| Message ID | 657d281490de3d0a60f210f8bc57e075c9afc40e.1508434514.git.mario.limonciello@dell.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Delegated to: | Darren Hart |
| Headers | show |
On Thursday 19 October 2017 12:50:14 Mario Limonciello wrote: > +/* When enabled this indicates that SMM won't work */ > +static bool test_wsmt_enabled(void) > +{ > + struct calling_interface_token *token; > + > + /* if token doesn't exist, SMM will work */ > + token = dell_smbios_find_token(WSMT_EN_TOKEN); > + if (!token) > + return false; > + > + /* if token exists, try to access over SMM */ > + buffer->class = CLASS_TOKEN_READ; > + buffer->select = SELECT_TOKEN_STD; > + memset(buffer, 0, sizeof(struct calling_interface_buffer)); > + buffer->input[0] = token->location; > + dell_smbios_smm_call(buffer); > + > + /* if lookup failed, we know WSMT was enabled */ > + if (buffer->output[0] != 0) > + return true; > + > + /* query token status if it didn't fail */ > + return (buffer->output[1] == token->value); > +} > + > static int __init dell_smbios_smm_init(void) > { > int ret; > @@ -115,6 +140,13 @@ static int __init dell_smbios_smm_init(void) > > dmi_walk(find_cmd_address, NULL); > > + ret = test_wsmt_enabled(); ret is int, but test_wsmt_enabled() returns bool.
> -----Original Message----- > From: Pali Rohár [mailto:pali.rohar@gmail.com] > Sent: Thursday, October 19, 2017 1:09 PM > To: Limonciello, Mario <Mario_Limonciello@Dell.com> > Cc: dvhart@infradead.org; Andy Shevchenko <andy.shevchenko@gmail.com>; > LKML <linux-kernel@vger.kernel.org>; platform-driver-x86@vger.kernel.org; Andy > Lutomirski <luto@kernel.org>; quasisec@google.com; rjw@rjwysocki.net; > mjg59@google.com; hch@lst.de; Greg KH <greg@kroah.com>; Alan Cox > <gnomes@lxorguk.ukuu.org.uk> > Subject: Re: [PATCH v10 11/15] platform/x86: dell-smbios-smm: test for WSMT > > On Thursday 19 October 2017 12:50:14 Mario Limonciello wrote: > > +/* When enabled this indicates that SMM won't work */ > > +static bool test_wsmt_enabled(void) > > +{ > > + struct calling_interface_token *token; > > + > > + /* if token doesn't exist, SMM will work */ > > + token = dell_smbios_find_token(WSMT_EN_TOKEN); > > + if (!token) > > + return false; > > + > > + /* if token exists, try to access over SMM */ > > + buffer->class = CLASS_TOKEN_READ; > > + buffer->select = SELECT_TOKEN_STD; > > + memset(buffer, 0, sizeof(struct calling_interface_buffer)); > > + buffer->input[0] = token->location; > > + dell_smbios_smm_call(buffer); > > + > > + /* if lookup failed, we know WSMT was enabled */ > > + if (buffer->output[0] != 0) > > + return true; > > + > > + /* query token status if it didn't fail */ > > + return (buffer->output[1] == token->value); > > +} > > + > > static int __init dell_smbios_smm_init(void) > > { > > int ret; > > @@ -115,6 +140,13 @@ static int __init dell_smbios_smm_init(void) > > > > dmi_walk(find_cmd_address, NULL); > > > > + ret = test_wsmt_enabled(); > > ret is int, but test_wsmt_enabled() returns bool. Yes, ret is re-used within this method. 0, 1 enum is a subset of int, so this seemed like a logical thing to me to do.
