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Set group status of PPIs and SGIs correctly on GICv3 systems 

On a GICv2 system, the group status of PPIs and SGIs is set in the GICD_IGROUPR0
register. On a GICv3 system, if affinity routing is enabled for the non-secure
state, then the group status of PPIs and SGIs should be set in the GICR_IGROUPR0
register. ARM Trusted firmware sets the group status using the GICv2
sequence. On a GICv3 system, if the group status of an interrupt is set to Group
1 through a write to the GICD_IGROUPR0, then the GICR_IGROUPR0 is updated as
well.

The current sequence is incorrect since it first marks all PPIs and SGIs as
Group 1. It then clears the bits in GICD_IGROUPR0 corresponding to secure
interrupts to set their group status to Group 0. This operation is a no-op. It
leaves the secure generic timer interrupt (#29) used by the TSP marked as Group
1. This causes the interrupt to interfere with the execution of non-secure
software. Once an interrupt has been marked as Group 1, the GICR_IGROUPR0 should
be programmed to change its group status.

This patch rectifies this issue by setting the group status of only the
non-secure PPI and SGIs to Group 1 in the first place. GICD_IGROUPR0 resets to
0. So secure interrupts are marked as Group 0 by default.

Change-Id: I958b4b15f3e2b2444ce4c17764def36216498d00
This commit is contained in:
Achin Gupta 2015-03-09 21:54:40 +00:00
parent 3b982be3b3
commit 8cfc3fd295
1 changed files with 12 additions and 6 deletions
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18
drivers/arm/gic/arm_gic.c
View File

@ -219,13 +219,10 @@ void arm_gic_cpuif_deactivate(void)
******************************************************************************/
void arm_gic_pcpu_distif_setup(void)
{
unsigned int index, irq_num;
unsigned int index, irq_num, sec_ppi_sgi_mask;
assert(g_gicd_base);
/* Mark all 32 SGI+PPI interrupts as Group 1 (non-secure) */
gicd_write_igroupr(g_gicd_base, 0, ~0);
/* Setup PPI priorities doing four at a time */
for (index = 0; index < 32; index += 4) {
gicd_write_ipriorityr(g_gicd_base, index,
@ -233,16 +230,25 @@ void arm_gic_pcpu_distif_setup(void)
}
assert(g_irq_sec_ptr);
sec_ppi_sgi_mask = 0;
for (index = 0; index < g_num_irqs; index++) {
irq_num = g_irq_sec_ptr[index];
if (irq_num < MIN_SPI_ID) {
/* We have an SGI or a PPI */
gicd_clr_igroupr(g_gicd_base, irq_num);
/* We have an SGI or a PPI. They are Group0 at reset */
sec_ppi_sgi_mask |= 1U << irq_num;
gicd_set_ipriorityr(g_gicd_base, irq_num,
GIC_HIGHEST_SEC_PRIORITY);
gicd_set_isenabler(g_gicd_base, irq_num);
}
}
/*
* Invert the bitmask to create a mask for non-secure PPIs and
* SGIs. Program the GICD_IGROUPR0 with this bit mask. This write will
* update the GICR_IGROUPR0 as well in case we are running on a GICv3
* system. This is critical if GICD_CTLR.ARE_NS=1.
*/
gicd_write_igroupr(g_gicd_base, 0, ~sec_ppi_sgi_mask);
}
/*******************************************************************************