From: Stefan Holst <mail@s-holst.de>
To: sparclinux@vger.kernel.org
Subject: Re: nonzero phys_base
Date: Wed, 17 Mar 2004 23:58:29 +0000 [thread overview]
Message-ID: <20040317235828.GB5754@spike> (raw)
In-Reply-To: <20040316114121.GA5170@spike>
On 03/16, Pete Zaitcev wrote:
> On Tue, 16 Mar 2004 12:41:21 +0100
> Stefan Holst <mail@s-holst.de> wrote:
>
> Looks good on the whole, especially in that you accepted a correct
> relationship between PFN and indexing into mem_map.
>
> The only little problem is:
>
> > +#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + phys_base)
> > +#define __va(x) ((void *)((unsigned long) (x) - phys_base + PAGE_OFFSET))
>
> This, obviously, overflows on highmem systems.
hmm, never thought about highmem support... i'm working on 4mb here - for
everything ;). i have no idea how to handle this issue yet.
> Do we have any users for __pa, __va, virt_to_phys and phys_to_virt?
> It would be helpful if you enumerated all of them and perhaps
> removed some.
greped a bit and saw that the number of users for these macros are almost
equal.
>
> > -#define virt_to_page(kaddr) (mem_map + (__pa(kaddr) >> PAGE_SHIFT))
> > +#define virt_to_page(kaddr) pfn_to_page(PFN(__pa(kaddr)))
>
> This was correct before, because of the way mem_map was placed,
> its physical address never overflowed. But with nonzero phys_base,
> it is not correct anymore.
>
> In fact you do not need this, just use
>
> mem_map + ((unsigned long)(x) - PAGE_OFFSET)
>
> > +#define virt_addr_valid(kaddr) pfn_valid(PFN(__pa(kaddr)))
thanks for the hints.
revised patch below, now also with pfn_base as keith suggested.
diff -ur a/arch/sparc/kernel/setup.c b/arch/sparc/kernel/setup.c
--- a/arch/sparc/kernel/setup.c 2004-03-11 11:32:58.000000000 +0100
+++ b/arch/sparc/kernel/setup.c 2004-03-17 23:57:08.993044448 +0100
@@ -330,6 +330,7 @@
if (highest_paddr < top)
highest_paddr = top;
}
+ pfn_base = phys_base >> PAGE_SHIFT;
if (!root_flags)
root_mountflags &= ~MS_RDONLY;
diff -ur a/arch/sparc/kernel/sparc_ksyms.c b/arch/sparc/kernel/sparc_ksyms.c
--- a/arch/sparc/kernel/sparc_ksyms.c 2004-03-11 11:32:58.000000000 +0100
+++ b/arch/sparc/kernel/sparc_ksyms.c 2004-03-17 23:57:09.005042624 +0100
@@ -145,6 +145,7 @@
EXPORT_SYMBOL(sparc_valid_addr_bitmap);
EXPORT_SYMBOL(phys_base);
+EXPORT_SYMBOL(pfn_base);
/* Atomic operations. */
EXPORT_SYMBOL(___atomic24_add);
diff -ur a/arch/sparc/mm/init.c b/arch/sparc/mm/init.c
--- a/arch/sparc/mm/init.c 2004-02-29 23:35:40.000000000 +0100
+++ b/arch/sparc/mm/init.c 2004-03-17 23:57:09.006042472 +0100
@@ -39,6 +39,8 @@
unsigned long phys_base;
+unsigned long pfn_base;
+
unsigned long page_kernel;
struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
@@ -134,7 +136,7 @@
unsigned long calc_max_low_pfn(void)
{
int i;
- unsigned long tmp = (SRMMU_MAXMEM >> PAGE_SHIFT);
+ unsigned long tmp = ((phys_base + SRMMU_MAXMEM) >> PAGE_SHIFT);
unsigned long curr_pfn, last_pfn;
