* [PATCH 2/2] parisc: use the generic remapping dma allocator
2022-11-21 13:16 RFC: switch to use the generic remapping dma-allocator Christoph Hellwig
2022-11-21 13:16 ` [PATCH 1/2] dma-mapping: add a arch_can_dma_alloc_coherent hook Christoph Hellwig
@ 2022-11-21 13:16 ` Christoph Hellwig
2022-11-21 14:22 ` RFC: switch to use the generic remapping dma-allocator Helge Deller
2 siblings, 0 replies; 5+ messages in thread
From: Christoph Hellwig @ 2022-11-21 13:16 UTC (permalink / raw)
To: James E.J. Bottomley, Helge Deller; +Cc: linux-parisc, iommu
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@lst.de>
---
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@tux.org>
-** (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@tux.org>
+ * (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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