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Message-ID: <20190228105612.GA31404@red-moon>
Date: Thu, 28 Feb 2019 10:56:12 +0000
From: Lorenzo Pieralisi <lorenzo.pieralisi@....com>
To: Ley Foon Tan <ley.foon.tan@...el.com>
Cc: Bjorn Helgaas <bhelgaas@...gle.com>, linux-kernel@...r.kernel.org,
linux-pci@...r.kernel.org, devicetree@...r.kernel.org,
lftan.linux@...il.com
Subject: Re: [PATCH v6 1/3] PCI: altera: Add Stratix 10 PCIe support
On Thu, Feb 28, 2019 at 06:52:50PM +0800, Ley Foon Tan wrote:
[...]
> +static int s10_tlp_read_packet(struct altera_pcie *pcie, u32 *value)
> +{
> + int i;
> + u32 ctrl;
> + u32 comp_status;
> + u32 dw[4];
> + u32 count;
> +
> + for (i = 0; i < TLP_LOOP; i++) {
> + ctrl = cra_readl(pcie, S10_RP_RXCPL_STATUS);
> + if (!(ctrl & RP_RXCPL_SOP)) {
> + udelay(5);
> + continue;
> + }
> +
> + /* Read first DW */
> + dw[0] = cra_readl(pcie, S10_RP_RXCPL_REG);
> + count = 1;
> +
> + /* Poll for EOP */
> + for (i = 0; i < TLP_LOOP && count < ARRAY_SIZE(dw); i++) {
> + ctrl = cra_readl(pcie, S10_RP_RXCPL_STATUS);
> + dw[count++] = cra_readl(pcie, S10_RP_RXCPL_REG);
> + if (ctrl & RP_RXCPL_EOP) {
> + comp_status = TLP_COMP_STATUS(dw[1]);
> + if (comp_status)
> + return PCIBIOS_DEVICE_NOT_FOUND;
> +
> + if (value &&
> + TLP_BYTE_COUNT(dw[1]) == sizeof(u32) &&
> + count == 4)
> + *value = dw[3];
> +
> + return PCIBIOS_SUCCESSFUL;
> + }
Two more things.
- Why don't you need a udelay() in the inner loop ?
- I think that count >= ARRAY_SIZE(dw) in the inner loop is an error
condition and it should be flagged up with a warning before exiting.
I can make these changes if you let me know your thoughts on this.
Lorenzo
> + }
> + }
> +
> + return PCIBIOS_DEVICE_NOT_FOUND;
> +}
> +
> static void tlp_write_packet(struct altera_pcie *pcie, u32 *headers,
> u32 data, bool align)
> {
> @@ -210,6 +306,15 @@ static void tlp_write_packet(struct altera_pcie *pcie, u32 *headers,
> tlp_write_tx(pcie, &tlp_rp_regdata);
> }
>
> +static void s10_tlp_write_packet(struct altera_pcie *pcie, u32 *headers,
> + u32 data, bool dummy)
> +{
> + s10_tlp_write_tx(pcie, headers[0], RP_TX_SOP);
> + s10_tlp_write_tx(pcie, headers[1], 0);
> + s10_tlp_write_tx(pcie, headers[2], 0);
> + s10_tlp_write_tx(pcie, data, RP_TX_EOP);
> +}
> +
> static int tlp_cfg_dword_read(struct altera_pcie *pcie, u8 bus, u32 devfn,
> int where, u8 byte_en, u32 *value)
> {
> @@ -219,9 +324,9 @@ static int tlp_cfg_dword_read(struct altera_pcie *pcie, u8 bus, u32 devfn,
> headers[1] = TLP_CFG_DW1(pcie, TLP_READ_TAG, byte_en);
> headers[2] = TLP_CFG_DW2(bus, devfn, where);
>
> - tlp_write_packet(pcie, headers, 0, false);
> + pcie->pcie_data->ops->tlp_write_pkt(pcie, headers, 0, false);
>
> - return tlp_read_packet(pcie, value);
> + return pcie->pcie_data->ops->tlp_read_pkt(pcie, value);
> }
>
> static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn,
> @@ -236,11 +341,13 @@ static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn,
>
> /* check alignment to Qword */
> if ((where & 0x7) == 0)
> - tlp_write_packet(pcie, headers, value, true);
> + pcie->pcie_data->ops->tlp_write_pkt(pcie, headers,
> + value, true);
> else
> - tlp_write_packet(pcie, headers, value, false);
> + pcie->pcie_data->ops->tlp_write_pkt(pcie, headers,
> + value, false);
>
