Commit 1184674d authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Thomas Gleixner
Browse files

powerpc: Split systemcfg data out of vdso data page 



The systemcfg data only has minimal overlap with the vdso data.
Splitting the two avoids mapping the implementation-defined vdso data
into /proc/ppc64/systemcfg.
It is also a preparation for the standardization of vdso data storage.

The only field actually used by both systemcfg and vdso is
tb_ticks_per_sec and it is only changed once during time_init().
Initialize it in both structures there.

Signed-off-by: default avatarThomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-26-b64f0842d512@linutronix.de
parent c22c06b4

arch/powerpc/include/asm/vdso_datapage.h

+6 −26
Original line number Diff line number Diff line
@@ -10,21 +10,6 @@ 
 */





/*

 * Note about this structure:

 *

 * This structure was historically called systemcfg and exposed to

 * userland via /proc/ppc64/systemcfg. Unfortunately, this became an

 * ABI issue as some proprietary software started relying on being able

 * to mmap() it, thus we have to keep the base layout at least for a

 * few kernel versions.

 *

 * However, since ppc32 doesn't suffer from this backward handicap,

 * a simpler version of the data structure is used there with only the

 * fields actually used by the vDSO.

 *

 */



/*

 * If the major version changes we are incompatible.

 * Minor version changes are a hint.
@@ -40,13 +25,9 @@ 


#define SYSCALL_MAP_SIZE      ((NR_syscalls + 31) / 32)



/*

 * So here is the ppc64 backward compatible version

 */



#ifdef CONFIG_PPC64



struct vdso_arch_data {

struct systemcfg {

	__u8  eye_catcher[16];		/* Eyecatcher: SYSTEMCFG:PPC64	0x00 */

	struct {			/* Systemcfg version numbers	     */

		__u32 major;		/* Major number			0x10 */
@@ -71,10 +52,12 @@ struct vdso_arch_data { 
	__u32 dcache_line_size;		/* L1 d-cache line size		0x64 */

	__u32 icache_size;		/* L1 i-cache size		0x68 */

	__u32 icache_line_size;		/* L1 i-cache line size		0x6C */

};



	/* those additional ones don't have to be located anywhere

	 * special as they were not part of the original systemcfg

	 */

extern struct systemcfg *systemcfg;



struct vdso_arch_data {

	__u64 tb_ticks_per_sec;			/* Timebase tics / sec */

	__u32 dcache_block_size;		/* L1 d-cache block size     */

	__u32 icache_block_size;		/* L1 i-cache block size     */

	__u32 dcache_log_block_size;		/* L1 d-cache log block size */
@@ -88,9 +71,6 @@ struct vdso_arch_data { 


#else /* CONFIG_PPC64 */



/*

 * And here is the simpler 32 bits version

 */

struct vdso_arch_data {

	__u64 tb_ticks_per_sec;		/* Timebase tics / sec */

	__u32 syscall_map[SYSCALL_MAP_SIZE]; /* Map of syscalls */

arch/powerpc/kernel/proc_powerpc.c

+24 −1
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
 */



#include <linux/init.h>

#include <linux/memblock.h>

#include <linux/mm.h>

#include <linux/proc_fs.h>

#include <linux/kernel.h>
@@ -44,13 +45,35 @@ static const struct proc_ops page_map_proc_ops = { 
	.proc_mmap	= page_map_mmap,

};



static union {

	struct systemcfg	data;

	u8			page[PAGE_SIZE];

} systemcfg_data_store __page_aligned_data;

struct systemcfg *systemcfg = &systemcfg_data_store.data;



static int __init proc_ppc64_init(void)

{

	struct proc_dir_entry *pde;



	strcpy((char *)systemcfg->eye_catcher, "SYSTEMCFG:PPC64");

	systemcfg->version.major = SYSTEMCFG_MAJOR;

	systemcfg->version.minor = SYSTEMCFG_MINOR;

	systemcfg->processor = mfspr(SPRN_PVR);

	/*

	 * Fake the old platform number for pSeries and add

	 * in LPAR bit if necessary

	 */

	systemcfg->platform = 0x100;

	if (firmware_has_feature(FW_FEATURE_LPAR))

		systemcfg->platform |= 1;

	systemcfg->physicalMemorySize = memblock_phys_mem_size();

	systemcfg->dcache_size = ppc64_caches.l1d.size;

	systemcfg->dcache_line_size = ppc64_caches.l1d.line_size;

	systemcfg->icache_size = ppc64_caches.l1i.size;

	systemcfg->icache_line_size = ppc64_caches.l1i.line_size;



	pde = proc_create_data("powerpc/systemcfg", S_IFREG | 0444, NULL,

			       &page_map_proc_ops, vdso_data);

			       &page_map_proc_ops, systemcfg);

	if (!pde)

		return 1;

	proc_set_size(pde, PAGE_SIZE);

arch/powerpc/kernel/setup-common.c

+3 −1
Original line number Diff line number Diff line
@@ -560,7 +560,9 @@ void __init smp_setup_cpu_maps(void) 
	out:

		of_node_put(dn);

	}

	vdso_data->processorCount = num_present_cpus();

#endif

#ifdef CONFIG_PPC64_PROC_SYSTEMCFG

	systemcfg->processorCount = num_present_cpus();

#endif /* CONFIG_PPC64 */



        /* Initialize CPU <=> thread mapping/

arch/powerpc/kernel/smp.c

+6 −4
Original line number Diff line number Diff line
@@ -1186,8 +1186,8 @@ int generic_cpu_disable(void) 
		return -EBUSY;



	set_cpu_online(cpu, false);

#ifdef CONFIG_PPC64

	vdso_data->processorCount--;

#ifdef CONFIG_PPC64_PROC_SYSTEMCFG

	systemcfg->processorCount--;

#endif

	/* Update affinity of all IRQs previously aimed at this CPU */

	irq_migrate_all_off_this_cpu();
@@ -1642,10 +1642,12 @@ void start_secondary(void *unused) 


	secondary_cpu_time_init();



#ifdef CONFIG_PPC64

#ifdef CONFIG_PPC64_PROC_SYSTEMCFG

	if (system_state == SYSTEM_RUNNING)

		vdso_data->processorCount++;

		systemcfg->processorCount++;

#endif



#ifdef CONFIG_PPC64

	vdso_getcpu_init();

#endif

	set_numa_node(numa_cpu_lookup_table[cpu]);

arch/powerpc/kernel/time.c

+3 −0
Original line number Diff line number Diff line
@@ -950,6 +950,9 @@ void __init time_init(void) 
	}



	vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;

#ifdef CONFIG_PPC64_PROC_SYSTEMCFG

	systemcfg->tb_ticks_per_sec = tb_ticks_per_sec;

#endif



	/* initialise and enable the large decrementer (if we have one) */

	set_decrementer_max();