Commit 684bd614 authored by Jeremy Kerr's avatar Jeremy Kerr Committed by Arnd Bergmann

[POWERPC] cell: handle SPE kernel mappings that cross segment boundaries

Currently, we have a possibilty that the SLBs setup during context
switch don't cover the entirety of the necessary lscsa and code
regions, if these regions cross a segment boundary.

This change checks the start and end of each region, and inserts a SLB
entry for each, if unique. We also remove the assumption that the
spu_save_code and spu_restore_code reside in the same segment, by using
the specific code array for save and restore.
Signed-off-by: default avatarJeremy Kerr <jk@ozlabs.org>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent f6eb7d7f
......@@ -274,20 +274,56 @@ static void __spu_kernel_slb(void *addr, struct spu_slb *slb)
slb->esid = (ea & ESID_MASK) | SLB_ESID_V;
}
/**
* Given an array of @nr_slbs SLB entries, @slbs, return non-zero if the
* address @new_addr is present.
*/
static inline int __slb_present(struct spu_slb *slbs, int nr_slbs,
void *new_addr)
{
unsigned long ea = (unsigned long)new_addr;
int i;
for (i = 0; i < nr_slbs; i++)
if (!((slbs[i].esid ^ ea) & ESID_MASK))
return 1;
return 0;
}
/**
* Setup the SPU kernel SLBs, in preparation for a context save/restore. We
* need to map both the context save area, and the save/restore code.
*
* Because the lscsa and code may cross segment boundaires, we check to see
* if mappings are required for the start and end of each range. We currently
* assume that the mappings are smaller that one segment - if not, something
* is seriously wrong.
*/
void spu_setup_kernel_slbs(struct spu *spu, struct spu_lscsa *lscsa, void *code)
void spu_setup_kernel_slbs(struct spu *spu, struct spu_lscsa *lscsa,
void *code, int code_size)
{
struct spu_slb code_slb, lscsa_slb;
struct spu_slb slbs[4];
int i, nr_slbs = 0;
/* start and end addresses of both mappings */
void *addrs[] = {
lscsa, (void *)lscsa + sizeof(*lscsa) - 1,
code, code + code_size - 1
};
/* check the set of addresses, and create a new entry in the slbs array
* if there isn't already a SLB for that address */
for (i = 0; i < ARRAY_SIZE(addrs); i++) {
if (__slb_present(slbs, nr_slbs, addrs[i]))
continue;
__spu_kernel_slb(lscsa, &lscsa_slb);
__spu_kernel_slb(code, &code_slb);
__spu_kernel_slb(addrs[i], &slbs[nr_slbs]);
nr_slbs++;
}
spu_load_slb(spu, 0, &lscsa_slb);
if (lscsa_slb.esid != code_slb.esid)
spu_load_slb(spu, 1, &code_slb);
/* Add the set of SLBs */
for (i = 0; i < nr_slbs; i++)
spu_load_slb(spu, i, &slbs[i]);
}
EXPORT_SYMBOL_GPL(spu_setup_kernel_slbs);
......
......@@ -691,7 +691,8 @@ static inline void resume_mfc_queue(struct spu_state *csa, struct spu *spu)
out_be64(&priv2->mfc_control_RW, MFC_CNTL_RESUME_DMA_QUEUE);
}
static inline void setup_mfc_slbs(struct spu_state *csa, struct spu *spu)
static inline void setup_mfc_slbs(struct spu_state *csa, struct spu *spu,
unsigned int *code, int code_size)
{
/* Save, Step 47:
* Restore, Step 30.
......@@ -708,7 +709,7 @@ static inline void setup_mfc_slbs(struct spu_state *csa, struct spu *spu)
* translation is desired by OS environment).
*/
spu_invalidate_slbs(spu);
spu_setup_kernel_slbs(spu, csa->lscsa, &spu_save_code);
spu_setup_kernel_slbs(spu, csa->lscsa, code, code_size);
}
static inline void set_switch_active(struct spu_state *csa, struct spu *spu)
......@@ -1835,7 +1836,8 @@ static void save_lscsa(struct spu_state *prev, struct spu *spu)
*/
resume_mfc_queue(prev, spu); /* Step 46. */
setup_mfc_slbs(prev, spu); /* Step 47. */
/* Step 47. */
setup_mfc_slbs(prev, spu, spu_save_code, sizeof(spu_save_code));
set_switch_active(prev, spu); /* Step 48. */
enable_interrupts(prev, spu); /* Step 49. */
save_ls_16kb(prev, spu); /* Step 50. */
......@@ -1940,7 +1942,8 @@ static void restore_lscsa(struct spu_state *next, struct spu *spu)
setup_spu_status_part1(next, spu); /* Step 27. */
setup_spu_status_part2(next, spu); /* Step 28. */
restore_mfc_rag(next, spu); /* Step 29. */
setup_mfc_slbs(next, spu); /* Step 30. */
/* Step 30. */
setup_mfc_slbs(next, spu, spu_restore_code, sizeof(spu_restore_code));
set_spu_npc(next, spu); /* Step 31. */
set_signot1(next, spu); /* Step 32. */
set_signot2(next, spu); /* Step 33. */
......
......@@ -201,8 +201,8 @@ int spu_irq_class_0_bottom(struct spu *spu);
int spu_irq_class_1_bottom(struct spu *spu);
void spu_irq_setaffinity(struct spu *spu, int cpu);
void spu_setup_kernel_slbs(struct spu *spu,
struct spu_lscsa *lscsa, void *code);
void spu_setup_kernel_slbs(struct spu *spu, struct spu_lscsa *lscsa,
void *code, int code_size);
#ifdef CONFIG_KEXEC
void crash_register_spus(struct list_head *list);
......
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