[PATCH 2/2] parisc: use the generic remapping dma allocator

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Use the dma-direct code that uses vmap to create an uncacheable mapping
for coherent allocations instead of the hand-crafted bitmap.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 arch/parisc/Kconfig               |   4 +
 arch/parisc/include/asm/pgtable.h |   1 -
 arch/parisc/kernel/pci-dma.c      | 446 +-----------------------------
 3 files changed, 16 insertions(+), 435 deletions(-)

diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index a98940e642432..c1c8bec74aa7c 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -8,6 +8,8 @@ config PARISC
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_SYSCALL_TRACEPOINTS
 	select ARCH_WANT_FRAME_POINTERS
+	select ARCH_HAS_CAN_DMA_ALLOC_COHERENT
+	select ARCH_HAS_DMA_PREP_COHERENT
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_STRICT_KERNEL_RWX
 	select ARCH_HAS_STRICT_MODULE_RWX
@@ -19,6 +21,8 @@ config PARISC
 	select ARCH_STACKWALK
 	select ARCH_HAS_DEBUG_VM_PGTABLE
 	select HAVE_RELIABLE_STACKTRACE
+	select DMA_COHERENT_POOL
+	select DMA_DIRECT_REMAP
 	select DMA_OPS
 	select RTC_CLASS
 	select RTC_DRV_GENERIC
diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
index ecd0288544698..d76013716f694 100644
--- a/arch/parisc/include/asm/pgtable.h
+++ b/arch/parisc/include/asm/pgtable.h
@@ -263,7 +263,6 @@ extern void __update_cache(pte_t pte);
 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL_EXEC)
 #define PAGE_KERNEL_RWX	__pgprot(_PAGE_KERNEL_RWX)
 #define PAGE_KERNEL_RO	__pgprot(_PAGE_KERNEL_RO)
-#define PAGE_KERNEL_UNC	__pgprot(_PAGE_KERNEL | _PAGE_NO_CACHE)
 #define PAGE_GATEWAY    __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_GATEWAY| _PAGE_READ)
 
 
diff --git a/arch/parisc/kernel/pci-dma.c b/arch/parisc/kernel/pci-dma.c
index ba87f791323be..b34d3442073d4 100644
--- a/arch/parisc/kernel/pci-dma.c
+++ b/arch/parisc/kernel/pci-dma.c
@@ -1,446 +1,24 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
-** PARISC 1.1 Dynamic DMA mapping support.
-** This implementation is for PA-RISC platforms that do not support
-** I/O TLBs (aka DMA address translation hardware).
-** See Documentation/core-api/dma-api-howto.rst for interface definitions.
-**
-**      (c) Copyright 1999,2000 Hewlett-Packard Company
-**      (c) Copyright 2000 Grant Grundler
-**	(c) Copyright 2000 Philipp Rumpf <prumpf@xxxxxxx>
-**      (c) Copyright 2000 John Marvin
-**
-** "leveraged" from 2.3.47: arch/ia64/kernel/pci-dma.c.
-** (I assume it's from David Mosberger-Tang but there was no Copyright)
-**
-** AFAIK, all PA7100LC and PA7300LC platforms can use this code.
-**
-** - ggg
-*/
-
-#include <linux/init.h>
-#include <linux/gfp.h>
-#include <linux/mm.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include <linux/string.h>
-#include <linux/types.h>
-#include <linux/dma-direct.h>
+ * PARISC helpers for noncoherent DMA.
