[PATCH 2/5] [POWERPC] 8xx: generic 8xx code arch/powerpc port

[Vitaly Bordug <vbordug@ru.mvista.com>]

Including support for non-coherent cache, some mm-related things +
relevant field in Kconfig and Makefiles. Also included rheap.o compilaiton
if 8xx is defined.

Signed-off-by: Vitaly Bordug <vbordug@ru.mvista.com>
---

 arch/powerpc/Kconfig              |   11 +
 arch/powerpc/kernel/Makefile      |    1 
 arch/powerpc/kernel/dma-mapping.c |  442 +++++++++++++++++++++++++++++++++++++
 arch/powerpc/lib/Makefile         |    1 
 arch/powerpc/mm/fault.c           |   99 ++++++++
 5 files changed, 552 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1d71aff..42c2b6b 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -158,6 +158,11 @@ config PPC_86xx
 	help
 	  The Freescale E600 SoCs have 74xx cores.
 
+config PPC_8xx
+	bool "Freescale 8xx"
+	select FSL_SOC
+	select 8xx
+
 config 40x
 	bool "AMCC 40x"
 	select PPC_DCR_NATIVE
@@ -166,8 +171,6 @@ config 44x
 	bool "AMCC 44x"
 	select PPC_DCR_NATIVE
 
-config 8xx
-	bool "Freescale 8xx"
 
 config E200
 	bool "Freescale e200"
@@ -196,6 +199,10 @@ config 6xx
 	bool
 
 # this is temp to handle compat with arch=ppc
+config 8xx
+	bool
+
+# this is temp to handle compat with arch=ppc
 config 83xx
 	bool
 
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index f9ce5d7..98111ee 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_PPC_UDBG_16550)	+= legacy_s
 
 module-$(CONFIG_PPC64)		+= module_64.o
 obj-$(CONFIG_MODULES)		+= $(module-y)
+obj-$(CONFIG_NOT_COHERENT_CACHE)	+= dma-mapping.o
 