last_pfn = (sp_banks[0].base_addr + sp_banks[0].num_bytes) >> PAGE_SHIFT;
@@ -189,9 +191,6 @@
*/
start_pfn = (unsigned long)__pa(PAGE_ALIGN((unsigned long) &_end));
- /* Adjust up to the physical address where the kernel begins. */
- start_pfn += phys_base;
-
/* Now shift down to get the real physical page frame number. */
start_pfn >>= PAGE_SHIFT;
@@ -202,7 +201,7 @@
max_low_pfn = max_pfn;
highstart_pfn = highend_pfn = max_pfn;
- if (max_low_pfn > (SRMMU_MAXMEM >> PAGE_SHIFT)) {
+ if (max_low_pfn > ((phys_base + SRMMU_MAXMEM) >> PAGE_SHIFT)) {
highstart_pfn = (SRMMU_MAXMEM >> PAGE_SHIFT);
max_low_pfn = calc_max_low_pfn();
printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
@@ -267,8 +266,8 @@
reserve_bootmem(initrd_start, size);
*pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
- initrd_start += PAGE_OFFSET;
- initrd_end += PAGE_OFFSET;
+ initrd_start = (initrd_start - phys_base) + PAGE_OFFSET;
+ initrd_end = (initrd_end - phys_base) + PAGE_OFFSET;
}
#endif
/* Reserve the kernel text/data/bss. */
@@ -432,7 +431,7 @@
taint_real_pages();
- max_mapnr = last_valid_pfn - (phys_base >> PAGE_SHIFT);
+ max_mapnr = last_valid_pfn - pfn_base;
high_memory = __va(max_low_pfn << PAGE_SHIFT);
num_physpages = totalram_pages = free_all_bootmem();
@@ -477,7 +476,7 @@
unsigned long page;
struct page *p;
- page = addr + phys_base;
+ page = addr;
p = virt_to_page(page);
ClearPageReserved(p);
diff -ur a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c
--- a/arch/sparc/mm/srmmu.c 2004-03-11 11:32:58.000000000 +0100
+++ b/arch/sparc/mm/srmmu.c 2004-03-17 23:56:24.168858760 +0100
@@ -213,7 +213,7 @@
* and a page entry and page directory to the page they refer to.
*/
static pte_t srmmu_mk_pte(struct page *page, pgprot_t pgprot)
-{ return __pte(((page - mem_map) << (PAGE_SHIFT-4)) | pgprot_val(pgprot)); }
+{ return __pte((page_to_pfn(page) << (PAGE_SHIFT-4)) | pgprot_val(pgprot)); }
static pte_t srmmu_mk_pte_phys(unsigned long page, pgprot_t pgprot)
{ return __pte(((page) >> 4) | pgprot_val(pgprot)); }
@@ -245,7 +245,7 @@
unsigned long ptp; /* Physical address, shifted right by 4 */
int i;
- ptp = (ptep - mem_map) << (PAGE_SHIFT-4); /* watch for overflow */
+ ptp = page_to_pfn(ptep) << (PAGE_SHIFT-4); /* watch for overflow */
for (i = 0; i < SRMMU_PTRS_PER_PTE_SOFT/SRMMU_PTRS_PER_PTE; i++) {
srmmu_set_pte((pte_t *)&pmdp->pmdv[i], SRMMU_ET_PTD | ptp);
ptp += (SRMMU_PTRS_PER_PTE*sizeof(pte_t) >> 4);
@@ -480,7 +480,7 @@
if ((pte = (unsigned long)srmmu_pte_alloc_one_kernel(mm, address)) = 0)
return NULL;
- return mem_map + (__nocache_pa(pte) >> PAGE_SHIFT);
+ return pfn_to_page( __nocache_pa(pte) >> PAGE_SHIFT );
}
static void srmmu_free_pte_fast(pte_t *pte)
@@ -495,7 +495,7 @@
p = (unsigned long)page_address(pte); /* Cached address (for test) */
if (p = 0)
BUG();
- p = ((pte - mem_map) << PAGE_SHIFT); /* Physical address */
+ p = page_to_pfn(pte) << PAGE_SHIFT; /* Physical address */
