* [PATCH v2 0/6] sparc32: replace sp_banks with memblock
@ 2026-08-30 12:06 Magnus Lindholm
2026-08-30 12:06 ` [PATCH v2 1/6] sparc32: use memblock when mapping the kernel Magnus Lindholm
` (5 more replies)
0 siblings, 6 replies; 10+ messages in thread
From: Magnus Lindholm @ 2026-08-30 12:06 UTC (permalink / raw)
To: sparclinux; +Cc: davem, andreas, linux-kernel, sam, glaubitz, Magnus Lindholm
Replace the sparc32-private sp_banks memory description with memblock.
The first two patches convert the SRMMU consumers that already run after
bootmem_init() has populated memblock. The third patch moves memblock
population to prom_meminit() and applies the mem= limit there. Patch 4
removes an unused address bitmap before patch 5 moves the early memory
setup into setup_32.c. Patch 6 removes the now-unused sp_banks array.
This work is based on an earlier eight-patch series by Sam Ravnborg.
Patch 2 directly carries over Sam's memblock sizing conversion. The series
has otherwise been substantially reorganized and reworked for the current
kernel. It retains the sparc32 mem= command-line option by using
memblock_enforce_memory_limit() and uses memblock's exclusive range-end
semantics throughout.
The series applies on top of the sparc32 phys_base and Viking fixes.
setup_memory() preserves relocated-kernel handling by removing RAM below
the physical address to which PAGE_OFFSET maps.
Link: https://lore.kernel.org/sparclinux/20260816075141.3489194-1-linmag7@gmail.com/T/#t
The v1 series was boot tested on a Sun SPARCstation 20 with dual
SuperSPARC-II CPUs (SM71).
The v2 series was boot tested on a Sun SPARCstation 20 with dual
ROSS Hypersparc (RT626) CPUSs.
Changes in v2:
- Add Sam's Reviewed-by tags to patches 1-3 and 6. Patch 6 is the
unchanged source change from patch 5 in v1, renumbered by the new patch.
- Drop the unused sparc_valid_addr_bitmap in a preparation patch.
- Use for_each_mem_pfn_range() and the standard max_low_pfn variable in
the early memory setup. This tightens LEON's _pfn_valid() upper bound
from all memory to the lowmem limit, with no functional change because
LEON does not use highmem.
Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://lore.kernel.org/r/20260817153237.GA702187@ravnborg.org
Magnus Lindholm (6):
sparc32: use memblock when mapping the kernel
sparc32: use memblock to find available system memory
sparc32: populate memblock from the PROM memory map
sparc32: drop unused valid address bitmap
sparc32: move early memory setup to setup_arch
sparc32: drop sp_banks
arch/sparc/include/asm/leon.h | 2 +-
arch/sparc/include/asm/page_32.h | 16 ---
arch/sparc/include/asm/pgtable_32.h | 3 +-
arch/sparc/include/asm/pgtsrmmu.h | 2 +-
arch/sparc/kernel/setup_32.c | 115 ++++++++++---------
arch/sparc/mm/init_32.c | 167 +---------------------------
arch/sparc/mm/srmmu.c | 67 ++++-------
arch/sparc/prom/memory.c | 51 ++-------
8 files changed, 100 insertions(+), 323 deletions(-)
base-commit: e6de5705a9f0d81f67bdb2917108784b5839cecd
--
2.43.0
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v2 1/6] sparc32: use memblock when mapping the kernel
2026-08-30 12:06 [PATCH v2 0/6] sparc32: replace sp_banks with memblock Magnus Lindholm
@ 2026-08-30 12:06 ` Magnus Lindholm
2026-08-30 12:06 ` [PATCH v2 2/6] sparc32: use memblock to find available system memory Magnus Lindholm
` (4 subsequent siblings)
5 siblings, 0 replies; 10+ messages in thread
From: Magnus Lindholm @ 2026-08-30 12:06 UTC (permalink / raw)
To: sparclinux; +Cc: davem, andreas, linux-kernel, sam, glaubitz, Magnus Lindholm
memblock already contains the available memory ranges when map_kernel()
runs. Iterate those ranges directly and remove the sp_banks-specific
mapping helper. memblock range ends are exclusive, so use end - start as
the range size.
Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
---
arch/sparc/mm/srmmu.c | 47 +++++++++++++++++++------------------------
1 file changed, 21 insertions(+), 26 deletions(-)
diff --git a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c
index f0fe09169528..483235458d69 100644
--- a/arch/sparc/mm/srmmu.c
+++ b/arch/sparc/mm/srmmu.c
@@ -846,39 +846,34 @@ static void __init do_large_mapping(unsigned long vaddr, unsigned long phys_base
*__nocache_fix(pgdp) = __pgd(big_pte);
}
-/* Map sp_bank entry SP_ENTRY, starting at virtual address VBASE. */
-static unsigned long __init map_spbank(unsigned long vbase, int sp_entry)
-{
- unsigned long pstart = (sp_banks[sp_entry].base_addr & PGDIR_MASK);
- unsigned long vstart = (vbase & PGDIR_MASK);
- unsigned long vend = PGDIR_ALIGN(vbase + sp_banks[sp_entry].num_bytes);
- /* Map "low" memory only */
- const unsigned long min_vaddr = PAGE_OFFSET;
- const unsigned long max_vaddr = PAGE_OFFSET + SRMMU_MAXMEM;
-
- if (vstart < min_vaddr || vstart >= max_vaddr)
- return vstart;
-
- if (vend > max_vaddr || vend < min_vaddr)
- vend = max_vaddr;
-
- while (vstart < vend) {
- do_large_mapping(vstart, pstart);
- vstart += PGDIR_SIZE; pstart += PGDIR_SIZE;
- }
- return vstart;
-}
-
static void __init map_kernel(void)
{
- int i;
+ phys_addr_t start, end;
+ u64 i;
if (phys_base > 0) {
do_large_mapping(PAGE_OFFSET, phys_base);
}
- for (i = 0; sp_banks[i].num_bytes != 0; i++) {
- map_spbank((unsigned long)__va(sp_banks[i].base_addr), i);
+ for_each_mem_range(i, &start, &end) {
+ unsigned long vbase = (unsigned long)__va(start);
+ unsigned long pstart = start & PGDIR_MASK;
+ unsigned long vstart = vbase & PGDIR_MASK;
+ unsigned long vend = PGDIR_ALIGN(vbase + end - start);
+ const unsigned long min_vaddr = PAGE_OFFSET;
+ const unsigned long max_vaddr = PAGE_OFFSET + SRMMU_MAXMEM;
+
+ /* Map low memory only. */
+ if (vstart < min_vaddr || vstart >= max_vaddr)
+ continue;
+ if (vend > max_vaddr || vend < min_vaddr)
+ vend = max_vaddr;
+
+ while (vstart < vend) {
+ do_large_mapping(vstart, pstart);
+ vstart += PGDIR_SIZE;
+ pstart += PGDIR_SIZE;
+ }
}
}
--
2.43.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v2 2/6] sparc32: use memblock to find available system memory
2026-08-30 12:06 [PATCH v2 0/6] sparc32: replace sp_banks with memblock Magnus Lindholm
2026-08-30 12:06 ` [PATCH v2 1/6] sparc32: use memblock when mapping the kernel Magnus Lindholm
@ 2026-08-30 12:06 ` Magnus Lindholm
2026-08-30 12:06 ` [PATCH v2 3/6] sparc32: populate memblock from the PROM memory map Magnus Lindholm
` (3 subsequent siblings)
5 siblings, 0 replies; 10+ messages in thread
From: Magnus Lindholm @ 2026-08-30 12:06 UTC (permalink / raw)
To: sparclinux; +Cc: davem, andreas, linux-kernel, sam, glaubitz, Magnus Lindholm
The SRMMU nocache pool is sized after memblock has been populated. Use
memblock_phys_mem_size() instead of summing the private sp_banks array.
Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
---
arch/sparc/mm/srmmu.c | 14 +-------------
1 file changed, 1 insertion(+), 13 deletions(-)
diff --git a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c
index 483235458d69..3029527a5a9f 100644
--- a/arch/sparc/mm/srmmu.c
+++ b/arch/sparc/mm/srmmu.c
@@ -226,25 +226,13 @@ void srmmu_free_nocache(void *addr, int size)
static void srmmu_early_allocate_ptable_skeleton(unsigned long start,
unsigned long end);
-/* Return how much physical memory we have. */
-static unsigned long __init probe_memory(void)
-{
- unsigned long total = 0;
- int i;
-
- for (i = 0; sp_banks[i].num_bytes; i++)
- total += sp_banks[i].num_bytes;
-
- return total;
-}
-
/*
* Reserve nocache dynamically proportionally to the amount of
* system RAM. -- Tomas Szepe <szepe@pinerecords.com>, June 2002
*/
static void __init srmmu_nocache_calcsize(void)
{
- unsigned long sysmemavail = probe_memory() / 1024;
+ unsigned long sysmemavail = memblock_phys_mem_size() / 1024;
int srmmu_nocache_npages;
srmmu_nocache_npages =
--
2.43.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v2 3/6] sparc32: populate memblock from the PROM memory map
2026-08-30 12:06 [PATCH v2 0/6] sparc32: replace sp_banks with memblock Magnus Lindholm
2026-08-30 12:06 ` [PATCH v2 1/6] sparc32: use memblock when mapping the kernel Magnus Lindholm
2026-08-30 12:06 ` [PATCH v2 2/6] sparc32: use memblock to find available system memory Magnus Lindholm
@ 2026-08-30 12:06 ` Magnus Lindholm
2026-08-30 12:06 ` [PATCH v2 4/6] sparc32: drop unused valid address bitmap Magnus Lindholm
` (2 subsequent siblings)
5 siblings, 0 replies; 10+ messages in thread
From: Magnus Lindholm @ 2026-08-30 12:06 UTC (permalink / raw)
To: sparclinux; +Cc: davem, andreas, linux-kernel, sam, glaubitz, Magnus Lindholm
Add each available PROM memory range to memblock as it is discovered.
Keep populating sp_banks temporarily so the remaining users continue to
work while they are converted in the following patches.
Since the complete PROM map is now present before bootmem_init(), enforce
the mem= limit after the legacy bank processing. Adding a smaller
overlapping range would otherwise leave memory beyond the requested limit
in memblock during this intermediate commit.
Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
---
arch/sparc/mm/init_32.c | 3 +++
arch/sparc/prom/memory.c | 3 +++
2 files changed, 6 insertions(+)
diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c
index e0e66f91ceeb..75050dfbc2ea 100644
--- a/arch/sparc/mm/init_32.c
+++ b/arch/sparc/mm/init_32.c
@@ -165,6 +165,9 @@ unsigned long __init bootmem_init(unsigned long *pages_avail)
memblock_add(sp_banks[i].base_addr, sp_banks[i].num_bytes);
}
+ if (cmdline_memory_size)
+ memblock_enforce_memory_limit(cmdline_memory_size);
+
/* Start with page aligned address of last symbol in kernel
* image.
*/
diff --git a/arch/sparc/prom/memory.c b/arch/sparc/prom/memory.c
index 269d6ab5ef5e..59962bc0bc82 100644
--- a/arch/sparc/prom/memory.c
+++ b/arch/sparc/prom/memory.c
@@ -7,6 +7,7 @@
*/
#include <linux/kernel.h>
+#include <linux/memblock.h>
#include <linux/sort.h>
#include <linux/init.h>
@@ -23,6 +24,7 @@ static int __init prom_meminit_v0(void)
for (p = *(romvec->pv_v0mem.v0_available); p; p = p->theres_more) {
sp_banks[index].base_addr = (unsigned long) p->start_adr;
sp_banks[index].num_bytes = p->num_bytes;
+ memblock_add(p->start_adr, p->num_bytes & PAGE_MASK);
index++;
}
@@ -42,6 +44,7 @@ static int __init prom_meminit_v2(void)
for (i = 0; i < num_ents; i++) {
sp_banks[i].base_addr = reg[i].phys_addr;
sp_banks[i].num_bytes = reg[i].reg_size;
+ memblock_add(reg[i].phys_addr, reg[i].reg_size & PAGE_MASK);
}
return num_ents;
--
2.43.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v2 4/6] sparc32: drop unused valid address bitmap
2026-08-30 12:06 [PATCH v2 0/6] sparc32: replace sp_banks with memblock Magnus Lindholm
` (2 preceding siblings ...)
2026-08-30 12:06 ` [PATCH v2 3/6] sparc32: populate memblock from the PROM memory map Magnus Lindholm
@ 2026-08-30 12:06 ` Magnus Lindholm
2026-08-30 17:22 ` Sam Ravnborg
2026-08-30 12:06 ` [PATCH v2 5/6] sparc32: move early memory setup to setup_arch Magnus Lindholm
2026-08-30 12:06 ` [PATCH v2 6/6] sparc32: drop sp_banks Magnus Lindholm
5 siblings, 1 reply; 10+ messages in thread
From: Magnus Lindholm @ 2026-08-30 12:06 UTC (permalink / raw)
To: sparclinux; +Cc: davem, andreas, linux-kernel, sam, glaubitz, Magnus Lindholm
sparc_valid_addr_bitmap is populated during early memory setup but never
read. Remove the bitmap, its allocation and the population helper.
Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
---
arch/sparc/mm/init_32.c | 36 ------------------------------------
1 file changed, 36 deletions(-)
diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c
index 75050dfbc2ea..6880d9cb30a5 100644
--- a/arch/sparc/mm/init_32.c
+++ b/arch/sparc/mm/init_32.c
@@ -13,7 +13,6 @@
#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>
@@ -24,7 +23,6 @@
#include <linux/highmem.h>
#include <linux/memblock.h>
#include <linux/pagemap.h>
-#include <linux/poison.h>
#include <linux/gfp.h>
#include <asm/sections.h>
@@ -37,8 +35,6 @@
#include "mm_32.h"
-static unsigned long *sparc_valid_addr_bitmap;
-
unsigned long phys_base;
EXPORT_SYMBOL(phys_base);
@@ -218,27 +214,8 @@ void __init paging_init(void)
device_scan();
}
-static void __init taint_real_pages(void)
-{
- int i;
-
- for (i = 0; sp_banks[i].num_bytes; i++) {
- unsigned long start, end;
-
- start = sp_banks[i].base_addr;
- end = start + sp_banks[i].num_bytes;
-
- while (start < end) {
- set_bit(start >> 20, sparc_valid_addr_bitmap);
- start += PAGE_SIZE;
- }
- }
-}
-
void __init arch_mm_preinit(void)
{
- int i;
-
if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
prom_printf("BUG: fixmap and pkmap areas overlap\n");
prom_printf("pkbase: 0x%lx pkend: 0x%lx fixstart 0x%lx\n",
@@ -248,19 +225,6 @@ void __init arch_mm_preinit(void)
prom_printf("Please mail sparclinux@vger.kernel.org.\n");
prom_halt();
}
-
- i = last_valid_pfn >> ((20 - PAGE_SHIFT) + 5);
- i += 1;
- sparc_valid_addr_bitmap = (unsigned long *)
- memblock_alloc(i << 2, SMP_CACHE_BYTES);
-
- if (sparc_valid_addr_bitmap == NULL) {
- prom_printf("mem_init: Cannot alloc valid_addr_bitmap.\n");
- prom_halt();
- }
- memset(sparc_valid_addr_bitmap, 0, i << 2);
-
- taint_real_pages();
}
void sparc_flush_page_to_ram(struct page *page)
--
2.43.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v2 5/6] sparc32: move early memory setup to setup_arch
2026-08-30 12:06 [PATCH v2 0/6] sparc32: replace sp_banks with memblock Magnus Lindholm
` (3 preceding siblings ...)
2026-08-30 12:06 ` [PATCH v2 4/6] sparc32: drop unused valid address bitmap Magnus Lindholm
@ 2026-08-30 12:06 ` Magnus Lindholm
2026-08-30 18:19 ` Sam Ravnborg
2026-08-30 12:06 ` [PATCH v2 6/6] sparc32: drop sp_banks Magnus Lindholm
5 siblings, 1 reply; 10+ messages in thread
From: Magnus Lindholm @ 2026-08-30 12:06 UTC (permalink / raw)
To: sparclinux; +Cc: davem, andreas, linux-kernel, sam, glaubitz, Magnus Lindholm
Move the early memory configuration out of SRMMU paging setup and next to
the rest of setup_arch(). Derive the PFN limits from memblock, reserve the
kernel and initrd there, and retain mem= support with
memblock_enforce_memory_limit().
Use for_each_mem_pfn_range() to find the lowmem boundary and replace
last_valid_pfn with the standard max_low_pfn variable. This tightens
LEON's _pfn_valid() upper bound from all RAM to the lowmem limit, with no
functional change because LEON does not use highmem.
When PAGE_OFFSET maps a relocated kernel, remove memory below phys_base
from memblock because it cannot be reached through the linear map. This
replaces the equivalent trimming of sp_banks.
Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
---
arch/sparc/include/asm/leon.h | 2 +-
arch/sparc/include/asm/pgtable_32.h | 3 +-
arch/sparc/include/asm/pgtsrmmu.h | 2 +-
arch/sparc/kernel/setup_32.c | 115 +++++++++++++-----------
arch/sparc/mm/init_32.c | 132 +---------------------------
arch/sparc/mm/srmmu.c | 6 --
6 files changed, 69 insertions(+), 191 deletions(-)
diff --git a/arch/sparc/include/asm/leon.h b/arch/sparc/include/asm/leon.h
index 053a24b67aed..815131c77ed7 100644
--- a/arch/sparc/include/asm/leon.h
+++ b/arch/sparc/include/asm/leon.h
@@ -251,7 +251,7 @@ extern int leon_ipi_irq;
/* macros used in leon_mm.c */
#define PFN(x) ((x) >> PAGE_SHIFT)
-#define _pfn_valid(pfn) ((pfn < last_valid_pfn) && (pfn >= PFN(phys_base)))
+#define _pfn_valid(pfn) ((pfn < max_low_pfn) && (pfn >= PFN(phys_base)))
#define _SRMMU_PTE_PMASK_LEON 0xffffffff
/*
diff --git a/arch/sparc/include/asm/pgtable_32.h b/arch/sparc/include/asm/pgtable_32.h
index f89b1250661d..91a6032cf6a2 100644
--- a/arch/sparc/include/asm/pgtable_32.h
+++ b/arch/sparc/include/asm/pgtable_32.h
@@ -37,8 +37,7 @@ struct vm_area_struct;
struct page;
void load_mmu(void);
-unsigned long calc_highpages(void);
-unsigned long __init bootmem_init(unsigned long *pages_avail);
+void __init find_ramdisk(unsigned long end_of_phys_memory);
#define pte_ERROR(e) __builtin_trap()
#define pmd_ERROR(e) __builtin_trap()
diff --git a/arch/sparc/include/asm/pgtsrmmu.h b/arch/sparc/include/asm/pgtsrmmu.h
index a265822a475e..9ce7558113f8 100644
--- a/arch/sparc/include/asm/pgtsrmmu.h
+++ b/arch/sparc/include/asm/pgtsrmmu.h
@@ -98,7 +98,7 @@
restore %g0, %g0, %g0;
#ifndef __ASSEMBLER__
-extern unsigned long last_valid_pfn;
+extern unsigned long max_low_pfn;
/* This makes sense. Honest it does - Anton */
/* XXX Yes but it's ugly as sin. FIXME. -KMW */
diff --git a/arch/sparc/kernel/setup_32.c b/arch/sparc/kernel/setup_32.c
index 795714959da6..c3c3274e55af 100644
--- a/arch/sparc/kernel/setup_32.c
+++ b/arch/sparc/kernel/setup_32.c
@@ -23,6 +23,7 @@
#include <linux/syscalls.h>
#include <linux/kdev_t.h>
#include <linux/major.h>
+#include <linux/memblock.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/interrupt.h>
@@ -254,28 +255,74 @@ static __init void leon_patch(void)
struct tt_entry *sparc_ttable;
-/* Drop RAM below the kernel; the linear map runs upward from phys_base
- * and cannot reach it.
