linux_dsm_epyc7002/drivers/video/fbdev/efifb.c
Dave Airlie dd0c41f8a7 efifb: allow user to disable write combined mapping.
This patch allows the user to disable write combined mapping
of the efifb framebuffer console using an nowc option.

A customer noticed major slowdowns while logging to the console
with write combining enabled, on other tasks running on the same
CPU. (10x or greater slow down on all other cores on the same CPU
as is doing the logging).

I reproduced this on a machine with dual CPUs.
Intel(R) Xeon(R) CPU E5-2609 v3 @ 1.90GHz (6 core)

I wrote a test that just mmaps the pci bar and writes to it in
a loop, while this was running in the background one a single
core with (taskset -c 1), building a kernel up to init/version.o
(taskset -c 8) went from 13s to 133s or so. I've yet to explain
why this occurs or what is going wrong I haven't managed to find
a perf command that in any way gives insight into this.

    11,885,070,715      instructions              #    1.39  insns per cycle
vs
    12,082,592,342      instructions              #    0.13  insns per cycle

is the only thing I've spotted of interest, I've tried at least:
dTLB-stores,dTLB-store-misses,L1-dcache-stores,LLC-store,LLC-store-misses,LLC-load-misses,LLC-loads,\mem-loads,mem-stores,iTLB-loads,iTLB-load-misses,cache-references,cache-misses

For now it seems at least a good idea to allow a user to disable write
combining if they see this until we can figure it out.

Note also most users get a real framebuffer driver loaded when kms
kicks in, it just happens on these machines the kernel didn't support
the gpu specific driver.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Acked-by: Peter Jones <pjones@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
2017-07-31 18:45:41 +02:00

