[PATCH] x86_64: Allow kernel page tables upto the end of memory

[profile/ivi/kernel-adaptation-intel-automotive.git] / arch / x86_64 / mm / init.c

diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c
index 286f6a6..eca6012 100644 (file)
--- a/arch/x86_64/mm/init.c
+++ b/arch/x86_64/mm/init.c
@@ -23,6 +23,7 @@
 #include <linux/bootmem.h>
 #include <linux/proc_fs.h>
 #include <linux/pci.h>
+#include <linux/dma-mapping.h>
 
 #include <asm/processor.h>
 #include <asm/system.h>
@@ -38,11 +39,16 @@
 #include <asm/proto.h>
 #include <asm/smp.h>
 #include <asm/sections.h>
+#include <asm/dma-mapping.h>
+#include <asm/swiotlb.h>
 
 #ifndef Dprintk
 #define Dprintk(x...)
 #endif
 
+struct dma_mapping_ops* dma_ops;
+EXPORT_SYMBOL(dma_ops);
+
 static unsigned long dma_reserve __initdata;
 
 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
@@ -249,14 +255,26 @@ static void __init phys_pud_init(pud_t *pud, unsigned long address, unsigned lon
 
 static void __init find_early_table_space(unsigned long end)
 {
-       unsigned long puds, pmds, tables;
+       unsigned long puds, pmds, tables, start;
 
        puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
        pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
        tables = round_up(puds * sizeof(pud_t), PAGE_SIZE) +
                 round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
 
-       table_start = find_e820_area(0x8000, __pa_symbol(&_text), tables);
+       /* Put page tables beyond the DMA zones if possible.
+          RED-PEN might be better to spread them out more over
+          memory to avoid hotspots */
+       if (end > MAX_DMA32_PFN<<PAGE_SHIFT)
+               start = MAX_DMA32_PFN << PAGE_SHIFT;
+       else if (end > MAX_DMA_PFN << PAGE_SHIFT)
+               start = MAX_DMA_PFN << PAGE_SHIFT;
+       else
+               start = 0x8000;
+
+       table_start = find_e820_area(start, end, tables);
+       if (table_start == -1)
+               table_start = find_e820_area(0x8000, end, tables);
        if (table_start == -1UL)
                panic("Cannot find space for the kernel page tables");
 
@@ -348,7 +366,7 @@ size_zones(unsigned long *z, unsigned long *h,
        }
 
        /* Compute holes */
-       w = 0;
+       w = start_pfn;
        for (i = 0; i < MAX_NR_ZONES; i++) {
                unsigned long s = w;
                w += z[i];
@@ -423,12 +441,9 @@ void __init mem_init(void)
        long codesize, reservedpages, datasize, initsize;
 
 #ifdef CONFIG_SWIOTLB
-       if (!iommu_aperture &&
-           (end_pfn >= 0xffffffff>>PAGE_SHIFT || force_iommu))
-              swiotlb = 1;
-       if (swiotlb)
-               swiotlb_init(); 
+       pci_swiotlb_init();
 #endif
+       no_iommu_init();
 
        /* How many end-of-memory variables you have, grandma! */
        max_low_pfn = end_pfn;
@@ -498,6 +513,29 @@ void free_initmem(void)
        printk ("Freeing unused kernel memory: %luk freed\n", (__init_end - __init_begin) >> 10);
 }
 
+#ifdef CONFIG_DEBUG_RODATA
+
+extern char __start_rodata, __end_rodata;
+void mark_rodata_ro(void)
+{
+       unsigned long addr = (unsigned long)&__start_rodata;
+
+       for (; addr < (unsigned long)&__end_rodata; addr += PAGE_SIZE)
+               change_page_attr_addr(addr, 1, PAGE_KERNEL_RO);
+
+       printk ("Write protecting the kernel read-only data: %luk\n",
+                       (&__end_rodata - &__start_rodata) >> 10);
+
+       /*
+        * change_page_attr_addr() requires a global_flush_tlb() call after it.
+        * We do this after the printk so that if something went wrong in the
+        * change, the printk gets out at least to give a better debug hint
+        * of who is the culprit.
+        */
+       global_flush_tlb();
+}
+#endif
+
 #ifdef CONFIG_BLK_DEV_INITRD
 void free_initrd_mem(unsigned long start, unsigned long end)
 {