Some tests for the IPRIORITY registers. The significant number of bits
is IMPLEMENTATION DEFINED, but should be the same for every IRQ.
Also these registers must be byte-accessible.
Check that accesses beyond the implemented IRQ limit are actually
read-as-zero/write-ignore.
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
arm/gic.c | 79 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 79 insertions(+)
diff --git a/arm/gic.c b/arm/gic.c
index 23cb9a4..57a2995 100644
--- a/arm/gic.c
+++ b/arm/gic.c
@@ -354,6 +354,83 @@ static void test_typer_v2(uint32_t reg)
nr_gic_cpus);
}
+#define BYTE(reg32, byte) (((reg32) >> ((byte) * 8)) & 0xff)
+#define REPLACE_BYTE(reg32, byte, new) (((reg32) & ~(0xff << ((byte) * 8))) |\
+ ((new) << ((byte) * 8)))
+
+/*
+ * Some registers are byte accessible, do a byte-wide read and write of known
+ * content to check for this.
+ * Apply a @mask to cater for special register properties.
+ * @pattern contains the value already in the register.
+ */
+static void test_byte_access(void *base_addr, u32 pattern, u32 mask)
+{
+ u32 reg = readb(base_addr + 1);
+
+ report("byte reads successful (0x%08x => 0x%02x)",
+ reg == (BYTE(pattern, 1) & (mask >> 8)),
+ pattern & mask, reg);
+
+ pattern = REPLACE_BYTE(pattern, 2, 0x1f);
+ writeb(BYTE(pattern, 2), base_addr + 2);
+ reg = readl(base_addr);
+ report("byte writes successful (0x%02x => 0x%08x)",
+ reg == (pattern & mask), BYTE(pattern, 2), reg);
+}
+
+static void test_priorities(int nr_irqs, void *priptr)
+{
+ u32 orig_prio, reg, pri_bits;
+ u32 pri_mask, pattern;
+ void *first_spi = priptr + GIC_FIRST_SPI;
+
+ orig_prio = readl(first_spi);
+ report_prefix_push("IPRIORITYR");
+
+ /*
+ * Determine implemented number of priority bits by writing all 1's
+ * and checking the number of cleared bits in the value read back.
+ */
+ writel(0xffffffff, first_spi);
+ pri_mask = readl(first_spi);
+
+ reg = ~pri_mask;
+ report("consistent priority masking (0x%08x)",
+ (((reg >> 16) == (reg & 0xffff)) &&
+ ((reg & 0xff) == ((reg >> 8) & 0xff))), pri_mask);
+
+ reg = reg & 0xff;
+ for (pri_bits = 8; reg & 1; reg >>= 1, pri_bits--)
+ ;
+ report("implements at least 4 priority bits (%d)",
+ pri_bits >= 4, pri_bits);
+
+ pattern = 0;
+ writel(pattern, first_spi);
+ report("clearing priorities", readl(first_spi) == pattern);
+
+ /* setting all priorities to their max valus was tested above */
+
+ report("accesses beyond limit RAZ/WI",
+ test_readonly_32(priptr + nr_irqs, true));
+
+ writel(pattern, priptr + nr_irqs - 4);
+ report("accessing last SPIs",
+ readl(priptr + nr_irqs - 4) == (pattern & pri_mask));
+
+ pattern = 0xff7fbf3f;
+ writel(pattern, first_spi);
+ report("priorities are preserved",
+ readl(first_spi) == (pattern & pri_mask));
+
+ /* The PRIORITY registers are byte accessible. */
+ test_byte_access(first_spi, pattern, pri_mask);
+
+ report_prefix_pop();
+ writel(orig_prio, first_spi);
+}
+
static void gic_test_mmio(void)
{
u32 reg;
@@ -388,6 +465,8 @@ static void gic_test_mmio(void)
report("ICPIDR2 is read-only (0x%08x)",
test_readonly_32(idreg, false),
reg);
+
+ test_priorities(nr_irqs, gic_dist_base + GICD_IPRIORITYR);
}
int main(int argc, char **argv)
--
2.14.4