> - ret = tlp_read_packet(pcie, NULL);
> + ret = pcie->pcie_data->ops->tlp_read_pkt(pcie, NULL);
> if (ret != PCIBIOS_SUCCESSFUL)
> return ret;
>
> @@ -254,6 +361,53 @@ static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn,
> return PCIBIOS_SUCCESSFUL;
> }
>
> +static int s10_rp_read_cfg(struct altera_pcie *pcie, int where,
> + int size, u32 *value)
> +{
> + void *addr = S10_RP_CFG_ADDR(pcie, where);
> +
> + switch (size) {
> + case 1:
> + *value = readb(addr);
> + break;
> + case 2:
> + *value = readw(addr);
> + break;
> + default:
> + *value = readl(addr);
> + break;
> + }
> +
> + return PCIBIOS_SUCCESSFUL;
> +}
> +
> +static int s10_rp_write_cfg(struct altera_pcie *pcie, u8 busno,
> + int where, int size, u32 value)
> +{
> + void *addr = S10_RP_CFG_ADDR(pcie, where);
> +
> + switch (size) {
> + case 1:
> + writeb(value, addr);
> + break;
> + case 2:
> + writew(value, addr);
> + break;
> + default:
> + writel(value, addr);
> + break;
> + }
> +
> + /*
> + * Monitor changes to PCI_PRIMARY_BUS register on root port
> + * and update local copy of root bus number accordingly.
> + */
> + if (busno == pcie->root_bus_nr && where == PCI_PRIMARY_BUS)
> + pcie->root_bus_nr = value & 0xff;
> +
> + return PCIBIOS_SUCCESSFUL;
> +}
> +
> static int _altera_pcie_cfg_read(struct altera_pcie *pcie, u8 busno,
> unsigned int devfn, int where, int size,
> u32 *value)
> @@ -262,6 +416,10 @@ static int _altera_pcie_cfg_read(struct altera_pcie *pcie, u8 busno,
> u32 data;
> u8 byte_en;
>
> + if (busno == pcie->root_bus_nr && pcie->pcie_data->ops->rp_read_cfg)
> + return pcie->pcie_data->ops->rp_read_cfg(pcie, where,
> + size, value);
> +
> switch (size) {
> case 1:
> byte_en = 1 << (where & 3);
> @@ -302,6 +460,10 @@ static int _altera_pcie_cfg_write(struct altera_pcie *pcie, u8 busno,
> u32 shift = 8 * (where & 3);
> u8 byte_en;
>
> + if (busno == pcie->root_bus_nr && pcie->pcie_data->ops->rp_write_cfg)
> + return pcie->pcie_data->ops->rp_write_cfg(pcie, busno,
> + where, size, value);
> +
> switch (size) {
> case 1:
> data32 = (value & 0xff) << shift;
> @@ -365,7 +527,8 @@ static int altera_read_cap_word(struct altera_pcie *pcie, u8 busno,
> int ret;
>
> ret = _altera_pcie_cfg_read(pcie, busno, devfn,
> - PCIE_CAP_OFFSET + offset, sizeof(*value),
> + pcie->pcie_data->cap_offset + offset,
> + sizeof(*value),
> &data);
> *value = data;
> return ret;
> @@ -375,7 +538,8 @@ static int altera_write_cap_word(struct altera_pcie *pcie, u8 busno,
> unsigned int devfn, int offset, u16 value)
> {
> return _altera_pcie_cfg_write(pcie, busno, devfn,
> - PCIE_CAP_OFFSET + offset, sizeof(value),
> + pcie->pcie_data->cap_offset + offset,
> + sizeof(value),
> value);
> }
>
> @@ -403,7 +567,7 @@ static void altera_wait_link_retrain(struct altera_pcie *pcie)
> /* Wait for link is up */
> start_jiffies = jiffies;
> for (;;) {
> - if (altera_pcie_link_up(pcie))
> + if (pcie->pcie_data->ops->get_link_status(pcie))
> break;
>
> if (time_after(jiffies, start_jiffies + LINK_UP_TIMEOUT)) {
> @@ -418,7 +582,7 @@ static void altera_pcie_retrain(struct altera_pcie *pcie)
> {
> u16 linkcap, linkstat, linkctl;
>
> - if (!altera_pcie_link_up(pcie))
> + if (!pcie->pcie_data->ops->get_link_status(pcie))
> return;
>
> /*
> @@ -540,12 +704,20 @@ static int altera_pcie_parse_dt(struct altera_pcie *pcie)
