| Message ID | 053fa4806a2c63efcde80caca473a8b670a2701c.1722249878.git.baruch@tkos.co.il (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | dma: support DMA zone starting above 4GB | expand |
Hi Baruch,
kernel test robot noticed the following build warnings:
[auto build test WARNING on arm64/for-next/core]
[also build test WARNING on powerpc/next powerpc/fixes s390/features linus/master v6.11-rc1 next-20240729]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Baruch-Siach/dma-mapping-improve-DMA-zone-selection/20240729-211018
base: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
patch link: https://lore.kernel.org/r/053fa4806a2c63efcde80caca473a8b670a2701c.1722249878.git.baruch%40tkos.co.il
patch subject: [PATCH v3 2/3] dma-mapping: replace zone_dma_bits by zone_dma_limit
config: arm-allnoconfig (https://download.01.org/0day-ci/archive/20240730/202407300338.oaUo6jtB-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project ccae7b461be339e717d02f99ac857cf0bc7d17fc)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240730/202407300338.oaUo6jtB-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202407300338.oaUo6jtB-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from kernel/dma/direct.c:7:
In file included from include/linux/memblock.h:12:
In file included from include/linux/mm.h:2253:
include/linux/vmstat.h:514:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
514 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
| ~~~~~~~~~~~ ^ ~~~
>> kernel/dma/direct.c:23:46: warning: implicit conversion from 'unsigned long long' to 'phys_addr_t' (aka 'unsigned int') changes value from 18446744073709551615 to 4294967295 [-Wconstant-conversion]
23 | phys_addr_t zone_dma_limit __ro_after_init = DMA_BIT_MASK(24);
| ~~~~~~~~~~~~~~ ^~~~~~~~~~~~~~~~
include/linux/dma-mapping.h:77:40: note: expanded from macro 'DMA_BIT_MASK'
77 | #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
| ^~~~~
2 warnings generated.
vim +23 kernel/dma/direct.c
> 7 #include <linux/memblock.h>
8 #include <linux/export.h>
9 #include <linux/mm.h>
10 #include <linux/dma-map-ops.h>
11 #include <linux/scatterlist.h>
12 #include <linux/pfn.h>
13 #include <linux/vmalloc.h>
14 #include <linux/set_memory.h>
15 #include <linux/slab.h>
16 #include "direct.h"
17
18 /*
19 * Most architectures use ZONE_DMA for the first 16 Megabytes, but some use
20 * it for entirely different regions. In that case the arch code needs to
21 * override the variable below for dma-direct to work properly.
22 */
> 23 phys_addr_t zone_dma_limit __ro_after_init = DMA_BIT_MASK(24);
24
On Tue, Jul 30, 2024 at 04:20:51AM +0800, kernel test robot wrote: > Hi Baruch, > > kernel test robot noticed the following build warnings: > > [auto build test WARNING on arm64/for-next/core] > [also build test WARNING on powerpc/next powerpc/fixes s390/features linus/master v6.11-rc1 next-20240729] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch#_base_tree_information] > > url: https://github.com/intel-lab-lkp/linux/commits/Baruch-Siach/dma-mapping-improve-DMA-zone-selection/20240729-211018 > base: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core > patch link: https://lore.kernel.org/r/053fa4806a2c63efcde80caca473a8b670a2701c.1722249878.git.baruch%40tkos.co.il > patch subject: [PATCH v3 2/3] dma-mapping: replace zone_dma_bits by zone_dma_limit > config: arm-allnoconfig (https://download.01.org/0day-ci/archive/20240730/202407300338.oaUo6jtB-lkp@intel.com/config) > compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project ccae7b461be339e717d02f99ac857cf0bc7d17fc) > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240730/202407300338.oaUo6jtB-lkp@intel.com/reproduce) > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > the same patch/commit), kindly add following tags > | Reported-by: kernel test robot <lkp@intel.com> > | Closes: https://lore.kernel.org/oe-kbuild-all/202407300338.oaUo6jtB-lkp@intel.com/ > > All warnings (new ones prefixed by >>): > > In file included from kernel/dma/direct.c:7: > In file included from include/linux/memblock.h:12: > In file included from include/linux/mm.h:2253: > include/linux/vmstat.h:514:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion] > 514 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_" > | ~~~~~~~~~~~ ^ ~~~ > >> kernel/dma/direct.c:23:46: warning: implicit conversion from 'unsigned long long' to 'phys_addr_t' (aka 'unsigned int') changes value from 18446744073709551615 to 4294967295 [-Wconstant-conversion] > 23 | phys_addr_t zone_dma_limit __ro_after_init = DMA_BIT_MASK(24); > | ~~~~~~~~~~~~~~ ^~~~~~~~~~~~~~~~ > include/linux/dma-mapping.h:77:40: note: expanded from macro 'DMA_BIT_MASK' > 77 | #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1)) > | ^~~~~ > 2 warnings generated. FWIW, this is likely a false positive due to an issue in Clang with the control flow graph for global variables: https://github.com/ClangBuiltLinux/linux/issues/92 DMA_BIT_MASK() has been the biggest offender :/ If there is any way to refactor this code to avoid this, that would be great (as that has been one of our longest outstanding issues and getting it fixed in the compiler does not seem super easy at this point). Cheers, Nathan > vim +23 kernel/dma/direct.c > > > 7 #include <linux/memblock.h> > 8 #include <linux/export.h> > 9 #include <linux/mm.h> > 10 #include <linux/dma-map-ops.h> > 11 #include <linux/scatterlist.h> > 12 #include <linux/pfn.h> > 13 #include <linux/vmalloc.h> > 14 #include <linux/set_memory.h> > 15 #include <linux/slab.h> > 16 #include "direct.h" > 17 > 18 /* > 19 * Most architectures use ZONE_DMA for the first 16 Megabytes, but some use > 20 * it for entirely different regions. In that case the arch code needs to > 21 * override the variable below for dma-direct to work properly. > 22 */ > > 23 phys_addr_t zone_dma_limit __ro_after_init = DMA_BIT_MASK(24); > 24 > > -- > 0-DAY CI Kernel Test Service > https://github.com/intel/lkp-tests/wiki >
On Mon, Jul 29, 2024 at 07:12:08PM -0700, Nathan Chancellor wrote: > > | ~~~~~~~~~~~~~~ ^~~~~~~~~~~~~~~~ > > include/linux/dma-mapping.h:77:40: note: expanded from macro 'DMA_BIT_MASK' > > 77 | #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1)) > > | ^~~~~ > > 2 warnings generated. > > FWIW, this is likely a false positive due to an issue in Clang with the > control flow graph for global variables: > > https://github.com/ClangBuiltLinux/linux/issues/92 > > DMA_BIT_MASK() has been the biggest offender :/ If there is any way to > refactor this code to avoid this, that would be great (as that has been > one of our longest outstanding issues and getting it fixed in the > compiler does not seem super easy at this point). I have no idea what you'd want changed here, but I'll happily take patches.
On Mon, Jul 29, 2024 at 01:51:25PM +0300, Baruch Siach wrote: > From: Catalin Marinas <catalin.marinas@arm.com> > > Hardware DMA limit might not be power of 2. When RAM range starts above > 0, say 4GB, DMA limit of 30 bits should end at 5GB. A single high bit > can not encode this limit. > > Use direct phys_addr_t limit address for DMA zone limit. > > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> > Signed-off-by: Baruch Siach <baruch@tkos.co.il> You should add your Co-developed-by line, the patch evolved a bit from initial my partial diff. > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index 9b5ab6818f7f..870fd967c610 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -114,36 +114,28 @@ static void __init arch_reserve_crashkernel(void) > low_size, high); > } > > -/* > - * Return the maximum physical address for a zone accessible by the given bits > - * limit. If DRAM starts above 32-bit, expand the zone to the maximum > - * available memory, otherwise cap it at 32-bit. > - */ > -static phys_addr_t __init max_zone_phys(unsigned int zone_bits) > +static phys_addr_t __init max_zone_phys(phys_addr_t zone_limit) > { > - phys_addr_t zone_mask = DMA_BIT_MASK(zone_bits); > - phys_addr_t phys_start = memblock_start_of_DRAM(); > - > - if (phys_start > U32_MAX) > - zone_mask = PHYS_ADDR_MAX; > - else if (phys_start > zone_mask) > - zone_mask = U32_MAX; > + /* We have RAM in low 32-bit area, keep DMA zone there */ > + if (memblock_start_of_DRAM() < U32_MAX) > + zone_limit = min(U32_MAX, zone_limit); Does this matter anymore? Or is it to keep ZONE_DMA below (or equal to) the ZONE_DMA32 limit? Anyway, since this patch is about replacing zone_dma_bits with zone_dma_limit, we should not introduce functional changes. AFAICT, we