Skip to contentSkip to conversation

x86: Handle 64bit framebuffer memory address properly

PATCH In review Kairui Song 2 participants 4 messages Dec 5, 2018 – Jan 28, 2019

Subsystems (2)
Live update kexec handover (KHO)
lore
Share & tools
lore

Kairui Song

author
#0 lore raw

PATCH v2 1/1 x86: Handle 64bit framebuffer memory address properly

In a EFI system, the frame buffer address is 64bit, so currently if the address is beyound 4G, kexec will set wrong address due to truncate.

Linux kernel commit ae2ee627dc87 ('efifb: Add support for 64-bit frame buffer addresses') added support for 64bit frame buffer address, an 'ext_lfb_base' field is added as the upper 32-bits of the frame buffer, and introduced a new capability flag 'VIDEO_TYPE_CAPABILITY_64BIT_BASE' to indicate if the extend field is used.

This patch adopts this change, set proper extent address and capability flag when the address is beyound 4G.

Signed-off-by Kairui Song <[email protected]>

---
Update from V1:
- Use 0xffffffffUL instead of 0xffffffff for comparing and bit operation with smem_start to make it cleaner and safer, as smem_start is an unsigned long.

 include/x86/x86-linux.h           | 7 +++++--
 kexec/arch/i386/x86-linux-setup.c | 7 ++++++-
 2 files changed, 11 insertions(+), 3 deletions(-)
include/x86/x86-linux.h +5 -2
index 7834751..352ea02 100644
@@ -107,7 +107,10 @@ struct x86_linux_param_header {
 	uint16_t vesapm_seg;			/* 0x2e */
 	uint16_t vesapm_off;			/* 0x30 */
 	uint16_t pages;				/* 0x32 */
-	uint8_t  reserved4[12];			/* 0x34 -- 0x3f reserved for future expansion */
+	uint16_t vesa_attributes;		/* 0x34 */
+	uint32_t capabilities;			/* 0x36 */
+	uint32_t ext_lfb_base;			/* 0x3a */
+	uint8_t  reserved4[2];			/* 0x3e -- 0x3f reserved for future expansion */
 
 	struct apm_bios_info apm_bios_info;	/* 0x40 */
 	struct drive_info_struct drive_info;	/* 0x80 */

@@ -199,7 +202,7 @@ struct x86_linux_param_header {
 	struct 	edd_info eddbuf[EDDMAXNR];	/* 0xd00 */
 						/* 0xeec */
 #define COMMAND_LINE_SIZE 2048
-};
+} __attribute__((packed));
 
 struct x86_linux_faked_param_header {
 	struct x86_linux_param_header hdr;	/* 0x00 */
kexec/arch/i386/x86-linux-setup.c +6 -1
index 6cda12c..1bd408b 100644
@@ -158,10 +158,15 @@ static int setup_linux_vesafb(struct x86_linux_param_header *real_mode)
 	real_mode->lfb_width      = var.xres;
 	real_mode->lfb_height     = var.yres;
 	real_mode->lfb_depth      = var.bits_per_pixel;
-	real_mode->lfb_base       = fix.smem_start;
+	real_mode->lfb_base       = fix.smem_start & 0xffffffffUL;
 	real_mode->lfb_linelength = fix.line_length;
 	real_mode->vesapm_seg     = 0;
 
+	if (fix.smem_start > 0xffffffffUL) {
+		real_mode->ext_lfb_base = fix.smem_start >> 32;
+		real_mode->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
+	}
+
 	/* FIXME: better get size from the file returned by proc_iomem() */
 	real_mode->lfb_size       = (fix.smem_len + 65535) / 65536;
 	real_mode->pages          = (fix.smem_len + 4095) / 4096;
Signature · 7 lines
2.19.1


_______________________________________________
kexec mailing list
[email protected]
http://lists.infradead.org/mailman/listinfo/kexec
author
#1 lore raw
Quoted 73 lines · Kairui Song

In a EFI system, the frame buffer address is 64bit, so currently if the address is beyound 4G, kexec will set wrong address due to truncate.

Linux kernel commit ae2ee627dc87 ('efifb: Add support for 64-bit frame buffer addresses') added support for 64bit frame buffer address, an 'ext_lfb_base' field is added as the upper 32-bits of the frame buffer, and introduced a new capability flag 'VIDEO_TYPE_CAPABILITY_64BIT_BASE' to indicate if the extend field is used.

This patch adopts this change, set proper extent address and capability flag when the address is beyound 4G.