- */
-static void __init trim_sp_banks_below(unsigned long base)
+unsigned long phys_base;
+EXPORT_SYMBOL(phys_base);
+
+unsigned long pfn_base;
+EXPORT_SYMBOL(pfn_base);
+
+unsigned long highend_pfn;
+
+static unsigned long __init calc_max_low_pfn(void)
{
- int i, j = 0;
+ unsigned long limit = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
+ unsigned long start_pfn, end_pfn;
+ unsigned long last_pfn = 0;
+ int i;
+
+ for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn,
+ NULL) {
+ if (start_pfn >= limit) {
+ if (last_pfn < limit)
+ limit = last_pfn;
+ break;
+ }
- for (i = 0; sp_banks[i].num_bytes != 0; i++) {
- unsigned long start = sp_banks[i].base_addr;
- unsigned long end = start + sp_banks[i].num_bytes;
+ last_pfn = end_pfn;
+ }
- if (end <= base)
- continue; /* wholly below - drop it */
- if (start < base)
- start = base; /* straddles - trim the front */
+ return limit;
+}
- sp_banks[j].base_addr = start;
- sp_banks[j].num_bytes = end - start;
- j++;
+static void __init setup_memory(void)
+{
+ unsigned long ram_base = memblock_start_of_DRAM();
+ unsigned long real_base = __get_phys(PAGE_OFFSET);
+ unsigned long size;
+
+ memblock_set_bottom_up(true);
+ memblock_allow_resize();
+
+ phys_base = ram_base;
+ if (real_base && real_base != phys_base) {
+ prom_printf("phys_base: RAM starts 0x%x but kernel is at 0x%x\n",
+ (unsigned int)phys_base, (unsigned int)real_base);
+ phys_base = real_base;
+ memblock_remove(0, phys_base);
+ prom_printf("phys_base: adopted 0x%x, RAM below it dropped\n",
+ (unsigned int)phys_base);
}
- sp_banks[j].base_addr = 0;
- sp_banks[j].num_bytes = 0;
+
+ if (cmdline_memory_size)
+ memblock_enforce_memory_limit(cmdline_memory_size);
+
+ min_low_pfn = PFN_DOWN(memblock_start_of_DRAM());
+ pfn_base = phys_base >> PAGE_SHIFT;
+ max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
+ highend_pfn = max_low_pfn;
+
+ if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT))
+ max_low_pfn = calc_max_low_pfn();
+
+ find_ramdisk(memblock_end_of_DRAM());
+
+ /* Reserve the kernel text/data/bss. */
+ size = __pa(PAGE_ALIGN((unsigned long)&_end)) - phys_base;
+ memblock_reserve(phys_base, size);
+ memblock_add(phys_base, size);
+
+ /* Only allow low memory to be allocated by memblock. */
+ memblock_set_current_limit(PFN_PHYS(max_low_pfn));
}
/* Called from head_32.S - before we have setup anything
@@ -306,9 +353,6 @@ void __init sparc32_start_kernel(struct linux_romvec *rp)
void __init setup_arch(char **cmdline_p)
{
- int i;
- unsigned long highest_paddr;
-
sparc_ttable = &trapbase[0];
/* Initialize PROM console and command line. */
@@ -343,36 +387,7 @@ void __init setup_arch(char **cmdline_p)
idprom_init();
load_mmu();
-
- phys_base = 0xffffffffUL;
- highest_paddr = 0UL;
- for (i = 0; sp_banks[i].num_bytes != 0; i++) {
- unsigned long top;
-
- if (sp_banks[i].base_addr < phys_base)
- phys_base = sp_banks[i].base_addr;
- top = sp_banks[i].base_addr +
- sp_banks[i].num_bytes;
- if (highest_paddr < top)
- highest_paddr = top;
- }
-
- /* phys_base must describe what PAGE_OFFSET maps to, not where RAM starts. */
- {
- unsigned long real_base = __get_phys(PAGE_OFFSET);
-
- if (real_base && real_base != phys_base) {
- prom_printf("phys_base: RAM starts 0x%x but kernel is at 0x%x\n",
- (unsigned int)phys_base,
- (unsigned int)real_base);
- phys_base = real_base;
- trim_sp_banks_below(phys_base);
- prom_printf("phys_base: adopted 0x%x, RAM below it dropped\n",
- (unsigned int)phys_base);
- }
- }
-
- pfn_base = phys_base >> PAGE_SHIFT;
+ setup_memory();
if (!root_flags)
root_mountflags &= ~MS_RDONLY;
diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c
index 6880d9cb30a5..ac4462f1cf76 100644
--- a/arch/sparc/mm/init_32.c
+++ b/arch/sparc/mm/init_32.c
@@ -35,66 +35,13 @@
#include "mm_32.h"
-unsigned long phys_base;
-EXPORT_SYMBOL(phys_base);
-
-unsigned long pfn_base;
-EXPORT_SYMBOL(pfn_base);
-
struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
/* Initial ramdisk setup */
extern unsigned int sparc_ramdisk_image;
extern unsigned int sparc_ramdisk_size;
-unsigned long highstart_pfn, highend_pfn;
-
-unsigned long last_valid_pfn;
-
-unsigned long calc_highpages(void)
-{
- int i;
- int nr = 0;
-
- for (i = 0; sp_banks[i].num_bytes != 0; i++) {
- unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
- unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
-
- if (end_pfn <= max_low_pfn)
- continue;
-
- if (start_pfn < max_low_pfn)
- start_pfn = max_low_pfn;
-
- nr += end_pfn - start_pfn;
- }
-
- return nr;
-}
-
-static unsigned long calc_max_low_pfn(void)
-{
- int i;
- unsigned long tmp = pfn_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;
- for (i = 1; sp_banks[i].num_bytes != 0; i++) {
- curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
-
- if (curr_pfn >= tmp) {
- if (last_pfn < tmp)
- tmp = last_pfn;
- break;
- }
-
- last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
- }
-
- return tmp;
-}
-
-static void __init find_ramdisk(unsigned long end_of_phys_memory)
+void __init find_ramdisk(unsigned long end_of_phys_memory)
{
#ifdef CONFIG_BLK_DEV_INITRD
unsigned long size;
@@ -124,83 +71,6 @@ static void __init find_ramdisk(unsigned long end_of_phys_memory)
#endif
}
-unsigned long __init bootmem_init(unsigned long *pages_avail)
-{
- unsigned long start_pfn, bytes_avail, size;
- unsigned long end_of_phys_memory = 0;
- unsigned long high_pages = 0;
- int i;
-
- memblock_set_bottom_up(true);
- memblock_allow_resize();
-
- bytes_avail = 0UL;
- for (i = 0; sp_banks[i].num_bytes != 0; i++) {
- end_of_phys_memory = sp_banks[i].base_addr +
- sp_banks[i].num_bytes;
- bytes_avail += sp_banks[i].num_bytes;
- if (cmdline_memory_size) {
- if (bytes_avail > cmdline_memory_size) {
- unsigned long slack = bytes_avail - cmdline_memory_size;
-
- bytes_avail -= slack;
- end_of_phys_memory -= slack;
-
- sp_banks[i].num_bytes -= slack;
- if (sp_banks[i].num_bytes == 0) {
- sp_banks[i].base_addr = 0xdeadbeef;
- } else {
- memblock_add(sp_banks[i].base_addr,
- sp_banks[i].num_bytes);
- sp_banks[i+1].num_bytes = 0;
- sp_banks[i+1].base_addr = 0xdeadbeef;
- }
- break;
- }
- }
- memblock_add(sp_banks[i].base_addr, sp_banks[i].num_bytes);
- }
-
- if (cmdline_memory_size)
- memblock_enforce_memory_limit(cmdline_memory_size);
-
- /* Start with page aligned address of last symbol in kernel
- * image.