need zone_limit to be set to memblock_end_of_DRAM() when phys_start is above U32_MAX. You can do the functional change in a subsequent patch once all the other refactoring has been handled. > > - return min(zone_mask, memblock_end_of_DRAM() - 1) + 1; > + return min(zone_limit, memblock_end_of_DRAM() - 1) + 1; > } [...] > diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h > index edbe13d00776..98b7d8015043 100644 > --- a/include/linux/dma-direct.h > +++ b/include/linux/dma-direct.h > @@ -12,7 +12,7 @@ > #include <linux/mem_encrypt.h> > #include <linux/swiotlb.h> > > -extern unsigned int zone_dma_bits; > +extern phys_addr_t zone_dma_limit; > > /* > * Record the mapping of CPU physical to DMA addresses for a given region. > diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c > index 3b4be4ca3b08..3dbc0b89d6fb 100644 > --- a/kernel/dma/direct.c > +++ b/kernel/dma/direct.c > @@ -20,7 +20,7 @@ > * it for entirely different regions. In that case the arch code needs to > * override the variable below for dma-direct to work properly. > */ > -unsigned int zone_dma_bits __ro_after_init = 24; > +phys_addr_t zone_dma_limit __ro_after_init = DMA_BIT_MASK(24); > > static inline dma_addr_t phys_to_dma_direct(struct device *dev, > phys_addr_t phys) > @@ -580,7 +580,7 @@ int dma_direct_supported(struct device *dev, u64 mask) > * part of the check. > */ > if (IS_ENABLED(CONFIG_ZONE_DMA)) > - min_mask = min_t(u64, min_mask, DMA_BIT_MASK(zone_dma_bits)); > + min_mask = min_t(u64, min_mask, zone_dma_limit); > return mask >= phys_to_dma_unencrypted(dev, min_mask); > } > > diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c > index d10613eb0f63..410a7b40e496 100644 > --- a/kernel/dma/pool.c > +++ b/kernel/dma/pool.c > @@ -70,7 +70,7 @@ static bool cma_in_zone(gfp_t gfp) > /* CMA can't cross zone boundaries, see cma_activate_area() */ > end = cma_get_base(cma) + size - 1; > if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA)) > - return end <= DMA_BIT_MASK(zone_dma_bits); > + return end <= zone_dma_limit; > if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32)) > return end <= DMA_BIT_MASK(32); > return true; I haven't got to the third patch yet but with this series we can have zone_dma_limit above DMA_BIT_MASK(32). The above function could return false for GFP_DMA32 when 'end' is perfectly valid within ZONE_DMA (which implies safe for GFP_DMA32). > diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c > index df68d29740a0..dfd83e5ee0b3 100644 > --- a/kernel/dma/swiotlb.c > +++ b/kernel/dma/swiotlb.c > @@ -450,7 +450,7 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask, > if (!remap) > io_tlb_default_mem.can_grow = true; > if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp_mask & __GFP_DMA)) > - io_tlb_default_mem.phys_limit = DMA_BIT_MASK(zone_dma_bits); > + io_tlb_default_mem.phys_limit = zone_dma_limit; > else if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp_mask & __GFP_DMA32)) > io_tlb_default_mem.phys_limit = DMA_BIT_MASK(32); > else > @@ -629,7 +629,7 @@ static struct page *swiotlb_alloc_tlb(struct device *dev, size_t bytes, > } > > gfp &= ~GFP_ZONEMASK; > - if (phys_limit <= DMA_BIT_MASK(zone_dma_bits)) > + if (phys_limit <= zone_dma_limit) > gfp |= __GFP_DMA; > else if (phys_limit <= DMA_BIT_MASK(32)) > gfp |= __GFP_DMA32; I think this has the same issue as dma_direct_optimal_gfp_mask(). If the requested limit is strictly smaller than DMA_BIT_MASK(32) (but potentially bigger than zone_dma_limit), we should go for __GFP_DMA rather than __GFP_DMA32. You should probably fix this in the first patch as well. As above, with this series we can end up with zone_dma_limit above DMA_BIT_MASK(32) and all these checks become confusing. Even the swiotlb_init_late() above if called with GFP_DMA32 will set a phys_limit that may not be accessible at all if the DRAM starts above 4GB. Similarly, cma_in_zone() could return false with GFP_DMA32 in similar hardware configurations. So we either introduce a zone_dma32_limit variable and allow a 32-bit range above the start of DRAM or sanitise these sites to make sure passing GFP_DMA32 is safe - i.e. assume we only have ZONE_DMA if zone_dma_limit is above 32-bit. I prefer the latter without introducing a zone_dma32_limit.
