drm/gma500: Pass fb_info to psb_fbdev_vm_fault()

Instead of the DRM framebuffer, pass the FB info strcuture to the
fbdev page-fault handler psb_fbdev_vm_fault(). The framebuffer is a
high-level data structure and does not belong into fault handling.
The fb_info has all necessary information. Also set fix.smem_start
to the correct value (the beginning of the framebuffer in physical
address space) and streamline the page-fault handler.

v2:
	* remove unused struct drm_psb_private.fb_base (Patrik)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230313151610.14367-8-tzimmermann@suse.de

drivers/gpu/drm/gma500/fbdev.c

@@ -22,32 +22,24 @@
 static vm_fault_t psb_fbdev_vm_fault(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;
-	struct drm_framebuffer *fb = vma->vm_private_data;
-	struct drm_device *dev = fb->dev;
-	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
-	struct psb_gem_object *pobj = to_psb_gem_object(fb->obj[0]);
-	int page_num;
-	int i;
-	unsigned long address;
-	vm_fault_t ret = VM_FAULT_SIGBUS;
-	unsigned long pfn;
-	unsigned long phys_addr = (unsigned long)dev_priv->stolen_base + pobj->offset;
-
-	page_num = vma_pages(vma);
-	address = vmf->address - (vmf->pgoff << PAGE_SHIFT);
+	struct fb_info *info = vma->vm_private_data;
+	unsigned long address = vmf->address - (vmf->pgoff << PAGE_SHIFT);
+	unsigned long pfn = info->fix.smem_start >> PAGE_SHIFT;
+	vm_fault_t err = VM_FAULT_SIGBUS;
+	unsigned long page_num = vma_pages(vma);
+	unsigned long i;
 
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 
-	for (i = 0; i < page_num; i++) {
-		pfn = (phys_addr >> PAGE_SHIFT);
-
-		ret = vmf_insert_mixed(vma, address, __pfn_to_pfn_t(pfn, PFN_DEV));
-		if (unlikely(ret & VM_FAULT_ERROR))
+	for (i = 0; i < page_num; ++i) {
+		err = vmf_insert_mixed(vma, address, __pfn_to_pfn_t(pfn, PFN_DEV));
+		if (unlikely(err & VM_FAULT_ERROR))
 			break;
 		address += PAGE_SIZE;
-		phys_addr += PAGE_SIZE;
+		++pfn;
 	}
-	return ret;
+
+	return err;
 }
 
 static const struct vm_operations_struct psb_fbdev_vm_ops = {
@@ -102,9 +94,6 @@ static int psb_fbdev_fb_setcolreg(unsigned int regno,
 
 static int psb_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 {
-	struct drm_fb_helper *fb_helper = info->par;
-	struct drm_framebuffer *fb = fb_helper->fb;
-
 	if (vma->vm_pgoff != 0)
 		return -EINVAL;
 	if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
@@ -116,7 +105,7 @@ static int psb_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 	 * suitable for our mmap work
 	 */
 	vma->vm_ops = &psb_fbdev_vm_ops;
-	vma->vm_private_data = (void *)fb;
+	vma->vm_private_data = info;
 	vm_flags_set(vma, VM_IO | VM_MIXEDMAP | VM_DONTEXPAND | VM_DONTDUMP);
 
 	return 0;
@@ -235,7 +224,7 @@ static int psb_fbdev_fb_probe(struct drm_fb_helper *fb_helper,
 
 	drm_fb_helper_fill_info(info, fb_helper, sizes);
 
-	info->fix.smem_start = dev_priv->fb_base;
+	info->fix.smem_start = dev_priv->stolen_base + backing->offset;
 	info->fix.smem_len = size;
 	info->fix.ywrapstep = 0;
 	info->fix.ypanstep = 0;

drivers/gpu/drm/gma500/framebuffer.c

@@ -186,7 +186,6 @@ void psb_modeset_init(struct drm_device *dev)
 {
 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 	struct psb_intel_mode_device *mode_dev = &dev_priv->mode_dev;
-	struct pci_dev *pdev = to_pci_dev(dev->dev);
 	int i;
 
 	if (drmm_mode_config_init(dev))
@@ -197,10 +196,6 @@ void psb_modeset_init(struct drm_device *dev)
 
 	dev->mode_config.funcs = &psb_mode_funcs;
 
-	/* set memory base */
-	/* Oaktrail and Poulsbo should use BAR 2*/
-	pci_read_config_dword(pdev, PSB_BSM, (u32 *)&(dev_priv->fb_base));
-
 	/* num pipes is 2 for PSB but 1 for Mrst */
 	for (i = 0; i < dev_priv->num_pipe; i++)
 		psb_intel_crtc_init(dev, i, mode_dev);

drivers/gpu/drm/gma500/psb_drv.h

@@ -520,8 +520,6 @@ struct drm_psb_private {
 	uint32_t blc_adj1;
 	uint32_t blc_adj2;
 
-	resource_size_t fb_base;
-
 	bool dsr_enable;
 	u32 dsr_fb_update;
 	bool dpi_panel_on[3];