+ *
+ *	(c) Copyright 1999,2000 Hewlett-Packard Company
+ *	(c) Copyright 2000 Grant Grundler
+ *	(c) Copyright 2000 Philipp Rumpf <prumpf@xxxxxxx>
+ *	(c) Copyright 2000 John Marvin
+ */
 #include <linux/dma-map-ops.h>
-
 #include <asm/cacheflush.h>
-#include <asm/dma.h>    /* for DMA_CHUNK_SIZE */
-#include <asm/io.h>
-#include <asm/page.h>	/* get_order */
-#include <linux/uaccess.h>
-#include <asm/tlbflush.h>	/* for purge_tlb_*() macros */
-
-static struct proc_dir_entry * proc_gsc_root __read_mostly = NULL;
-static unsigned long pcxl_used_bytes __read_mostly;
-static unsigned long pcxl_used_pages __read_mostly;
-
-extern unsigned long pcxl_dma_start; /* Start of pcxl dma mapping area */
-static DEFINE_SPINLOCK(pcxl_res_lock);
-static char    *pcxl_res_map;
-static int     pcxl_res_hint;
-static int     pcxl_res_size;
-
-#ifdef DEBUG_PCXL_RESOURCE
-#define DBG_RES(x...)	printk(x)
-#else
-#define DBG_RES(x...)
-#endif
-
-
-/*
-** Dump a hex representation of the resource map.
-*/
-
-#ifdef DUMP_RESMAP
-static
-void dump_resmap(void)
-{
-	u_long *res_ptr = (unsigned long *)pcxl_res_map;
-	u_long i = 0;
-
-	printk("res_map: ");
-	for(; i < (pcxl_res_size / sizeof(unsigned long)); ++i, ++res_ptr)
-		printk("%08lx ", *res_ptr);
-
-	printk("\n");
-}
-#else
-static inline void dump_resmap(void) {;}
-#endif
-
-static inline int map_pte_uncached(pte_t * pte,
-		unsigned long vaddr,
-		unsigned long size, unsigned long *paddr_ptr)
-{
-	unsigned long end;
-	unsigned long orig_vaddr = vaddr;
-
-	vaddr &= ~PMD_MASK;
-	end = vaddr + size;
-	if (end > PMD_SIZE)
-		end = PMD_SIZE;
-	do {
-		unsigned long flags;
-
-		if (!pte_none(*pte))
-			printk(KERN_ERR "map_pte_uncached: page already exists\n");
-		purge_tlb_start(flags);
-		set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC));
-		pdtlb(SR_KERNEL, orig_vaddr);
-		purge_tlb_end(flags);
-		vaddr += PAGE_SIZE;
-		orig_vaddr += PAGE_SIZE;
-		(*paddr_ptr) += PAGE_SIZE;
-		pte++;
-	} while (vaddr < end);
-	return 0;
-}
-
-static inline int map_pmd_uncached(pmd_t * pmd, unsigned long vaddr,
-		unsigned long size, unsigned long *paddr_ptr)
-{
-	unsigned long end;
-	unsigned long orig_vaddr = vaddr;
-
-	vaddr &= ~PGDIR_MASK;
-	end = vaddr + size;
-	if (end > PGDIR_SIZE)
-		end = PGDIR_SIZE;
-	do {
-		pte_t * pte = pte_alloc_kernel(pmd, vaddr);
-		if (!pte)
-			return -ENOMEM;
-		if (map_pte_uncached(pte, orig_vaddr, end - vaddr, paddr_ptr))
-			return -ENOMEM;
-		vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
-		orig_vaddr += PMD_SIZE;
-		pmd++;
-	} while (vaddr < end);
-	return 0;
-}
 
-static inline int map_uncached_pages(unsigned long vaddr, unsigned long size,
-		unsigned long paddr)
+bool arch_can_dma_alloc_coherent(void)
 {
-	pgd_t * dir;
-	unsigned long end = vaddr + size;
-
-	dir = pgd_offset_k(vaddr);
-	do {
-		p4d_t *p4d;
-		pud_t *pud;
-		pmd_t *pmd;
-