 pci64-$(CONFIG_PPC64)		+= pci_64.o pci_dn.o
 pci32-$(CONFIG_PPC32)		:= pci_32.o
diff --git a/arch/powerpc/kernel/dma-mapping.c b/arch/powerpc/kernel/dma-mapping.c
new file mode 100644
index 0000000..10fec73
--- /dev/null
+++ b/arch/powerpc/kernel/dma-mapping.c
@@ -0,0 +1,442 @@
+/*
+ *  PowerPC version derived from arch/arm/mm/consistent.c
+ *    Copyright (C) 2001 Dan Malek (dmalek@jlc.net)
+ *
+ *  Copyright (C) 2000 Russell King
+ *
+ * Consistent memory allocators.  Used for DMA devices that want to
+ * share uncached memory with the processor core.  The function return
+ * is the virtual address and 'dma_handle' is the physical address.
+ * Mostly stolen from the ARM port, with some changes for PowerPC.
+ *						-- Dan
+ *
+ * Reorganized to get rid of the arch-specific consistent_* functions
+ * and provide non-coherent implementations for the DMA API. -Matt
+ *
+ * Added in_interrupt() safe dma_alloc_coherent()/dma_free_coherent()
+ * implementation. This is pulled straight from ARM and barely
+ * modified. -Matt
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/stddef.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/dma-mapping.h>
+#include <linux/hardirq.h>
+
+#include <asm/pgalloc.h>
+#include <asm/prom.h>
+#include <asm/io.h>
+#include <asm/mmu_context.h>
+#include <asm/pgtable.h>
+#include <asm/mmu.h>
+#include <asm/uaccess.h>
+#include <asm/smp.h>
+#include <asm/machdep.h>
+
+int map_page(unsigned long va, phys_addr_t pa, int flags);
+
+#include <asm/tlbflush.h>
+
+/*
+ * This address range defaults to a value that is safe for all
+ * platforms which currently set CONFIG_NOT_COHERENT_CACHE. It
+ * can be further configured for specific applications under
+ * the "Advanced Setup" menu. -Matt
+ */
+#define CONSISTENT_BASE	(CONFIG_CONSISTENT_START)
+#define CONSISTENT_END	(CONFIG_CONSISTENT_START + CONFIG_CONSISTENT_SIZE)
+#define CONSISTENT_OFFSET(x)	(((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT)
+
+/*
+ * This is the page table (2MB) covering uncached, DMA consistent allocations
+ */
+static pte_t *consistent_pte;
+static DEFINE_SPINLOCK(consistent_lock);
+
+/*
+ * VM region handling support.
+ *
+ * This should become something generic, handling VM region allocations for
+ * vmalloc and similar (ioremap, module space, etc).
+ *
+ * I envisage vmalloc()'s supporting vm_struct becoming:
+ *
+ *  struct vm_struct {
+ *    struct vm_region	region;
+ *    unsigned long	flags;
+ *    struct page	**pages;
+ *    unsigned int	nr_pages;
+ *    unsigned long	phys_addr;
+ *  };
+ *
+ * get_vm_area() would then call vm_region_alloc with an appropriate
+ * struct vm_region head (eg):
+ *
+ *  struct vm_region vmalloc_head = {
+ *	.vm_list	= LIST_HEAD_INIT(vmalloc_head.vm_list),
+ *	.vm_start	= VMALLOC_START,
+ *	.vm_end		= VMALLOC_END,
+ *  };
+ *
+ * However, vmalloc_head.vm_start is variable (typically, it is dependent on
+ * the amount of RAM found at boot time.)  I would imagine that get_vm_area()
+ * would have to initialise this each time prior to calling vm_region_alloc().
+ */
+struct vm_region {
+	struct list_head	vm_list;
+	unsigned long		vm_start;
+	unsigned long		vm_end;
+};
+
+static struct vm_region consistent_head = {
+	.vm_list	= LIST_HEAD_INIT(consistent_head.vm_list),
+	.vm_start	= CONSISTENT_BASE,
+	.vm_end		= CONSISTENT_END,
+};
+
+static struct vm_region *
+vm_region_alloc(struct vm_region *head, size_t size, gfp_t gfp)
+{
+	unsigned long addr = head->vm_start, end = head->vm_end - size;
+	unsigned long flags;
+	struct vm_region *c, *new;
+
+	new = kmalloc(sizeof(struct vm_region), gfp);
+	if (!new)
+		goto out;
+
+	spin_lock_irqsave(&consistent_lock, flags);
+
+	list_for_each_entry(c, &head->vm_list, vm_list) {