> struct device *dev = &pcie->pdev->dev;
> struct platform_device *pdev = pcie->pdev;
> struct resource *cra;
> + struct resource *hip;
>
> cra = platform_get_resource_byname(pdev, IORESOURCE_MEM, "Cra");
> pcie->cra_base = devm_ioremap_resource(dev, cra);
> if (IS_ERR(pcie->cra_base))
> return PTR_ERR(pcie->cra_base);
>
> + if (pcie->pcie_data->version == ALTERA_PCIE_V2) {
> + hip = platform_get_resource_byname(pdev, IORESOURCE_MEM, "Hip");
> + pcie->hip_base = devm_ioremap_resource(&pdev->dev, hip);
> + if (IS_ERR(pcie->hip_base))
> + return PTR_ERR(pcie->hip_base);
> + }
> +
> /* setup IRQ */
> pcie->irq = platform_get_irq(pdev, 0);
> if (pcie->irq < 0) {
> @@ -562,6 +734,48 @@ static void altera_pcie_host_init(struct altera_pcie *pcie)
> altera_pcie_retrain(pcie);
> }
>
> +static const struct altera_pcie_ops altera_pcie_ops_1_0 = {
> + .tlp_read_pkt = tlp_read_packet,
> + .tlp_write_pkt = tlp_write_packet,
> + .get_link_status = altera_pcie_link_up,
> +};
> +
> +static const struct altera_pcie_ops altera_pcie_ops_2_0 = {
> + .tlp_read_pkt = s10_tlp_read_packet,
> + .tlp_write_pkt = s10_tlp_write_packet,
> + .get_link_status = s10_altera_pcie_link_up,
> + .rp_read_cfg = s10_rp_read_cfg,
> + .rp_write_cfg = s10_rp_write_cfg,
> +};
> +
> +static const struct altera_pcie_data altera_pcie_1_0_data = {
> + .ops = &altera_pcie_ops_1_0,
> + .cap_offset = 0x80,
> + .version = ALTERA_PCIE_V1,
> + .cfgrd0 = TLP_FMTTYPE_CFGRD0,
> + .cfgrd1 = TLP_FMTTYPE_CFGRD1,
> + .cfgwr0 = TLP_FMTTYPE_CFGWR0,
> + .cfgwr1 = TLP_FMTTYPE_CFGWR1,
> +};
> +
> +static const struct altera_pcie_data altera_pcie_2_0_data = {
> + .ops = &altera_pcie_ops_2_0,
> + .version = ALTERA_PCIE_V2,
> + .cap_offset = 0x70,
> + .cfgrd0 = S10_TLP_FMTTYPE_CFGRD0,
> + .cfgrd1 = S10_TLP_FMTTYPE_CFGRD1,
> + .cfgwr0 = S10_TLP_FMTTYPE_CFGWR0,
> + .cfgwr1 = S10_TLP_FMTTYPE_CFGWR1,
> +};
> +
> +static const struct of_device_id altera_pcie_of_match[] = {
> + {.compatible = "altr,pcie-root-port-1.0",
> + .data = &altera_pcie_1_0_data },
> + {.compatible = "altr,pcie-root-port-2.0",
> + .data = &altera_pcie_2_0_data },
> + {},
> +};
> +
> static int altera_pcie_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> @@ -570,6 +784,7 @@ static int altera_pcie_probe(struct platform_device *pdev)
> struct pci_bus *child;
> struct pci_host_bridge *bridge;
> int ret;
> + const struct of_device_id *match;
>
> bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
> if (!bridge)
> @@ -578,6 +793,12 @@ static int altera_pcie_probe(struct platform_device *pdev)
> pcie = pci_host_bridge_priv(bridge);
> pcie->pdev = pdev;
>
> + match = of_match_device(altera_pcie_of_match, &pdev->dev);
> + if (!match)
> + return -ENODEV;
> +
> + pcie->pcie_data = match->data;
> +
> ret = altera_pcie_parse_dt(pcie);
> if (ret) {
> dev_err(dev, "Parsing DT failed\n");
> @@ -628,11 +849,6 @@ static int altera_pcie_probe(struct platform_device *pdev)
> return ret;
> }
>
> -static const struct of_device_id altera_pcie_of_match[] = {
> - { .compatible = "altr,pcie-root-port-1.0", },
> - {},
> -};
> -
> static struct platform_driver altera_pcie_driver = {
> .probe = altera_pcie_probe,
> .driver = {
> --
> 2.19.0
>
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