On Tue, Jul 30, 2024 at 05:34:50PM +0200, Christoph Hellwig wrote: > On Mon, Jul 29, 2024 at 07:12:08PM -0700, Nathan Chancellor wrote: > > > | ~~~~~~~~~~~~~~ ^~~~~~~~~~~~~~~~ > > > include/linux/dma-mapping.h:77:40: note: expanded from macro 'DMA_BIT_MASK' > > > 77 | #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1)) > > > | ^~~~~ > > > 2 warnings generated. > > > > FWIW, this is likely a false positive due to an issue in Clang with the > > control flow graph for global variables: > > > > https://github.com/ClangBuiltLinux/linux/issues/92 > > > > DMA_BIT_MASK() has been the biggest offender :/ If there is any way to > > refactor this code to avoid this, that would be great (as that has been > > one of our longest outstanding issues and getting it fixed in the > > compiler does not seem super easy at this point). > > I have no idea what you'd want changed here, but I'll happily take > patches. Unfortunately, I am not sure either... I do not see anything obviously, so perhaps it could just be avoided with the __diag() infrastructure? diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 3dbc0b89d6fb..b58e7eb9c8f1 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -20,7 +20,12 @@ * it for entirely different regions. In that case the arch code needs to * override the variable below for dma-direct to work properly. */ +__diag_push(); +__diag_ignore(clang, 13, "-Wconstant-conversion", + "Clang incorrectly thinks the n == 64 case in DMA_BIT_MASK() can happen here," + "which would truncate with a 32-bit phys_addr_t"); phys_addr_t zone_dma_limit __ro_after_init = DMA_BIT_MASK(24); +__diag_pop(); static inline dma_addr_t phys_to_dma_direct(struct device *dev, phys_addr_t phys)
On Wed, Jul 31, 2024 at 06:24:24PM -0700, Nathan Chancellor wrote: > Unfortunately, I am not sure either... I do not see anything obviously, > so perhaps it could just be avoided with the __diag() infrastructure? > > diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c > index 3dbc0b89d6fb..b58e7eb9c8f1 100644 > --- a/kernel/dma/direct.c > +++ b/kernel/dma/direct.c > @@ -20,7 +20,12 @@ > * it for entirely different regions. In that case the arch code needs to > * override the variable below for dma-direct to work properly. > */ > +__diag_push(); > +__diag_ignore(clang, 13, "-Wconstant-conversion", > + "Clang incorrectly thinks the n == 64 case in DMA_BIT_MASK() can happen here," > + "which would truncate with a 32-bit phys_addr_t"); > phys_addr_t zone_dma_limit __ro_after_init = DMA_BIT_MASK(24); So.. The code above is clearly wrong, as DMA_BIT_MASK always returns a u64, and phys_addr_t can be smaller than that. So at least in this case the warning seems perfectly valid and the code has issues because it is mixing different concepts. Where do you see warnings like this upstream?
