RE: [PATCH v2] dcdbas: Add support for WSMT ACPI table

2018-05-27 Thread Mario.Limonciello 


> -Original Message-
> From: Warzecha, Douglas
> Sent: Friday, May 25, 2018 2:02 PM
> To: Stuart Hayes
> Cc: Limonciello, Mario; Dominguez, Jared; linux-kernel@vger.kernel.org
> Subject: RE: [PATCH v2] dcdbas: Add support for WSMT ACPI table
> 
> 
> On 05/16/2018 9:06 AM, Stuart Hayes wrote:
> > If the WSMT ACPI table is present and indicates that a fixed communication
> > buffer should be used, use the firmware-specified buffer instead of
> > allocating a buffer in memory for communications between the dcdbas driver
> > and firmare.
> >
> > Signed-off-by: Stuart Hayes <stuart.w.ha...@gmail.com>
> > ---
> > v2 Bumped driver version to 5.6.0-3.3
> >
> >
> >  drivers/firmware/Kconfig  |   2 +-
> >  drivers/firmware/dcdbas.c | 102
> > +++---
> >  drivers/firmware/dcdbas.h |  11 +
> >  3 files changed, 109 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig index
> > b7c748248e53..a2bd6092bfa1 100644
> > --- a/drivers/firmware/Kconfig
> > +++ b/drivers/firmware/Kconfig
> > @@ -125,7 +125,7 @@ config DELL_RBU
> >
> >  config DCDBAS
> > tristate "Dell Systems Management Base Driver"
> > -   depends on X86
> > +   depends on X86 && ACPI
> > help
> >   The Dell Systems Management Base Driver provides a sysfs
> > interface
> >   for systems management software to perform System
> > Management diff --git a/drivers/firmware/dcdbas.c
> > b/drivers/firmware/dcdbas.c index 0bdea60c65dd..1699cfdcefe4 100644
> > --- a/drivers/firmware/dcdbas.c
> > +++ b/drivers/firmware/dcdbas.c
> > @@ -36,12 +36,13 @@
> >  #include 
> >  #include 
> >  #include 
> > +#include 
> >  #include 
> >
> >  #include "dcdbas.h"
> >
> >  #define DRIVER_NAME"dcdbas"
> > -#define DRIVER_VERSION "5.6.0-3.2"
> > +#define DRIVER_VERSION "5.6.0-3.3"
> >  #define DRIVER_DESCRIPTION "Dell Systems Management Base Driver"
> >
> >  static struct platform_device *dcdbas_pdev; @@ -49,19 +50,23 @@ static
> > struct platform_device *dcdbas_pdev;  static u8 *smi_data_buf;  static
> > dma_addr_t smi_data_buf_handle;  static unsigned long smi_data_buf_size;
> > +static unsigned long max_smi_data_buf_size = MAX_SMI_DATA_BUF_SIZE;
> >  static u32 smi_data_buf_phys_addr;
> >  static DEFINE_MUTEX(smi_data_lock);
> > +static u8 *eps_buffer;
> >
> >  static unsigned int host_control_action;  static unsigned int
> > host_control_smi_type;  static unsigned int host_control_on_shutdown;
> >
> > +static bool wsmt_enabled;
> > +
> >  /**
> >   * smi_data_buf_free: free SMI data buffer
> >   */
> >  static void smi_data_buf_free(void)
> >  {
> > -   if (!smi_data_buf)
> > +   if (!smi_data_buf || wsmt_enabled)
> > return;
> >
> > dev_dbg(_pdev->dev, "%s: phys: %x size: %lu\n", @@ -86,7
> > +91,7 @@ static int smi_data_buf_realloc(unsigned long size)
> > if (smi_data_buf_size >= size)
> > return 0;
> >
> > -   if (size > MAX_SMI_DATA_BUF_SIZE)
> > +   if (size > max_smi_data_buf_size)
> > return -EINVAL;
> >
> > /* new buffer is needed */
> > @@ -169,7 +174,7 @@ static ssize_t smi_data_write(struct file *filp, struct
> > kobject *kobj,  {
> > ssize_t ret;
> >
> > -   if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
> > +   if ((pos + count) > max_smi_data_buf_size)
> > return -EINVAL;
> >
> > mutex_lock(_data_lock);
> > @@ -323,7 +328,8 @@ static ssize_t smi_request_store(struct device *dev,
> > break;
> > case 1:
> > /* Calling Interface SMI */
> > -   smi_cmd->ebx = (u32) virt_to_phys(smi_cmd-
> > >command_buffer);
> > +   smi_cmd->ebx = smi_data_buf_phys_addr
> > +   + offsetof(struct smi_cmd,
> > command_buffer);
> > ret = dcdbas_smi_request(smi_cmd);
> > if (!ret)
> > ret = count;
> > @@ -482,6 +488,85 @@ static void dcdbas_host_control(void)
> > }
> >  }
> >
> > +/* WSMT */
> > +
> > +static u8 checksum(u8 *buffer, u8 length) {
> > +   u8 sum = 0;
> > +   u8 *end = buffer + length;
> > +
> > +   while (buffer < end)
> > +