433 lines
12 KiB
C

/*
* Framebuffer driver for EFI/UEFI based system
*
* (c) 2006 Edgar Hucek <gimli@dark-green.com>
* Original efi driver written by Gerd Knorr <kraxel@goldbach.in-berlin.de>
*
*/
#include <linux/kernel.h>
#include <linux/efi.h>
#include <linux/errno.h>
#include <linux/fb.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/screen_info.h>
#include <video/vga.h>
#include <asm/efi.h>
static bool request_mem_succeeded = false;
static bool nowc = false;
static struct fb_var_screeninfo efifb_defined = {
.activate = FB_ACTIVATE_NOW,
.height = -1,
.width = -1,
.right_margin = 32,
.upper_margin = 16,
.lower_margin = 4,
.vsync_len = 4,
.vmode = FB_VMODE_NONINTERLACED,
};
static struct fb_fix_screeninfo efifb_fix = {
.id = "EFI VGA",
.type = FB_TYPE_PACKED_PIXELS,
.accel = FB_ACCEL_NONE,
.visual = FB_VISUAL_TRUECOLOR,
};
static int efifb_setcolreg(unsigned regno, unsigned red, unsigned green,
unsigned blue, unsigned transp,
struct fb_info *info)
{
/*
* Set a single color register. The values supplied are
* already rounded down to the hardware's capabilities
* (according to the entries in the `var' structure). Return
* != 0 for invalid regno.
*/
if (regno >= info->cmap.len)
return 1;
if (regno < 16) {
red >>= 16 - info->var.red.length;
green >>= 16 - info->var.green.length;
blue >>= 16 - info->var.blue.length;
((u32 *)(info->pseudo_palette))[regno] =
(red << info->var.red.offset) |
(green << info->var.green.offset) |
(blue << info->var.blue.offset);
}
return 0;
}
static void efifb_destroy(struct fb_info *info)
{
if (info->screen_base)
iounmap(info->screen_base);
if (request_mem_succeeded)
release_mem_region(info->apertures->ranges[0].base,
info->apertures->ranges[0].size);
fb_dealloc_cmap(&info->cmap);
}
static struct fb_ops efifb_ops = {
.owner = THIS_MODULE,
.fb_destroy = efifb_destroy,
.fb_setcolreg = efifb_setcolreg,
.fb_fillrect = cfb_fillrect,
.fb_copyarea = cfb_copyarea,
.fb_imageblit = cfb_imageblit,
};
static int efifb_setup(char *options)
{
char *this_opt;
if (options && *options) {
while ((this_opt = strsep(&options, ",")) != NULL) {
if (!*this_opt) continue;
efifb_setup_from_dmi(&screen_info, this_opt);
if (!strncmp(this_opt, "base:", 5))
screen_info.lfb_base = simple_strtoul(this_opt+5, NULL, 0);
else if (!strncmp(this_opt, "stride:", 7))
screen_info.lfb_linelength = simple_strtoul(this_opt+7, NULL, 0) * 4;
else if (!strncmp(this_opt, "height:", 7))
screen_info.lfb_height = simple_strtoul(this_opt+7, NULL, 0);
else if (!strncmp(this_opt, "width:", 6))
screen_info.lfb_width = simple_strtoul(this_opt+6, NULL, 0);
else if (!strcmp(this_opt, "nowc"))
nowc = true;
}
}
return 0;
}
static inline bool fb_base_is_valid(void)
{
if (screen_info.lfb_base)
return true;
if (!(screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE))
return false;
if (screen_info.ext_lfb_base)
return true;
return false;
}
#define efifb_attr_decl(name, fmt) \
static ssize_t name##_show(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
return sprintf(buf, fmt "\n", (screen_info.lfb_##name)); \
} \
static DEVICE_ATTR_RO(name)
efifb_attr_decl(base, "0x%x");
efifb_attr_decl(linelength, "%u");
efifb_attr_decl(height, "%u");
efifb_attr_decl(width, "%u");
efifb_attr_decl(depth, "%u");
static struct attribute *efifb_attrs[] = {
&dev_attr_base.attr,
&dev_attr_linelength.attr,
&dev_attr_width.attr,
&dev_attr_height.attr,
&dev_attr_depth.attr,
NULL
};
ATTRIBUTE_GROUPS(efifb);
static bool pci_dev_disabled; /* FB base matches BAR of a disabled device */
static int efifb_probe(struct platform_device *dev)
{
struct fb_info *info;
int err;
unsigned int size_vmode;
unsigned int size_remap;
unsigned int size_total;
char *option = NULL;
if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI || pci_dev_disabled)
return -ENODEV;
if (fb_get_options("efifb", &option))
return -ENODEV;
efifb_setup(option);
/* We don't get linelength from UGA Draw Protocol, only from
* EFI Graphics Protocol. So if it's not in DMI, and it's not
* passed in from the user, we really can't use the framebuffer.
*/
if (!screen_info.lfb_linelength)
return -ENODEV;
if (!screen_info.lfb_depth)
screen_info.lfb_depth = 32;
if (!screen_info.pages)
screen_info.pages = 1;
if (!fb_base_is_valid()) {
printk(KERN_DEBUG "efifb: invalid framebuffer address\n");
return -ENODEV;
}
printk(KERN_INFO "efifb: probing for efifb\n");
/* just assume they're all unset if any are */
if (!screen_info.blue_size) {
screen_info.blue_size = 8;
screen_info.blue_pos = 0;
screen_info.green_size = 8;
screen_info.green_pos = 8;
screen_info.red_size = 8;
screen_info.red_pos = 16;
screen_info.rsvd_size = 8;
screen_info.rsvd_pos = 24;
}
efifb_fix.smem_start = screen_info.lfb_base;
if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) {
u64 ext_lfb_base;
ext_lfb_base = (u64)(unsigned long)screen_info.ext_lfb_base << 32;
efifb_fix.smem_start |= ext_lfb_base;
}
efifb_defined.bits_per_pixel = screen_info.lfb_depth;
efifb_defined.xres = screen_info.lfb_width;
efifb_defined.yres = screen_info.lfb_height;
efifb_fix.line_length = screen_info.lfb_linelength;
/* size_vmode -- that is the amount of memory needed for the
* used video mode, i.e. the minimum amount of
* memory we need. */
size_vmode = efifb_defined.yres * efifb_fix.line_length;
/* size_total -- all video memory we have. Used for
* entries, ressource allocation and bounds
* checking. */
size_total = screen_info.lfb_size;
if (size_total < size_vmode)
size_total = size_vmode;
/* size_remap -- the amount of video memory we are going to
* use for efifb. With modern cards it is no
* option to simply use size_total as that
* wastes plenty of kernel address space. */
size_remap = size_vmode * 2;
if (size_remap > size_total)
size_remap = size_total;
if (size_remap % PAGE_SIZE)
size_remap += PAGE_SIZE - (size_remap % PAGE_SIZE);
efifb_fix.smem_len = size_remap;
if (request_mem_region(efifb_fix.smem_start, size_remap, "efifb")) {
request_mem_succeeded = true;
} else {
/* We cannot make this fatal. Sometimes this comes from magic
spaces our resource handlers simply don't know about */
pr_warn("efifb: cannot reserve video memory at 0x%lx\n",
efifb_fix.smem_start);
}
info = framebuffer_alloc(sizeof(u32) * 16, &dev->dev);
if (!info) {
pr_err("efifb: cannot allocate framebuffer\n");
err = -ENOMEM;
goto err_release_mem;
}
platform_set_drvdata(dev, info);
info->pseudo_palette = info->par;
info->par = NULL;
info->apertures = alloc_apertures(1);
if (!info->apertures) {
err = -ENOMEM;
goto err_release_fb;
}
info->apertures->ranges[0].base = efifb_fix.smem_start;
info->apertures->ranges[0].size = size_remap;
if (nowc)
info->screen_base = ioremap(efifb_fix.smem_start, efifb_fix.smem_len);
else
info->screen_base = ioremap_wc(efifb_fix.smem_start, efifb_fix.smem_len);
if (!info->screen_base) {
pr_err("efifb: abort, cannot ioremap video memory 0x%x @ 0x%lx\n",
efifb_fix.smem_len, efifb_fix.smem_start);
err = -EIO;
goto err_release_fb;
}
pr_info("efifb: framebuffer at 0x%lx, using %dk, total %dk\n",
efifb_fix.smem_start, size_remap/1024, size_total/1024);
pr_info("efifb: mode is %dx%dx%d, linelength=%d, pages=%d\n",
efifb_defined.xres, efifb_defined.yres,
efifb_defined.bits_per_pixel, efifb_fix.line_length,
screen_info.pages);
efifb_defined.xres_virtual = efifb_defined.xres;
efifb_defined.yres_virtual = efifb_fix.smem_len /
efifb_fix.line_length;
pr_info("efifb: scrolling: redraw\n");
efifb_defined.yres_virtual = efifb_defined.yres;
/* some dummy values for timing to make fbset happy */
efifb_defined.pixclock = 10000000 / efifb_defined.xres *
1000 / efifb_defined.yres;
efifb_defined.left_margin = (efifb_defined.xres / 8) & 0xf8;
efifb_defined.hsync_len = (efifb_defined.xres / 8) & 0xf8;
efifb_defined.red.offset = screen_info.red_pos;
efifb_defined.red.length = screen_info.red_size;
efifb_defined.green.offset = screen_info.green_pos;
efifb_defined.green.length = screen_info.green_size;
efifb_defined.blue.offset = screen_info.blue_pos;
efifb_defined.blue.length = screen_info.blue_size;
efifb_defined.transp.offset = screen_info.rsvd_pos;
efifb_defined.transp.length = screen_info.rsvd_size;
pr_info("efifb: %s: "
"size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
"Truecolor",
screen_info.rsvd_size,
screen_info.red_size,
screen_info.green_size,
screen_info.blue_size,
screen_info.rsvd_pos,
screen_info.red_pos,
screen_info.green_pos,
screen_info.blue_pos);
efifb_fix.ypanstep = 0;
efifb_fix.ywrapstep = 0;
info->fbops = &efifb_ops;
info->var = efifb_defined;
info->fix = efifb_fix;
info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE;
err = sysfs_create_groups(&dev->dev.kobj, efifb_groups);
if (err) {
pr_err("efifb: cannot add sysfs attrs\n");
goto err_unmap;
}
err = fb_alloc_cmap(&info->cmap, 256, 0);
if (err < 0) {
pr_err("efifb: cannot allocate colormap\n");
goto err_groups;
}
err = register_framebuffer(info);
if (err < 0) {
pr_err("efifb: cannot register framebuffer\n");
goto err_fb_dealoc;
}
fb_info(info, "%s frame buffer device\n", info->fix.id);
return 0;
err_fb_dealoc:
fb_dealloc_cmap(&info->cmap);
err_groups:
sysfs_remove_groups(&dev->dev.kobj, efifb_groups);
err_unmap:
iounmap(info->screen_base);
err_release_fb:
framebuffer_release(info);
err_release_mem:
if (request_mem_succeeded)
release_mem_region(efifb_fix.smem_start, size_total);
return err;
}
static int efifb_remove(struct platform_device *pdev)
{
struct fb_info *info = platform_get_drvdata(pdev);
unregister_framebuffer(info);
sysfs_remove_groups(&pdev->dev.kobj, efifb_groups);
framebuffer_release(info);
return 0;
}
static struct platform_driver efifb_driver = {
.driver = {
.name = "efi-framebuffer",
},
.probe = efifb_probe,
.remove = efifb_remove,
};
builtin_platform_driver(efifb_driver);
#if defined(CONFIG_PCI) && !defined(CONFIG_X86)
static bool pci_bar_found; /* did we find a BAR matching the efifb base? */
static void claim_efifb_bar(struct pci_dev *dev, int idx)
{
u16 word;
pci_bar_found = true;
pci_read_config_word(dev, PCI_COMMAND, &word);
if (!(word & PCI_COMMAND_MEMORY)) {
pci_dev_disabled = true;
dev_err(&dev->dev,
"BAR %d: assigned to efifb but device is disabled!\n",
idx);
return;
}
if (pci_claim_resource(dev, idx)) {
pci_dev_disabled = true;
dev_err(&dev->dev,
"BAR %d: failed to claim resource for efifb!\n", idx);
return;
}
dev_info(&dev->dev, "BAR %d: assigned to efifb\n", idx);
}
static void efifb_fixup_resources(struct pci_dev *dev)
{
u64 base = screen_info.lfb_base;
u64 size = screen_info.lfb_size;
int i;
if (pci_bar_found || screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
return;
if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
base |= (u64)screen_info.ext_lfb_base << 32;
if (!base)
return;
for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
struct resource *res = &dev->resource[i];
if (!(res->flags & IORESOURCE_MEM))
continue;
if (res->start <= base && res->end >= base + size - 1) {
claim_efifb_bar(dev, i);
break;
}
}
}
DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_ANY_ID, PCI_ANY_ID, PCI_BASE_CLASS_DISPLAY,
16, efifb_fixup_resources);
#endif