys_addr_t start, phys_addr_t end)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&l3cache_lock, flags);
+	l3cache_maint_range(start, end, L3_MAINT_TYPE_FLUSH);
+	raw_spin_unlock_irqrestore(&l3cache_lock, flags);
+}
+
+static void l3cache_disable(void)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&l3cache_lock, flags);
+	l3cache_flush_all_nolock();
+	writel(L3_CTRL_DISABLE, l3_ctrl_base + L3_CTRL);
+	raw_spin_unlock_irqrestore(&l3cache_lock, flags);
+}
+
+static const struct of_device_id l3cache_ids[] __initconst = {
+	{.compatible = "hisilicon,kunpeng-l3cache", .data = NULL},
+	{}
+};
+
+static int __init l3cache_init(void)
+{
+	u32 reg;
+	struct device_node *node;
+
+	node = of_find_matching_node(NULL, l3cache_ids);
+	if (!node)
+		return -ENODEV;
+
+	l3_ctrl_base = of_iomap(node, 0);
+	if (!l3_ctrl_base) {
+		pr_err("failed to map Kunpeng L3 cache controller registers\n");
+		return -ENOMEM;
+	}
+
+	reg = readl_relaxed(l3_ctrl_base + L3_CTRL);
+	if (!(reg & L3_CTRL_ENABLE)) {
+		unsigned long flags;
+
+		raw_spin_lock_irqsave(&l3cache_lock, flags);
+
+		/*
+		 * Ensure that no L3 cache hardware maintenance operations are
+		 * being performed before enabling the L3 cache. Wait for it to
+		 * finish.
+		 */
+		do {
+			cpu_relax();
+			reg = readl(l3_ctrl_base + L3_MAINT_CTRL);
+		} while ((reg & L3_MAINT_STATUS_MASK) != L3_MAINT_STATUS_END);
+
+		reg = readl_relaxed(l3_ctrl_base + L3_AUCTRL);
+		reg |= L3_AUCTRL_EVENT_EN | L3_AUCTRL_ECC_EN;
+		writel_relaxed(reg, l3_ctrl_base + L3_AUCTRL);
+
+		writel(L3_CTRL_ENABLE, l3_ctrl_base + L3_CTRL);
+
+		raw_spin_unlock_irqrestore(&l3cache_lock, flags);
+	}
+
+	outer_cache.inv_range = l3cache_inv_range;
+	outer_cache.clean_range = l3cache_clean_range;
+	outer_cache.flush_range = l3cache_flush_range;
+	outer_cache.flush_all = l3cache_flush_all;
+	outer_cache.disable = l3cache_disable;
+
+	pr_info("Hisilicon Kunpeng L3 cache controller enabled\n");
+
+	return 0;
+}
+arch_initcall(l3cache_init);