RE: [PATCH v2] dcdbas: Add support for WSMT ACPI table

2018-05-27 Thread Mario.Limonciello 


> -Original Message-
> From: Warzecha, Douglas
> Sent: Friday, May 25, 2018 2:02 PM
> To: Stuart Hayes
> Cc: Limonciello, Mario; Dominguez, Jared; linux-kernel@vger.kernel.org
> Subject: RE: [PATCH v2] dcdbas: Add support for WSMT ACPI table
> 
> 
> On 05/16/2018 9:06 AM, Stuart Hayes wrote:
> > If the WSMT ACPI table is present and indicates that a fixed communication
> > buffer should be used, use the firmware-specified buffer instead of
> > allocating a buffer in memory for communications between the dcdbas driver
> > and firmare.
> >
> > Signed-off-by: Stuart Hayes 
> > ---
> > v2 Bumped driver version to 5.6.0-3.3
> >
> >
> >  drivers/firmware/Kconfig  |   2 +-
> >  drivers/firmware/dcdbas.c | 102
> > +++---
> >  drivers/firmware/dcdbas.h |  11 +
> >  3 files changed, 109 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig index
> > b7c748248e53..a2bd6092bfa1 100644
> > --- a/drivers/firmware/Kconfig
> > +++ b/drivers/firmware/Kconfig
> > @@ -125,7 +125,7 @@ config DELL_RBU
> >
> >  config DCDBAS
> > tristate "Dell Systems Management Base Driver"
> > -   depends on X86
> > +   depends on X86 && ACPI
> > help
> >   The Dell Systems Management Base Driver provides a sysfs
> > interface
> >   for systems management software to perform System
> > Management diff --git a/drivers/firmware/dcdbas.c
> > b/drivers/firmware/dcdbas.c index 0bdea60c65dd..1699cfdcefe4 100644
> > --- a/drivers/firmware/dcdbas.c
> > +++ b/drivers/firmware/dcdbas.c
> > @@ -36,12 +36,13 @@
> >  #include 
> >  #include 
> >  #include 
> > +#include 
> >  #include 
> >
> >  #include "dcdbas.h"
> >
> >  #define DRIVER_NAME"dcdbas"
> > -#define DRIVER_VERSION "5.6.0-3.2"
> > +#define DRIVER_VERSION "5.6.0-3.3"
> >  #define DRIVER_DESCRIPTION "Dell Systems Management Base Driver"
> >
> >  static struct platform_device *dcdbas_pdev; @@ -49,19 +50,23 @@ static
> > struct platform_device *dcdbas_pdev;  static u8 *smi_data_buf;  static
> > dma_addr_t smi_data_buf_handle;  static unsigned long smi_data_buf_size;
> > +static unsigned long max_smi_data_buf_size = MAX_SMI_DATA_BUF_SIZE;
> >  static u32 smi_data_buf_phys_addr;
> >  static DEFINE_MUTEX(smi_data_lock);
> > +static u8 *eps_buffer;
> >
> >  static unsigned int host_control_action;  static unsigned int
> > host_control_smi_type;  static unsigned int host_control_on_shutdown;
> >
> > +static bool wsmt_enabled;
> > +
> >  /**
> >   * smi_data_buf_free: free SMI data buffer
> >   */
> >  static void smi_data_buf_free(void)
> >  {
> > -   if (!smi_data_buf)
> > +   if (!smi_data_buf || wsmt_enabled)
> > return;
> >
> > dev_dbg(_pdev->dev, "%s: phys: %x size: %lu\n", @@ -86,7
> > +91,7 @@ static int smi_data_buf_realloc(unsigned long size)
> > if (smi_data_buf_size >= size)
> > return 0;
> >
> > -   if (size > MAX_SMI_DATA_BUF_SIZE)
> > +   if (size > max_smi_data_buf_size)
> > return -EINVAL;
> >
> > /* new buffer is needed */
> > @@ -169,7 +174,7 @@ static ssize_t smi_data_write(struct file *filp, struct
> > kobject *kobj,  {
> > ssize_t ret;
> >
> > -   if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
> > +   if ((pos + count) > max_smi_data_buf_size)
> > return -EINVAL;
> >
> > mutex_lock(_data_lock);
> > @@ -323,7 +328,8 @@ static ssize_t smi_request_store(struct device *dev,
> > break;
> > case 1:
> > /* Calling Interface SMI */
> > -   smi_cmd->ebx = (u32) virt_to_phys(smi_cmd-
> > >command_buffer);
> > +   smi_cmd->ebx = smi_data_buf_phys_addr
> > +   + offsetof(struct smi_cmd,
> > command_buffer);
> > ret = dcdbas_smi_request(smi_cmd);
> > if (!ret)
> > ret = count;
> > @@ -482,6 +488,85 @@ static void dcdbas_host_control(void)
> > }
> >  }
> >
> > +/* WSMT */
> > +
> > +static u8 checksum(u8 *buffer, u8 length) {
> > +   u8 sum = 0;
> > +   u8 *end = buffer + length;
> > +
> > +   while (buffer < end)
> > +   sum