-		p4d = p4d_offset(dir, vaddr);
-		pud = pud_offset(p4d, vaddr);
-		pmd = pmd_alloc(NULL, pud, vaddr);
-
-		if (!pmd)
-			return -ENOMEM;
-		if (map_pmd_uncached(pmd, vaddr, end - vaddr, &paddr))
-			return -ENOMEM;
-		vaddr = vaddr + PGDIR_SIZE;
-		dir++;
-	} while (vaddr && (vaddr < end));
-	return 0;
-}
-
-static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr,
-		unsigned long size)
-{
-	pte_t * pte;
-	unsigned long end;
-	unsigned long orig_vaddr = vaddr;
-
-	if (pmd_none(*pmd))
-		return;
-	if (pmd_bad(*pmd)) {
-		pmd_ERROR(*pmd);
-		pmd_clear(pmd);
-		return;
-	}
-	pte = pte_offset_map(pmd, vaddr);
-	vaddr &= ~PMD_MASK;
-	end = vaddr + size;
-	if (end > PMD_SIZE)
-		end = PMD_SIZE;
-	do {
-		unsigned long flags;
-		pte_t page = *pte;
-
-		pte_clear(&init_mm, vaddr, pte);
-		purge_tlb_start(flags);
-		pdtlb(SR_KERNEL, orig_vaddr);
-		purge_tlb_end(flags);
-		vaddr += PAGE_SIZE;
-		orig_vaddr += PAGE_SIZE;
-		pte++;
-		if (pte_none(page) || pte_present(page))
-			continue;
-		printk(KERN_CRIT "Whee.. Swapped out page in kernel page table\n");
-	} while (vaddr < end);
-}
-
-static inline void unmap_uncached_pmd(pgd_t * dir, unsigned long vaddr,
-		unsigned long size)
-{
-	pmd_t * pmd;
-	unsigned long end;
-	unsigned long orig_vaddr = vaddr;
-
-	if (pgd_none(*dir))
-		return;
-	if (pgd_bad(*dir)) {
-		pgd_ERROR(*dir);
-		pgd_clear(dir);
-		return;
-	}
-	pmd = pmd_offset(pud_offset(p4d_offset(dir, vaddr), vaddr), vaddr);
-	vaddr &= ~PGDIR_MASK;
-	end = vaddr + size;
-	if (end > PGDIR_SIZE)
-		end = PGDIR_SIZE;
-	do {
-		unmap_uncached_pte(pmd, orig_vaddr, end - vaddr);
-		vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
-		orig_vaddr += PMD_SIZE;
-		pmd++;
-	} while (vaddr < end);
+	return boot_cpu_data.cpu_type == pcxl2 ||
+		boot_cpu_data.cpu_type == pcxl;
 }
 
-static void unmap_uncached_pages(unsigned long vaddr, unsigned long size)
+void arch_dma_prep_coherent(struct page *page, size_t size)
 {
-	pgd_t * dir;
-	unsigned long end = vaddr + size;
-
-	dir = pgd_offset_k(vaddr);
-	do {
-		unmap_uncached_pmd(dir, vaddr, end - vaddr);
-		vaddr = vaddr + PGDIR_SIZE;
-		dir++;
-	} while (vaddr && (vaddr < end));
-}
-
-#define PCXL_SEARCH_LOOP(idx, mask, size)  \
-       for(; res_ptr < res_end; ++res_ptr) \
-       { \
-               if(0 == ((*res_ptr) & mask)) { \
-                       *res_ptr |= mask; \
-		       idx = (int)((u_long)res_ptr - (u_long)pcxl_res_map); \
-		       pcxl_res_hint = idx + (size >> 3); \
-                       goto resource_found; \
-               } \
-       }
-
-#define PCXL_FIND_FREE_MAPPING(idx, mask, size)  { \
-       u##size *res_ptr = (u##size *)&(pcxl_res_map[pcxl_res_hint & ~((size >> 3) - 1)]); \
-       u##size *res_end = (u##size *)&pcxl_res_map[pcxl_res_size]; \
-       PCXL_SEARCH_LOOP(idx, mask, size); \
-       res_ptr = (u##size *)&pcxl_res_map[0]; \