- */
- start_pfn = (unsigned long)__pa(PAGE_ALIGN((unsigned long) &_end));
-
- /* Now shift down to get the real physical page frame number. */
- start_pfn >>= PAGE_SHIFT;
-
- max_pfn = end_of_phys_memory >> PAGE_SHIFT;
-
- max_low_pfn = max_pfn;
- highstart_pfn = highend_pfn = max_pfn;
-
- if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT)) {
- highstart_pfn = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
- max_low_pfn = calc_max_low_pfn();
- high_pages = calc_highpages();
- printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
- high_pages >> (20 - PAGE_SHIFT));
- }
-
- find_ramdisk(end_of_phys_memory);
-
- /* Reserve the kernel text/data/bss. */
- size = (start_pfn << PAGE_SHIFT) - phys_base;
- memblock_reserve(phys_base, size);
- memblock_add(phys_base, size);
-
- size = memblock_phys_mem_size() - memblock_reserved_size();
- *pages_avail = (size >> PAGE_SHIFT) - high_pages;
-
- /* Only allow low memory to be allocated via memblock allocation */
- memblock_set_current_limit(max_low_pfn << PAGE_SHIFT);
-
- return max_pfn;
-}
-
/*
* paging_init() sets up the page tables: We call the MMU specific
* init routine based upon the Sun model type on the Sparc.
diff --git a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c
index 3029527a5a9f..cf66a108b411 100644
--- a/arch/sparc/mm/srmmu.c
+++ b/arch/sparc/mm/srmmu.c
@@ -59,8 +59,6 @@ int vac_line_size;
extern struct resource sparc_iomap;
-extern unsigned long last_valid_pfn;
-
static pgd_t *srmmu_swapper_pg_dir;
const struct sparc32_cachetlb_ops *sparc32_cachetlb_ops;
@@ -884,7 +882,6 @@ void __init srmmu_paging_init(void)
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
- unsigned long pages_avail;
init_mm.context = (unsigned long) NO_CONTEXT;
sparc_iomap.start = SUN4M_IOBASE_VADDR; /* 16MB of IOSPACE on all sun4m's. */
@@ -910,9 +907,6 @@ void __init srmmu_paging_init(void)
prom_halt();
}
- pages_avail = 0;
- last_valid_pfn = bootmem_init(&pages_avail);
-
srmmu_nocache_calcsize();
srmmu_nocache_init();
srmmu_inherit_prom_mappings(0xfe400000, (LINUX_OPPROM_ENDVM - PAGE_SIZE));
--
2.43.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v2 6/6] sparc32: drop sp_banks
2026-08-30 12:06 [PATCH v2 0/6] sparc32: replace sp_banks with memblock Magnus Lindholm
` (4 preceding siblings ...)
2026-08-30 12:06 ` [PATCH v2 5/6] sparc32: move early memory setup to setup_arch Magnus Lindholm
@ 2026-08-30 12:06 ` Magnus Lindholm
5 siblings, 0 replies; 10+ messages in thread
From: Magnus Lindholm @ 2026-08-30 12:06 UTC (permalink / raw)
To: sparclinux; +Cc: davem, andreas, linux-kernel, sam, glaubitz, Magnus Lindholm
All memory-map consumers now use memblock. Stop duplicating the PROM map
in sp_banks and remove the array, its type, and its fixed bank limit.
Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
---
arch/sparc/include/asm/page_32.h | 16 -----------
arch/sparc/mm/init_32.c | 2 --
arch/sparc/prom/memory.c | 48 ++++----------------------------
3 files changed, 6 insertions(+), 60 deletions(-)
diff --git a/arch/sparc/include/asm/page_32.h b/arch/sparc/include/asm/page_32.h
index c1bccbedf567..5daa5fd8eaa5 100644
--- a/arch/sparc/include/asm/page_32.h
+++ b/arch/sparc/include/asm/page_32.h
@@ -26,22 +26,6 @@
sparc_flush_page_to_ram(page); \
} while (0)
-/* The following structure is used to hold the physical
- * memory configuration of the machine. This is filled in
- * prom_meminit() and is later used by mem_init() to set up
- * mem_map[]. We statically allocate SPARC_PHYS_BANKS+1 of
- * these structs, this is arbitrary. The entry after the
- * last valid one has num_bytes==0.
- */
-struct sparc_phys_banks {
- unsigned long base_addr;
- unsigned long num_bytes;
-};
-
-#define SPARC_PHYS_BANKS 32
-
-extern struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
-
/* passing structs on the Sparc slow us down tremendously... */
/* #define STRICT_MM_TYPECHECKS */
diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c
index ac4462f1cf76..2f693b70dbd8 100644
--- a/arch/sparc/mm/init_32.c
+++ b/arch/sparc/mm/init_32.c
@@ -35,8 +35,6 @@
#include "mm_32.h"
-struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
-
/* Initial ramdisk setup */
extern unsigned int sparc_ramdisk_image;
extern unsigned int sparc_ramdisk_size;
diff --git a/arch/sparc/prom/memory.c b/arch/sparc/prom/memory.c
index 59962bc0bc82..3f65bde2bb89 100644
--- a/arch/sparc/prom/memory.c
+++ b/arch/sparc/prom/memory.c
@@ -8,30 +8,21 @@
#include <linux/kernel.h>
#include <linux/memblock.h>
-#include <linux/sort.h>
#include <linux/init.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
#include <asm/page.h>
-static int __init prom_meminit_v0(void)
+static void __init prom_meminit_v0(void)
{
struct linux_mlist_v0 *p;
- int index;
- index = 0;
- for (p = *(romvec->pv_v0mem.v0_available); p; p = p->theres_more) {
- sp_banks[index].base_addr = (unsigned long) p->start_adr;
- sp_banks[index].num_bytes = p->num_bytes;
+ for (p = *(romvec->pv_v0mem.v0_available); p; p = p->theres_more)
memblock_add(p->start_adr, p->num_bytes & PAGE_MASK);
- index++;
- }
-
- return index;
}
-static int __init prom_meminit_v2(void)
+static void __init prom_meminit_v2(void)
{
struct linux_prom_registers reg[64];
phandle node;
@@ -41,51 +32,24 @@ static int __init prom_meminit_v2(void)
size = prom_getproperty(node, "available", (char *) reg, sizeof(reg));
num_ents = size / sizeof(struct linux_prom_registers);
- for (i = 0; i < num_ents; i++) {
- sp_banks[i].base_addr = reg[i].phys_addr;
- sp_banks[i].num_bytes = reg[i].reg_size;
+ for (i = 0; i < num_ents; i++)
memblock_add(reg[i].phys_addr, reg[i].reg_size & PAGE_MASK);
- }
-
- return num_ents;
-}
-
-static int sp_banks_cmp(const void *a, const void *b)
-{
- const struct sparc_phys_banks *x = a, *y = b;
-
- if (x->base_addr > y->base_addr)
- return 1;
- if (x->base_addr < y->base_addr)
- return -1;
- return 0;
}
/* Initialize the memory lists based upon the prom version. */
void __init prom_meminit(void)
{
- int i, num_ents = 0;
-
switch (prom_vers) {
case PROM_V0:
- num_ents = prom_meminit_v0();
+ prom_meminit_v0();
break;
case PROM_V2:
case PROM_V3:
- num_ents = prom_meminit_v2();
+ prom_meminit_v2();
break;
default:
break;
}
- sort(sp_banks, num_ents, sizeof(struct sparc_phys_banks),
- sp_banks_cmp, NULL);
-
- /* Sentinel. */
- sp_banks[num_ents].base_addr = 0xdeadbeef;
- sp_banks[num_ents].num_bytes = 0;
-
- for (i = 0; i < num_ents; i++)
- sp_banks[i].num_bytes &= PAGE_MASK;
}
--
2.43.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v2 4/6] sparc32: drop unused valid address bitmap
2026-08-30 12:06 ` [PATCH v2 4/6] sparc32: drop unused valid address bitmap Magnus Lindholm
@ 2026-08-30 17:22 ` Sam Ravnborg
0 siblings, 0 replies; 10+ messages in thread
From: Sam Ravnborg @ 2026-08-30 17:22 UTC (permalink / raw)
To: Magnus Lindholm; +Cc: sparclinux, davem, andreas, linux-kernel, glaubitz
On Sun, Aug 30, 2026 at 02:06:43PM +0200, Magnus Lindholm wrote:
> sparc_valid_addr_bitmap is populated during early memory setup but never
> read. Remove the bitmap, its allocation and the population helper.