RE: [PATCH v2] dcdbas: Add support for WSMT ACPI table

2018-05-25 Thread Douglas.Warzecha 

On 05/16/2018 9:06 AM, Stuart Hayes wrote:
> If the WSMT ACPI table is present and indicates that a fixed communication
> buffer should be used, use the firmware-specified buffer instead of
> allocating a buffer in memory for communications between the dcdbas driver
> and firmare.
> 
> Signed-off-by: Stuart Hayes 
> ---
> v2 Bumped driver version to 5.6.0-3.3
> 
> 
>  drivers/firmware/Kconfig  |   2 +-
>  drivers/firmware/dcdbas.c | 102
> +++---
>  drivers/firmware/dcdbas.h |  11 +
>  3 files changed, 109 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig index
> b7c748248e53..a2bd6092bfa1 100644
> --- a/drivers/firmware/Kconfig
> +++ b/drivers/firmware/Kconfig
> @@ -125,7 +125,7 @@ config DELL_RBU
> 
>  config DCDBAS
>   tristate "Dell Systems Management Base Driver"
> - depends on X86
> + depends on X86 && ACPI
>   help
> The Dell Systems Management Base Driver provides a sysfs
> interface
> for systems management software to perform System
> Management diff --git a/drivers/firmware/dcdbas.c
> b/drivers/firmware/dcdbas.c index 0bdea60c65dd..1699cfdcefe4 100644
> --- a/drivers/firmware/dcdbas.c
> +++ b/drivers/firmware/dcdbas.c
> @@ -36,12 +36,13 @@
>  #include 
>  #include 
>  #include 
> +#include 
>  #include 
> 
>  #include "dcdbas.h"
> 
>  #define DRIVER_NAME  "dcdbas"
> -#define DRIVER_VERSION   "5.6.0-3.2"
> +#define DRIVER_VERSION   "5.6.0-3.3"
>  #define DRIVER_DESCRIPTION   "Dell Systems Management Base Driver"
> 
>  static struct platform_device *dcdbas_pdev; @@ -49,19 +50,23 @@ static
> struct platform_device *dcdbas_pdev;  static u8 *smi_data_buf;  static
> dma_addr_t smi_data_buf_handle;  static unsigned long smi_data_buf_size;
> +static unsigned long max_smi_data_buf_size = MAX_SMI_DATA_BUF_SIZE;
>  static u32 smi_data_buf_phys_addr;
>  static DEFINE_MUTEX(smi_data_lock);
> +static u8 *eps_buffer;
> 
>  static unsigned int host_control_action;  static unsigned int
> host_control_smi_type;  static unsigned int host_control_on_shutdown;
> 
> +static bool wsmt_enabled;
> +
>  /**
>   * smi_data_buf_free: free SMI data buffer
>   */
>  static void smi_data_buf_free(void)
>  {
> - if (!smi_data_buf)
> + if (!smi_data_buf || wsmt_enabled)
>   return;
> 
>   dev_dbg(_pdev->dev, "%s: phys: %x size: %lu\n", @@ -86,7
> +91,7 @@ static int smi_data_buf_realloc(unsigned long size)
>   if (smi_data_buf_size >= size)
>   return 0;
> 
> - if (size > MAX_SMI_DATA_BUF_SIZE)
> + if (size > max_smi_data_buf_size)
>   return -EINVAL;
> 
>   /* new buffer is needed */
> @@ -169,7 +174,7 @@ static ssize_t smi_data_write(struct file *filp, struct
> kobject *kobj,  {
>   ssize_t ret;
> 
> - if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
> + if ((pos + count) > max_smi_data_buf_size)
>   return -EINVAL;
> 
>   mutex_lock(_data_lock);
> @@ -323,7 +328,8 @@ static ssize_t smi_request_store(struct device *dev,
>   break;
>   case 1:
>   /* Calling Interface SMI */
> - smi_cmd->ebx = (u32) virt_to_phys(smi_cmd-
> >command_buffer);
> + smi_cmd->ebx = smi_data_buf_phys_addr
> + + offsetof(struct smi_cmd,
> command_buffer);
>   ret = dcdbas_smi_request(smi_cmd);
>   if (!ret)
>   ret = count;
> @@ -482,6 +488,85 @@ static void dcdbas_host_control(void)
>   }
>  }
> 
> +/* WSMT */
> +
> +static u8 checksum(u8 *buffer, u8 length) {
> + u8 sum = 0;
> + u8 *end = buffer + length;
> +
> + while (buffer < end)
> + sum = (u8)(sum + *(buffer++));
> + return sum;
> +}
> +
> +static inline struct smm_eps_table *check_eps_table(u8 *addr) {
> + struct smm_eps_table *eps = (struct smm_eps_table *)addr;
> +
> + if (strncmp(SMM_EPS_SIG, eps->smm_comm_buff_anchor, 4) != 0)
> + return NULL;
> +
> + if (checksum(addr, eps->length) != 0)
> + return NULL;
> +
> + return eps;
> +}
> +
> +static int dcdbas_check_wsmt(void)
> +{
> + struct acpi_table_wsmt *wsmt = NULL;
> + struct smm_eps_table *eps = NULL;
> + u8 *addr;
> +
> + acpi_get_table(ACPI_SIG_WSMT, 0, (struct acpi_table_header
> **));
> + if (!wsmt)
> + return 0;
> +
> + /* Check if WSMT ACPI table shows that protection is enabled */
> + if (!(wsmt->protection_flags &
> ACPI_WSMT_FIXED_COMM_BUFFERS)
> + || !(wsmt->protection_flags
> +  &
> ACPI_WSMT_COMM_BUFFER_NESTED_PTR_PROTECTION))
> + return 0;
> +
> + /* Scan for EPS (entry point structure) */
> + for (addr = (u8 *)__va(0xf);
> +  addr < (u8 *)__va(0x10 - sizeof(struct smm_eps_table)) &&
> !eps;
> +  addr += 1)
> + eps = check_eps_table(addr);
> +
> +

RE: [PATCH v2] dcdbas: Add support for WSMT ACPI table

2018-05-25 Thread Douglas.Warzecha 

On 05/16/2018 9:06 AM, Stuart Hayes wrote:
> If the WSMT ACPI table is present and indicates that a fixed communication
> buffer should be used, use the firmware-specified buffer instead of
> allocating a buffer in memory for communications between the dcdbas driver
> and firmare.
> 
> Signed-off-by: Stuart Hayes 
> ---
> v2 Bumped driver version to 5.6.0-3.3
> 
> 
>  drivers/firmware/Kconfig  |   2 +-
>  drivers/firmware/dcdbas.c | 102
> +++---
>  drivers/firmware/dcdbas.h |  11 +
>  3 files changed, 109 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig index
> b7c748248e53..a2bd6092bfa1 100644
> --- a/drivers/firmware/Kconfig
> +++ b/drivers/firmware/Kconfig
> @@ -125,7 +125,7 @@ config DELL_RBU
> 
>  config DCDBAS
>   tristate "Dell Systems Management Base Driver"
> - depends on X86
> + depends on X86 && ACPI
>   help
> The Dell Systems Management Base Driver provides a sysfs
> interface
> for systems management software to perform System
> Management diff --git a/drivers/firmware/dcdbas.c
> b/drivers/firmware/dcdbas.c index 0bdea60c65dd..1699cfdcefe4 100644
> --- a/drivers/firmware/dcdbas.c
> +++ b/drivers/firmware/dcdbas.c
> @@ -36,12 +36,13 @@
>  #include 
>  #include 
>  #include 
> +#include 
>  #include 
> 
>  #include "dcdbas.h"
> 
>  #define DRIVER_NAME  "dcdbas"
> -#define DRIVER_VERSION   "5.6.0-3.2"
> +#define DRIVER_VERSION   "5.6.0-3.3"
>  #define DRIVER_DESCRIPTION   "Dell Systems Management Base Driver"
> 
>  static struct platform_device *dcdbas_pdev; @@ -49,19 +50,23 @@ static
> struct platform_device *dcdbas_pdev;  static u8 *smi_data_buf;  static
> dma_addr_t smi_data_buf_handle;  static unsigned long smi_data_buf_size;
> +static unsigned long max_smi_data_buf_size = MAX_SMI_DATA_BUF_SIZE;
>  static u32 smi_data_buf_phys_addr;
>  static DEFINE_MUTEX(smi_data_lock);
> +static u8 *eps_buffer;
> 
>  static unsigned int host_control_action;  static unsigned int
> host_control_smi_type;  static unsigned int host_control_on_shutdown;
> 
> +static bool wsmt_enabled;
> +
>  /**
>   * smi_data_buf_free: free SMI data buffer
>   */
>  static void smi_data_buf_free(void)
>  {
> - if (!smi_data_buf)
> + if (!smi_data_buf || wsmt_enabled)
>   return;
> 
>   dev_dbg(_pdev->dev, "%s: phys: %x size: %lu\n", @@ -86,7
> +91,7 @@ static int smi_data_buf_realloc(unsigned long size)
>   if (smi_data_buf_size >= size)
>   return 0;
> 
> - if (size > MAX_SMI_DATA_BUF_SIZE)
> + if (size > max_smi_data_buf_size)
>   return -EINVAL;
> 
>   /* new buffer is needed */
> @@ -169,7 +174,7 @@ static ssize_t smi_data_write(struct file *filp, struct
> kobject *kobj,  {
>   ssize_t ret;
> 
> - if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
> + if ((pos + count) > max_smi_data_buf_size)
>   return -EINVAL;
> 
>   mutex_lock(_data_lock);
> @@ -323,7 +328,8 @@ static ssize_t smi_request_store(struct device *dev,
>   break;
>   case 1:
>   /* Calling Interface SMI */
> - smi_cmd->ebx = (u32) virt_to_phys(smi_cmd-
> >command_buffer);
> + smi_cmd->ebx = smi_data_buf_phys_addr
> + + offsetof(struct smi_cmd,
> command_buffer);
>   ret = dcdbas_smi_request(smi_cmd);
>   if (!ret)
>   ret = count;
> @@ -482,6 +488,85 @@ static void dcdbas_host_control(void)
>   }
>  }
> 
> +/* WSMT */
> +
> +static u8 checksum(u8 *buffer, u8 length) {
> + u8 sum = 0;
> + u8 *end = buffer + length;
> +
> + while (buffer < end)
> + sum = (u8)(sum + *(buffer++));
> + return sum;
> +}
> +
> +static inline struct smm_eps_table *check_eps_table(u8 *addr) {
> + struct smm_eps_table *eps = (struct smm_eps_table *)addr;
> +
> + if (strncmp(SMM_EPS_SIG, eps->smm_comm_buff_anchor, 4) != 0)
> + return NULL;
> +
> + if (checksum(addr, eps->length) != 0)
> + return NULL;
> +
> + return eps;
> +}
> +
> +static int dcdbas_check_wsmt(void)
> +{
> + struct acpi_table_wsmt *wsmt = NULL;
> + struct smm_eps_table *eps = NULL;
> + u8 *addr;
> +
> + acpi_get_table(ACPI_SIG_WSMT, 0, (struct acpi_table_header
> **));
> + if (!wsmt)
> + return 0;
> +
> + /* Check if WSMT ACPI table shows that protection is enabled */
> + if (!(wsmt->protection_flags &
> ACPI_WSMT_FIXED_COMM_BUFFERS)
> + || !(wsmt->protection_flags
> +  &
> ACPI_WSMT_COMM_BUFFER_NESTED_PTR_PROTECTION))
> + return 0;
> +
> + /* Scan for EPS (entry point structure) */
> + for (addr = (u8 *)__va(0xf);
> +  addr < (u8 *)__va(0x10 - sizeof(struct smm_eps_table)) &&
> !eps;
> +  addr += 1)
> + eps = check_eps_table(addr);
> +
> + if (!eps) {
> +

[PATCH v2] dcdbas: Add support for WSMT ACPI table

2018-05-16 Thread Stuart Hayes 
If the WSMT ACPI table is present and indicates that a fixed communication
buffer should be used, use the firmware-specified buffer instead of
allocating a buffer in memory for communications between the dcdbas driver
and firmare.

Signed-off-by: Stuart Hayes 
---
v2 Bumped driver version to 5.6.0-3.3


 drivers/firmware/Kconfig  |   2 +-
 drivers/firmware/dcdbas.c | 102 +++---
 drivers/firmware/dcdbas.h |  11 +
 3 files changed, 109 insertions(+), 6 deletions(-)

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index b7c748248e53..a2bd6092bfa1 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -125,7 +125,7 @@ config DELL_RBU
 
 config DCDBAS
tristate "Dell Systems Management Base Driver"
-   depends on X86
+   depends on X86 && ACPI
help
  The Dell Systems Management Base Driver provides a sysfs interface
  for systems management software to perform System Management
diff --git a/drivers/firmware/dcdbas.c b/drivers/firmware/dcdbas.c
index 0bdea60c65dd..1699cfdcefe4 100644
--- a/drivers/firmware/dcdbas.c
+++ b/drivers/firmware/dcdbas.c
@@ -36,12 +36,13 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 
 #include "dcdbas.h"
 
 #define DRIVER_NAME"dcdbas"
-#define DRIVER_VERSION "5.6.0-3.2"
+#define DRIVER_VERSION "5.6.0-3.3"
 #define DRIVER_DESCRIPTION "Dell Systems Management Base Driver"
 
 static struct platform_device *dcdbas_pdev;
@@ -49,19 +50,23 @@ static struct platform_device *dcdbas_pdev;
 static u8 *smi_data_buf;
 static dma_addr_t smi_data_buf_handle;
 static unsigned long smi_data_buf_size;
+static unsigned long max_smi_data_buf_size = MAX_SMI_DATA_BUF_SIZE;
 static u32 smi_data_buf_phys_addr;
 static DEFINE_MUTEX(smi_data_lock);
+static u8 *eps_buffer;
 
 static unsigned int host_control_action;
 static unsigned int host_control_smi_type;
 static unsigned int host_control_on_shutdown;
 
+static bool wsmt_enabled;
+
 /**
  * smi_data_buf_free: free SMI data buffer
  */
 static void smi_data_buf_free(void)
 {
-   if (!smi_data_buf)
+   if (!smi_data_buf || wsmt_enabled)
return;
 
dev_dbg(_pdev->dev, "%s: phys: %x size: %lu\n",
@@ -86,7 +91,7 @@ static int smi_data_buf_realloc(unsigned long size)
if (smi_data_buf_size >= size)
return 0;
 
