irqchip/loongson-pch-msi: Use irq_domain_create_hierarchy()

Use the irq_domain_create_hierarchy() helper to create the hierarchical
domain, which both serves as documentation and avoids poking at
irqdomain internals.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230213104302.17307-19-johan+linaro@kernel.org

irqchip/loongarch: Fix irq_domain_alloc_fwnode() abuse

The recently merged LoongArch drivers paper over the lack of
topology information by creating a bunch of fwnodes for the
irqchips. So far, so good.

However, irq_domain_alloc_fwnode() is supposed to take a PA, and
not a kernel VA blindly cast as a PA, potentially disclosing
kernel VAs to userspace. In some other cases, even NULL is used
as the PA, which is entertaining.

Fix this by using the actual PA of the block when available,
and switch to a named fwnode in the other cases.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Jianmin Lv <lvjianmin@loongson.cn>
Link: https://lore.kernel.org/r/20220808105020.2689757-1-maz@kernel.org

irqchip/loongson-pch-msi: Add ACPI init support

PCH-PIC/PCH-MSI stands for "Interrupt Controller" that described in
Section 5 of "Loongson 7A1000 Bridge User Manual". For more information
please refer Documentation/loongarch/irq-chip-model.rst.

Co-developed-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1658314292-35346-10-git-send-email-lvjianmin@loongson.cn

irqchip/loongson-pch-ms: Use bitmap_free() to free bitmap

kfree() and bitmap_free() are the same. But using the latter is more
consistent when freeing memory allocated with bitmap_zalloc().

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/0b982ab54844803049c217b2899baa59602faacd.1640529916.git.christophe.jaillet@wanadoo.fr

irqchip/loongson-pch-msi: Use bitmap_zalloc() to allocate bitmap

Currently we use bitmap_alloc() to allocate msi bitmap which should be
initialized with zero. This is obviously wrong but it works because msi
can fallback to legacy interrupt mode. So use bitmap_zalloc() instead.

Fixes: 632dcc2c75ef6de3272aa ("irqchip: Add Loongson PCH MSI controller")
Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210209071051.2078435-1-chenhuacai@loongson.cn

irqchip/loongson-pch-msi: Remove unneeded variable

irq_domain_alloc_irqs_parent() returns 0 on success and non-zero value
on failure, it is redudant to check its non-zero return value and then
return it, so just remove the variable "ret" and return directly in the
function pch_msi_parent_domain_alloc().

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1594087972-21715-7-git-send-email-yangtiezhu@loongson.cn

irqchip: Add Loongson PCH MSI controller

This controller appears on Loongson LS7A family of PCH to transform
interrupts from PCI MSI into HyperTransport vectorized interrrupts
and send them to procrssor's HT vector controller.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200528152757.1028711-6-jiaxun.yang@flygoat.com