>
> Suggested-by: Sam Ravnborg <sam@ravnborg.org>
> Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Good to have this dead code gone.
Sam
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2 5/6] sparc32: move early memory setup to setup_arch
2026-08-30 12:06 ` [PATCH v2 5/6] sparc32: move early memory setup to setup_arch Magnus Lindholm
@ 2026-08-30 18:19 ` Sam Ravnborg
2026-09-01 13:54 ` Magnus Lindholm
0 siblings, 1 reply; 10+ messages in thread
From: Sam Ravnborg @ 2026-08-30 18:19 UTC (permalink / raw)
To: Magnus Lindholm; +Cc: sparclinux, davem, andreas, linux-kernel, glaubitz
On Sun, Aug 30, 2026 at 02:06:44PM +0200, Magnus Lindholm wrote:
> Move the early memory configuration out of SRMMU paging setup and next to
> the rest of setup_arch(). Derive the PFN limits from memblock, reserve the
> kernel and initrd there, and retain mem= support with
> memblock_enforce_memory_limit().
>
> Use for_each_mem_pfn_range() to find the lowmem boundary and replace
> last_valid_pfn with the standard max_low_pfn variable. This tightens
> LEON's _pfn_valid() upper bound from all RAM to the lowmem limit, with no
> functional change because LEON does not use highmem.
>
> When PAGE_OFFSET maps a relocated kernel, remove memory below phys_base
> from memblock because it cannot be reached through the linear map. This
> replaces the equivalent trimming of sp_banks.
We have several >> PAGE_SHIFT and << PAGE_SHIFT.
It would be more readable to use the corresponding:
PHYS_PFN() and PFN_PHYS().
Left a few comments in the following.
Sam
>
> Suggested-by: Sam Ravnborg <sam@ravnborg.org>
> Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
> ---
> arch/sparc/include/asm/leon.h | 2 +-
> arch/sparc/include/asm/pgtable_32.h | 3 +-
> arch/sparc/include/asm/pgtsrmmu.h | 2 +-
> arch/sparc/kernel/setup_32.c | 115 +++++++++++++-----------
> arch/sparc/mm/init_32.c | 132 +---------------------------
> arch/sparc/mm/srmmu.c | 6 --
> 6 files changed, 69 insertions(+), 191 deletions(-)
>
> diff --git a/arch/sparc/include/asm/leon.h b/arch/sparc/include/asm/leon.h
> index 053a24b67aed..815131c77ed7 100644
> --- a/arch/sparc/include/asm/leon.h
> +++ b/arch/sparc/include/asm/leon.h
> @@ -251,7 +251,7 @@ extern int leon_ipi_irq;
>
> /* macros used in leon_mm.c */
> #define PFN(x) ((x) >> PAGE_SHIFT)
A cleanup for another day is replacing PFN() with the standard PFN_DOWN().
> -#define _pfn_valid(pfn) ((pfn < last_valid_pfn) && (pfn >= PFN(phys_base)))
> +#define _pfn_valid(pfn) ((pfn < max_low_pfn) && (pfn >= PFN(phys_base)))
> #define _SRMMU_PTE_PMASK_LEON 0xffffffff
>
> /*
> diff --git a/arch/sparc/include/asm/pgtable_32.h b/arch/sparc/include/asm/pgtable_32.h
> index f89b1250661d..91a6032cf6a2 100644
> --- a/arch/sparc/include/asm/pgtable_32.h
> +++ b/arch/sparc/include/asm/pgtable_32.h
> @@ -37,8 +37,7 @@ struct vm_area_struct;
> struct page;
>
> void load_mmu(void);
> -unsigned long calc_highpages(void);
> -unsigned long __init bootmem_init(unsigned long *pages_avail);
> +void __init find_ramdisk(unsigned long end_of_phys_memory);
>
> #define pte_ERROR(e) __builtin_trap()
> #define pmd_ERROR(e) __builtin_trap()
> diff --git a/arch/sparc/include/asm/pgtsrmmu.h b/arch/sparc/include/asm/pgtsrmmu.h
> index a265822a475e..9ce7558113f8 100644
> --- a/arch/sparc/include/asm/pgtsrmmu.h
> +++ b/arch/sparc/include/asm/pgtsrmmu.h
> @@ -98,7 +98,7 @@
> restore %g0, %g0, %g0;
>
> #ifndef __ASSEMBLER__
> -extern unsigned long last_valid_pfn;
> +extern unsigned long max_low_pfn;
This is already declared in memblock.h:
$ git grep max_low_pfn
include/linux/memblock.h:extern unsigned long max_low_pfn;
>
> /* This makes sense. Honest it does - Anton */
> /* XXX Yes but it's ugly as sin. FIXME. -KMW */
> diff --git a/arch/sparc/kernel/setup_32.c b/arch/sparc/kernel/setup_32.c
> index 795714959da6..c3c3274e55af 100644
> --- a/arch/sparc/kernel/setup_32.c
> +++ b/arch/sparc/kernel/setup_32.c
> @@ -23,6 +23,7 @@
> #include <linux/syscalls.h>
> #include <linux/kdev_t.h>
> #include <linux/major.h>
> +#include <linux/memblock.h>
> #include <linux/string.h>
> #include <linux/init.h>
> #include <linux/interrupt.h>
> @@ -254,28 +255,74 @@ static __init void leon_patch(void)
>
> struct tt_entry *sparc_ttable;
>
> -/* Drop RAM below the kernel; the linear map runs upward from phys_base
> - * and cannot reach it.
> - */
> -static void __init trim_sp_banks_below(unsigned long base)
> +unsigned long phys_base;
> +EXPORT_SYMBOL(phys_base);
> +
> +unsigned long pfn_base;
> +EXPORT_SYMBOL(pfn_base);
It is likely just me, but I get a bit confused over all the names here.
pfn_phys_base had been easier for me, so I knew this was the PFN of
phys_base.
This is unrelated to this patch, just a comment while trying to page in
how this code works.
> +
> +unsigned long highend_pfn;
> +
> +static unsigned long __init calc_max_low_pfn(void)
> {
> - int i, j = 0;
> + unsigned long limit = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
> + unsigned long start_pfn, end_pfn;
> + unsigned long last_pfn = 0;
> + int i;
> +
> + for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn,
> + NULL) {
No need to break this up, we are not above 80 columns.