Signed-off-by Kairui Song <[email protected]>

---
Update from V1:
- Use 0xffffffffUL instead of 0xffffffff for comparing and bit operation with smem_start to make it cleaner and safer, as smem_start is an unsigned long.

 include/x86/x86-linux.h           | 7 +++++--
 kexec/arch/i386/x86-linux-setup.c | 7 ++++++-
 2 files changed, 11 insertions(+), 3 deletions(-)
include/x86/x86-linux.h +5 -2
index 7834751..352ea02 100644
@@ -107,7 +107,10 @@ struct x86_linux_param_header {
        uint16_t vesapm_seg;                    /* 0x2e */
        uint16_t vesapm_off;                    /* 0x30 */
        uint16_t pages;                         /* 0x32 */
-       uint8_t  reserved4[12];                 /* 0x34 -- 0x3f reserved for future expansion */
+       uint16_t vesa_attributes;               /* 0x34 */
+       uint32_t capabilities;                  /* 0x36 */
+       uint32_t ext_lfb_base;                  /* 0x3a */
+       uint8_t  reserved4[2];                  /* 0x3e -- 0x3f reserved for future expansion */
 
        struct apm_bios_info apm_bios_info;     /* 0x40 */
        struct drive_info_struct drive_info;    /* 0x80 */

@@ -199,7 +202,7 @@ struct x86_linux_param_header {
        struct  edd_info eddbuf[EDDMAXNR];      /* 0xd00 */
                                                /* 0xeec */
 #define COMMAND_LINE_SIZE 2048
-};
+} __attribute__((packed));
 
 struct x86_linux_faked_param_header {
        struct x86_linux_param_header hdr;      /* 0x00 */
kexec/arch/i386/x86-linux-setup.c +6 -2
index 6cda12c..1bd408b 100644
@@ -158,10 +158,15 @@ static int setup_linux_vesafb(struct x86_linux_param_header *real_mode)
        real_mode->lfb_width      = var.xres;
        real_mode->lfb_height     = var.yres;
        real_mode->lfb_depth      = var.bits_per_pixel;
-       real_mode->lfb_base       = fix.smem_start;
+       real_mode->lfb_base       = fix.smem_start & 0xffffffffUL;
        real_mode->lfb_linelength = fix.line_length;
        real_mode->vesapm_seg     = 0;
 
+       if (fix.smem_start > 0xffffffffUL) {
+               real_mode->ext_lfb_base = fix.smem_start >> 32;
+               real_mode->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
+       }
+
        /* FIXME: better get size from the file returned by proc_iomem() */
        real_mode->lfb_size       = (fix.smem_len + 65535) / 65536;
        real_mode->pages          = (fix.smem_len + 4095) / 4096;
--
Quoted 2 lines

2.19.1

Hi Simon,

Could you please have a look of this patch? Thanks

--
Best Regards,
Kairui Song

_______________________________________________
kexec mailing list
[email protected]
http://lists.infradead.org/mailman/listinfo/kexec

#2 lore raw
Quoted 79 lines · Kairui Song
Quoted 73 lines · Kairui Song

In a EFI system, the frame buffer address is 64bit, so currently if the address is beyound 4G, kexec will set wrong address due to truncate.

Linux kernel commit ae2ee627dc87 ('efifb: Add support for 64-bit frame buffer addresses') added support for 64bit frame buffer address, an 'ext_lfb_base' field is added as the upper 32-bits of the frame buffer, and introduced a new capability flag 'VIDEO_TYPE_CAPABILITY_64BIT_BASE' to indicate if the extend field is used.

This patch adopts this change, set proper extent address and capability flag when the address is beyound 4G.

Signed-off-by Kairui Song <[email protected]>

---
Update from V1:
- Use 0xffffffffUL instead of 0xffffffff for comparing and bit operation with smem_start to make it cleaner and safer, as smem_start is an unsigned long.

 include/x86/x86-linux.h           | 7 +++++--
 kexec/arch/i386/x86-linux-setup.c | 7 ++++++-
 2 files changed, 11 insertions(+), 3 deletions(-)
include/x86/x86-linux.h +5 -2
index 7834751..352ea02 100644
@@ -107,7 +107,10 @@ struct x86_linux_param_header {
        uint16_t vesapm_seg;                    /* 0x2e */
        uint16_t vesapm_off;                    /* 0x30 */
        uint16_t pages;                         /* 0x32 */
-       uint8_t  reserved4[12];                 /* 0x34 -- 0x3f reserved for future expansion */
+       uint16_t vesa_attributes;               /* 0x34 */
+       uint32_t capabilities;                  /* 0x36 */
+       uint32_t ext_lfb_base;                  /* 0x3a */
+       uint8_t  reserved4[2];                  /* 0x3e -- 0x3f reserved for future expansion */
 
        struct apm_bios_info apm_bios_info;     /* 0x40 */
        struct drive_info_struct drive_info;    /* 0x80 */

@@ -199,7 +202,7 @@ struct x86_linux_param_header {
        struct  edd_info eddbuf[EDDMAXNR];      /* 0xd00 */
                                                /* 0xeec */
 #define COMMAND_LINE_SIZE 2048
-};
+} __attribute__((packed));
 
 struct x86_linux_faked_param_header {
        struct x86_linux_param_header hdr;      /* 0x00 */
kexec/arch/i386/x86-linux-setup.c +6 -2
index 6cda12c..1bd408b 100644
@@ -158,10 +158,15 @@ static int setup_linux_vesafb(struct x86_linux_param_header *real_mode)
        real_mode->lfb_width      = var.xres;
        real_mode->lfb_height     = var.yres;
        real_mode->lfb_depth      = var.bits_per_pixel;
-       real_mode->lfb_base       = fix.smem_start;
+       real_mode->lfb_base       = fix.smem_start & 0xffffffffUL;
        real_mode->lfb_linelength = fix.line_length;
        real_mode->vesapm_seg     = 0;
 
