target/linux/bcm27xx/patches-5.4/950-0450-dma-direct-turn-ARCH_ZONE_DMA_BITS-into-a-variable.patch

   1 From 78b03f0aef9f67c4db700ba5dc56e2c8f562d181 Mon Sep 17 00:00:00 2001
   2 From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
   3 Date: Mon, 14 Oct 2019 20:31:03 +0200
   4 Subject: [PATCH] dma/direct: turn ARCH_ZONE_DMA_BITS into a variable
   5
   6 commit 8b5369ea580964dbc982781bfb9fb93459fc5e8d upstream.
   7
   8 Some architectures, notably ARM, are interested in tweaking this
   9 depending on their runtime DMA addressing limitations.
  10
  11 Acked-by: Christoph Hellwig <hch@lst.de>
  12 Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
  13 Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
  14 ---
  15  arch/arm64/include/asm/page.h   |  2 --
  16  arch/arm64/mm/init.c            |  9 +++++++--
  17  arch/powerpc/include/asm/page.h |  9 ---------
  18  arch/powerpc/mm/mem.c           | 20 +++++++++++++++-----
  19  arch/s390/include/asm/page.h    |  2 --
  20  arch/s390/mm/init.c             |  1 +
  21  include/linux/dma-direct.h      |  2 ++
  22  kernel/dma/direct.c             | 13 ++++++-------
  23  8 files changed, 31 insertions(+), 27 deletions(-)
  24
  25 --- a/arch/arm64/include/asm/page.h
  26 +++ b/arch/arm64/include/asm/page.h
  27 @@ -38,6 +38,4 @@ extern int pfn_valid(unsigned long);
  28
  29  #include <asm-generic/getorder.h>
  30
  31 -#define ARCH_ZONE_DMA_BITS 30
  32 -
  33  #endif
  34 --- a/arch/arm64/mm/init.c
  35 +++ b/arch/arm64/mm/init.c
  36 @@ -20,6 +20,7 @@
  37  #include <linux/sort.h>
  38  #include <linux/of.h>
  39  #include <linux/of_fdt.h>
  40 +#include <linux/dma-direct.h>
  41  #include <linux/dma-mapping.h>
  42  #include <linux/dma-contiguous.h>
  43  #include <linux/efi.h>
  44 @@ -41,6 +42,8 @@
  45  #include <asm/tlb.h>
  46  #include <asm/alternative.h>
  47
  48 +#define ARM64_ZONE_DMA_BITS    30
  49 +
  50  /*
  51   * We need to be able to catch inadvertent references to memstart_addr
  52   * that occur (potentially in generic code) before arm64_memblock_init()
  53 @@ -440,8 +443,10 @@ void __init arm64_memblock_init(void)
  54
  55         early_init_fdt_scan_reserved_mem();
  56
  57 -       if (IS_ENABLED(CONFIG_ZONE_DMA))
  58 -               arm64_dma_phys_limit = max_zone_phys(ARCH_ZONE_DMA_BITS);
  59 +       if (IS_ENABLED(CONFIG_ZONE_DMA)) {
  60 +               zone_dma_bits = ARM64_ZONE_DMA_BITS;
  61 +               arm64_dma_phys_limit = max_zone_phys(ARM64_ZONE_DMA_BITS);
  62 +       }
  63
  64         if (IS_ENABLED(CONFIG_ZONE_DMA32))
  65                 arm64_dma32_phys_limit = max_zone_phys(32);
  66 --- a/arch/powerpc/include/asm/page.h
  67 +++ b/arch/powerpc/include/asm/page.h
  68 @@ -334,13 +334,4 @@ struct vm_area_struct;
  69  #endif /* __ASSEMBLY__ */
  70  #include <asm/slice.h>
  71
  72 -/*
  73 - * Allow 30-bit DMA for very limited Broadcom wifi chips on many powerbooks.
  74 - */
  75 -#ifdef CONFIG_PPC32
  76 -#define ARCH_ZONE_DMA_BITS 30
  77 -#else
  78 -#define ARCH_ZONE_DMA_BITS 31
  79 -#endif
  80 -
  81  #endif /* _ASM_POWERPC_PAGE_H */
  82 --- a/arch/powerpc/mm/mem.c
  83 +++ b/arch/powerpc/mm/mem.c
  84 @@ -31,6 +31,7 @@
  85  #include <linux/slab.h>
  86  #include <linux/vmalloc.h>
  87  #include <linux/memremap.h>
  88 +#include <linux/dma-direct.h>
  89
  90  #include <asm/pgalloc.h>
  91  #include <asm/prom.h>
  92 @@ -223,10 +224,10 @@ static int __init mark_nonram_nosave(voi
  93   * everything else. GFP_DMA32 page allocations automatically fall back to
  94   * ZONE_DMA.