> + if (start_pfn >= limit) {
> + if (last_pfn < limit)
> + limit = last_pfn;
> + break;
> + }
>
> - for (i = 0; sp_banks[i].num_bytes != 0; i++) {
> - unsigned long start = sp_banks[i].base_addr;
> - unsigned long end = start + sp_banks[i].num_bytes;
> + last_pfn = end_pfn;
> + }
>
> - if (end <= base)
> - continue; /* wholly below - drop it */
> - if (start < base)
> - start = base; /* straddles - trim the front */
> + return limit;
> +}
>
> - sp_banks[j].base_addr = start;
> - sp_banks[j].num_bytes = end - start;
> - j++;
> +static void __init setup_memory(void)
> +{
> + unsigned long ram_base = memblock_start_of_DRAM();
> + unsigned long real_base = __get_phys(PAGE_OFFSET);
> + unsigned long size;
> +
> + memblock_set_bottom_up(true);
> + memblock_allow_resize();
> +
> + phys_base = ram_base;
> + if (real_base && real_base != phys_base) {
> + prom_printf("phys_base: RAM starts 0x%x but kernel is at 0x%x\n",
> + (unsigned int)phys_base, (unsigned int)real_base);
> + phys_base = real_base;
> + memblock_remove(0, phys_base);
> + prom_printf("phys_base: adopted 0x%x, RAM below it dropped\n",
> + (unsigned int)phys_base);
> }
> - sp_banks[j].base_addr = 0;
> - sp_banks[j].num_bytes = 0;
> +
> + if (cmdline_memory_size)
> + memblock_enforce_memory_limit(cmdline_memory_size);
> +
> + min_low_pfn = PFN_DOWN(memblock_start_of_DRAM());
> + pfn_base = phys_base >> PAGE_SHIFT;
> + max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
> + highend_pfn = max_low_pfn;
highend_pfn is only used to set max_zone_pfn[ZONE_HIGHMEM].
It would be simpler to just use max_low_pfn and get rid of
highend_pfn.
This part should also set max_pfn.
> +
> + if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT))
> + max_low_pfn = calc_max_low_pfn();
Set max_pfn here.
> +
> + find_ramdisk(memblock_end_of_DRAM());
> +
> + /* Reserve the kernel text/data/bss. */
> + size = __pa(PAGE_ALIGN((unsigned long)&_end)) - phys_base;
> + memblock_reserve(phys_base, size);
> + memblock_add(phys_base, size);
> +
> + /* Only allow low memory to be allocated by memblock. */
> + memblock_set_current_limit(PFN_PHYS(max_low_pfn));
> }
>
> /* Called from head_32.S - before we have setup anything
> @@ -306,9 +353,6 @@ void __init sparc32_start_kernel(struct linux_romvec *rp)
>
> void __init setup_arch(char **cmdline_p)
> {
> - int i;
> - unsigned long highest_paddr;
> -
> sparc_ttable = &trapbase[0];
>
> /* Initialize PROM console and command line. */
> @@ -343,36 +387,7 @@ void __init setup_arch(char **cmdline_p)
>
> idprom_init();
> load_mmu();
> -
> - phys_base = 0xffffffffUL;
> - highest_paddr = 0UL;
> - for (i = 0; sp_banks[i].num_bytes != 0; i++) {
> - unsigned long top;
> -
> - if (sp_banks[i].base_addr < phys_base)
> - phys_base = sp_banks[i].base_addr;
> - top = sp_banks[i].base_addr +
> - sp_banks[i].num_bytes;
> - if (highest_paddr < top)
> - highest_paddr = top;
> - }
> -
> - /* phys_base must describe what PAGE_OFFSET maps to, not where RAM starts. */
> - {
> - unsigned long real_base = __get_phys(PAGE_OFFSET);
> -
> - if (real_base && real_base != phys_base) {
> - prom_printf("phys_base: RAM starts 0x%x but kernel is at 0x%x\n",
> - (unsigned int)phys_base,
> - (unsigned int)real_base);
> - phys_base = real_base;
> - trim_sp_banks_below(phys_base);
> - prom_printf("phys_base: adopted 0x%x, RAM below it dropped\n",
> - (unsigned int)phys_base);
> - }
> - }
> -
> - pfn_base = phys_base >> PAGE_SHIFT;
> + setup_memory();
>
> if (!root_flags)
> root_mountflags &= ~MS_RDONLY;
> diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c
> index 6880d9cb30a5..ac4462f1cf76 100644
> --- a/arch/sparc/mm/init_32.c
> +++ b/arch/sparc/mm/init_32.c
> @@ -35,66 +35,13 @@
>
> #include "mm_32.h"
>
> -unsigned long phys_base;
> -EXPORT_SYMBOL(phys_base);
> -
> -unsigned long pfn_base;
> -EXPORT_SYMBOL(pfn_base);
> -
> struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
>
> /* Initial ramdisk setup */
> extern unsigned int sparc_ramdisk_image;
> extern unsigned int sparc_ramdisk_size;
>
> -unsigned long highstart_pfn, highend_pfn;
> -
> -unsigned long last_valid_pfn;
> -
> -unsigned long calc_highpages(void)
> -{
> - int i;
> - int nr = 0;
> -
> - for (i = 0; sp_banks[i].num_bytes != 0; i++) {
> - unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
> - unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
> -
> - if (end_pfn <= max_low_pfn)
> - continue;
> -
> - if (start_pfn < max_low_pfn)
> - start_pfn = max_low_pfn;
> -
> - nr += end_pfn - start_pfn;
> - }
> -
> - return nr;
> -}
> -
> -static unsigned long calc_max_low_pfn(void)
> -{
> - int i;
> - unsigned long tmp = pfn_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;
> - for (i = 1; sp_banks[i].num_bytes != 0; i++) {
> - curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
> -
> - if (curr_pfn >= tmp) {
> - if (last_pfn < tmp)
> - tmp = last_pfn;
> - break;
> - }
> -
> - last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
> - }
> -
> - return tmp;
> -}
> -
> -static void __init find_ramdisk(unsigned long end_of_phys_memory)
> +void __init find_ramdisk(unsigned long end_of_phys_memory)
> {
> #ifdef CONFIG_BLK_DEV_INITRD
> unsigned long size;
> @@ -124,83 +71,6 @@ static void __init find_ramdisk(unsigned long end_of_phys_memory)
> #endif
> }
>
> -unsigned long __init bootmem_init(unsigned long *pages_avail)
> -{
> - unsigned long start_pfn, bytes_avail, size;
> - unsigned long end_of_phys_memory = 0;
> - unsigned long high_pages = 0;
> - int i;
> -
> - memblock_set_bottom_up(true);
> - memblock_allow_resize();
> -
> - bytes_avail = 0UL;
> - for (i = 0; sp_banks[i].num_bytes != 0; i++) {
> - end_of_phys_memory = sp_banks[i].base_addr +
> - sp_banks[i].num_bytes;
> - bytes_avail += sp_banks[i].num_bytes;
> - if (cmdline_memory_size) {
> - if (bytes_avail > cmdline_memory_size) {
> - unsigned long slack = bytes_avail - cmdline_memory_size;
> -
> - bytes_avail -= slack;
> - end_of_phys_memory -= slack;
> -
> - sp_banks[i].num_bytes -= slack;
> - if (sp_banks[i].num_bytes == 0) {
> - sp_banks[i].base_addr = 0xdeadbeef;
> - } else {
> - memblock_add(sp_banks[i].base_addr,
> - sp_banks[i].num_bytes);
> - sp_banks[i+1].num_bytes = 0;
> - sp_banks[i+1].base_addr = 0xdeadbeef;
> - }
> - break;
> - }
> - }
> - memblock_add(sp_banks[i].base_addr, sp_banks[i].num_bytes);
> - }
> -
> - if (cmdline_memory_size)
> - memblock_enforce_memory_limit(cmdline_memory_size);
> -
> - /* Start with page aligned address of last symbol in kernel
> - * image.
