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Message-ID: <7c48df01-b641-40d9-95d3-8724d34f5c8d@roeck-us.net>
Date: Thu, 6 Apr 2017 04:42:04 -0700
From: Guenter Roeck <linux@...ck-us.net>
To: Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@...ux.intel.com>, andy@...radead.org,
qipeng.zha@...el.com, dvhart@...radead.org
Cc: wim@...ana.be, sathyaosid@...il.com, david.e.box@...ux.intel.com,
rajneesh.bhardwaj@...el.com, platform-driver-x86@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-watchdog@...r.kernel.org
Subject: Re: [PATCH v6 4/6] watchdog: iTCO_wdt: Add PMC specific noreboot
update api
On 04/05/2017 03:54 PM, Kuppuswamy Sathyanarayanan wrote:
> In some SoCs, setting noreboot bit needs modification to
> PMC GC registers. But not all PMC drivers allow other drivers
> to memory map their GC region. This could create mem request
> conflict in watchdog driver. So this patch adds facility to allow
> PMC drivers to pass noreboot update function to watchdog
> drivers via platform data.
>
> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@...ux.intel.com>
> Acked-by: Guenter Roeck <linux@...ck-us.net>
> ---
> drivers/watchdog/iTCO_wdt.c | 20 ++++++++++++++------
> include/linux/platform_data/itco_wdt.h | 4 ++++
> 2 files changed, 18 insertions(+), 6 deletions(-)
>
> Changes since v5:
> * Added priv_data to pass private data to no_reboot_bit update function.
> * Changed update_noreboot_flag() to update_no_reboot_bit
>
> Changes since v4:
> * Fixed some style issues.
> * used false for 0 and true for 1 in update_noreboot_flag function.
>
> Changes since v3:
> * Rebased on top of latest.
>
> Changes since v2:
> * Removed use of PMC API's directly in watchdog driver.
> * Added update_noreboot_flag to handle no IPC PMC compatibility
> issue mentioned by Guenter.
>
> diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c
> index d8768a2..3f00029 100644
> --- a/drivers/watchdog/iTCO_wdt.c
> +++ b/drivers/watchdog/iTCO_wdt.c
> @@ -106,6 +106,8 @@ struct iTCO_wdt_private {
> struct pci_dev *pci_dev;
> /* whether or not the watchdog has been suspended */
> bool suspended;
> + /* no reboot API private data */
> + void *no_reboot_priv;
> /* no reboot update function pointer */
> int (*update_no_reboot_bit)(void *p, bool set);
> };
> @@ -225,6 +227,8 @@ void iTCO_wdt_no_reboot_bit_setup(struct iTCO_wdt_private *p)
> p->update_no_reboot_bit = update_no_reboot_bit_pci;
> else
> p->update_no_reboot_bit = update_no_reboot_bit_def;
> +
> + p->no_reboot_priv = p;
> }
>
> static int iTCO_wdt_start(struct watchdog_device *wd_dev)
> @@ -237,7 +241,7 @@ static int iTCO_wdt_start(struct watchdog_device *wd_dev)
> iTCO_vendor_pre_start(p->smi_res, wd_dev->timeout);
>
> /* disable chipset's NO_REBOOT bit */
> - if (p->update_no_reboot_bit(p, false)) {
> + if (p->update_no_reboot_bit(p->no_reboot_priv, false)) {
> spin_unlock(&p->io_lock);
> pr_err("failed to reset NO_REBOOT flag, reboot disabled by hardware/BIOS\n");
> return -EIO;
> @@ -278,7 +282,7 @@ static int iTCO_wdt_stop(struct watchdog_device *wd_dev)
> val = inw(TCO1_CNT(p));
>
> /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
> - p->update_no_reboot_bit(p, true);
> + p->update_no_reboot_bit(p->no_reboot_priv, true);
>
> spin_unlock(&p->io_lock);
>
> @@ -442,14 +446,18 @@ static int iTCO_wdt_probe(struct platform_device *pdev)
>
> p->iTCO_version = pdata->version;
> p->pci_dev = to_pci_dev(dev->parent);
> + p->no_reboot_priv = pdata->no_reboot_priv;
>
This is really only for the if case below, and would be wrong otherwise.
> - iTCO_wdt_no_reboot_bit_setup(p);
> + if (pdata->update_no_reboot_bit)
> + p->update_no_reboot_bit = pdata->update_no_reboot_bit;
Can you move that initialization here ? Or, even better, pass pdata to
iTCO_wdt_no_reboot_bit_setup() and initialize it there.
> + else
> + iTCO_wdt_no_reboot_bit_setup(p);
>
> /*
> * Get the Memory-Mapped GCS or PMC register, we need it for the
> * NO_REBOOT flag (TCO v2 and v3).
> */
> - if (p->iTCO_version >= 2) {
> + if (p->iTCO_version >= 2 && !pdata->update_no_reboot_bit) {
> p->gcs_pmc_res = platform_get_resource(pdev,
> IORESOURCE_MEM,
> ICH_RES_MEM_GCS_PMC);
> @@ -459,14 +467,14 @@ static int iTCO_wdt_probe(struct platform_device *pdev)
> }
>
> /* Check chipset's NO_REBOOT bit */
> - if (p->update_no_reboot_bit(p, false) &&
> + if (p->update_no_reboot_bit(p->no_reboot_priv, false) &&
> iTCO_vendor_check_noreboot_on()) {
> pr_info("unable to reset NO_REBOOT flag, device disabled by hardware/BIOS\n");
> return -ENODEV; /* Cannot reset NO_REBOOT bit */
> }
>
> /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
> - p->update_no_reboot_bit(p, true);
> + p->update_no_reboot_bit(p->no_reboot_priv, true);
>
> /* The TCO logic uses the TCO_EN bit in the SMI_EN register */
> if (!devm_request_region(dev, p->smi_res->start,
> diff --git a/include/linux/platform_data/itco_wdt.h b/include/linux/platform_data/itco_wdt.h
> index f16542c..0e95527 100644
> --- a/include/linux/platform_data/itco_wdt.h
> +++ b/include/linux/platform_data/itco_wdt.h
> @@ -14,6 +14,10 @@
> struct itco_wdt_platform_data {
> char name[32];
> unsigned int version;
> + /* private data to be passed to update_no_reboot_bit API */
> + void *no_reboot_priv;
> + /* pointer for platform specific no reboot update function */
> + int (*update_no_reboot_bit)(void *priv, bool set);
> };
>
> #endif /* _ITCO_WDT_H_ */
>
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