drop 7170130e4c72ce0caa0cb42a1627c635cc262821 from 5.15

diff --git a/queue-5.15/series b/queue-5.15/series
index 6da07d97de1e626cb0a912008ad7db60585fbed3..f5297275167e45e6bb305f54af2b169825292034 100644 (file)
--- a/queue-5.15/series
+++ b/queue-5.15/series
@@ -1,4 +1,3 @@
-x86-mm-init-handle-the-special-case-of-device-private-pages-in-add_pages-to-not-increase-max_pfn-and-trigger-dma_addressing_limited-bounce-buffers.patch
 scsi-target-iscsi-fix-timeout-on-deleted-connection.patch
 virtio_ring-fix-data-race-by-tagging-event_triggered.patch
 dma-mapping-avoid-potential-unused-data-compilation-.patch

diff --git a/queue-5.15/x86-mm-init-handle-the-special-case-of-device-private-pages-in-add_pages-to-not-increase-max_pfn-and-trigger-dma_addressing_limited-bounce-buffers.patch b/queue-5.15/x86-mm-init-handle-the-special-case-of-device-private-pages-in-add_pages-to-not-increase-max_pfn-and-trigger-dma_addressing_limited-bounce-buffers.patch
deleted file mode 100644 (file)
index 937e7eb..0000000
--- a/queue-5.15/x86-mm-init-handle-the-special-case-of-device-private-pages-in-add_pages-to-not-increase-max_pfn-and-trigger-dma_addressing_limited-bounce-buffers.patch
+++ /dev/null
@@ -1,106 +0,0 @@
-From 7170130e4c72ce0caa0cb42a1627c635cc262821 Mon Sep 17 00:00:00 2001
-From: Balbir Singh <balbirs@nvidia.com>
-Date: Tue, 1 Apr 2025 11:07:52 +1100
-Subject: x86/mm/init: Handle the special case of device private pages in add_pages(), to not increase max_pfn and trigger dma_addressing_limited() bounce buffers
- bounce buffers
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-From: Balbir Singh <balbirs@nvidia.com>
-
-commit 7170130e4c72ce0caa0cb42a1627c635cc262821 upstream.
-
-As Bert Karwatzki reported, the following recent commit causes a
-performance regression on AMD iGPU and dGPU systems:
-
-  7ffb791423c7 ("x86/kaslr: Reduce KASLR entropy on most x86 systems")
-
-It exposed a bug with nokaslr and zone device interaction.
-
-The root cause of the bug is that, the GPU driver registers a zone
-device private memory region. When KASLR is disabled or the above commit
-is applied, the direct_map_physmem_end is set to much higher than 10 TiB
-typically to the 64TiB address. When zone device private memory is added
-to the system via add_pages(), it bumps up the max_pfn to the same
-value. This causes dma_addressing_limited() to return true, since the
-device cannot address memory all the way up to max_pfn.
-
-This caused a regression for games played on the iGPU, as it resulted in
-the DMA32 zone being used for GPU allocations.
-
-Fix this by not bumping up max_pfn on x86 systems, when pgmap is passed
-into add_pages(). The presence of pgmap is used to determine if device
-private memory is being added via add_pages().
-
-More details:
-
-devm_request_mem_region() and request_free_mem_region() request for
-device private memory. iomem_resource is passed as the base resource
-with start and end parameters. iomem_resource's end depends on several
-factors, including the platform and virtualization. On x86 for example
-on bare metal, this value is set to boot_cpu_data.x86_phys_bits.
-boot_cpu_data.x86_phys_bits can change depending on support for MKTME.
-By default it is set to the same as log2(direct_map_physmem_end) which
-is 46 to 52 bits depending on the number of levels in the page table.
-The allocation routines used iomem_resource's end and
-direct_map_physmem_end to figure out where to allocate the region.
-
-[ arch/powerpc is also impacted by this problem, but this patch does not fix
-  the issue for PowerPC. ]
-
-Testing:
-
- 1. Tested on a virtual machine with test_hmm for zone device inseration
-
- 2. A previous version of this patch was tested by Bert, please see:
-    https://lore.kernel.org/lkml/d87680bab997fdc9fb4e638983132af235d9a03a.camel@web.de/
-
-[ mingo: Clarified the comments and the changelog. ]
-
-Reported-by: Bert Karwatzki <spasswolf@web.de>
-Tested-by: Bert Karwatzki <spasswolf@web.de>
-Fixes: 7ffb791423c7 ("x86/kaslr: Reduce KASLR entropy on most x86 systems")
-Signed-off-by: Balbir Singh <balbirs@nvidia.com>
-Signed-off-by: Ingo Molnar <mingo@kernel.org>
-Cc: Brian Gerst <brgerst@gmail.com>
-Cc: Juergen Gross <jgross@suse.com>
-Cc: H. Peter Anvin <hpa@zytor.com>
-Cc: Linus Torvalds <torvalds@linux-foundation.org>
-Cc: Andrew Morton <akpm@linux-foundation.org>
-Cc: Christoph Hellwig <hch@lst.de>
-Cc: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
-Cc: Alex Deucher <alexander.deucher@amd.com>
-Cc: Christian König <christian.koenig@amd.com>
-Cc: David Airlie <airlied@gmail.com>
-Cc: Simona Vetter <simona@ffwll.ch>
-Link: https://lore.kernel.org/r/20250401000752.249348-1-balbirs@nvidia.com
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- arch/x86/mm/init_64.c |   15 ++++++++++++---
- 1 file changed, 12 insertions(+), 3 deletions(-)
-
---- a/arch/x86/mm/init_64.c
-+++ b/arch/x86/mm/init_64.c
-@@ -955,9 +955,18 @@ int add_pages(int nid, unsigned long sta
-       ret = __add_pages(nid, start_pfn, nr_pages, params);
-       WARN_ON_ONCE(ret);
- 
--      /* update max_pfn, max_low_pfn and high_memory */
--      update_end_of_memory_vars(start_pfn << PAGE_SHIFT,
--                                nr_pages << PAGE_SHIFT);
-+      /*
-+       * Special case: add_pages() is called by memremap_pages() for adding device
-+       * private pages. Do not bump up max_pfn in the device private path,
-+       * because max_pfn changes affect dma_addressing_limited().
-+       *
-+       * dma_addressing_limited() returning true when max_pfn is the device's
-+       * addressable memory can force device drivers to use bounce buffers
-+       * and impact their performance negatively:
-+       */
-+      if (!params->pgmap)
-+              /* update max_pfn, max_low_pfn and high_memory */
-+              update_end_of_memory_vars(start_pfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT);
- 
-       return ret;
- }