+       if (fix.smem_start > 0xffffffffUL) {
+               real_mode->ext_lfb_base = fix.smem_start >> 32;
+               real_mode->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
+       }
+
        /* FIXME: better get size from the file returned by proc_iomem() */
        real_mode->lfb_size       = (fix.smem_len + 65535) / 65536;
        real_mode->pages          = (fix.smem_len + 4095) / 4096;
--
Quoted 2 lines

2.19.1

Hi Simon,

Quoted 1 line

Could you please have a look of this patch? Thanks

Sorry, for the delay.
This got stuck in my TODO list for way to long.

This patch looks good to me and I have applied it for inclusion in the next release of kexec-tools.

_______________________________________________
kexec mailing list
[email protected]
http://lists.infradead.org/mailman/listinfo/kexec

author
#3 lore raw
Quoted 81 lines · Simon Horman
Quoted 79 lines · Kairui Song
Quoted 73 lines · Kairui Song

In a EFI system, the frame buffer address is 64bit, so currently if the address is beyound 4G, kexec will set wrong address due to truncate.

Linux kernel commit ae2ee627dc87 ('efifb: Add support for 64-bit frame buffer addresses') added support for 64bit frame buffer address, an 'ext_lfb_base' field is added as the upper 32-bits of the frame buffer, and introduced a new capability flag 'VIDEO_TYPE_CAPABILITY_64BIT_BASE' to indicate if the extend field is used.

This patch adopts this change, set proper extent address and capability flag when the address is beyound 4G.

Signed-off-by Kairui Song <[email protected]>

---
Update from V1:
- Use 0xffffffffUL instead of 0xffffffff for comparing and bit operation with smem_start to make it cleaner and safer, as smem_start is an unsigned long.

 include/x86/x86-linux.h           | 7 +++++--
 kexec/arch/i386/x86-linux-setup.c | 7 ++++++-
 2 files changed, 11 insertions(+), 3 deletions(-)
include/x86/x86-linux.h +5 -2
index 7834751..352ea02 100644
@@ -107,7 +107,10 @@ struct x86_linux_param_header {
        uint16_t vesapm_seg;                    /* 0x2e */
        uint16_t vesapm_off;                    /* 0x30 */
        uint16_t pages;                         /* 0x32 */
-       uint8_t  reserved4[12];                 /* 0x34 -- 0x3f reserved for future expansion */
+       uint16_t vesa_attributes;               /* 0x34 */
+       uint32_t capabilities;                  /* 0x36 */
+       uint32_t ext_lfb_base;                  /* 0x3a */
+       uint8_t  reserved4[2];                  /* 0x3e -- 0x3f reserved for future expansion */
 
        struct apm_bios_info apm_bios_info;     /* 0x40 */
        struct drive_info_struct drive_info;    /* 0x80 */

@@ -199,7 +202,7 @@ struct x86_linux_param_header {
        struct  edd_info eddbuf[EDDMAXNR];      /* 0xd00 */
                                                /* 0xeec */
 #define COMMAND_LINE_SIZE 2048
-};
+} __attribute__((packed));
 
 struct x86_linux_faked_param_header {
        struct x86_linux_param_header hdr;      /* 0x00 */
kexec/arch/i386/x86-linux-setup.c +6 -2
index 6cda12c..1bd408b 100644
@@ -158,10 +158,15 @@ static int setup_linux_vesafb(struct x86_linux_param_header *real_mode)
        real_mode->lfb_width      = var.xres;
        real_mode->lfb_height     = var.yres;
        real_mode->lfb_depth      = var.bits_per_pixel;
-       real_mode->lfb_base       = fix.smem_start;
+       real_mode->lfb_base       = fix.smem_start & 0xffffffffUL;
        real_mode->lfb_linelength = fix.line_length;
        real_mode->vesapm_seg     = 0;
 
+       if (fix.smem_start > 0xffffffffUL) {
+               real_mode->ext_lfb_base = fix.smem_start >> 32;
+               real_mode->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
+       }
+
        /* FIXME: better get size from the file returned by proc_iomem() */
        real_mode->lfb_size       = (fix.smem_len + 65535) / 65536;
        real_mode->pages          = (fix.smem_len + 4095) / 4096;
--
Quoted 2 lines

2.19.1

Hi Simon,

Quoted 7 lines
Quoted 1 line

Could you please have a look of this patch? Thanks

Sorry, for the delay.
This got stuck in my TODO list for way to long.

This patch looks good to me and I have applied it for inclusion in the next release of kexec-tools.

No worry, thanks for the merge.

--
Best Regards,
Kairui Song

_______________________________________________
kexec mailing list
[email protected]
http://lists.infradead.org/mailman/listinfo/kexec