On Thu, Aug 01, 2024 at 03:44:54PM +0200, Christoph Hellwig wrote: > On Wed, Jul 31, 2024 at 06:24:24PM -0700, Nathan Chancellor wrote: > > Unfortunately, I am not sure either... I do not see anything obviously, > > so perhaps it could just be avoided with the __diag() infrastructure? > > > > diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c > > index 3dbc0b89d6fb..b58e7eb9c8f1 100644 > > --- a/kernel/dma/direct.c > > +++ b/kernel/dma/direct.c > > @@ -20,7 +20,12 @@ > > * it for entirely different regions. In that case the arch code needs to > > * override the variable below for dma-direct to work properly. > > */ > > +__diag_push(); > > +__diag_ignore(clang, 13, "-Wconstant-conversion", > > + "Clang incorrectly thinks the n == 64 case in DMA_BIT_MASK() can happen here," > > + "which would truncate with a 32-bit phys_addr_t"); > > phys_addr_t zone_dma_limit __ro_after_init = DMA_BIT_MASK(24); > > So.. The code above is clearly wrong, as DMA_BIT_MASK always returns a > u64, and phys_addr_t can be smaller than that. So at least in this case > the warning seems perfectly valid and the code has issues because it is > mixing different concepts. Sure, that seems like a reasonable way to look at things even if the warning itself is a false positive. > Where do you see warnings like this upstream? I don't see this upstream, this is from patch 2 of this series: https://lore.kernel.org/053fa4806a2c63efcde80caca473a8b670a2701c.1722249878.git.baruch@tkos.co.il/ Cheers, Nathan
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 9b5ab6818f7f..870fd967c610 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -114,36 +114,28 @@ static void __init arch_reserve_crashkernel(void) low_size, high); } -/* - * Return the maximum physical address for a zone accessible by the given bits - * limit. If DRAM starts above 32-bit, expand the zone to the maximum - * available memory, otherwise cap it at 32-bit. - */ -static phys_addr_t __init max_zone_phys(unsigned int zone_bits) +static phys_addr_t __init max_zone_phys(phys_addr_t zone_limit) { - phys_addr_t zone_mask = DMA_BIT_MASK(zone_bits); - phys_addr_t phys_start = memblock_start_of_DRAM(); - - if (phys_start > U32_MAX) - zone_mask = PHYS_ADDR_MAX; - else if (phys_start > zone_mask) - zone_mask = U32_MAX; + /* We have RAM in low 32-bit area, keep DMA zone there */ + if (memblock_start_of_DRAM() < U32_MAX) + zone_limit = min(U32_MAX, zone_limit); - return min(zone_mask, memblock_end_of_DRAM() - 1) + 1; + return min(zone_limit, memblock_end_of_DRAM() - 1) + 1; } static void __init zone_sizes_init(void) { unsigned long max_zone_pfns[MAX_NR_ZONES] = {0}; - unsigned int __maybe_unused acpi_zone_dma_bits; - unsigned int __maybe_unused dt_zone_dma_bits; - phys_addr_t __maybe_unused dma32_phys_limit = max_zone_phys(32); + phys_addr_t __maybe_unused acpi_zone_dma_limit; + phys_addr_t __maybe_unused dt_zone_dma_limit; + phys_addr_t __maybe_unused dma32_phys_limit = + max_zone_phys(DMA_BIT_MASK(32)); #ifdef CONFIG_ZONE_DMA - acpi_zone_dma_bits = fls64(acpi_iort_dma_get_max_cpu_address()); - dt_zone_dma_bits = fls64(of_dma_get_max_cpu_address(NULL)); - zone_dma_bits = min3(32U, dt_zone_dma_bits, acpi_zone_dma_bits); - arm64_dma_phys_limit = max_zone_phys(zone_dma_bits); + acpi_zone_dma_limit = acpi_iort_dma_get_max_cpu_address(); + dt_zone_dma_limit = of_dma_get_max_cpu_address(NULL); + zone_dma_limit = min(dt_zone_dma_limit, acpi_zone_dma_limit); + arm64_dma_phys_limit = max_zone_phys(zone_dma_limit); max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit); #endif #ifdef CONFIG_ZONE_DMA32 diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index d325217ab201..342c006cc1b8 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -216,7 +216,7 @@ static int __init mark_nonram_nosave(void) * everything else. GFP_DMA32 page allocations automatically