+		if ((addr + size) < addr)
+			goto nospc;
+		if ((addr + size) <= c->vm_start)
+			goto found;
+		addr = c->vm_end;
+		if (addr > end)
+			goto nospc;
+	}
+
+ found:
+	/*
+	 * Insert this entry _before_ the one we found.
+	 */
+	list_add_tail(&new->vm_list, &c->vm_list);
+	new->vm_start = addr;
+	new->vm_end = addr + size;
+
+	spin_unlock_irqrestore(&consistent_lock, flags);
+	return new;
+
+ nospc:
+	spin_unlock_irqrestore(&consistent_lock, flags);
+	kfree(new);
+ out:
+	return NULL;
+}
+
+static struct vm_region *vm_region_find(struct vm_region *head, unsigned long addr)
+{
+	struct vm_region *c;
+
+	list_for_each_entry(c, &head->vm_list, vm_list) {
+		if (c->vm_start == addr)
+			goto out;
+	}
+	c = NULL;
+ out:
+	return c;
+}
+
+/*
+ * Allocate DMA-coherent memory space and return both the kernel remapped
+ * virtual and bus address for that space.
+ */
+void *
+__dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp)
+{
+	struct page *page;
+	struct vm_region *c;
+	unsigned long order;
+	u64 mask = 0x00ffffff, limit; /* ISA default */
+
+	if (!consistent_pte) {
+		printk(KERN_ERR "%s: not initialised\n", __func__);
+		dump_stack();
+		return NULL;
+	}
+
+	size = PAGE_ALIGN(size);
+	limit = (mask + 1) & ~mask;
+	if ((limit && size >= limit) || size >= (CONSISTENT_END - CONSISTENT_BASE)) {
+		printk(KERN_WARNING "coherent allocation too big (requested %#x mask %#Lx)\n",
+		       size, mask);
+		return NULL;
+	}
+
+	order = get_order(size);
+
+	if (mask != 0xffffffff)
+		gfp |= GFP_DMA;
+
+	page = alloc_pages(gfp, order);
+	if (!page)
+		goto no_page;
+
+	/*
+	 * Invalidate any data that might be lurking in the
+	 * kernel direct-mapped region for device DMA.
+	 */
+	{
+		unsigned long kaddr = (unsigned long)page_address(page);
+		memset(page_address(page), 0, size);
+		flush_dcache_range(kaddr, kaddr + size);
+	}
+
+	/*
+	 * Allocate a virtual address in the consistent mapping region.
+	 */
+	c = vm_region_alloc(&consistent_head, size,
+			    gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
+	if (c) {
+		unsigned long vaddr = c->vm_start;
+		pte_t *pte = consistent_pte + CONSISTENT_OFFSET(vaddr);
+		struct page *end = page + (1 << order);
+
+		split_page(page, order);
+
+		/*
+		 * Set the "dma handle"
+		 */
+		*handle = page_to_bus(page);
+
+		do {
+			BUG_ON(!pte_none(*pte));
+
+			SetPageReserved(page);
+			set_pte_at(&init_mm, vaddr,
+				   pte, mk_pte(page, pgprot_noncached(PAGE_KERNEL)));
+			page++;
+			pte++;
+			vaddr += PAGE_SIZE;
+		} while (size -= PAGE_SIZE);
+
+		/*
+		 * Free the otherwise unused pages.
+		 */
+		while (page < end) {
+			__free_page(page);
+			page++;
+		}
+
+		return (void *)c->vm_start;
+	}
+
+	if (page)
+		__free_pages(page, order);
+ no_page:
+	return NULL;
+}
+EXPORT_SYMBOL(__dma_alloc_coherent);
+
+/*
+ * free a page as defined by the above mapping.
+ */
+void __dma_free_coherent(size_t size, void *vaddr)
+{
+	struct vm_region *c;
+	unsigned long flags, addr;
+	pte_t *ptep;
+
+	size = PAGE_ALIGN(size);
+
+	spin_lock_irqsave(&consistent_lock, flags);
+
+	c = vm_region_find(&consistent_head, (unsigned long)vaddr);
+	if (!c)
+		goto no_area;
+
+	if ((c->vm_end - c->vm_start) != size) {
+		printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n",
+		       __func__, c->vm_end - c->vm_start, size);
+		dump_stack();
+		size = c->vm_end - c->vm_start;
+	}
+
+	ptep = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
+	addr = c->vm_start;
+	do {
+		pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
+		unsigned long pfn;
+
+		ptep++;
+		addr += PAGE_SIZE;
+
+		if (!pte_none(pte) && pte_present(pte)) {
+			pfn = pte_pfn(pte);
+
+			if (pfn_valid(pfn)) {
+				struct page *page = pfn_to_page(pfn);
