Re: [PATCH V8 1/5] PCI: loongson: Use correct pci config access operations
flat view
From: Bjorn Helgaas <helgaas@kernel.org>
Date: 2021-08-25 17:32:12
Things like "Use correct ..." in subject lines are useless. *Every* patch should do the "proper" or "correct" thing, so it should go without saying. Repeating it doesn't make it more true. This doesn't apply to *all* loongson devices, so it would be useful to hint at the devices it *does* apply to. Maybe something like: PCI: loongson: Use generic 8/16/32-bit config ops on LS2K/LS7A On Wed, Aug 25, 2021 at 02:07:20PM +0800, Huacai Chen wrote:
LS2K/LS7A support 8/16/32-bits pci config access operations via CFG1, so we can disable CFG0 for them and safely use pci_generic_config_read()/ pci_generic_config_write() instead of pci_generic_config_read32()/pci_ generic_config_write32().
s/pci/PCI/
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Signed-off-by: Huacai Chen <redacted> --- drivers/pci/controller/pci-loongson.c | 36 +++++++++++++++++---------- 1 file changed, 23 insertions(+), 13 deletions(-)diff --git a/drivers/pci/controller/pci-loongson.c b/drivers/pci/controller/pci-loongson.c index 48169b1e3817..b2c81c762599 100644 --- a/drivers/pci/controller/pci-loongson.c +++ b/drivers/pci/controller/pci-loongson.c@@ -159,8 +159,15 @@ static int loongson_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) return val; } -/* H/w only accept 32-bit PCI operations */ +/* LS2K/LS7A accept 8/16/32-bit PCI operations */
*config* operations
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static struct pci_ops loongson_pci_ops = { + .map_bus = pci_loongson_map_bus, + .read = pci_generic_config_read, + .write = pci_generic_config_write, +}; + +/* RS780/SR5690 only accept 32-bit PCI operations */ +static struct pci_ops loongson_pci_ops32 = { .map_bus = pci_loongson_map_bus, .read = pci_generic_config_read32, .write = pci_generic_config_write32,@@ -168,9 +175,9 @@ static struct pci_ops loongson_pci_ops = { static const struct of_device_id loongson_pci_of_match[] = { { .compatible = "loongson,ls2k-pci", - .data = (void *)(FLAG_CFG0 | FLAG_CFG1 | FLAG_DEV_FIX), }, + .data = (void *)(FLAG_CFG1 | FLAG_DEV_FIX), }, { .compatible = "loongson,ls7a-pci", - .data = (void *)(FLAG_CFG0 | FLAG_CFG1 | FLAG_DEV_FIX), }, + .data = (void *)(FLAG_CFG1 | FLAG_DEV_FIX), }, { .compatible = "loongson,rs780e-pci", .data = (void *)(FLAG_CFG0), },
It'd be nice if you used the same strategy as most other drivers, e.g., ".data = &loongson_ls2k_data" or similar.
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{}@@ -195,17 +202,17 @@ static int loongson_pci_probe(struct platform_device *pdev) priv->pdev = pdev; priv->flags = (unsigned long)of_device_get_match_data(dev); - regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!regs) { - dev_err(dev, "missing mem resources for cfg0\n"); - return -EINVAL; + if (priv->flags & FLAG_CFG0) { + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!regs) + dev_err(dev, "missing mem resources for cfg0\n"); + else { + priv->cfg0_base = devm_pci_remap_cfg_resource(dev, regs); + if (IS_ERR(priv->cfg0_base)) + return PTR_ERR(priv->cfg0_base); + } } - priv->cfg0_base = devm_pci_remap_cfg_resource(dev, regs); - if (IS_ERR(priv->cfg0_base)) - return PTR_ERR(priv->cfg0_base); - - /* CFG1 is optional */ if (priv->flags & FLAG_CFG1) { regs = platform_get_resource(pdev, IORESOURCE_MEM, 1); if (!regs)@@ -218,8 +225,11 @@ static int loongson_pci_probe(struct platform_device *pdev) } bridge->sysdata = priv; - bridge->ops = &loongson_pci_ops; bridge->map_irq = loongson_map_irq; + if (!of_device_is_compatible(node, "loongson,rs780e-pci"))
You already called of_device_get_match_data() above, which does essentially the same work as of_device_is_compatible().
+ bridge->ops = &loongson_pci_ops; + else + bridge->ops = &loongson_pci_ops32; return pci_host_probe(bridge); } -- 2.27.0