Re: [Linux-ia64] runtime platform detection in GENERIC kernels

Martin Hicks
2003-05-16T19:21:01Z

On Wed, May 14, 2003 at 09:32:53AM -0600, Alex Williamson wrote:
>
> Why not just make a runtime strcmp to platform_name? Then
> you could make a generic is_platform("sn2") type function/macro
> that everyone could use and you'd get rid of that nasty init
> function. If you realy need to make such a check in a perfmance
> path, it should probably be a machvec. Thanks,
>

Here is the next iteration, based on your suggestions. It also caches
the result of the first acpi_get_sysname() call, since this really
shouldn't change while the machine is running.

This is against the linux-ia64-2.5 bk tree.

It does include the sn2 platform detection in acpi_get_sysname(), which
may be duplicated in jbarnes' 2.5 patch.

mh

--
Wild Open Source Inc. mort@wildopensource.com

=== arch/ia64/kernel/acpi.c 1.40 vs edited ==--- 1.40/arch/ia64/kernel/acpi.c Sat May 10 03:28:45 2003
+++ edited/arch/ia64/kernel/acpi.c Fri May 16 17:23:28 2003
@@ -73,31 +73,43 @@
struct acpi20_table_rsdp *rsdp;
struct acpi_table_xsdt *xsdt;
struct acpi_table_header *hdr;
+ static char *sysname;
+
+ if (sysname)
+ return sysname;

rsdp_phys = acpi_find_rsdp();
if (!rsdp_phys) {
printk(KERN_ERR "ACPI 2.0 RSDP not found, default to \"dig\"\n");
- return "dig";
+ sysname = "dig";
+ return sysname;
}

rsdp = (struct acpi20_table_rsdp *) __va(rsdp_phys);
if (strncmp(rsdp->signature, RSDP_SIG, sizeof(RSDP_SIG) - 1)) {
printk(KERN_ERR "ACPI 2.0 RSDP signature incorrect, default to \"dig\"\n");
- return "dig";
+ sysname = "dig";
+ return sysname;
}

xsdt = (struct acpi_table_xsdt *) __va(rsdp->xsdt_address);
hdr = &xsdt->header;
if (strncmp(hdr->signature, XSDT_SIG, sizeof(XSDT_SIG) - 1)) {
printk(KERN_ERR "ACPI 2.0 XSDT signature incorrect, default to \"dig\"\n");
- return "dig";
+ sysname = "dig";
+ return sysname;
}

if (!strcmp(hdr->oem_id, "HP")) {
- return "hpzx1";
+ sysname = "hpzx1";
+ return sysname;
+ } else if (!strcmp(hdr->oem_id, "SGI")) {
+ sysname = "sn2";
+ return sysname;
}

- return "dig";
+ sysname = "sn2";
+ return sysname;
#else
# if defined (CONFIG_IA64_HP_SIM)
return "hpsim";
=== include/asm-ia64/system.h 1.37 vs edited ==--- 1.37/include/asm-ia64/system.h Thu May 15 05:45:02 2003
+++ edited/include/asm-ia64/system.h Fri May 16 16:50:51 2003
@@ -29,6 +29,7 @@

#include <linux/kernel.h>
#include <linux/types.h>
+#include <linux/string.h>

struct pci_vector_struct {
__u16 segment; /* PCI Segment number */
@@ -275,6 +276,14 @@
} while (0)
#define finish_arch_switch(rq, prev) spin_unlock_irq(&(prev)->switch_lock)
#define task_running(rq, p) ((rq)->curr = (p) || spin_is_locked(&(p)->switch_lock))
+
+extern const char * acpi_get_sysname(void);
+static inline int ia64_platform_is(const char *str)
+{
+ if (!strcmp(str,acpi_get_sysname()))
+ return 1;
+ return 0;
+}

#endif /* __KERNEL__ */