[PATCH v2 2/5] firmware: dcdbas: Add support for WSMT ACPI table
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
---
This patch has been discussed previously, see history at
https://lore.kernel.org/patchwork/patch/958893/
drivers/firmware/dcdbas.c | 123 --
drivers/firmware/dcdbas.h | 10
2 files changed, 127 insertions(+), 6 deletions(-)
diff --git a/drivers/firmware/dcdbas.c b/drivers/firmware/dcdbas.c
index 0bdea60c65dd..ae28e48ff7dc 100644
--- a/drivers/firmware/dcdbas.c
+++ b/drivers/firmware/dcdbas.c
@@ -21,6 +21,7 @@
*/
#include
+#include
#include
#include
#include
@@ -41,7 +42,7 @@
#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);
@@ -322,8 +327,20 @@ static ssize_t smi_request_store(struct device *dev,
ret = count;
break;
case 1:
- /* Calling Interface SMI */
- smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
+ /*
+* Calling Interface SMI
+*
+* Provide physical address of command buffer field within
+* the struct smi_cmd to BIOS.
+*
+* Because the address that smi_cmd (smi_data_buf) points to
+* will be from memremap() of a non-memory address if WSMT
+* is present, we can't use virt_to_phys() on smi_cmd, so
+* we have to use the physical address that was saved when
+* the virtual address for smi_cmd was received.
+*/
+ 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 +499,93 @@ 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 += *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(eps->smm_comm_buff_anchor, SMM_EPS_SIG, 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;
+ u64 remap_size;
+ 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));
+addr += 16) {
+ eps = check_eps_table(addr);
+ if (eps)
+ break;
+ }
+
+ if
[PATCH v2 2/5] firmware: dcdbas: Add support for WSMT ACPI table
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
---
This patch has been discussed previously, see history at
https://lore.kernel.org/patchwork/patch/958893/
drivers/firmware/dcdbas.c | 123 --
drivers/firmware/dcdbas.h | 10
2 files changed, 127 insertions(+), 6 deletions(-)
diff --git a/drivers/firmware/dcdbas.c b/drivers/firmware/dcdbas.c
index 0bdea60c65dd..ae28e48ff7dc 100644
--- a/drivers/firmware/dcdbas.c
+++ b/drivers/firmware/dcdbas.c
@@ -21,6 +21,7 @@
*/
#include
+#include
#include
#include
#include
@@ -41,7 +42,7 @@
#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);
@@ -322,8 +327,20 @@ static ssize_t smi_request_store(struct device *dev,
ret = count;
break;
case 1:
- /* Calling Interface SMI */
- smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
+ /*
+* Calling Interface SMI
+*
+* Provide physical address of command buffer field within
+* the struct smi_cmd to BIOS.
+*
+* Because the address that smi_cmd (smi_data_buf) points to
+* will be from memremap() of a non-memory address if WSMT
+* is present, we can't use virt_to_phys() on smi_cmd, so
+* we have to use the physical address that was saved when
+* the virtual address for smi_cmd was received.
+*/
+ 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 +499,93 @@ 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 += *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(eps->smm_comm_buff_anchor, SMM_EPS_SIG, 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;
+ u64 remap_size;
+ 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));
+addr += 16) {
+ eps = check_eps_table(addr);
+ if (eps)
+ break;
+ }
+
+ if