-   if (size > MAX_SMI_DATA_BUF_SIZE)
+   if (size > max_smi_data_buf_size)
return -EINVAL;
 
/* new buffer is needed */
@@ -169,7 +174,7 @@ static ssize_t smi_data_write(struct file *filp, struct 
kobject *kobj,
 {
ssize_t ret;
 
-   if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
+   if ((pos + count) > max_smi_data_buf_size)
return -EINVAL;
 
mutex_lock(_data_lock);
@@ -323,7 +328,8 @@ static ssize_t smi_request_store(struct device *dev,
break;
case 1:
/* Calling Interface SMI */
-   smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
+   smi_cmd->ebx = smi_data_buf_phys_addr
+   + offsetof(struct smi_cmd, command_buffer);
ret = dcdbas_smi_request(smi_cmd);
if (!ret)
ret = count;
@@ -482,6 +488,85 @@ static void dcdbas_host_control(void)
}
 }
 
+/* WSMT */
+
+static u8 checksum(u8 *buffer, u8 length)
+{
+   u8 sum = 0;
+   u8 *end = buffer + length;
+
+   while (buffer < end)
+   sum = (u8)(sum + *(buffer++));
+   return sum;
+}
+
+static inline struct smm_eps_table *check_eps_table(u8 *addr)
+{
+   struct smm_eps_table *eps = (struct smm_eps_table *)addr;
+
+   if (strncmp(SMM_EPS_SIG, eps->smm_comm_buff_anchor, 4) != 0)
+   return NULL;
+
+   if (checksum(addr, eps->length) != 0)
+   return NULL;
+
+   return eps;
+}
+
+static int dcdbas_check_wsmt(void)
+{
+   struct acpi_table_wsmt *wsmt = NULL;
+   struct smm_eps_table *eps = NULL;
+   u8 *addr;
+
+   acpi_get_table(ACPI_SIG_WSMT, 0, (struct acpi_table_header **));
+   if (!wsmt)
+   return 0;
+
+   /* Check if WSMT ACPI table shows that protection is enabled */
+   if (!(wsmt->protection_flags & ACPI_WSMT_FIXED_COMM_BUFFERS)
+   || !(wsmt->protection_flags
+& ACPI_WSMT_COMM_BUFFER_NESTED_PTR_PROTECTION))
+   return 0;
+
+   /* Scan for EPS (entry point structure) */
+   for (addr = (u8 *)__va(0xf);
+addr < (u8 *)__va(0x10 - sizeof(struct smm_eps_table)) && !eps;
+addr += 1)
+   eps = check_eps_table(addr);
+
+   if (!eps) {
+   dev_dbg(_pdev->dev, "found WSMT, but no EPS found\n");
+   return -ENODEV;
+   }
+
+   /*
+* Get physical address of buffer and map to virtual address.
+* Table gives

[PATCH v2] dcdbas: Add support for WSMT ACPI table

2018-05-16 Thread Stuart Hayes 
If the WSMT ACPI table is present and indicates that a fixed communication
buffer should be used, use the firmware-specified buffer instead of
allocating a buffer in memory for communications between the dcdbas driver
and firmare.

Signed-off-by: Stuart Hayes 
---
v2 Bumped driver version to 5.6.0-3.3


 drivers/firmware/Kconfig  |   2 +-
 drivers/firmware/dcdbas.c | 102 +++---
 drivers/firmware/dcdbas.h |  11 +
 3 files changed, 109 insertions(+), 6 deletions(-)

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index b7c748248e53..a2bd6092bfa1 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -125,7 +125,7 @@ config DELL_RBU
 
 config DCDBAS
tristate "Dell Systems Management Base Driver"
-   depends on X86
+   depends on X86 && ACPI
help
  The Dell Systems Management Base Driver provides a sysfs interface
  for systems management software to perform System Management
diff --git a/drivers/firmware/dcdbas.c b/drivers/firmware/dcdbas.c
index 0bdea60c65dd..1699cfdcefe4 100644
--- a/drivers/firmware/dcdbas.c
+++ b/drivers/firmware/dcdbas.c
@@ -36,12 +36,13 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 
 #include "dcdbas.h"
 