-       PCXL_SEARCH_LOOP(idx, mask, size); \
-}
-
-unsigned long
-pcxl_alloc_range(size_t size)
-{
-	int res_idx;
-	u_long mask, flags;
-	unsigned int pages_needed = size >> PAGE_SHIFT;
-
-	mask = (u_long) -1L;
- 	mask >>= BITS_PER_LONG - pages_needed;
-
-	DBG_RES("pcxl_alloc_range() size: %d pages_needed %d pages_mask 0x%08lx\n", 
-		size, pages_needed, mask);
-
-	spin_lock_irqsave(&pcxl_res_lock, flags);
-
-	if(pages_needed <= 8) {
-		PCXL_FIND_FREE_MAPPING(res_idx, mask, 8);
-	} else if(pages_needed <= 16) {
-		PCXL_FIND_FREE_MAPPING(res_idx, mask, 16);
-	} else if(pages_needed <= 32) {
-		PCXL_FIND_FREE_MAPPING(res_idx, mask, 32);
-	} else {
-		panic("%s: pcxl_alloc_range() Too many pages to map.\n",
-		      __FILE__);
-	}
-
-	dump_resmap();
-	panic("%s: pcxl_alloc_range() out of dma mapping resources\n",
-	      __FILE__);
-	
-resource_found:
-	
-	DBG_RES("pcxl_alloc_range() res_idx %d mask 0x%08lx res_hint: %d\n",
-		res_idx, mask, pcxl_res_hint);
-
-	pcxl_used_pages += pages_needed;
-	pcxl_used_bytes += ((pages_needed >> 3) ? (pages_needed >> 3) : 1);
-
-	spin_unlock_irqrestore(&pcxl_res_lock, flags);
-
-	dump_resmap();
-
-	/* 
-	** return the corresponding vaddr in the pcxl dma map
-	*/
-	return (pcxl_dma_start + (res_idx << (PAGE_SHIFT + 3)));
-}
-
-#define PCXL_FREE_MAPPINGS(idx, m, size) \
-		u##size *res_ptr = (u##size *)&(pcxl_res_map[(idx) + (((size >> 3) - 1) & (~((size >> 3) - 1)))]); \
-		/* BUG_ON((*res_ptr & m) != m); */ \
-		*res_ptr &= ~m;
-
-/*
-** clear bits in the pcxl resource map
-*/
-static void
-pcxl_free_range(unsigned long vaddr, size_t size)
-{
-	u_long mask, flags;
-	unsigned int res_idx = (vaddr - pcxl_dma_start) >> (PAGE_SHIFT + 3);
-	unsigned int pages_mapped = size >> PAGE_SHIFT;
-
-	mask = (u_long) -1L;
- 	mask >>= BITS_PER_LONG - pages_mapped;
-
-	DBG_RES("pcxl_free_range() res_idx: %d size: %d pages_mapped %d mask 0x%08lx\n", 
-		res_idx, size, pages_mapped, mask);
-
-	spin_lock_irqsave(&pcxl_res_lock, flags);
-
-	if(pages_mapped <= 8) {
-		PCXL_FREE_MAPPINGS(res_idx, mask, 8);
-	} else if(pages_mapped <= 16) {
-		PCXL_FREE_MAPPINGS(res_idx, mask, 16);
-	} else if(pages_mapped <= 32) {
-		PCXL_FREE_MAPPINGS(res_idx, mask, 32);
-	} else {
-		panic("%s: pcxl_free_range() Too many pages to unmap.\n",
-		      __FILE__);
-	}
-	
-	pcxl_used_pages -= (pages_mapped ? pages_mapped : 1);
-	pcxl_used_bytes -= ((pages_mapped >> 3) ? (pages_mapped >> 3) : 1);
-
-	spin_unlock_irqrestore(&pcxl_res_lock, flags);
-
-	dump_resmap();
-}
-
-static int __maybe_unused proc_pcxl_dma_show(struct seq_file *m, void *v)
-{
-#if 0
-	u_long i = 0;
-	unsigned long *res_ptr = (u_long *)pcxl_res_map;
-#endif
-	unsigned long total_pages = pcxl_res_size << 3;   /* 8 bits per byte */
-
-	seq_printf(m, "\nDMA Mapping Area size    : %d bytes (%ld pages)\n",
-		PCXL_DMA_MAP_SIZE, total_pages);
-
-	seq_printf(m, "Resource bitmap : %d bytes\n", pcxl_res_size);
