RE: [EXT] [PATCH v2 6/6] soc/fsl/qe: qe.c: fold qe_get_num_of_snums into qe_snums_init
From: Qiang Zhao <qiang.zhao@nxp.com>
Date: 2019-05-09 02:36:03
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On 2019/5/1 17:29, Rasmus Villemoes [off-list ref] wrote:
-----Original Message----- From: Rasmus Villemoes <redacted> Sent: 2019年5月1日 17:29 To: devicetree@vger.kernel.org; Qiang Zhao <qiang.zhao@nxp.com>; Leo Li [off-list ref] Cc: linuxppc-dev@lists.ozlabs.org; linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org; Rob Herring [off-list ref]; Scott Wood [off-list ref]; Christophe Leroy [off-list ref]; Mark Rutland [off-list ref]; Rasmus Villemoes [off-list ref] Subject: [PATCH v2 6/6] soc/fsl/qe: qe.c: fold qe_get_num_of_snums into qe_snums_init The comment "No QE ever has fewer than 28 SNUMs" is false; e.g. the MPC8309 has 14. The code path returning -EINVAL is also a recipe for instant disaster, since the caller (qe_snums_init) uncritically assigns the return value to the unsigned qe_num_of_snum, and would thus proceed to attempt to copy 4GB from snum_init_46[] to the snum[] array. So fold the handling of the legacy fsl,qe-num-snums into qe_snums_init, and make sure we do not end up using the snum_init_46 array in cases other than the two where we know it makes sense. Signed-off-by: Rasmus Villemoes <redacted> ---
Reviewed-by: Qiang Zhao <qiang.zhao@nxp.com>
quoted hunk ↗ jump to hunk
drivers/soc/fsl/qe/qe.c | 46 ++++++++++++++--------------------------- 1 file changed, 16 insertions(+), 30 deletions(-)diff --git a/drivers/soc/fsl/qe/qe.c b/drivers/soc/fsl/qe/qe.c index325d689cbf5c..276d7d78ebfc 100644--- a/drivers/soc/fsl/qe/qe.c +++ b/drivers/soc/fsl/qe/qe.c@@ -308,24 +308,33 @@ static void qe_snums_init(void) int i; bitmap_zero(snum_state, QE_NUM_OF_SNUM); + qe_num_of_snum = 28; /* The default number of snum for threads + is 28 */ qe = qe_get_device_node(); if (qe) { i = of_property_read_variable_u8_array(qe, "fsl,qe-snums", snums, 1,QE_NUM_OF_SNUM); - of_node_put(qe); if (i > 0) { + of_node_put(qe); qe_num_of_snum = i; return; } + /* + * Fall back to legacy binding of using the value of + * fsl,qe-num-snums to choose one of the static arrays + * above. + */ + of_property_read_u32(qe, "fsl,qe-num-snums", &qe_num_of_snum); + of_node_put(qe); } - qe_num_of_snum = qe_get_num_of_snums(); - - if (qe_num_of_snum == 76) + if (qe_num_of_snum == 76) { snum_init = snum_init_76; - else + } else if (qe_num_of_snum == 28 || qe_num_of_snum == 46) { snum_init = snum_init_46; - + } else { + pr_err("QE: unsupported value of fsl,qe-num-snums: %u\n", qe_num_of_snum); + return; + } memcpy(snums, snum_init, qe_num_of_snum); }@@ -641,30 +650,7 @@ EXPORT_SYMBOL(qe_get_num_of_risc); unsigned int qe_get_num_of_snums(void) { - struct device_node *qe; - int size; - unsigned int num_of_snums; - const u32 *prop; - - num_of_snums = 28; /* The default number of snum for threads is 28*/ - qe = qe_get_device_node(); - if (!qe) - return num_of_snums; - - prop = of_get_property(qe, "fsl,qe-num-snums", &size); - if (prop && size == sizeof(*prop)) { - num_of_snums = *prop; - if ((num_of_snums < 28) || (num_of_snums > QE_NUM_OF_SNUM)) { - /* No QE ever has fewer than 28 SNUMs */ - pr_err("QE: number of snum is invalid\n"); - of_node_put(qe); - return -EINVAL; - } - } - - of_node_put(qe); - - return num_of_snums; + return qe_num_of_snum; } EXPORT_SYMBOL(qe_get_num_of_snums); -- 2.20.1
Best Regards Qiang Zhao _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel