hyperv-fb: add support for generation 2 virtual machines.

UEFI-based generation 2 virtual machines support vmbus devices only.
There is no pci bus.  Thus they use a different mechanism for the
graphics framebuffer:  Instead of using the vga pci bar a chunk of
memory muct be allocated from the hyperv mmio region declared using
APCI.  This patch implements support for it.

Based on a patch by Haiyang Zhang <haiyangz@microsoft.com>

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/video/hyperv_fb.c b/drivers/video/hyperv_fb.c
index 130708f..b7b3dd0 100644 (file)
--- a/drivers/video/hyperv_fb.c
+++ b/drivers/video/hyperv_fb.c
@@ -42,6 +42,7 @@
 #include <linux/completion.h>
 #include <linux/fb.h>
 #include <linux/pci.h>
+#include <linux/efi.h>
 
 #include <linux/hyperv.h>
 
@@ -212,6 +213,7 @@ struct synthvid_msg {
 
 struct hvfb_par {
        struct fb_info *info;
+       struct resource mem;
        bool fb_ready; /* fb device is ready */
        struct completion wait;
        u32 synthvid_version;
@@ -460,13 +462,13 @@ static int synthvid_connect_vsp(struct hv_device *hdev)
                goto error;
        }
 
-       if (par->synthvid_version == SYNTHVID_VERSION_WIN7) {
+       if (par->synthvid_version == SYNTHVID_VERSION_WIN7)
                screen_depth = SYNTHVID_DEPTH_WIN7;
-               screen_fb_size = SYNTHVID_FB_SIZE_WIN7;
-       } else {
+       else
                screen_depth = SYNTHVID_DEPTH_WIN8;
-               screen_fb_size = SYNTHVID_FB_SIZE_WIN8;
-       }
+
+       screen_fb_size = hdev->channel->offermsg.offer.
+                               mmio_megabytes * 1024 * 1024;
 
        return 0;
 
@@ -627,26 +629,46 @@ static void hvfb_get_option(struct fb_info *info)
 /* Get framebuffer memory from Hyper-V video pci space */
 static int hvfb_getmem(struct fb_info *info)
 {
-       struct pci_dev *pdev;
-       ulong fb_phys;
+       struct hvfb_par *par = info->par;
+       struct pci_dev *pdev  = NULL;
        void __iomem *fb_virt;
+       int gen2vm = efi_enabled(EFI_BOOT);
+       int ret;
 
-       pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
+       par->mem.name = KBUILD_MODNAME;
+       par->mem.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+       if (gen2vm) {
+               ret = allocate_resource(&hyperv_mmio, &par->mem,
+                                       screen_fb_size,
+                                       0, -1,
+                                       screen_fb_size,
+                                       NULL, NULL);
+               if (ret != 0) {
+                       pr_err("Unable to allocate framebuffer memory\n");
+                       return -ENODEV;
+               }
+       } else {
+               pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
                              PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
-       if (!pdev) {
-               pr_err("Unable to find PCI Hyper-V video\n");
-               return -ENODEV;
-       }
+               if (!pdev) {
+                       pr_err("Unable to find PCI Hyper-V video\n");
+                       return -ENODEV;
+               }
 
-       if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM) ||
-           pci_resource_len(pdev, 0) < screen_fb_size)
-               goto err1;
+               if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM) ||
+                   pci_resource_len(pdev, 0) < screen_fb_size)
+                       goto err1;
 
-       fb_phys = pci_resource_end(pdev, 0) - screen_fb_size + 1;
-       if (!request_mem_region(fb_phys, screen_fb_size, KBUILD_MODNAME))
-               goto err1;
+               par->mem.end = pci_resource_end(pdev, 0);
+               par->mem.start = par->mem.end - screen_fb_size + 1;
+               ret = request_resource(&pdev->resource[0], &par->mem);
+               if (ret != 0) {
+                       pr_err("Unable to request framebuffer memory\n");
+                       goto err1;
+               }
+       }
 
-       fb_virt = ioremap(fb_phys, screen_fb_size);
+       fb_virt = ioremap(par->mem.start, screen_fb_size);
        if (!fb_virt)
                goto err2;
 
@@ -654,30 +676,42 @@ static int hvfb_getmem(struct fb_info *info)
        if (!info->apertures)
                goto err3;
 
-       info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
-       info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
-       info->fix.smem_start = fb_phys;
+       if (gen2vm) {
+               info->apertures->ranges[0].base = screen_info.lfb_base;
+               info->apertures->ranges[0].size = screen_info.lfb_size;
+       } else {
+               info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
+               info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
+       }
+
+       info->fix.smem_start = par->mem.start;
        info->fix.smem_len = screen_fb_size;
        info->screen_base = fb_virt;
        info->screen_size = screen_fb_size;
 
-       pci_dev_put(pdev);
+       if (!gen2vm)
+               pci_dev_put(pdev);
+
        return 0;
 
 err3:
        iounmap(fb_virt);
 err2:
-       release_mem_region(fb_phys, screen_fb_size);
+       release_resource(&par->mem);
 err1:
-       pci_dev_put(pdev);
+       if (!gen2vm)
+               pci_dev_put(pdev);
+
        return -ENOMEM;
 }
 
 /* Release the framebuffer */
 static void hvfb_putmem(struct fb_info *info)
 {
+       struct hvfb_par *par = info->par;
+
        iounmap(info->screen_base);
-       release_mem_region(info->fix.smem_start, screen_fb_size);
+       release_resource(&par->mem);
 }