| // 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> |
| #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 = 0; |
| static unsigned long pcxl_used_pages __read_mostly = 0; |
| |
| 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_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) |
| { |
| 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_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); |
| } |
| |
| static void unmap_uncached_pages(unsigned long vaddr, unsigned long 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); |
| } |
| |
| void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, |
| enum dma_data_direction dir) |
| { |
| /* |
| * fdc: The data cache line is written back to memory, if and only if |
| * it is dirty, and then invalidated from the data cache. |
| */ |
| flush_kernel_dcache_range((unsigned long)phys_to_virt(paddr), size); |
| } |
| |
| void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size, |
| enum dma_data_direction dir) |
| { |
| unsigned long addr = (unsigned long) phys_to_virt(paddr); |
| |
| switch (dir) { |
| case DMA_TO_DEVICE: |
| case DMA_BIDIRECTIONAL: |
| flush_kernel_dcache_range(addr, size); |
| return; |
| case DMA_FROM_DEVICE: |
| purge_kernel_dcache_range_asm(addr, addr + size); |
| return; |
| default: |
| BUG(); |
| } |
| } |