+				ClearPageReserved(page);
+
+				__free_page(page);
+				continue;
+			}
+		}
+
+		printk(KERN_CRIT "%s: bad page in kernel page table\n",
+		       __func__);
+	} while (size -= PAGE_SIZE);
+
+	flush_tlb_kernel_range(c->vm_start, c->vm_end);
+
+	list_del(&c->vm_list);
+
+	spin_unlock_irqrestore(&consistent_lock, flags);
+
+	kfree(c);
+	return;
+
+ no_area:
+	spin_unlock_irqrestore(&consistent_lock, flags);
+	printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n",
+	       __func__, vaddr);
+	dump_stack();
+}
+EXPORT_SYMBOL(__dma_free_coherent);
+
+/*
+ * Initialise the consistent memory allocation.
+ */
+static int __init dma_alloc_init(void)
+{
+	pgd_t *pgd;
+	pmd_t *pmd;
+	pte_t *pte;
+	int ret = 0;
+
+	do {
+		pgd = pgd_offset(&init_mm, CONSISTENT_BASE);
+		pmd = pmd_alloc(&init_mm, pgd, CONSISTENT_BASE);
+		if (!pmd) {
+			printk(KERN_ERR "%s: no pmd tables\n", __func__);
+			ret = -ENOMEM;
+			break;
+		}
+		WARN_ON(!pmd_none(*pmd));
+
+		pte = pte_alloc_kernel(pmd, CONSISTENT_BASE);
+		if (!pte) {
+			printk(KERN_ERR "%s: no pte tables\n", __func__);
+			ret = -ENOMEM;
+			break;
+		}
+
+		consistent_pte = pte;
+	} while (0);
+
+	return ret;
+}
+
+core_initcall(dma_alloc_init);
+
+/*
+ * make an area consistent.
+ */
+void __dma_sync(void *vaddr, size_t size, int direction)
+{
+	unsigned long start = (unsigned long)vaddr;
+	unsigned long end   = start + size;
+
+	switch (direction) {
+	case DMA_NONE:
+		BUG();
+	case DMA_FROM_DEVICE:	/* invalidate only */
+		invalidate_dcache_range(start, end);
+		break;
+	case DMA_TO_DEVICE:		/* writeback only */
+		clean_dcache_range(start, end);
+		break;
+	case DMA_BIDIRECTIONAL:	/* writeback and invalidate */
+		flush_dcache_range(start, end);
+		break;
+	}
+}
+EXPORT_SYMBOL(__dma_sync);
+
+#ifdef CONFIG_HIGHMEM
+/*
+ * __dma_sync_page() implementation for systems using highmem.
+ * In this case, each page of a buffer must be kmapped/kunmapped
+ * in order to have a virtual address for __dma_sync(). This must
+ * not sleep so kmap_atomic()/kunmap_atomic() are used.
+ *
+ * Note: yes, it is possible and correct to have a buffer extend
+ * beyond the first page.
+ */
+static inline void __dma_sync_page_highmem(struct page *page,
+		unsigned long offset, size_t size, int direction)
+{
+	size_t seg_size = min((size_t)(PAGE_SIZE - offset), size);
+	size_t cur_size = seg_size;
+	unsigned long flags, start, seg_offset = offset;
+	int nr_segs = 1 + ((size - seg_size) + PAGE_SIZE - 1)/PAGE_SIZE;
+	int seg_nr = 0;
+
+	local_irq_save(flags);
+
+	do {
+		start = (unsigned long)kmap_atomic(page + seg_nr,
+				KM_PPC_SYNC_PAGE) + seg_offset;
+
+		/* Sync this buffer segment */
+		__dma_sync((void *)start, seg_size, direction);
+		kunmap_atomic((void *)start, KM_PPC_SYNC_PAGE);
+		seg_nr++;
+
+		/* Calculate next buffer segment size */
+		seg_size = min((size_t)PAGE_SIZE, size - cur_size);
+
+		/* Add the segment size to our running total */
+		cur_size += seg_size;
+		seg_offset = 0;
+	} while (seg_nr < nr_segs);
+
+	local_irq_restore(flags);
+}
+#endif /* CONFIG_HIGHMEM */
+
+/*
+ * __dma_sync_page makes memory consistent. identical to __dma_sync, but
+ * takes a struct page instead of a virtual address
+ */
+void __dma_sync_page(struct page *page, unsigned long offset,
+	size_t size, int direction)
+{
+#ifdef CONFIG_HIGHMEM
+	__dma_sync_page_highmem(page, offset, size, direction);
+#else
+	unsigned long start = (unsigned long)page_address(page) + offset;
+	__dma_sync((void *)start, size, direction);
+#endif
+}
+EXPORT_SYMBOL(__dma_sync_page);
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index a0360ae..ad5c30b 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -24,5 +24,6 @@ endif
 