  95   *
  96 - * By using 31-bit unconditionally, we can exploit ARCH_ZONE_DMA_BITS to
  97 - * inform the generic DMA mapping code.  32-bit only devices (if not handled
  98 - * by an IOMMU anyway) will take a first dip into ZONE_NORMAL and get
  99 - * otherwise served by ZONE_DMA.
 100 + * By using 31-bit unconditionally, we can exploit zone_dma_bits to inform the
 101 + * generic DMA mapping code.  32-bit only devices (if not handled by an IOMMU
 102 + * anyway) will take a first dip into ZONE_NORMAL and get otherwise served by
 103 + * ZONE_DMA.
 104   */
 105  static unsigned long max_zone_pfns[MAX_NR_ZONES];
 106
 107 @@ -259,9 +260,18 @@ void __init paging_init(void)
 108         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 109                (long int)((top_of_ram - total_ram) >> 20));
 110
 111 +       /*
 112 +        * Allow 30-bit DMA for very limited Broadcom wifi chips on many
 113 +        * powerbooks.
 114 +        */
 115 +       if (IS_ENABLED(CONFIG_PPC32))
 116 +               zone_dma_bits = 30;
 117 +       else
 118 +               zone_dma_bits = 31;
 119 +
 120  #ifdef CONFIG_ZONE_DMA
 121         max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
 122 -                                     1UL << (ARCH_ZONE_DMA_BITS - PAGE_SHIFT));
 123 +                                     1UL << (zone_dma_bits - PAGE_SHIFT));
 124  #endif
 125         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 126  #ifdef CONFIG_HIGHMEM
 127 --- a/arch/s390/include/asm/page.h
 128 +++ b/arch/s390/include/asm/page.h
 129 @@ -179,8 +179,6 @@ static inline int devmem_is_allowed(unsi
 130  #define VM_DATA_DEFAULT_FLAGS  (VM_READ | VM_WRITE | \
 131                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 132
 133 -#define ARCH_ZONE_DMA_BITS     31
 134 -
 135  #include <asm-generic/memory_model.h>
 136  #include <asm-generic/getorder.h>
 137
 138 --- a/arch/s390/mm/init.c
 139 +++ b/arch/s390/mm/init.c
 140 @@ -118,6 +118,7 @@ void __init paging_init(void)
 141
 142         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 143         sparse_init();
 144 +       zone_dma_bits = 31;
 145         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 146         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 147         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 148 --- a/include/linux/dma-direct.h
 149 +++ b/include/linux/dma-direct.h
 150 @@ -8,6 +8,8 @@
 151
 152  static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
 153
 154 +extern unsigned int zone_dma_bits;
 155 +
 156  #ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
 157  #include <asm/dma-direct.h>
 158  #else
 159 --- a/kernel/dma/direct.c
 160 +++ b/kernel/dma/direct.c
 161 @@ -16,12 +16,11 @@
 162  #include <linux/swiotlb.h>
 163
 164  /*
 165 - * Most architectures use ZONE_DMA for the first 16 Megabytes, but
 166 - * some use it for entirely different regions:
 167 + * Most architectures use ZONE_DMA for the first 16 Megabytes, but some use it
 168 + * it for entirely different regions. In that case the arch code needs to
 169 + * override the variable below for dma-direct to work properly.
 170   */
 171 -#ifndef ARCH_ZONE_DMA_BITS
 172 -#define ARCH_ZONE_DMA_BITS 24
 173 -#endif
 174 +unsigned int zone_dma_bits __ro_after_init = 24;
 175
 176  static void report_addr(struct device *dev, dma_addr_t dma_addr, size_t size)
 177  {
 178 @@ -69,7 +68,7 @@ static gfp_t __dma_direct_optimal_gfp_ma
 179          * Note that GFP_DMA32 and GFP_DMA are no ops without the corresponding
 180          * zones.
 181          */
 182 -       if (*phys_mask <= DMA_BIT_MASK(ARCH_ZONE_DMA_BITS))
 183 +       if (*phys_mask <= DMA_BIT_MASK(zone_dma_bits))
 184                 return GFP_DMA;
 185         if (*phys_mask <= DMA_BIT_MASK(32))
 186                 return GFP_DMA32;
 187 @@ -395,7 +394,7 @@ int dma_direct_supported(struct device *
 188         u64 min_mask;
 189
 190         if (IS_ENABLED(CONFIG_ZONE_DMA))
 191 -               min_mask = DMA_BIT_MASK(ARCH_ZONE_DMA_BITS);
 192 +               min_mask = DMA_BIT_MASK(zone_dma_bits);
 193         else
 194                 min_mask = DMA_BIT_MASK(30);
 195