Date: Mon, 19 Dec 2016 15:56:24 +0200
From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Jiandi An <anjiandi@codeaurora.org>
Cc: peterhuewe@gmx.de, tpmdd@selhorst.net, jgunthorpe@obsidianresearch.com,
        tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] tpm, tpm_crb: Handle 64-bit resource in
 crb_check_resource()
Message-ID: <20161219135624.2e7okpswnbqbvic7@intel.com>
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On Sun, Dec 18, 2016 at 10:20:53PM -0600, Jiandi An wrote:
> crb_check_resource() in TPM CRB driver calls
> acpi_dev_resource_memory() which only handles 32-bit resources.
> Adding a call to acpi_dev_resource_address_space() in TPM CRB
> driver which handles 64-bit resources.
> 
> Signed-off-by: Jiandi An <anjiandi@codeaurora.org>

1. Is there a platform in existence where this change fixes a problem?
2. What is difference between "memory" and "address space" conceptually?
   Just wondering why 32-bit stuff is "memory" and 64-bit stuff is
   "address space". Could there be a one function that would work both
   for 32-bit and 64-bit cases?
   
Yeah, I do not know this API too well. That's why I'm asking.

/Jarkko

> ---
>  drivers/char/tpm/tpm_crb.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> index 717b6b4..86f355b 100644
> --- a/drivers/char/tpm/tpm_crb.c
> +++ b/drivers/char/tpm/tpm_crb.c
> @@ -264,10 +264,12 @@ static bool crb_req_canceled(struct tpm_chip *chip, u8 status)
>  static int crb_check_resource(struct acpi_resource *ares, void *data)
>  {
>  	struct resource *io_res = data;
> -	struct resource res;
> +	struct resource_win win;
> +	struct resource *res = &(win.res);
>  
> -	if (acpi_dev_resource_memory(ares, &res)) {
> -		*io_res = res;
> +	if (acpi_dev_resource_memory(ares, res) ||
> +	    acpi_dev_resource_address_space(ares, &win)) {
> +		*io_res = *res;
>  		io_res->name = NULL;
>  	}
>  
> -- 
> Jiandi An
> Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
> Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
>