 # Temporary hack until we have migrated to asm-powerpc
 ifeq ($(CONFIG_PPC_MERGE),y)
+obj-$(CONFIG_8xx)	+= rheap.o
 obj-$(CONFIG_CPM2)	+= rheap.o
 endif
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 03aeb3a..539917f 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -447,3 +447,102 @@ void bad_page_fault(struct pt_regs *regs
 
 	die("Kernel access of bad area", regs, sig);
 }
+
+#ifdef CONFIG_8xx
+
+/* The pgtable.h claims some functions generically exist, but I
+ * can't find them......
+ */
+pte_t *va_to_pte(unsigned long address)
+{
+	pgd_t *dir;
+	pmd_t *pmd;
+	pte_t *pte;
+
+	if (address < TASK_SIZE)
+		return NULL;
+
+	dir = pgd_offset(&init_mm, address);
+	if (dir) {
+		pmd = pmd_offset(dir, address & PAGE_MASK);
+		if (pmd && pmd_present(*pmd)) {
+			pte = pte_offset_kernel(pmd, address & PAGE_MASK);
+			if (pte && pte_present(*pte))
+				return(pte);
+		}
+	}
+	return NULL;
+}
+
+unsigned long va_to_phys(unsigned long address)
+{
+	pte_t *pte;
+
+	pte = va_to_pte(address);
+	if (pte)
+		return(((unsigned long)(pte_val(*pte)) & PAGE_MASK) | (address & ~(PAGE_MASK)));
+	return (0);
+}
+
+void
+print_8xx_pte(struct mm_struct *mm, unsigned long addr)
+{
+        pgd_t * pgd;
+        pmd_t * pmd;
+        pte_t * pte;
+
+        printk(" pte @ 0x%8lx: ", addr);
+        pgd = pgd_offset(mm, addr & PAGE_MASK);
+        if (pgd) {
+                pmd = pmd_offset(pgd, addr & PAGE_MASK);
+                if (pmd && pmd_present(*pmd)) {
+                        pte = pte_offset_kernel(pmd, addr & PAGE_MASK);
+                        if (pte) {
+                                printk(" (0x%08lx)->(0x%08lx)->0x%08lx\n",
+                                        (long)pgd, (long)pte, (long)pte_val(*pte));
+#define pp ((long)pte_val(*pte))
+				printk(" RPN: %05lx PP: %lx SPS: %lx SH: %lx "
+				       "CI: %lx v: %lx\n",
+				       pp>>12,    /* rpn */
+				       (pp>>10)&3, /* pp */
+				       (pp>>3)&1, /* small */
+				       (pp>>2)&1, /* shared */
+				       (pp>>1)&1, /* cache inhibit */
+				       pp&1       /* valid */
+				       );
+#undef pp
+                        }
+                        else {
+                                printk("no pte\n");
+                        }
+                }
+                else {
+                        printk("no pmd\n");
+                }
+        }
+        else {
+                printk("no pgd\n");
+        }
+}
+
+int
+get_8xx_pte(struct mm_struct *mm, unsigned long addr)
+{
+        pgd_t * pgd;
+        pmd_t * pmd;
+        pte_t * pte;
+        int     retval = 0;
+
+        pgd = pgd_offset(mm, addr & PAGE_MASK);
+        if (pgd) {
+                pmd = pmd_offset(pgd, addr & PAGE_MASK);
+                if (pmd && pmd_present(*pmd)) {
+                        pte = pte_offset_kernel(pmd, addr & PAGE_MASK);
+                        if (pte) {
+				retval = (int)pte_val(*pte);
+                        }
+                }
+        }
+        return(retval);
+}
+#endif /* CONFIG_8xx */