 #define DRIVER_NAME"dcdbas"
-#define DRIVER_VERSION "5.6.0-3.2"
+#define DRIVER_VERSION "5.6.0-3.3"
 #define DRIVER_DESCRIPTION "Dell Systems Management Base Driver"
 
 static struct platform_device *dcdbas_pdev;
@@ -49,19 +50,23 @@ static struct platform_device *dcdbas_pdev;
 static u8 *smi_data_buf;
 static dma_addr_t smi_data_buf_handle;
 static unsigned long smi_data_buf_size;
+static unsigned long max_smi_data_buf_size = MAX_SMI_DATA_BUF_SIZE;
 static u32 smi_data_buf_phys_addr;
 static DEFINE_MUTEX(smi_data_lock);
+static u8 *eps_buffer;
 
 static unsigned int host_control_action;
 static unsigned int host_control_smi_type;
 static unsigned int host_control_on_shutdown;
 
+static bool wsmt_enabled;
+
 /**
  * smi_data_buf_free: free SMI data buffer
  */
 static void smi_data_buf_free(void)
 {
-   if (!smi_data_buf)
+   if (!smi_data_buf || wsmt_enabled)
return;
 
dev_dbg(_pdev->dev, "%s: phys: %x size: %lu\n",
@@ -86,7 +91,7 @@ static int smi_data_buf_realloc(unsigned long size)
if (smi_data_buf_size >= size)
return 0;
 
-   if (size > MAX_SMI_DATA_BUF_SIZE)
+   if (size > max_smi_data_buf_size)
return -EINVAL;
 
/* new buffer is needed */
@@ -169,7 +174,7 @@ static ssize_t smi_data_write(struct file *filp, struct 
kobject *kobj,
 {
ssize_t ret;
 
-   if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
+   if ((pos + count) > max_smi_data_buf_size)
return -EINVAL;
 
mutex_lock(_data_lock);
@@ -323,7 +328,8 @@ static ssize_t smi_request_store(struct device *dev,
break;
case 1:
/* Calling Interface SMI */
-   smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
+   smi_cmd->ebx = smi_data_buf_phys_addr
+   + offsetof(struct smi_cmd, command_buffer);
ret = dcdbas_smi_request(smi_cmd);
if (!ret)
ret = count;
@@ -482,6 +488,85 @@ static void dcdbas_host_control(void)
}
 }
 
+/* WSMT */
+
+static u8 checksum(u8 *buffer, u8 length)
+{
+   u8 sum = 0;
+   u8 *end = buffer + length;
+
+   while (buffer < end)
+   sum = (u8)(sum + *(buffer++));
+   return sum;
+}
+
+static inline struct smm_eps_table *check_eps_table(u8 *addr)
+{
+   struct smm_eps_table *eps = (struct smm_eps_table *)addr;
+
+   if (strncmp(SMM_EPS_SIG, eps->smm_comm_buff_anchor, 4) != 0)
+   return NULL;
+
+   if (checksum(addr, eps->length) != 0)
+   return NULL;
+
+   return eps;
+}
+
+static int dcdbas_check_wsmt(void)
+{
+   struct acpi_table_wsmt *wsmt = NULL;
+   struct smm_eps_table *eps = NULL;
+   u8 *addr;
+
+   acpi_get_table(ACPI_SIG_WSMT, 0, (struct acpi_table_header **));
+   if (!wsmt)
+   return 0;
+
+   /* Check if WSMT ACPI table shows that protection is enabled */
+   if (!(wsmt->protection_flags & ACPI_WSMT_FIXED_COMM_BUFFERS)
+   || !(wsmt->protection_flags
+& ACPI_WSMT_COMM_BUFFER_NESTED_PTR_PROTECTION))
+   return 0;
+
+   /* Scan for EPS (entry point structure) */
+   for (addr = (u8 *)__va(0xf);
+addr < (u8 *)__va(0x10 - sizeof(struct smm_eps_table)) && !eps;
+addr += 1)
+   eps = check_eps_table(addr);
+
+   if (!eps) {
+   dev_dbg(_pdev->dev, "found WSMT, but no EPS found\n");
+   return -ENODEV;
+   }
+
+   /*
+* Get physical address of buffer and map to virtual address.
+* Table gives size in 4K pages,