-
-	seq_puts(m,  "     	  total:    free:    used:   % used:\n");
-	seq_printf(m, "blocks  %8d %8ld %8ld %8ld%%\n", pcxl_res_size,
-		pcxl_res_size - pcxl_used_bytes, pcxl_used_bytes,
-		(pcxl_used_bytes * 100) / pcxl_res_size);
-
-	seq_printf(m, "pages   %8ld %8ld %8ld %8ld%%\n", total_pages,
-		total_pages - pcxl_used_pages, pcxl_used_pages,
-		(pcxl_used_pages * 100 / total_pages));
-
-#if 0
-	seq_puts(m, "\nResource bitmap:");
-
-	for(; i < (pcxl_res_size / sizeof(u_long)); ++i, ++res_ptr) {
-		if ((i & 7) == 0)
-		    seq_puts(m,"\n   ");
-		seq_printf(m, "%s %08lx", buf, *res_ptr);
-	}
-#endif
-	seq_putc(m, '\n');
-	return 0;
-}
-
-static int __init
-pcxl_dma_init(void)
-{
-	if (pcxl_dma_start == 0)
-		return 0;
-
-	pcxl_res_size = PCXL_DMA_MAP_SIZE >> (PAGE_SHIFT + 3);
-	pcxl_res_hint = 0;
-	pcxl_res_map = (char *)__get_free_pages(GFP_KERNEL,
-					    get_order(pcxl_res_size));
-	memset(pcxl_res_map, 0, pcxl_res_size);
-	proc_gsc_root = proc_mkdir("gsc", NULL);
-	if (!proc_gsc_root)
-    		printk(KERN_WARNING
-			"pcxl_dma_init: Unable to create gsc /proc dir entry\n");
-	else {
-		struct proc_dir_entry* ent;
-		ent = proc_create_single("pcxl_dma", 0, proc_gsc_root,
-				proc_pcxl_dma_show);
-		if (!ent)
-			printk(KERN_WARNING
-				"pci-dma.c: Unable to create pcxl_dma /proc entry.\n");
-	}
-	return 0;
-}
-
-__initcall(pcxl_dma_init);
-
-void *arch_dma_alloc(struct device *dev, size_t size,
-		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
-{
-	unsigned long vaddr;
-	unsigned long paddr;
-	int order;
-
-	if (boot_cpu_data.cpu_type != pcxl2 && boot_cpu_data.cpu_type != pcxl)
-		return NULL;
-
-	order = get_order(size);
-	size = 1 << (order + PAGE_SHIFT);
-	vaddr = pcxl_alloc_range(size);
-	paddr = __get_free_pages(gfp | __GFP_ZERO, order);
-	flush_kernel_dcache_range(paddr, size);
-	paddr = __pa(paddr);
-	map_uncached_pages(vaddr, size, paddr);
-	*dma_handle = (dma_addr_t) paddr;
-
-#if 0
-/* This probably isn't needed to support EISA cards.
-** ISA cards will certainly only support 24-bit DMA addressing.
-** Not clear if we can, want, or need to support ISA.
-*/
-	if (!dev || *dev->coherent_dma_mask < 0xffffffff)
-		gfp |= GFP_DMA;
-#endif
-	return (void *)vaddr;
-}
-
-void arch_dma_free(struct device *dev, size_t size, void *vaddr,
-		dma_addr_t dma_handle, unsigned long attrs)
-{
-	int order = get_order(size);
-
-	WARN_ON_ONCE(boot_cpu_data.cpu_type != pcxl2 &&
-		     boot_cpu_data.cpu_type != pcxl);
-
-	size = 1 << (order + PAGE_SHIFT);
-	unmap_uncached_pages((unsigned long)vaddr, size);
-	pcxl_free_range((unsigned long)vaddr, size);
-
-	free_pages((unsigned long)__va(dma_handle), order);
+	flush_kernel_dcache_range((unsigned long)page_address(page), size);
 }
 
 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
-- 
2.30.2




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