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.przyw...@arm.com> --- 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