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powerpc/iseries: Fix early init access to lppaca

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The combination of commit

8154c5d22d and
93c22703ef

Broke boot on iSeries.

The problem is that iSeries very early boot code, which generates
the device-tree and runs before our normal early initializations
does need access the lppaca's very early, before the PACA array is
initialized, and in fact even before the boot PACA has been
initialized (it contains all 0's at this stage).

However, the first patch above makes that code use the new
llpaca_of(cpu) accessor, which itself is changed by the second patch to
use the PACA array.

We fix that by reverting iSeries to directly dereferencing the array. In
addition, we fix all iterators in the iSeries code to always skip CPU
whose number is above 63 which is the maximum size of that array and
the maximum number of supported CPUs on these machines.

Additionally, we make sure the boot_paca is properly initialized
in our early startup code.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Benjamin Herrenschmidt 2011-03-06 18:02:31 +00:00
parent a5abba989d
commit f2f6dad6ca
4 changed files with 20 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
arch/powerpc/include/asm/lppaca.h
View File

@ -33,9 +33,25 @@
//
//----------------------------------------------------------------------------
#include <linux/cache.h>
#include <linux/threads.h>
#include <asm/types.h>
#include <asm/mmu.h>
/*
* We only have to have statically allocated lppaca structs on
* legacy iSeries, which supports at most 64 cpus.
*/
#ifdef CONFIG_PPC_ISERIES
#if NR_CPUS < 64
#define NR_LPPACAS NR_CPUS
#else
#define NR_LPPACAS 64
#endif
#else /* not iSeries */
#define NR_LPPACAS 1
#endif
/* The Hypervisor barfs if the lppaca crosses a page boundary. A 1k
* alignment is sufficient to prevent this */
struct lppaca {

14
arch/powerpc/kernel/paca.c
View File

@ -26,20 +26,6 @@ extern unsigned long __toc_start;
#ifdef CONFIG_PPC_BOOK3S
/*
* We only have to have statically allocated lppaca structs on
* legacy iSeries, which supports at most 64 cpus.
*/
#ifdef CONFIG_PPC_ISERIES
#if NR_CPUS < 64
#define NR_LPPACAS NR_CPUS
#else
#define NR_LPPACAS 64
#endif
#else /* not iSeries */
#define NR_LPPACAS 1
#endif
/*
* The structure which the hypervisor knows about - this structure
* should not cross a page boundary. The vpa_init/register_vpa call

6
arch/powerpc/platforms/iseries/dt.c
View File

@ -242,8 +242,8 @@ static void __init dt_cpus(struct iseries_flat_dt *dt)
pft_size[0] = 0; /* NUMA CEC cookie, 0 for non NUMA */
pft_size[1] = __ilog2(HvCallHpt_getHptPages() * HW_PAGE_SIZE);
for (i = 0; i < NR_CPUS; i++) {
if (lppaca_of(i).dyn_proc_status >= 2)
for (i = 0; i < NR_LPPACAS; i++) {
if (lppaca[i].dyn_proc_status >= 2)
continue;
snprintf(p, 32 - (p - buf), "@%d", i);
@ -251,7 +251,7 @@ static void __init dt_cpus(struct iseries_flat_dt *dt)
dt_prop_str(dt, "device_type", device_type_cpu);
index = lppaca_of(i).dyn_hv_phys_proc_index;
index = lppaca[i].dyn_hv_phys_proc_index;
d = &xIoHriProcessorVpd[index];
dt_prop_u32(dt, "i-cache-size", d->xInstCacheSize * 1024);

1
arch/powerpc/platforms/iseries/setup.c
View File

@ -680,6 +680,7 @@ void * __init iSeries_early_setup(void)
* on but calling this function multiple times is fine.
*/
identify_cpu(0, mfspr(SPRN_PVR));
initialise_paca(&boot_paca, 0);
powerpc_firmware_features |= FW_FEATURE_ISERIES;
powerpc_firmware_features |= FW_FEATURE_LPAR;