p = (unsigned long) __nocache_va(p); /* Nocached virtual */
srmmu_free_nocache(p, SRMMU_PTE_SZ_SOFT);
}
@@ -1331,10 +1331,6 @@
phys_base >> PAGE_SHIFT, zholes_size);
mem_map = contig_page_data.node_mem_map;
}
-
-/* P3: easy to fix, todo. Current code is utterly broken, though. */
- if (phys_base != 0)
- panic("phys_base nonzero");
}
static void srmmu_mmu_info(struct seq_file *m)
diff -ur a/include/asm-sparc/page.h b/include/asm-sparc/page.h
--- a/include/asm-sparc/page.h 2004-02-29 23:35:48.000000000 +0100
+++ b/include/asm-sparc/page.h 2004-03-17 23:57:09.006042472 +0100
@@ -156,17 +156,22 @@
#define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK)
#define PAGE_OFFSET 0xf0000000
-#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET)
-#define __va(x) ((void *)((unsigned long) (x) + PAGE_OFFSET))
+#ifndef __ASSEMBLY__
+extern unsigned long phys_base;
+extern unsigned long pfn_base;
+#endif
+#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + phys_base)
+#define __va(x) ((void *)((unsigned long) (x) - phys_base + PAGE_OFFSET))
+
+#define virt_to_phys __pa
+#define phys_to_virt __va
+
+#define pfn_to_page(pfn) (mem_map + ((pfn)-(pfn_base)))
+#define page_to_pfn(page) ((unsigned long)(((page) - mem_map) + pfn_base))
+#define virt_to_page(kaddr) (mem_map + ((((unsigned long)(kaddr)-PAGE_OFFSET)>>PAGE_SHIFT)))
-#define virt_to_phys(x) __pa((unsigned long)(x))
-#define phys_to_virt(x) __va((unsigned long)(x))
-
-#define pfn_to_page(pfn) (mem_map + (pfn))
-#define page_to_pfn(page) ((unsigned long)((page) - mem_map))
-#define virt_to_page(kaddr) (mem_map + (__pa(kaddr) >> PAGE_SHIFT))
-#define pfn_valid(pfn) ((pfn) < max_mapnr)
-#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
+#define pfn_valid(pfn) (((pfn) >= (pfn_base)) && (((pfn)-(pfn_base)) < max_mapnr))
+#define virt_addr_valid(kaddr) ((((unsigned long)(kaddr)-PAGE_OFFSET)>>PAGE_SHIFT) < max_mapnr)
#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
diff -ur a/include/asm-sparc/pgtable.h b/include/asm-sparc/pgtable.h
--- a/include/asm-sparc/pgtable.h 2004-02-29 23:36:24.000000000 +0100
+++ b/include/asm-sparc/pgtable.h 2004-03-17 23:57:09.039037456 +0100
@@ -181,6 +181,7 @@
* hit for all __pa()/__va() operations.
*/
extern unsigned long phys_base;
+extern unsigned long pfn_base;
/*
* BAD_PAGETABLE is used when we need a bogus page-table, while
--
RY Stefan
+-----------------+----------------+
| mail@s-holst.de | www.s-holst.de |
+-----------------+----------------+
next prev parent reply other threads:[~2004-03-17 23:58 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-16 11:41 nonzero phys_base Stefan Holst
2004-03-16 16:55 ` Keith M Wesolowski
2004-03-16 17:10 ` Pete Zaitcev
2004-03-17 23:58 ` Stefan Holst [this message]
2004-03-18 0:09 ` Stefan Holst
2004-03-18 2:45 ` Keith M Wesolowski
2004-03-18 3:36 ` Pete Zaitcev
2004-03-21 22:51 ` Keith M Wesolowski
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