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Message-ID: <55F6829F.8090707@suse.de>
Date: Mon, 14 Sep 2015 10:17:35 +0200
From: Hannes Reinecke <hare@...e.de>
To: Jiang Liu <jiang.liu@...ux.intel.com>,
Thomas Gleixner <tglx@...utronix.de>,
Bjorn Helgaas <bhelgaas@...gle.com>,
Arthur Marsh <arthur.marsh@...ernode.on.net>,
Dario Ballabio <ballabio_dario@....com>,
"James E.J. Bottomley" <JBottomley@...n.com>
Cc: linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org,
linux-scsi@...r.kernel.org, x86@...nel.org
Subject: Re: [Bugfix 2/3] eata: Implement PCI driver to manage eata PCI
devices
On 09/14/2015 05:08 AM, Jiang Liu wrote:
> Previously the eata driver just grabs and accesses eata PCI devices
> without implementing a PCI device driver, that causes troubles with
> latest IRQ related
>
> Commit 991de2e59090 ("PCI, x86: Implement pcibios_alloc_irq() and
> pcibios_free_irq()") changes the way to allocate PCI legacy IRQ
> for PCI devices on x86 platforms. Instead of allocating PCI legacy
> IRQs when pcibios_enable_device() gets called, now pcibios_alloc_irq()
> will be called by pci_device_probe() to allocate PCI legacy IRQs
> when binding PCI drivers to PCI devices.
>
> But the eata driver directly accesses PCI devices without implementing
> corresponding PCI drivers, so pcibios_alloc_irq() won't be called for
> those PCI devices and wrong IRQ number may be used to manage the PCI
> device.
>
> This patch implements a PCI device driver to manage eata PCI devices,
> so eata driver could properly cooperate with the PCI core. It also
> provides headroom for PCI hotplug with eata driver.
>
> Signed-off-by: Jiang Liu <jiang.liu@...ux.intel.com>
> ---
> drivers/scsi/eata.c | 170 ++++++++++++++++++++++-----------------------------
> 1 file changed, 74 insertions(+), 96 deletions(-)
>
> diff --git a/drivers/scsi/eata.c b/drivers/scsi/eata.c
> index b45d3b532b70..b92e6856f909 100644
> --- a/drivers/scsi/eata.c
> +++ b/drivers/scsi/eata.c
> @@ -850,10 +850,6 @@ static unsigned long io_port[] = {
> /* First ISA */
> 0x1f0,
>
> - /* Space for MAX_PCI ports possibly reported by PCI_BIOS */
> - SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP,
> - SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP,
> -
> /* MAX_EISA ports */
> 0x1c88, 0x2c88, 0x3c88, 0x4c88, 0x5c88, 0x6c88, 0x7c88, 0x8c88,
> 0x9c88, 0xac88, 0xbc88, 0xcc88, 0xdc88, 0xec88, 0xfc88,
> @@ -1024,60 +1020,13 @@ static int read_pio(unsigned long iobase, ushort * start, ushort * end)
> return 0;
> }
>
> -static struct pci_dev *get_pci_dev(unsigned long port_base)
> -{
> -#if defined(CONFIG_PCI)
> - unsigned int addr;
> - struct pci_dev *dev = NULL;
> -
> - while ((dev = pci_get_class(PCI_CLASS_STORAGE_SCSI << 8, dev))) {
> - addr = pci_resource_start(dev, 0);
> -
> -#if defined(DEBUG_PCI_DETECT)
> - printk("%s: get_pci_dev, bus %d, devfn 0x%x, addr 0x%x.\n",
> - driver_name, dev->bus->number, dev->devfn, addr);
> -#endif
> -
> - /* we are in so much trouble for a pci hotplug system with this driver
> - * anyway, so doing this at least lets people unload the driver and not
> - * cause memory problems, but in general this is a bad thing to do (this
> - * driver needs to be converted to the proper PCI api someday... */
> - pci_dev_put(dev);
> - if (addr + PCI_BASE_ADDRESS_0 == port_base)
> - return dev;
> - }
> -#endif /* end CONFIG_PCI */
> - return NULL;
> -}
> -
> -static void enable_pci_ports(void)
> -{
> -#if defined(CONFIG_PCI)
> - struct pci_dev *dev = NULL;
> -
> - while ((dev = pci_get_class(PCI_CLASS_STORAGE_SCSI << 8, dev))) {
> -#if defined(DEBUG_PCI_DETECT)
> - printk("%s: enable_pci_ports, bus %d, devfn 0x%x.\n",
> - driver_name, dev->bus->number, dev->devfn);
> -#endif
> -
> - if (pci_enable_device(dev))
> - printk
> - ("%s: warning, pci_enable_device failed, bus %d devfn 0x%x.\n",
> - driver_name, dev->bus->number, dev->devfn);
> - }
> -
> -#endif /* end CONFIG_PCI */
> -}
> -
> static int port_detect(unsigned long port_base, unsigned int j,