On Thu, Oct 19, 2017 at 06:12:09PM +0000, Mario.Limonciello@dell.com wrote: > > -----Original Message----- > > From: Pali Rohár [mailto:pali.rohar@gmail.com] > > Sent: Thursday, October 19, 2017 1:09 PM > > To: Limonciello, Mario <Mario_Limonciello@Dell.com> > > Cc: dvhart@infradead.org; Andy Shevchenko <andy.shevchenko@gmail.com>; > > LKML <linux-kernel@vger.kernel.org>; platform-driver-x86@vger.kernel.org; Andy > > Lutomirski <luto@kernel.org>; quasisec@google.com; rjw@rjwysocki.net; > > mjg59@google.com; hch@lst.de; Greg KH <greg@kroah.com>; Alan Cox > > <gnomes@lxorguk.ukuu.org.uk> > > Subject: Re: [PATCH v10 11/15] platform/x86: dell-smbios-smm: test for WSMT > > > > On Thursday 19 October 2017 12:50:14 Mario Limonciello wrote: > > > +/* When enabled this indicates that SMM won't work */ > > > +static bool test_wsmt_enabled(void) > > > +{ > > > + struct calling_interface_token *token; > > > + > > > + /* if token doesn't exist, SMM will work */ > > > + token = dell_smbios_find_token(WSMT_EN_TOKEN); > > > + if (!token) > > > + return false; > > > + > > > + /* if token exists, try to access over SMM */ > > > + buffer->class = CLASS_TOKEN_READ; > > > + buffer->select = SELECT_TOKEN_STD; > > > + memset(buffer, 0, sizeof(struct calling_interface_buffer)); > > > + buffer->input[0] = token->location; > > > + dell_smbios_smm_call(buffer); > > > + > > > + /* if lookup failed, we know WSMT was enabled */ > > > + if (buffer->output[0] != 0) > > > + return true; > > > + > > > + /* query token status if it didn't fail */ > > > + return (buffer->output[1] == token->value); > > > +} > > > + > > > static int __init dell_smbios_smm_init(void) > > > { > > > int ret; > > > @@ -115,6 +140,13 @@ static int __init dell_smbios_smm_init(void) > > > > > > dmi_walk(find_cmd_address, NULL); > > > > > > + ret = test_wsmt_enabled(); > > > > ret is int, but test_wsmt_enabled() returns bool. > > Yes, ret is re-used within this method. > 0, 1 enum is a subset of int, so this seemed like a logical thing to me to do. Agreed, the conversion is automatic and he tests for it and returns an appropriate error code. I don't see a real problem with this.
diff --git a/drivers/platform/x86/dell-smbios-smm.c b/drivers/platform/x86/dell-smbios-smm.c index 53eabb14fb48..4175ccbded15 100644 --- a/drivers/platform/x86/dell-smbios-smm.c +++ b/drivers/platform/x86/dell-smbios-smm.c @@ -102,6 +102,31 @@ int dell_smbios_smm_call(struct calling_interface_buffer *input) return 0; } +/* When enabled this indicates that SMM won't work */ +static bool test_wsmt_enabled(void) +{ + struct calling_interface_token *token; + + /* if token doesn't exist, SMM will work */ + token = dell_smbios_find_token(WSMT_EN_TOKEN); + if (!token) + return false; + + /* if token exists, try to access over SMM */ + buffer->class = CLASS_TOKEN_READ; + buffer->select = SELECT_TOKEN_STD; + memset(buffer, 0, sizeof(struct calling_interface_buffer)); + buffer->input[0] = token->location; + dell_smbios_smm_call(buffer); + + /* if lookup failed, we know WSMT was enabled */ + if (buffer->output[0] != 0) + return true; + + /* query token status if it didn't fail */ + return (buffer->output[1] == token->value); +} + static int __init dell_smbios_smm_init(void) { int ret; @@ -115,6 +140,13 @@ static int __init dell_smbios_smm_init(void) dmi_walk(find_cmd_address, NULL); + ret = test_wsmt_enabled(); + pr_debug("WSMT enable test: %d\n", ret); + if (ret) { + ret = -ENODEV; + goto fail_wsmt; + } + platform_device = platform_device_alloc("dell-smbios", 1); if (!platform_device) { ret = -ENOMEM; @@ -138,6 +170,7 @@ static int __init dell_smbios_smm_init(void) fail_platform_device_add: platform_device_put(platform_device); +fail_wsmt: fail_platform_device_alloc: free_page((unsigned long)buffer); return ret; diff --git a/drivers/platform/x86/dell-smbios.h b/drivers/platform/x86/dell-smbios.h index 079776421b46..956fe9304ed7 100644 --- a/drivers/platform/x86/dell-smbios.h +++ b/drivers/platform/x86/dell-smbios.h @@ -44,6 +44,8 @@ #define KBD_LED_AUTO_100_TOKEN 0x02F6 #define GLOBAL_MIC_MUTE_ENABLE 0x0364 #define GLOBAL_MIC_MUTE_DISABLE 0x0365 +#define WSMT_EN_TOKEN 0x04EC +#define WSMT_DIS_TOKEN 0x04ED struct notifier_block;