From 0839ccb8ac6a9e2d5e175a4ae9c82b5c574d510d Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Thu, 30 Oct 2008 19:38:48 -0700 Subject: [PATCH] i915: use io-mapping interfaces instead of a variety of mapping kludges Impact: optimize/clean-up the IO mapping implementation of the i915 DRM driver Switch the i915 device aperture mapping to the io-mapping interface, taking advantage of the cleaner API to extend it across all of the mapping uses, including both pwrite and relocation updates. This dramatically improves performance on 64-bit kernels which were using the same slow path as 32-bit non-HIGHMEM kernels prior to this patch. Signed-off-by: Keith Packard Signed-off-by: Eric Anholt Signed-off-by: Ingo Molnar --- drivers/gpu/drm/i915/i915_drv.h | 3 + drivers/gpu/drm/i915/i915_gem.c | 174 +++++++++++++++----------------- 2 files changed, 83 insertions(+), 94 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index f20ffe17df7..126b2f13258 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -31,6 +31,7 @@ #define _I915_DRV_H_ #include "i915_reg.h" +#include /* General customization: */ @@ -246,6 +247,8 @@ typedef struct drm_i915_private { struct { struct drm_mm gtt_space; + struct io_mapping *gtt_mapping; + /** * List of objects currently involved in rendering from the * ringbuffer. diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 17ae330ff26..61183b95b10 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -171,35 +171,50 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data, return 0; } -/* - * Try to write quickly with an atomic kmap. Return true on success. - * - * If this fails (which includes a partial write), we'll redo the whole - * thing with the slow version. - * - * This is a workaround for the low performance of iounmap (approximate - * 10% cpu cost on normal 3D workloads). kmap_atomic on HIGHMEM kernels - * happens to let us map card memory without taking IPIs. When the vmap - * rework lands we should be able to dump this hack. +/* This is the fast write path which cannot handle + * page faults in the source data */ -static inline int fast_user_write(unsigned long pfn, char __user *user_data, - int l, int o) + +static inline int +fast_user_write(struct io_mapping *mapping, + loff_t page_base, int page_offset, + char __user *user_data, + int length) { -#ifdef CONFIG_HIGHMEM - unsigned long unwritten; char *vaddr_atomic; + unsigned long unwritten; - vaddr_atomic = kmap_atomic_pfn(pfn, KM_USER0); -#if WATCH_PWRITE - DRM_INFO("pwrite i %d o %d l %d pfn %ld vaddr %p\n", - i, o, l, pfn, vaddr_atomic); -#endif - unwritten = __copy_from_user_inatomic_nocache(vaddr_atomic + o, user_data, l); - kunmap_atomic(vaddr_atomic, KM_USER0); - return !unwritten; -#else + vaddr_atomic = io_mapping_map_atomic_wc(mapping, page_base); + unwritten = __copy_from_user_inatomic_nocache(vaddr_atomic + page_offset, + user_data, length); + io_mapping_unmap_atomic(vaddr_atomic); + if (unwritten) + return -EFAULT; + return 0; +} + +/* Here's the write path which can sleep for + * page faults + */ + +static inline int +slow_user_write(struct io_mapping *mapping, + loff_t page_base, int page_offset, + char __user *user_data, + int length) +{ + char __iomem *vaddr; + unsigned long unwritten; + + vaddr = io_mapping_map_wc(mapping, page_base); + if (vaddr == NULL) + return -EFAULT; + unwritten = __copy_from_user(vaddr + page_offset, + user_data, length); + io_mapping_unmap(vaddr); + if (unwritten) + return -EFAULT; return 0; -#endif } static int @@ -208,10 +223,12 @@ i915_gem_gtt_pwrite(struct drm_device *dev, struct drm_gem_object *obj, struct drm_file *file_priv) { struct drm_i915_gem_object *obj_priv = obj->driver_private; + drm_i915_private_t *dev_priv = dev->dev_private; ssize_t remain; - loff_t offset; + loff_t offset, page_base; char __user *user_data; - int ret = 0; + int page_offset, page_length; + int ret; user_data = (char __user *) (uintptr_t) args->data_ptr; remain = args->size; @@ -235,57 +252,37 @@ i915_gem_gtt_pwrite(struct drm_device *dev, struct drm_gem_object *obj, obj_priv->dirty = 1; while (remain > 0) { - unsigned long pfn; - int i, o, l; - /* Operation in this page * - * i = page number - * o = offset within page - * l = bytes to copy + * page_base = page offset within aperture + * page_offset = offset within page + * page_length = bytes to copy for this page */ - i = offset >> PAGE_SHIFT; - o = offset & (PAGE_SIZE-1); - l = remain; - if ((o + l) > PAGE_SIZE) - l = PAGE_SIZE - o; - - pfn = (dev->agp->base >> PAGE_SHIFT) + i; - - if (!fast_user_write(pfn, user_data, l, o)) { - unsigned long unwritten; - char __iomem *vaddr; - - vaddr = ioremap_wc(pfn << PAGE_SHIFT, PAGE_SIZE); -#if WATCH_PWRITE - DRM_INFO("pwrite slow i %d o %d l %d " - "pfn %ld vaddr %p\n", - i, o, l, pfn, vaddr); -#endif - if (vaddr == NULL) { - ret = -EFAULT; - goto fail; - } - unwritten = __copy_from_user(vaddr + o, user_data, l); -#if WATCH_PWRITE - DRM_INFO("unwritten %ld\n", unwritten); -#endif - iounmap(vaddr); - if (unwritten) { - ret = -EFAULT; + page_base = (offset & ~(PAGE_SIZE-1)); + page_offset = offset & (PAGE_SIZE-1); + page_length = remain; + if ((page_offset + remain) > PAGE_SIZE) + page_length = PAGE_SIZE - page_offset; + + ret = fast_user_write (dev_priv->mm.gtt_mapping, page_base, + page_offset, user_data, page_length); + + /* If we get a fault while copying data, then (presumably) our + * source page isn't available. In this case, use the + * non-atomic function + */ + if (ret) { + ret = slow_user_write (dev_priv->mm.gtt_mapping, + page_base, page_offset, + user_data, page_length); + if (ret) goto fail; - } } - remain -= l; - user_data += l; - offset += l; + remain -= page_length; + user_data += page_length; + offset += page_length; } -#if WATCH_PWRITE && 1 - i915_gem_clflush_object(obj); - i915_gem_dump_object(obj, args->offset + args->size, __func__, ~0); - i915_gem_clflush_object(obj); -#endif fail: i915_gem_object_unpin(obj); @@ -1503,12 +1500,12 @@ i915_gem_object_pin_and_relocate(struct drm_gem_object *obj, struct drm_i915_gem_exec_object *entry) { struct drm_device *dev = obj->dev; + drm_i915_private_t *dev_priv = dev->dev_private; struct drm_i915_gem_relocation_entry reloc; struct drm_i915_gem_relocation_entry __user *relocs; struct drm_i915_gem_object *obj_priv = obj->driver_private; int i, ret; - uint32_t last_reloc_offset = -1; - void __iomem *reloc_page = NULL; + void __iomem *reloc_page; /* Choose the GTT offset for our buffer and put it there. */ ret = i915_gem_object_pin(obj, (uint32_t) entry->alignment); @@ -1631,26 +1628,11 @@ i915_gem_object_pin_and_relocate(struct drm_gem_object *obj, * perform. */ reloc_offset = obj_priv->gtt_offset + reloc.offset; - if (reloc_page == NULL || - (last_reloc_offset & ~(PAGE_SIZE - 1)) != - (reloc_offset & ~(PAGE_SIZE - 1))) { - if (reloc_page != NULL) - iounmap(reloc_page); - - reloc_page = ioremap_wc(dev->agp->base + - (reloc_offset & - ~(PAGE_SIZE - 1)), - PAGE_SIZE); - last_reloc_offset = reloc_offset; - if (reloc_page == NULL) { - drm_gem_object_unreference(target_obj); - i915_gem_object_unpin(obj); - return -ENOMEM; - } - } - + reloc_page = io_mapping_map_atomic_wc(dev_priv->mm.gtt_mapping, + (reloc_offset & + ~(PAGE_SIZE - 1))); reloc_entry = (uint32_t __iomem *)(reloc_page + - (reloc_offset & (PAGE_SIZE - 1))); + (reloc_offset & (PAGE_SIZE - 1))); reloc_val = target_obj_priv->gtt_offset + reloc.delta; #if WATCH_BUF @@ -1659,6 +1641,7 @@ i915_gem_object_pin_and_relocate(struct drm_gem_object *obj, readl(reloc_entry), reloc_val); #endif writel(reloc_val, reloc_entry); + io_mapping_unmap_atomic(reloc_page); /* Write the updated presumed offset for this entry back out * to the user. @@ -1674,9 +1657,6 @@ i915_gem_object_pin_and_relocate(struct drm_gem_object *obj, drm_gem_object_unreference(target_obj); } - if (reloc_page != NULL) - iounmap(reloc_page); - #if WATCH_BUF if (0) i915_gem_dump_object(obj, 128, __func__, ~0); @@ -2518,6 +2498,10 @@ i915_gem_entervt_ioctl(struct drm_device *dev, void *data, if (ret != 0) return ret; + dev_priv->mm.gtt_mapping = io_mapping_create_wc(dev->agp->base, + dev->agp->agp_info.aper_size + * 1024 * 1024); + mutex_lock(&dev->struct_mutex); BUG_ON(!list_empty(&dev_priv->mm.active_list)); BUG_ON(!list_empty(&dev_priv->mm.flushing_list)); @@ -2535,11 +2519,13 @@ int i915_gem_leavevt_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { + drm_i915_private_t *dev_priv = dev->dev_private; int ret; ret = i915_gem_idle(dev); drm_irq_uninstall(dev); + io_mapping_free(dev_priv->mm.gtt_mapping); return ret; } -- 2.41.1