> - */
> - start_pfn = (unsigned long)__pa(PAGE_ALIGN((unsigned long) &_end));
> -
> - /* Now shift down to get the real physical page frame number. */
> - start_pfn >>= PAGE_SHIFT;
> -
> - max_pfn = end_of_phys_memory >> PAGE_SHIFT;
> -
> - max_low_pfn = max_pfn;
> - highstart_pfn = highend_pfn = max_pfn;
> -
> - if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT)) {
> - highstart_pfn = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
> - max_low_pfn = calc_max_low_pfn();
> - high_pages = calc_highpages();
> - printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
> - high_pages >> (20 - PAGE_SHIFT));
> - }
All the above are not needed as the kernel already print HIGHMEM, and
this patch removes it - good.
Maybe tell so in the commit message?
This could also go in before to keep this not-so-readable patch smaller.
> -
> - find_ramdisk(end_of_phys_memory);
> -
> - /* Reserve the kernel text/data/bss. */
> - size = (start_pfn << PAGE_SHIFT) - phys_base;
> - memblock_reserve(phys_base, size);
> - memblock_add(phys_base, size);
> -
> - size = memblock_phys_mem_size() - memblock_reserved_size();
> - *pages_avail = (size >> PAGE_SHIFT) - high_pages;
> -
> - /* Only allow low memory to be allocated via memblock allocation */
> - memblock_set_current_limit(max_low_pfn << PAGE_SHIFT);
> -
> - return max_pfn;
> -}
> -
> /*
> * paging_init() sets up the page tables: We call the MMU specific
> * init routine based upon the Sun model type on the Sparc.
> diff --git a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c
> index 3029527a5a9f..cf66a108b411 100644
> --- a/arch/sparc/mm/srmmu.c
> +++ b/arch/sparc/mm/srmmu.c
> @@ -59,8 +59,6 @@ int vac_line_size;
>
> extern struct resource sparc_iomap;
>
> -extern unsigned long last_valid_pfn;
> -
> static pgd_t *srmmu_swapper_pg_dir;
>
> const struct sparc32_cachetlb_ops *sparc32_cachetlb_ops;
> @@ -884,7 +882,6 @@ void __init srmmu_paging_init(void)
> pud_t *pud;
> pmd_t *pmd;
> pte_t *pte;
> - unsigned long pages_avail;
>
> init_mm.context = (unsigned long) NO_CONTEXT;
> sparc_iomap.start = SUN4M_IOBASE_VADDR; /* 16MB of IOSPACE on all sun4m's. */
> @@ -910,9 +907,6 @@ void __init srmmu_paging_init(void)
> prom_halt();
> }
>
> - pages_avail = 0;
> - last_valid_pfn = bootmem_init(&pages_avail);
> -
> srmmu_nocache_calcsize();
> srmmu_nocache_init();
> srmmu_inherit_prom_mappings(0xfe400000, (LINUX_OPPROM_ENDVM - PAGE_SIZE));
> --
> 2.43.0
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2 5/6] sparc32: move early memory setup to setup_arch
2026-08-30 18:19 ` Sam Ravnborg
@ 2026-09-01 13:54 ` Magnus Lindholm
0 siblings, 0 replies; 10+ messages in thread
From: Magnus Lindholm @ 2026-09-01 13:54 UTC (permalink / raw)
To: Sam Ravnborg; +Cc: sparclinux, davem, andreas, linux-kernel, glaubitz
Hi Sam,
Thanks for taking the time to review this, I've put together a v3 to address
your feedback, will post it after some more polishing.
On Sun, Aug 30, 2026 at 8:19 PM Sam Ravnborg <sam@ravnborg.org> wrote:
>
> We have several >> PAGE_SHIFT and << PAGE_SHIFT.
>
> It would be more readable to use the corresponding:
> PHYS_PFN() and PFN_PHYS().
I agree this makes sense.
>> #define PFN(x) ((x) >> PAGE_SHIFT)
>A cleanup for another day is replacing PFN() with the standard PFN_DOWN()
I'll make a note of this, maybe we come back to it later than.
> > -extern unsigned long last_valid_pfn;
> > +extern unsigned long max_low_pfn;
> This is already declared in memblock.h:
>
> $ git grep max_low_pfn
> include/linux/memblock.h:extern unsigned long max_low_pfn;
>
>
This is the better solution, thanks
> > + for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn,
> > + NULL) {
> No need to break this up, we are not above 80 columns.
>
Yes, I'll fix this.
> > + min_low_pfn = PFN_DOWN(memblock_start_of_DRAM());
> > + pfn_base = phys_base >> PAGE_SHIFT;
> > + max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
> > + highend_pfn = max_low_pfn;
> highend_pfn is only used to set max_zone_pfn[ZONE_HIGHMEM].
> It would be simpler to just use max_low_pfn and get rid of
> highend_pfn.
>
>
> This part should also set max_pfn.
>
Well spotted, that makes sense.
> > - if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT)) {
> > - highstart_pfn = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
> > - max_low_pfn = calc_max_low_pfn();
> > - high_pages = calc_highpages();
> > - printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
> > - high_pages >> (20 - PAGE_SHIFT));
> > - }
> All the above are not needed as the kernel already print HIGHMEM, and
> this patch removes it - good.
> Maybe tell so in the commit message?
Yes. will fix this.
Magnus
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2026-09-01 13:54 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-08-30 12:06 [PATCH v2 0/6] sparc32: replace sp_banks with memblock Magnus Lindholm
2026-08-30 12:06 ` [PATCH v2 1/6] sparc32: use memblock when mapping the kernel Magnus Lindholm
2026-08-30 12:06 ` [PATCH v2 2/6] sparc32: use memblock to find available system memory Magnus Lindholm
2026-08-30 12:06 ` [PATCH v2 3/6] sparc32: populate memblock from the PROM memory map Magnus Lindholm
2026-08-30 12:06 ` [PATCH v2 4/6] sparc32: drop unused valid address bitmap Magnus Lindholm
2026-08-30 17:22 ` Sam Ravnborg
2026-08-30 12:06 ` [PATCH v2 5/6] sparc32: move early memory setup to setup_arch Magnus Lindholm
2026-08-30 18:19 ` Sam Ravnborg
2026-09-01 13:54 ` Magnus Lindholm
2026-08-30 12:06 ` [PATCH v2 6/6] sparc32: drop sp_banks Magnus Lindholm
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