> - struct scsi_host_template *tpnt)
> + struct scsi_host_template *tpnt, struct pci_dev *pdev)
> {
> unsigned char irq, dma_channel, subversion, i, is_pci = 0;
> unsigned char protocol_rev;
> struct eata_info info;
> char *bus_type, dma_name[16];
> - struct pci_dev *pdev;
> /* Allowed DMA channels for ISA (0 indicates reserved) */
> unsigned char dma_channel_table[4] = { 5, 6, 7, 0 };
> struct Scsi_Host *shost;
> @@ -1199,15 +1148,8 @@ static int port_detect(unsigned long port_base, unsigned int j,
> ("%s: warning, LEVEL triggering is suggested for IRQ %u.\n",
> name, irq);
>
> - if (is_pci) {
> - pdev = get_pci_dev(port_base);
> - if (!pdev)
> - printk
> - ("%s: warning, failed to get pci_dev structure.\n",
> - name);
> - } else
> - pdev = NULL;
> -
> + if (is_pci && !pdev)
> + printk("%s: warning, failed to get pci_dev structure.\n", name);
> if (pdev && (irq != pdev->irq)) {
> printk("%s: IRQ %u mapped to IO-APIC IRQ %u.\n", name, irq,
> pdev->irq);
> @@ -1510,14 +1452,17 @@ static int option_setup(char *str)
> }
>
> static unsigned int port_probe(unsigned long port_base,
> - struct scsi_host_template *tpnt)
> + struct scsi_host_template *tpnt,
> + struct pci_dev *pdev)
> {
> int id;
>
> id = ida_simple_get(&eata_ida, 0, MAX_BOARDS, GFP_KERNEL);
> if (id >= 0) {
> set_bit(id, eata_board_bitmap);
> - if (port_detect(port_base, id, tpnt))
> + if (pdev)
> + dev_set_drvdata(&pdev->dev, (void *)(long)id);
> + if (port_detect(port_base, id, tpnt, pdev))
> return id;
> clear_bit(id, eata_board_bitmap);
> ida_simple_remove(&eata_ida, id);
> @@ -1526,42 +1471,81 @@ static unsigned int port_probe(unsigned long port_base,
> return -1;
> }
>
> -static void add_pci_ports(void)
> -{
> -#if defined(CONFIG_PCI)
> - unsigned int addr, k;
> - struct pci_dev *dev = NULL;
> -
> - for (k = 0; k < MAX_PCI; k++) {
> +#ifdef CONFIG_PCI
> +static int eata2x_pci_device_count;
>
> - if (!(dev = pci_get_class(PCI_CLASS_STORAGE_SCSI << 8, dev)))
> - break;
> +static int eata2x_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
> +{
> + int i, ret = -ENXIO;
> + resource_size_t addr;
> + unsigned long port_base;
> + struct scsi_host_template *tpnt = (void *)id->driver_data;
>
> - if (pci_enable_device(dev)) {
> + if (pci_enable_device(dev)) {
> #if defined(DEBUG_PCI_DETECT)
> - printk
> - ("%s: detect, bus %d, devfn 0x%x, pci_enable_device failed.\n",
> - driver_name, dev->bus->number, dev->devfn);
> + pr_warn("%s: detect, bus %d, devfn 0x%x, pci_enable_device failed.\n",
> + driver_name, dev->bus->number, dev->devfn);
> #endif
> + goto out_error;
> + }
>
> - continue;
> - }
> -
> - addr = pci_resource_start(dev, 0);
> -
> + addr = pci_resource_start(dev, 0);
> + port_base = addr + PCI_BASE_ADDRESS_0;
> #if defined(DEBUG_PCI_DETECT)
> - printk("%s: detect, seq. %d, bus %d, devfn 0x%x, addr 0x%x.\n",
> - driver_name, k, dev->bus->number, dev->devfn, addr);
> + printk("%s: detect, bus %d, devfn 0x%x, addr 0x%x.\n",
> + driver_name, dev->bus->number, dev->devfn, (unsigned int)addr);
> #endif
>
> - /* Order addresses according to rev_scan value */
> - io_port[MAX_INT_PARAM + (rev_scan ? (MAX_PCI - k) : (1 + k))] =
> - addr + PCI_BASE_ADDRESS_0;
> + if (setup_done) {
> + /*
> + * Handle kernel or module parameter
> + * . probe board if its port is specified by user
> + * . otherwise ignore the board
> + */
> + for (i = 1; i < MAX_INT_PARAM; i++)
> + if (io_port[i] == port_base) {
> + io_port[i] = SKIP;
> + break;
> + }
> + if (i >= MAX_INT_PARAM)
> + goto out_disable_device;
> + }
Hmm. I must admit I don't like the 'setup_done' thingie. As the driver
is now converted to a 'real' PCI device we should be using driver-core
mechanisms to avoid driver binding, not the prefabricated 'setup_done'
variable.
Can't we just do away with it completely?
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@...e.de +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
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