| Message ID | e552ba67da7281d184936a551501c4040510b372.1508259916.git.mario.limonciello@dell.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Delegated to: | Darren Hart |
| Headers | show |
On Tuesday 17 October 2017 13:21:55 Mario Limonciello wrote: > +/* When enabled this indicates that SMM won't work */ > +static int 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 0; > + > + /* 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 1; > + > + /* query token status if it didn't fail */ > + return (buffer->output[1] == token->value); > +} Maybe small suggestion... function returns only zero or one -- what is a good candidate to have return value boolean and not basic int.
On Tue, Oct 17, 2017 at 09:22:58PM +0200, Pali Rohár wrote: > On Tuesday 17 October 2017 13:21:55 Mario Limonciello wrote: > > +/* When enabled this indicates that SMM won't work */ > > +static int 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 0; > > + > > + /* 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 1; > > + > > + /* query token status if it didn't fail */ > > + return (buffer->output[1] == token->value); > > +} > > Maybe small suggestion... function returns only zero or one -- what is a > good candidate to have return value boolean and not basic int. Yes please.
> -----Original Message----- > From: Darren Hart [mailto:dvhart@infradead.org] > Sent: Wednesday, October 18, 2017 2:09 PM > To: Pali Rohár <pali.rohar@gmail.com> > Cc: Limonciello, Mario <Mario_Limonciello@Dell.com>; 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 v9 11/17] platform/x86: dell-smbios-smm: test for WSMT > > On Tue, Oct 17, 2017 at 09:22:58PM +0200, Pali Rohár wrote: > > On Tuesday 17 October 2017 13:21:55 Mario Limonciello wrote: > > > +/* When enabled this indicates that SMM won't work */ > > > +static int 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 0; > > > + > > > + /* 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 1; > > > + > > > + /* query token status if it didn't fail */ > > > + return (buffer->output[1] == token->value); > > > +} > > > > Maybe small suggestion... function returns only zero or one -- what is a > > good candidate to have return value boolean and not basic int. > > Yes please. > OK I'll adjust this (and the other things Pali sent recently) in the next submission. Just waiting on feedback for some of the other areas before sending off again.
diff --git a/drivers/platform/x86/dell-smbios-smm.c b/drivers/platform/x86/dell-smbios-smm.c index 53eabb14fb48..c2dfe4c5908c 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 int 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 0; + + /* 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 1; + + /* 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 8df330abeb5d..db6a16e5f87c 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;