fall back to * ZONE_DMA. * - * By using 31-bit unconditionally, we can exploit zone_dma_bits to inform the + * By using 31-bit unconditionally, we can exploit zone_dma_limit to inform the * generic DMA mapping code. 32-bit only devices (if not handled by an IOMMU * anyway) will take a first dip into ZONE_NORMAL and get otherwise served by * ZONE_DMA. @@ -252,13 +252,12 @@ void __init paging_init(void) * powerbooks. */ if (IS_ENABLED(CONFIG_PPC32)) - zone_dma_bits = 30; + zone_dma_limit = DMA_BIT_MASK(30); else - zone_dma_bits = 31; + zone_dma_limit = DMA_BIT_MASK(31); #ifdef CONFIG_ZONE_DMA - max_zone_pfns[ZONE_DMA] = min(max_low_pfn, - 1UL << (zone_dma_bits - PAGE_SHIFT)); + max_zone_pfns[ZONE_DMA] = min(max_low_pfn, zone_dma_limit >> PAGE_SHIFT); #endif max_zone_pfns[ZONE_NORMAL] = max_low_pfn; #ifdef CONFIG_HIGHMEM diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index ddcd39ef4346..91fc2b91adfc 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -97,7 +97,7 @@ void __init paging_init(void) vmem_map_init(); sparse_init(); - zone_dma_bits = 31; + zone_dma_limit = DMA_BIT_MASK(31); memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); max_zone_pfns[ZONE_DMA] = virt_to_pfn(MAX_DMA_ADDRESS); max_zone_pfns[ZONE_NORMAL] = max_low_pfn; diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h index edbe13d00776..98b7d8015043 100644 --- a/include/linux/dma-direct.h +++ b/include/linux/dma-direct.h @@ -12,7 +12,7 @@ #include <linux/mem_encrypt.h> #include <linux/swiotlb.h> -extern unsigned int zone_dma_bits; +extern phys_addr_t zone_dma_limit; /* * Record the mapping of CPU physical to DMA addresses for a given region. diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 3b4be4ca3b08..3dbc0b89d6fb 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -20,7 +20,7 @@ * it for entirely different regions. In that case the arch code needs to * override the variable below for dma-direct to work properly. */ -unsigned int zone_dma_bits __ro_after_init = 24; +phys_addr_t zone_dma_limit __ro_after_init = DMA_BIT_MASK(24); static inline dma_addr_t phys_to_dma_direct(struct device *dev, phys_addr_t phys) @@ -580,7 +580,7 @@ int dma_direct_supported(struct device *dev, u64 mask) * part of the check. */ if (IS_ENABLED(CONFIG_ZONE_DMA)) - min_mask = min_t(u64, min_mask, DMA_BIT_MASK(zone_dma_bits)); + min_mask = min_t(u64, min_mask, zone_dma_limit); return mask >= phys_to_dma_unencrypted(dev, min_mask); } diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c index d10613eb0f63..410a7b40e496 100644 --- a/kernel/dma/pool.c +++ b/kernel/dma/pool.c @@ -70,7 +70,7 @@ static bool cma_in_zone(gfp_t gfp) /* CMA can't cross zone boundaries, see cma_activate_area() */ end = cma_get_base(cma) + size - 1; if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA)) - return end <= DMA_BIT_MASK(zone_dma_bits); + return end <= zone_dma_limit; if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32)) return end <= DMA_BIT_MASK(32); return true; diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index df68d29740a0..dfd83e5ee0b3 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -450,7 +450,7 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask, if (!remap) io_tlb_default_mem.can_grow = true; if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp_mask & __GFP_DMA)) - io_tlb_default_mem.phys_limit = DMA_BIT_MASK(zone_dma_bits); + io_tlb_default_mem.phys_limit = zone_dma_limit; else if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp_mask & __GFP_DMA32)) io_tlb_default_mem.phys_limit = DMA_BIT_MASK(32); else @@ -629,7 +629,7 @@ static struct page *swiotlb_alloc_tlb(struct device *dev, size_t bytes, } gfp &= ~GFP_ZONEMASK; - if (phys_limit <= DMA_BIT_MASK(zone_dma_bits)) + if (phys_limit <= zone_dma_limit) gfp |= __GFP_DMA; else if (phys_limit <= DMA_BIT_MASK(32)) gfp |= __GFP_DMA32;